Paper | Title | Other Keywords | Page |
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MOXBB101 | Challenges facing High Power Proton Accelerators | proton, ion, injection, rfq | 1 |
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Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. This presentation will provide an overview of the challenges and experiences of high power proton accelerators such as SNS, J-PARC, etc. and what we have learned from experiences and how to mitigate beam losses. |
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Slides MOXBB101 [6.734 MB] | ||
MOZB201 | Overview of the LHeC Design Study at CERN | lepton, luminosity, proton, electron | 40 |
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The LHeC is a potential future lepton-hadron collider project at CERN based on the existing LHC infrastructure. The presentation highlights the main results of the recently published conceptual design report, including the findings of an international review committee that evaluated it. The presentation outlines the planed future studies and R&D activities for the next years. | |||
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Slides MOZB201 [11.894 MB] | ||
MOPEA001 | Status of the Australian Synchrotron Top-Up Operations | injection, storage-ring, synchrotron, diagnostics | 58 |
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In May 2012 the Australian Synchrotron commenced Top-Up Operations for User beamtime. The facility was designed for top-up from the start with a full energy 3 GeV injection system, however top-up only became a priority once the beamline user community had established itself at the new facility in operation since April 2007. New beam diagnostic and equipment protections systems were implemented as part of the move to top-up, including a new injection efficiency monitoring system. The effect of top-up on the beamline data was also tested with each beamline prior to engaging top-up during user runs. Top-up has now been running successfully for one year and the performance statistics from this period will be presented. Top-up operations is a very popular standard mode for user beam and falling into decay mode is now treated almost as a beam dump. | |||
MOPEA005 | A Linear Beam Raster System for the European Spallation Source? | target, quadrupole, optics, beam-losses | 70 |
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The European Spallation Source (ESS) will, when built, be the most intense neutron source in the world. The neutrons are generated by a high power (5 MW) proton beam impacting a rotating W spallation target. To reduce the replacement frequency of components subjected to the full beam current, i.e. the proton beam window and the target, means to introduce low peak current densities, i.e. flat transverse beam profiles, are necessary. The relatively long beam pulse duration of 2.86 ms (at 14 Hz) leaves ample time to facilitate a Lissajous-like, linear raster system that illuminates a footprint area by sweeping an only moderately enlarged LINAC beamlet. Although slightly more technically challenging, this method has many advantages over the previously envisaged beam expander system based on non-linear DC magnets. The design, specifications, performance, and benefits of the beam raster system will be described and discussed. | |||
MOPEA028 | Present Status of the KEK PF-Ring and PF-AR | undulator, injection, polarization, photon | 136 |
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In KEK, two synchrotron light sources have been operated. One is the 2.5 GeV Photon Factory storage ring (PF-ring) and the other is the 6.5 GeV Photon Factory advanced ring (PF-AR). In this paper, present operational status and recent R&D activities such as fast local bump system for helicity switching undulator, hybrid injection system, pulsed-sextupole injection, etc. Futhermore, upgrade plan towards the top-up injection of 6.5 GeV PF-AR ring is underway. Construction of the straight injection tunnel from linac to PF-AR will be started next fiscal year. Design detail and strategy for the injection scheme will be reported. | |||
MOPEA036 | Transport Line Orbit Correction for CSNS/RTBT | alignment, target, quadrupole, extraction | 154 |
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Dipole field kicks arisen from the construction and alignment of the magnets may cause the orbit distortion and reduce the efficiency of beam extraction and striking target in RTBT transport line of CSNS. In this paper, orbit correction is done based on XAL Orbit Correction application with the algorithm modified partially and the result was according with by AT toolbox. Meanwhile, the orbit correction before the target was special considered for the beams striking the target center vertically. | |||
MOPEA046 | Solaris Project Progress | storage-ring, vacuum, injection, klystron | 181 |
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Funding: Work supported by the European Regional Development Fund within the frame of the Innovative Economy Operational Program:POIG.02.01.00-12-213/09 Solaris is a 3rd generation light source facility being built in Kraków, Poland at the Jagiellonian University Campus. The project is being accomplished in a tight collaboration with the MAX IV Laboratory in Lund, Sweden. The Solaris 1.5 GeV storage ring is a replica of the MAX IV 1.5 GeV machine, whereas the injector and the transfer line although based on the same components, are unique for Solaris. One of the main differences is the 600 MeV injection energy requiring an energy ramp in the storage ring to the final operating energy of 1.5 GeV. The construction of the facility started in early 2010 and is planned to be finished in the autumn 2014. Up to now, 70% of the components have been procured and construction of the buildings in progress with expected handover in autumn 2013. This paper will give an update on infrastructure progress and design choices for shielding, service area placement of racks and routing of piping and cables. An update is also presented of machine layout that includes the injector, transfer line and storage ring. |
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MOPEA049 | The First Experience of PLS-II Operation | injection, storage-ring, lattice, insertion | 190 |
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Funding: Mministry of Education, Science and Technology (MEST) of Korea One of recent major activities of the Pohang Accelerator Laboratory (PAL) in Korea has been PLS-II user operation. The PLS-II is a Korea’s only and brand new 3rd generation synchrotron radiation source that was upgraded from the 16-year-old PLS in 2011. The old PLS started user service from 1995 and shutdown on Dec. 10, 2010. The PLS-II has been open to users from March 2012 with upgraded performance. The performance parameters of the PLS-II are 5.8 nm-rad emittance, 3.0GeV beam energy, and 400mA beam current with the top-up injection. The unique feature of PLS-II will be the implementation of 20 insertion-devices in a compact double-bend-achromat storage ring of 280m-long circumference. Among 20 insertion-devices, 14 are in-vacuum undulators. The first year operation in 2012 will be successfully completed and the operational statistics will be summarized and discussed. |
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MOPEA069 | Tuning of the Injector System to Match Possible Lattice Upgrades at Diamond Light Source | booster, lattice, injection, storage-ring | 243 |
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Studies of novel lattice upgrades for Diamond Light Source to achieve an increase in the number of insertion devices and/or a lower natural emittance are underway (as reported elsewhere at this conference). Such upgrades if carried out progressively would result in successive reductions in storage ring circumference. To maintain synchronous injection then requires the injector system to operate at various frequencies to match these changes. This paper describes the tests carried out with beam, to prove that the injector system of Linac and full energy Booster can be tuned over an extended frequency range. | |||
MOPEA080 | Status of the NSLS-II Injector | booster, injection, storage-ring, kicker | 273 |
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We discuss the current status and plans for developing the NSLS-II injector. The latter consists of a 200 MeV linac, a 3-GeV booster, transport lines and the storage ring injection straight section. The system design and installation are complete. Last year we concluded 200-MeV linac commissioning and are planning to commission the 3 GeV booster during summer of 2013. | |||
MOPFI004 | The Injector Layout of BERLinPro | emittance, cathode, cavity, gun | 288 |
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Funding: The Bundesministerium für Bildung und Forschung (BMBF) and the state of Berlin, Germany. BERLinPro is an Energy Recovery Linac Project running since 2011 at the HZB in Berlin. The key component of the project is the 100mA superconducting RF photocathode gun under development at the HZB since 2010. Starting in 2016 the injector will go into operation providing 6 MeV electrons with an emittance well below 1mm mrad and bunches shorter than 4ps. 2017 the 50MeV linac will be set up and full recirculation is planned for 2018. The injector design including a dogleg merger has been finalized and is described in detail in this paper. Emphasis is laid on the final layout including collimators and diagnostics and performance simulations of two different gun cavities and first tolerance studies. |
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MOPFI011 | Construction and First Tests of the New Injection System for the Linac II at DESY | electron, gun, injection, positron | 303 |
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For the Linac II, which supplies the accelerator chain at DESY with electrons and positrons, a new injection system is planned. It is supposed to ensure reliable operation and to avoid the beam loss of about 60% at energies up to 400 MeV and the associated activation. The function of the injector components, the entire injection system and the acceleration in the linac sections were optimized in simulations. The main components are a 6 A/100 kV triode gun, buncher and a dispersive section for energy collimation. The output energy is 5 MeV and the beam pulse length can be chosen from 5 ns to 50 ns. The new buncher structure is a hybrid of a standing wave and traveling wave structure and allows a compact design and good electron capture. One of two assembled structures has been tuned and completed a test rig in the linac tunnel. In this test system detailed analysis of its properties is in progress as well as minor corrections like alignment and improvements of reliability. The final installation is going to take place from September 2013. First experimental analysis compared to simulation results will be presented. | |||
MOPFI023 | Development of Better Quantum Efficiency and Long Lifetime Iridium Cerium Photocathode for High Charge electron RF Gun | laser, cathode, electron, gun | 327 |
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We developed an Ir5Ce photocathode as a high charge electron source for SuperKEKB electron linac. The required electron beam parameters are 5 nC and 10 mm•mrad from the electron gun of the SuperKEKB electron linac. We plan to generate this electron beam using a laser-driven RF gun installed with a photocathode that has a long lifetime and a high-power laser system through more than a year without replacement. Therefore, we focused on the Ir5Ce compound as a new photocathode which has a high melting point (> 2100 K) and a low work function (2.57 eV). The results of measurements showed that the quantum efficiency of Ir5Ce photocathode was 1.0×10-4 treated by the laser cleaning using the 4nd harmonic of Nd:YAG laser or the heater treatment. Furthermore, its photoemission properties could be maintained for a long term even if its photocathode was in the low vacuum conditions ( ~10-6 Pa) since the Ir5Ce compound is far less contaminated than other photocathodes. Finally, We have succeed to generate electron beams of 4.4 nC by the Ir5Ce photocathode installed at the 3-2 sector DAW type RF gun and accelerate it through a linac end in KEK electron linac. | |||
MOPFI031 | Progress on the Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source | electron, neutron, controls, dipole | 351 |
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IHEP, China is constructing a 100 MeV / 100 kW electron linac for NSC KIPT, Ukraine. This linac will be used as the driver of a neutron source based on a subcritical assembly. In 2012, the injector part of the linac was pre-installed as a testing facility in the experimental hall #2 of IHEP. The injector beam and key hardware testing results were satisfying. Recently, the injector testing facility was disassembled and all of the components for the whole linac have been shipped to Ukraine from China by ocean shipping. The installation of the whole machine in KIPT will be started in June. The progress on the construction are reported, injector beam and key hardware testing results are presented. | |||
MOPFI057 | Studies for the LHeC Beam Transfer Systems | kicker, injection, electron, extraction | 410 |
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The LHeC would allow for collisions between an electron beam from a new accelerator with the existing LHC hadron beam. Two possible configurations were studied: a separate LINAC (LINAC-ring) or a new electron ring superimposed on the LHC (ring-ring). The racetrack LINAC is now considered as the baseline for the LHeC design, with the ring-ring solution a back up. The studies performed for all the considered options are presented in this paper. For the LINAC-ring option the requirements for the post-collision line and the beam dump design have been evaluated in the cases of a 140 GeV and a 60 GeV electron beam. In the ring-ring option studies have been performed of the optics design of the transfer line from the a 10 GeV injector LINAC into the LHeC ring and of the injection system. The internal 60 GeV electron ring dump design has also been considered. | |||
MOPFI078 | The Possibility of Generation of High Energy Electron Beam at the SNS Facility | electron, acceleration, laser, solenoid | 458 |
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Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725 The linac of the SNS accelerator facility can be used to produce an electron beam with 300-400 MeV energy. At present there are a few predesigned experiments with electron beam that can be alternatively carried out at the SNS. However, the SNS linac is designed and optimized for acceleration of H− , which brings some problems when considering direct acceleration of electrons. Alternative machine setup for electron acceleration and transport are discussed. Here, we present a study of the optimal electron beam parameters that can be achieved without any significant changes of the SNS accelerator. |
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MOPME018 | BEAM OSCILLATION MONITOR FOR THE MULTI-BUNCH BEAM | kicker, damping, wakefield, extraction | 506 |
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In order to observe the motion of bunch-by-bunch beam oscillation of multi-bunch in the storage ring, we developed two measurement tools. One is a signal process electronics circuit using fast analogue switches. The circuit picks up one of the selected bunch signal of the beam position monitor from the multi-bunch. The selected beam position signal can be processed as a single bunch beam. By changing the gate timing, arbitrary bunch signal can be selected. The other is a waveform memory using a high bandwidth oscilloscope. The long waveform memory of the oscilloscope has a capability to acquire the multi-turn waveform of the button electrode signals. The beam test of the circuit has been carried out at KEK-ATF damping ring in the cases of 2.8ns bunch spacing and 5.6ns bunch spacing, respectively. The detail of the hardware and the result of the beam test are reported. | |||
MOPME024 | Status of Beam Loss Spatial Distribution Measurements at J-PARC Linac | proton, controls, status, klystron | 524 |
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Funding: This work was supported by JSPS KAKENHI Grant Number 24510134. We have developed 8-plane (4 horizontal and 4 vertical) scintillating fiber hodoscope system to measure proton tracks due to beam loss in the ACS section at the J-PARC linac. The detector consists of upstream 4 planes (two horizontal and two vertical) and downstream 4 planes (two horizontal and 4 vertical). The time of flight measuremments between the upstream and downstream subsystems allow proton identification and energy mesurements. In summer of 2012, we have installed remote position movement system, which enables measurements of spatial distributions of proton tracks. In this presentation we show status of mesurements and data analysis. |
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MOPME026 | Beam Monitor Layout for Future ACS Section in J-PARC Linac | cavity, DTL, beam-transport, monitoring | 529 |
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In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. With this upgrade, the design peak current will be increased from the present 30 mA to 50 mA, and the energy from 181 MeV to 400 MeV. Along with these significant upgrades of the beam parameters, beam monitors should be followed. Also, the bunch shape monitor and new beam loss monitoring system will be employed for the new beam line. Newly fabricated devices will be delivered in the ACS beam line. And beam monitor layout of the upstream and downstream of ACS beam line will be modified. In this paper, we introduce the development of the beam diagnostic devices for the project and the new designed beam monitor layout. | |||
MOPME027 | Bunch Length Measurement of 181 MeV Beam in J-PARC Linac | electron, target, vacuum, simulation | 532 |
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In J-PARC Linac, an energy and intensity upgrade project has started since 2009 using Annular Coupled Structure (ACS) cavities. Because the longitudinal matching before ACS cavities is additionally required, we decided to employ the bunch shape monitors (BSMs) to measure the longitudinal beam profile. After three years from the start of BSM project, three BSMs were fabricated. All three BSMs were installed during the summer shutdown of 2012. We tried to measure the longitudinal beam profile exited from SDTL cavities. In this paper, we introduce the outline of BSM project, the first data acquisition and related small problems. | |||
MOPME028 | A Preliminary Study of the Vibration Wire Monitor for Beam Halo Diagnostic in J-PARC L3BT | diagnostics, proton, electron, injection | 535 |
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In the J-PARC 3-GeV Rapid Cycle Synchrotron (RCS), transverse beam halo diagnostic and scraping are required to increase the output beam power. Wire scanners and halo scrapers were used for measurement of projected beam distributions to determine the extent of beam halo formation at Linac-3GeV Beam Transport line (L3BT). In order to determine more detail of halo formation, Vibration Wire Monitor (VWM) was installed in L3BT for the beam halo measurement and the offline study at the test stand with low energy electron gun are started. The high sensitivity of the VWM makes it a prospective one for investigation of beam halo and weak beam scanning. In this paper, we will report a preliminary results of offline studies and beam halo measurement by VWM at L3BT. | |||
MOPME031 | Emittance Measurement with Multi-wire Scanners for BEPC-II Linac | emittance, positron, electron, injection | 541 |
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During the BEPC-II linac upgrade, five wire scanners have been installed in the common transport line, which makes a fast emittance measurement possible. In this paper, we will show the primary results of BEPC-II linac emittance measurement using multi-wire scanner method. The least squares method will be used for data analysis. A comparison of the results with the ones obtained by quad scan method will also be given. | |||
MOPME033 | Wire Scanner Emittance Measurement and Software Design at BEPCII | emittance, target, quadrupole, EPICS | 544 |
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Wire scanners are diagnostic devices to measure the beam profile. Resent years, BEPCII adopts wire scanner measurement system for accurate beam size and emittance measurements. Beam emittance measurements can be performed with no adverse impact on beam and no interruption to normal machine operation. The BEPCII wire scanner system includes sets of four scanners in linac by which the linac output emittance is determined. In order to make the measurement procedure automated and easily accessible to all operators, wire scanner measurement software is developed. The software can obtain real-time signal data from the Experimental Physics and Industrial Control System(EPICS) and emittance calculation, phase chart and optics envelope display will be done. In this paper we describe the construction, performance and uses of BEPCII wire scanners measurement system and software. | |||
MOPME043 | Calibration of Beam Position Monitors in the Injector of HLS II | quadrupole, brilliance, coupling, emittance | 568 |
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Funding: Supported by the National Science Foundation of China (11175173, 11105141) A beam position monitor(BPM) system is being installed to improve the beam position measurement of the injector at the upgrade project of Hefei Light Source (HLS II). The new BPM system is consists of 19 stripline BPMs and 19 Libera Brilliance Single Pass modules. Before installation, the response of the BPMs must be mapped to improve the accuracy of measurement. The theoretical equations of both position and quadrupole component of the BPM are calculated first, using both formula and matlab simulation. A laboratory calibration system is built. The inconsistency of Libera Brilliance Single Pass channels is measured to improve the accuracy of calibration. The calibrating results show the position sensitivity is less than 5% difference compare to the theoretical value, while the quadrupole component sensitivity is less than 10% difference. |
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MOPME045 | Design and Test Status of Beam Position Monitors for ADS Injector II Proton LINAC | proton, cryomodule, vacuum, alignment | 574 |
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Beam Position Monitors (BPM) based on capacitive pick-ups are designed for Accelerator-Driven System (ADS) Injector II proton LINAC. This LINAC is aiming to produce a maximum design current of 15 mA at the 10 MeV energy with an operating frequency of 162.5 MHz. Non-interceptive BPM will be installed to measure the transverse beam position and beam phase in the vacuum chamber. Depending on the location, the response of the BPMs must be optimized for a beam with an energy range from 2.1 up to 10 MeV and an average current between 0.01 and 15 mA. Apart from the broadening of the electromagnetic field due to the low-beta beam, specific issues are affecting some of the BPMs: tiny space in the transport line between the RFQ and the cryomodule and the cryogenic temperature inside the cryomodule. For this reason two types of BPMs are being designed for each location (MEBT and cryomoudle). In this contribution, the present status of the design and measured results for each BPM will be presented in room and cold temperature, focusing on the electromagnetic response for low-beta beams. | |||
MOPME056 | Measurement of the Beam Position Monitor’s Electrical Performance and Electronics Sensitivity for 100 MeV Proton Linac and Beam Lines | proton, pick-up, instrumentation, monitoring | 598 |
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Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government. The development of the beam position monitor (BPM) is in progress for the 100-MeV proton linac and 10 beam lines of the 1st phase of KOMAC. Those were selected the strip line type BPM for the proton linac and beam lines. 5 beam-line BPMs and 9 linac BPMs were checked their electrical performance in the RF test using by developed test stand and tested the Log-ratio BPM (Beam Position Monitor) electronics module of the Bergoz Instrumentation for direct beam position derivation signal from the pickup signal. After then, those will be installed 100-MeV proton Linac and beam lines for beam commissioning in February 2013. This presentation summarized the results of measured BPM’s electrical performance and the Log-ratio BPM electronics pickup sensitivity. |
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MOPME057 | Preliminary Operation of the Beam Loss Monitoring System at the 100-MeV Proton Linac | monitoring, high-voltage, neutron | 601 |
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A 100-MeV proton linac has been developed as the 1st phase of KOMAC (Korea Multi-purpose Accelerator Complex) under the project name of PEFP (Proton Engineering Frontier Project). The accelerator operation has to be carried out with the objective of limiting beam losses to less than 1 W/m. When the un-intended excessive beam loss occur, the BLM(Beam Loss Monitor) inform this beam loss to operator and transmit the signal to the MPS (Machine Protection System) for the rapid shut-off of the machine. The scintillation detector and proportional counter were selected as the BLM detector because of their fast response time and high sensitivity. At the beam commissioning stage, 20 BLMs will be prepared for the beam loss monitoring. This paper will report preliminary operation results of beam loss monitoring system.
This work was supported by the Ministry of Education, Science and Technology of the Korean Government. |
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MOPME059 | R&D of a Beam Position Monitor for RISP | impedance, ion, heavy-ion, pick-up | 607 |
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We have investigated on the R&D of stripline beam position monitor for the heavy-ion accelearator at Korea. We present the detailed design and fabrications on the beam position monitor in superconducting linac that the beam is accelerated to 200 MeV/u. | |||
MOPME061 | Femtosecond e-bunch Length Measurement at fs-THz Accelerator at PAL | radiation, electron, laser, gun | 613 |
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Longitudinal distribution of femto-second electron beam has been evaluated by the coherent transition radiation Michelson interferometer with the reconstruction procedure from interferograms. We measure the bunch length of the Thz Accelerator using interferogram method in Pohang Accelerator Lab and compare with the energy of transition radiation and bunch length. | |||
MOPME069 | Multi-OTR System for Linear Colliders | emittance, target, diagnostics, optics | 637 |
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We study the feasibility of using a multi-Optical Transition Radiation (mOTR) system for fast transverse emittance reconstruction and x-y coupling correction in the Ring to Main Linac (RTML) of the future linear colliders: ILC and CLIC. OTR monitors are mature and reliable diagnostic tools that could be very suitable for the setup and tuning of the machine in single-bunch mode. Here we study the requirements for a mOTR system adapted to the optical conditions and beam parameters of the RTML of both the ILC and CLIC. | |||
MOPME070 | Emittance and Beta Functions Measurements for the MAX IV Linac | quadrupole, emittance, simulation, controls | 640 |
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We plan to determine beam emittance and Twiss parameters for the MAX IV linac using multiple-quadrupoles scans. We investigate the possibility to perform such scans using matching sections' quadrupoles combined with beam profile measurements by fluorescent YAG screens. Beam pipe size, resolution and screen saturation limits and strengths of quadrupoles are taken into consideration. Our approach to this problem using Kalman filter is presented. | |||
MOPME073 | Measurement of Schottky-like Signals from Linac Bunched Hadron Beams for Momentum Spread Evaluation | cavity, synchrotron, pick-up, bunching | 649 |
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We present a novel method for the measurement of Linac beam parameters in the longitudinal phase space. The longitudinal momentum spread can be evaluated by means of Schottky type signal analysis of bunched beams. There is a close similarity between a repetitive Linac bunch train and a circulating beam with a single short batch in a large machine like the LHC. A dedicated longitudinal cavity pick-up was used in the Linac where resonance frequency and Q-value were carefully selected in order to get an optimum compromise between the unavoidable coherent signal and the desired incoherent part of the beam spectrum. A time domain gating similar to the 4.8 GHz LHC Schottky front-end is applied. As a cross-check of the validity of the interpretation in terms of momentum spread, the Linac beam is analyzed in the downstream synchrotron using standard Schottky methods. In principle, this approach can be understood as an extension of Schottky analysis for circular machines with a perfect “mixing” between subsequent bunch trains. This contribution describes the test set-up and discusses the results of the measurements with a heavy ion beam. | |||
MOPME075 | Laser Based Stripping System for Measurement of the Transverse Emittance of H− Beams at the CERN LINAC4 | laser, electron, background, emittance | 652 |
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Funding: LA3NET is funded by the European Commission under Grant Agreement Number GA-ITN-2011-289191 The new LINAC4 at CERN will accelerate H− particles to 160 MeV and allow high brightness proton beam transfers to the Proton Synchrotron Booster, via a charge-exchange injection scheme. This paper describes the conceptual design of a laser system proposed for transverse profile and emittance measurements based on photon detachment of electrons from the H− ions. The binding energy of the outer electron is only 0.75 eV and can easily be stripped with a laser beam. Measuring the electron signal as function of the laser position allows the transverse beam profile to be reconstructed. A downstream dipole can also be used to separate the laser neutralized H0 atoms from the main H− beam. By imaging these H0 atoms as a function of laser position the transverse emittance can be reconstructed in the same way as in traditional slit-and-grid systems. By properly dimensioning the laser power and spot size, this method results in negligible beam losses and is therefore non-destructive. In addition, the absence of material intercepting the H− beam allows the measurement of a full power H− beam. This paper will focus on the general design and integration of both the laser and H0 detector systems. |
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MOPWA037 | Commissioning of the CERN Linac4 BPM System with 50 MeV Proton Beams | pick-up, proton, simulation, optics | 750 |
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The new Linac4 at CERN will provide a 160 MeV H− ion beam for charge-exchange injection into the existing CERN accelerator complex. Shorted stripline pick-ups placed in the Linac intertank regions and the transfer lines will measure beam orbit, relative beam current, beam phase, and average beam energy via the time-of-flight between two beam pickups. A prototype Beam Position Monitor (BPM) system has been installed in the transfer line between the existing Linac2 and the Proton Synchrotron Booster (PSB) in order to study and review the complete acquisition chain. This paper presents measurements and performance of this BPM system operating with 50 MeV proton beams, and compares the results with laboratory measurements and electromagnetic simulations. | |||
MOPWA062 | Transverse Beam Halo Measurements at High Intensity Neutrino Source (HINS) using Vibrating Wire Monitor | ion, target, proton, ion-source | 819 |
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Funding: Research supported by the U.S. Department of Energy. Measurement and control of transverse beam halo will be critical for the applications of future high-intensity hadron linacs. In particular, beam profile monitors require a very high dynamic range when using for transverse beam halo measurements. In this study, the Vibrating Wire Monitor (VWM) with aperture 60 mm was installed at the High Intensity Neutrino Source (HINS) front-end to measure transverse beam halo. A vibrating wire is excited at its resonance frequency with the help of a magnetic feedback loop, and the vibrating and sensitive wires are connected through a balanced arm. The sensitive wire is moved into the beam halo region by a stepper motor controlled translational stage. We study the feasibility of the vibrating wire for transverse beam halo measurements in the low-energy front-end of the proton linac. |
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MOPWA076 | Improvements to Existing Jefferson Lab Wire Scanners | emittance, optics, diagnostics, controls | 855 |
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This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes. | |||
MOPWO002 | PTCC: New Beam Dynamics Design Code for Linear Accelerators | space-charge, simulation, plasma, cavity | 882 |
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Funding: Work supported by the Egyptian Science and Technology Development Fund (STDF) No. 953. A fast and accurate beam dynamics design code, named PTCC (Particle Tracking Code in C) is developed to simulate particles dynamic in linear accelerators. PTCC solves the relativistic equations of motion for the macro-particles when subjected to electromagnetic fields excited in RF cavities. The self-fields of the particles are also part of the electromagnetic fields through which the particles are tracked. Self-fields are calculated using a modified 2D cylindrically symmetric mesh based method, making use of beam and field symmetry to provide fast simulation. The code has been benchmarked with the well known code ASTRA which is used mainly in simulations of next generation FEL linacs. PTCC provides a new tool for designing buncher section of linear accelerators that convert DC beam into bunches. New buncher design tool and benchmark results of PTCC with ASTRA are presented. |
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MOPWO009 | Numerical Studies on the Impact of Ionized Residual Gas on an Electron Beam in an ERL | ion, emittance, electron, simulation | 903 |
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Funding: Supported by BMBF under contract number 05K10HRC Energy Recovery Linacs (ERLs) are the most promising candidates for next-generation light sources now under active development. An optimal performance of these machines requires the preservation of the high beam brightness generated in the injector. For this, the impact of the ionized residual gas on the beam has to be avoided as it causes instabilities and emittance growth. Typical measures to reduce the effect of ion clouds are clearing electrodes and clearing gaps in the bunch train. In this paper, we present numerical studies of the impact of ion clouds on the electron bunch train. The simulations are performed with the software package MOEVE PIC Tracking developed at Rostock University. ’The model for the bunch and the ion cloud takes into account a distribution of macro particles. The interaction of the bunch with the ion cloud is computed with a 3D space charge model. Hence, particle tracking allows for detailed studies of bunch characteristics such as the emittance. The presented numerical investigations take into account the parameters of the ERL BERLinPro with the objective to deduce appropriate measures for the design and operation of BERLinPro. |
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MOPWO011 | Surface Field Optimization of Accelerating Structures for CLIC using ACE3P on Remote Computing Facility | simulation, GUI, target, damping | 909 |
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Funding: Research Council of Norway This paper presents a computer program for searching for the optimum shape of an accelerating structure cell by scanning a multidimensional geometry parameter space. For each geometry, RF parameters and peak surface fields are calculated using ACE3P on a remote high-performance computational system. Parameter point selection, mesh generation, result storage and post-analysis are handled by a GUI program running on the user’s workstation. This pa- per describes the program, AcdOptiGui. AcdOptiGui also includes some capability for automatically selecting scan points based on results from earlier simulations, which en- ables rapid optimization of a given parameterized geome- try. The software has previously been used as a part of the design process for accelerating structures for a 500 GeV CLIC. |
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MOPWO024 | Design of the CLIC Pre-Main Linac Collimation System | collimation, emittance, wakefield, damping | 936 |
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A main beam collimation system, upstream of the main linac, is essential to protect the linac from particles in the beam halo. The proposed system consists of an energy collimation (EC) system just after the booster linac near the start of the Ring-to-Main Linac (RTML) transfer line and an EC and betatron collimation (BC) system at the end of the RTML, just before the main linac. The design requirements are presented and the cleaning efficiency of the proposed systems is analysed for different design choices. | |||
MOPWO036 | Civil Engineering Feasibility Studies for Future Ring Colliders at CERN | civil-engineering, collider, hadron, electron | 969 |
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CERN civil engineers are studying the feasibility of future ring colliders to complement the LHC. Infrastructure works typically represent one third of the cost of major physics projects, so it's critical that the construction costs are well understood from the conceptual stage. This poster presents the first results of the feasibility studies for two potential ring colliders at CERN: the racetrack shaped Linac-Ring LHeC and an 80km circular tunnel to house the High Energy LHC (SHE-LHC) and the TLEP. Some of the key civil engineering challenges faced in such large scale projects are presented with particular emphasis on geology, design and risk. | |||
MOPWO053 | Evolution of the Tracking Code PLACET | wakefield, simulation, cavity, collider | 1014 |
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The tracking code PLACET simulates beam transport and orbit corrections in linear accelerators. It incorporates single- and multi-bunch effects, static and dynamic imperfections. A major restructuring of its core has resulted in an improvement in its modularity, with some immediate advantages: its tracking core, which is one of the fastest available for this kind of simulations, is now interfaced toward three different scripting languages to offer great simulation capabilities: Tcl/Tk, Octave and Python. These three languages provide access to a vast library of scientific tools, mechanisms for parallel computing, and access to Java interfaces for control systems (such as that of CTF3). Also, new functionalities have been added: parallel tracking to exploit modern multicore CPUs, the possibility to track through the interaction region in presence of external magnetic fields (detector solenoid) and higher order imperfections in magnets. PLACET is currently used to simulate the CLIC Drive Beam, the CLIC Main Beam, CTF3, FACET at SLAC, and ATF2 at KEK. | |||
MOPWO054 | The LHeC as a Higgs Boson Factory | luminosity, factory, lepton, electron | 1017 |
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The LHeC is designed to collide a new 60 GeV energy electron beam, from a 3-pass ERL, with the 7 TeV energy LHC proton beam. At the present target ep luminosity of 1033cm-2s-1, the LHeC would produce a few 1000 Higgs bosons per year, allowing for precision coupling measurements, especially of the H –> b bbar decay in charged current deep inelastic scattering (ep –> nu H X). With a significant increase of the luminosity, rarer channels become accessible, as the charm decay. Here such an increase, to the level of 1034cm-2s-1 or even beyond, is considered from a combination of improvements, namely with a smaller proton beam emittance, with a further reduction of the proton IP beta function, an increase of the proton bunch intensity and with doubling the lepton beam current, compared to the canonical values assumed in the CDR. | |||
MOPWO059 | Development of MATLAB-based Application Programs for the Optics Matching, Beam Steering, and Injection Conditioning in TPS Commissioning | optics, injection, lattice, electron | 1025 |
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Taiwan Photon Source (TPS) is a third generation 3GeV synchrotron light source. Its first beam commissioning is scheduled in 2014. Intensive efforts are devoted to achieve efficient transportation of the first beam from the LINAC, passing through the LTB transfer line, and its injection into the booster ring. After the beam energy has been ramped up to 3GeV in booster, the beam is extracted to the BTS transfer line. At the end of BTS, the beam is injected into the storage ring and circulates around the storage ring. In order to achieve efficient beam transportation, we have developed various MATLAB-based commissioning tools for the optics matching of transfer lines, beam steering and injection conditioning of booster and storage ring. | |||
MOPWO085 | A Hybrid Technique for Computing Courant-Snyder Parameters from Beam Profile Data | space-charge, emittance, simulation, DTL | 1073 |
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Funding: Work supported by ORNL/SNS, which is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. We present a technique for computing the Courant-Snyder parameters of a charged-particle beam from profile measurement data. Such algorithms are not new, but this particular method has very robust convergence properties resulting from a novel approach that combines both deterministic and non-deterministic methods. The general idea is as follows: given a model of the beamline, in the zero-current case it is possible to compute the Courant-Snyder parameters directly from profile data using a deterministic, linear-algebraic approach. For the finite beam current case we can construct a smooth curve of these deterministic solutions starting from the zero-current solution and terminating at the finite-current case. We are guaranteed convergence, and convergence to the finite-current solution connected to the zero-current Courant-Snyder parameters. This approach avoids the convergence issues associated with a fully iterative, non-deterministic method. The details of the technique are outlined and examples are presented using profile data taken from the SNS accelerator. |
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TUOAB101 | Installation and Commissioning of the 1.1 MW Deuteron Prototype Linac for IFMIF | neutron, rfq, proton, ion | 1090 |
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IFMIF, the International Fusion Materials Irradiation Facility, will learn the degradation of the mechanical properties of purpose designed reduced activation ferritic-martensitic steels under bombardment of 14 MeV neutrons at 1018 n/m2s flux reaching values of 150 displacements per atom in the steel lattice. The understanding of the impact of Deuterium-Tritium fusion neutrons in next decade is essential to design and construct a fusion power plant; the next step after ITER. The 14 MeV neutrons are stripped from a liquid Li screen flowing at 15 m/s impacted by 2 parallel 125 mA deuteron beam at 40 MeV. IFMIF project, in its engineering validation phase, will operate in Rokkasho a 125 mA deuteron LINAC at 9 MeV that will validate the concept of IFMIF accelerator, LIPAc. The ion source will inject 140 mA deuterons at 100 KeV in a normal-conducting RFQ that will deliver the bunched beam at 5MeV to be accelerated up to 9 MeV thanks to 8 half-wave superconducting resonators. The installation and commissioning of LIPAc in Rokkasho (Japan) is sequential and the first stage is starting now; the strategy to overcome potential difficulties is detailed. | |||
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Slides TUOAB101 [2.396 MB] | ||
TUYB101 | Progress in Super B-Factories | emittance, luminosity, positron, alignment | 1096 |
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The upgrade of B-Factories to Super B-Factories, which will search for new physics beyond the Standard Model, opens the way for new luminosity frontier. The status of Super B-Factories will be reported. | |||
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Slides TUYB101 [42.300 MB] | ||
TUYB102 | Summary of the ILC R&D and Design | positron, electron, damping, cavity | 1101 |
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This talk should provide a summary of the main activities of ILC-GDE since 2005, and an overview of the Technical Design Report with prospects for the next steps for the future. | |||
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Slides TUYB102 [6.544 MB] | ||
TUOCB101 | Argonne Wakefield Accelerator (AWA): A Facility for the Development of High Gradient Accelerating Structures and Wakefield Measurements | wakefield, electron, acceleration, gun | 1111 |
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Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-06CH11357. The recently upgraded AWA facility is being commissioned. Operation of the new L-Band RF gun with a Cesium Telluride photocathode will generate long electron bunch trains, with high charge per bunch (up to 100 nC). The six new linac tanks will boost the beam energy to 75 MeV, making it an extremely well suited drive beam to excite wakefields in structures. One of the main goals of the facility is to generate RF pulses with GW power levels, corresponding to accelerating gradients of hundreds of MV/m and energy gains on the order of 100 MeV per structure. A key aspect of the studies and experiments carried out at the AWA facility is the use of relatively short RF pulses (15 – 25 ns), which is believed to mitigate the risk of breakdown and structure damage. |
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Slides TUOCB101 [3.416 MB] | ||
TUODB101 | Studies on An S-band Bunching System with Hybrid Buncher | bunching, cavity, electron, gun | 1120 |
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Generally, a standard bunching system is composed by a SW pre-buncher, a TW buncher and a standard accelerating section. However, there is one way to simplify the whole system to some extent by using the hybrid buncher, which is a combined structure of the SW pre-buncher and the TW buncher. Here the beam dynamics studies on an S-band bunching system with hybrid buncher is presented, simulation results shows that similar beam performance can be obtained at the linac exit by using this kind of bunching system rather than the standard one. In the meantime, the structure design of the hybrid buncher is also described. Furthermore, the standard accelerating section can also be integrated with the hybrid buncher, this can further simplify the bunching system and lower the construction cost. | |||
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Slides TUODB101 [22.120 MB] | ||
TUOAB201 | Ultra-Short X-ray Pulse Generation by Electron Beam Slicing in Storage Rings | electron, storage-ring, emittance, photon | 1134 |
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Funding: Department of Energy, USA We propose a new method to generate ultra-short x-ray pulses using focused short low energy (5-10MeV) electron bunch to slice a short electron bunch from the electron bunches in a synchrotron radiation storage ring. When the low energy electron bunch crosses from top the high energy electron bunch at right angle, its coulomb force will kick a short slice of high energy electrons away from the core of the storage ring electron bunch. When the low energy electron bunch (about 50 pC) is focused to about 50 micron size and compressed to about 150fs bunch length and is positioned on top of the high energy electron bunch by a distance about 30 micron, the coulomb force is sufficient to give a kick vertically to the electrons within a short slice of the storage ring bunch about 200 fs long with a deflection about 4 micro-radian. This is sufficient to deflect the slice away from the core by a separation of 5 times the angular divergence of the beam. The separated slice when passing through an undulator, will radiate ulstra-short x-ray pulses at about 200 fs. We discuss the advantages and challenges of this new method. We provide data to demonstrate the feasibility of this method. |
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Slides TUOAB201 [1.578 MB] | ||
TUODB203 | Dual Chip in Single Module Solid-State Power Amplifier Design for Compact Transmitter Architecture | insertion, impedance, storage-ring, booster | 1158 |
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At present, the high power solid-state technique transmitter design are composed of hundreds parallel combined single chip for hundreds Watts power modules to achieve enough output power. Although the large numbers can bring high redundancy during system operation, the power hungry of next generation RF system of accelerator would need much more modules to reach its power requirement. Huge amount of power modules would bring the complexity and difficulty in power combining, system construction, management and maintenance. To overcome this problem, upgrading the power level of a single module could be the solution. Besides depending on the power level growing with technology advancement in semiconductor industry, a circuit level solution to combine dual chip in advance in a single PCB board is proposed to produce twice power as single chip. Such feasible solution can overcome the over-complexity of future several-hundreds kW solid-state transmitter design. | |||
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Slides TUODB203 [2.337 MB] | ||
TUPEA003 | Components for CW and LP Operation of the XFEL Linac | cavity, cryomodule, HOM, cathode | 1164 |
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The European XFEL will use superconducting TESLA cavities operating with 650 μs long bunch trains. With 220 ns bunch spacing and 10 Hz RF-pulse repetition rate, up to 27000 high quality bunches/s will be delivered to insertion devices generating unprecedented high average brilliance photon beams at very short wavelength. While many experiments can take advantage of full bunch trains, others prefer an increased intra-pulse distance of several μ-seconds between bunches, or short bursts with a kHz repetition rate. In this contribution, we discuss progress in the R&D program for a future upgrade of the European XFEL linac, to operation in the continuous wave (cw) and long pulse (lp) mode, which will allow for much more flexibility in the electron and photon beam time structure. Modifications and cw tests of XFEL cryomodules, recent tests result of the SRF injector, test of the second prototype of 120 kW IOT are presented. In addition, computer modeling of the cw-operating TESLA-like cavity with modified HOM couplers is briefly discussed. | |||
TUPEA004 | The Free-electron Laser FLASH at DESY | FEL, photon, gun, undulator | 1167 |
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The free-electron laser FLASH at DESY routinely produces up to several thousand photon pulses per second with wavelengths ranging from 44 nm down to as low as 4.25 nm and with pulse energies of up to 400μJoule. After a significant technical upgrade in 2010, which included an energy upgrade to 1.25 GeV and linearization of the longitudinal phase space by 3-rd harmonic cavities, emphasis was put on consolidation and automatization of operational procedures and better control of the electron/photon beam properties. Some highlights are: on-line measurements of the electron bunch-length in the regime of several 10 fs to 100 fs, reaching into the water window, increased photon pulse energies and the improved machine reproducibility. Moreover, first evidence of HHG seeding was found at the sFLASH experiment in spring 2012. Construction work is ongoing for a 2-nd beam-line (FLASH-2) for which commissioning will start in late 2013. | |||
TUPEA042 | Linac Design for Dalian Coherent Light Source | FEL, emittance, simulation, laser | 1226 |
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Dalian Coherent Light (DCL) Source is a FEL user facility in which HGHG scheme is adopted. Beam quality requirements for the linear accelerator (linac) are critical, including not only the beam brightness, but also the stability and the reliability. In this paper, optimization study is performed for the linac. Based on beam stability simulation in the longitudinal direction, the tolerant budget is formed for the short period jitter. For the transverse orbit error, beam based alignment (BBA) technique is implemented by beam dynamics simulations and the transverse jitter is also presented accordingly. Measurement method for the beam quality is also described in the paper. | |||
TUPEA043 | Linac Design for Nuclear Data Measurement Facility | neutron, electron, cavity, target | 1229 |
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Pulsed neutrons based on an electron linear accelerator (linac) are effective for measuring energy dependent cross-sections with high resolution by using the time-of-flight (TOF) technique. In this paper, we describe the 15-MeV linac design for the Nuclear Data project in Shanghai Institute of Applied Physics (SINAP). The linac has three operating modes and the maximum average power is 7.5kW. We describe the characteristics of the linac and the study of the beam dynamics is also presented. | |||
TUPEA050 | Extension of the MAX IV Linac for a Free Electron Laser in the X-ray Region | FEL, undulator, emittance, electron | 1244 |
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The 3 GeV linac for the MAX IV laboratory is currently under construction in Lund (Sweden). As full energy injector for the MAX IV rings, a thermionic gun will be used to create electrons. However a photocathode gun planned for a short pulse facility (SPF) will deliver small emittance and ultra-short electron bunches that will be suitable to also drive a Free-Electron Laser. Moreover extending the linac energy with 1 or 2 GeV will give the opportunity to get closer to 1 Angstrom radiation with much more flexibility and better performances. Given these opportunities at the MAX IV laboratory, a free electron laser is envisaged in the long term perspective of the facility. In this study we investigate the case of a 5 GeV machine which can produce radiation in the X-ray region. The FEL design will benefit from the implementation of self-seeding, to enhance stability of the central wavelength and spectral bandwidth. Tapering along variable gap undulators will help to extract the maximum photon flux and increase the brilliance of the source. Among others, this kind of machine would be suitable for time resolved experiments and imaging. | |||
TUPEA058 | The Conceptual Design of CLARA, A Novel FEL Test Facility for Ultrashort Pulse Generation | FEL, electron, laser, photon | 1265 |
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The conceptual design of CLARA, a novel FEL test facility focussed on the generation of ultrashort photon pulses with extreme levels of stability and synchronisation is described. The ultimate aim of CLARA is to experimentally demonstrate, for the first time, that sub-coherence length pulse generation with FELs is viable. The results will translate directly to existing and future X-Ray FELs, enabling them to generate attosecond pulses, thereby extending the science capabilities of these intense light sources. This paper will describe the design of CLARA, pointing out the flexible features that will be incorporated to allow multiple novel FEL schemes to be proven. | |||
TUPEA059 | CLARA Accelerator Design and Simulations | diagnostics, FEL, laser, emittance | 1268 |
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Funding: Science & Technology Facilities Council We present the accelerator design for CLARA (Compact Linear Advanced Research Accelerator) at Daresbury Laboratory. CLARA will be a testbed for novel FEL configurations. The accelerator will consist of an RF photoinjector, S-band acceleration and transport to 250 MeV including X-band linearisation and magnetic bunch compression. We describe the transport in detail including dedicated diagnostic sections. Beam dynamics simulations are then used to define a set of operating working points suitable for the different FEL schemes intended to be tested on CLARA. |
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TUPEA060 | Jitter Tolerance for CLARA | laser, electron, cathode, FEL | 1271 |
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Funding: Science & Technology Facilities Council CLARA (Compact Linear Accelerator for Research and Applications) at Daresbury Laboratory will be a test-bed for novel FEL configurations. CLARA will consist of an RF photoinjector, S-band acceleration and transport to 250 MeV including X-band linearisation and magnetic bunch compression. Ensuring stability of the VUV radiation pulses is a key aim of the project. To this end, we investigate in detail the jitter tolerance of the machine. This will ultimately determine the pulse stability. |
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TUPEA075 | Passively Driving X-band Structures to Achieve Higher Beam Energies | electron, impedance, laser, gun | 1304 |
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Particle accelerators at X-band frequencies have gradients of around 100 MV/m. This technology permits more compact accelerators. One of our aims at the Colorado State University Accelerator Laboratory is to adapt this technology to our L-band (1.3 GHz) accelerator system to increase our overall beam energy; however, we would like to do this in a passive manner, i.e. one that does not require investment in an expensive, custom, high-power klystron system. In this paper we explore using the beam from our L-band 6 MeV photoinjector to power an x-band structure tuned to the 9th harmonic of our L-band system, 11.7 GHz. Electron bunches will be generated at a repetition rate of 81.25 MHz and passed through a high shunt impedance x-band accelerating structure where they will resonantly excite the fundamental field. We will optimize the system to create the highest accelerating potential within this structure. Once the peak gradient is achieved we will send a single electron bunch through the system at a phase that places it on the crest of the X-band accelerating wave thereby increasing the electron bunch energy by some amount without need for additional external power sources. | |||
TUPEA086 | Femtosecond Electron Beam and X-ray Beams at the Linac Coherent Light Source | FEL, emittance, electron, laser | 1316 |
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Generation of ultrashort x-ray pulses (femtoseconds to attoseconds) is attracting much attention within the x-ray FEL user community. At the Linac Coherent Light Source (LCLS), we have successfully delivered femtosecond x-ray pulses to the users with two operating modes – low-charge (20-40pC) scheme and emittance spoiling foil method. Diagnostics on the femtosecond beams is also a challenging topic and good progresses have been made at LCLS. In this paper we report the experimental studies on the two femtosecond operation schemes, the x-ray performance and also the diagnostic progress. | |||
TUPEA088 | Argonne Flexible Linear Collider | collider, linear-collider, klystron, wakefield | 1322 |
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We propose a linear collider based on a short rf pulse (~22ns flat top), high gradient (~120MV/m loaded gradient), high frequency (26GHz) two beam accelerator design. This is a modular design and its unique locally repetitive drive beam structure allows a flexible configuration to meet different needs. Major parameters of a conceptual 250GeV linear collider are presented. This preliminary study shows that an efficient (~5% overall), 4MW beam power collider may be achievable. The concept is extendable to the TeV scale. | |||
TUPFI040 | Experimental Verification of the CLIC Two-Beam Acceleration Technology in CTF3 | acceleration, feedback, collider, bunching | 1436 |
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The Compact Linear Collider (CLIC) International Collaboration is pursuing an extensive R&D program towards a multi-TeV electron-positron collider. In particular, the development of two beam acceleration technology is the focus of the CLIC test facility CTF3. In this paper we summarize the most recent results obtained at CTF3: the results of the studies on the drive beam generation are presented, the achieved two beam acceleration performance is reported and the measured break-down rates and related observations are summarized. The stability of deceleration process performed over 13 subsequent modules and the comparison of the obtained results with the theoretical expectations are discussed. We also outline and discuss the future experimental program. | |||
TUPME008 | Beam Dynamics Studies for the Injection System of a High Luminosity Flavour Factory | injection, electron, positron, luminosity | 1577 |
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The requirements, in terms of average luminosity and lifetimes, of high luminosity e+e− colliders such as the Flavor factories, pose stringent constraints to the design of the injection complex. For the SuperB B-factory project at Tor Vergata, Italy, a design was developed to deliver full energy bunches (4.2 GeV e- and 6.7 GeV e+) to the main rings every 30 ms aiming at a high and nearly constant luminosity. The system included a polarized electron gun, a positron production system, linac sections, a Damping Ring (DR) and transfer lines connecting to the collider Main Rings (MR). After the decision, due to budget issues, to rescale the project to a lower energy (2.3 GeV/beam) for a tau/charm flavour factory, the same design principles have been applied. In this paper beam dynamics studies from the DR to the MR entrance is presented, including optimization of the transfer lines and of the bunch compressor. A start to end simulation shows that the beam quality satisfies theinjection requirements, even in the presence of energy errors and collective effects like CSR and wakefields. | |||
TUPME010 | High-intensity and Low-emittance Upgrade of 7-GeV Injector Linac towards SuperKEKB | positron, emittance, electron, laser | 1583 |
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After a decade of successful operation at KEKB a new electron/positron collider, SuperKEKB, is being constructed to commission within FY2014. It aims at a luminosity of 8 x 1035 /s.cm2, 40-times higher than that of KEKB, in order to study the flavor physics of elementary particles further, by mainly squeezing the beams at the collision point. The injector linac should provide high-intensity and low-emittance beams of 7-GeV electron and 4-GeV positron by newly installing a RF-gun, a flux concentrator, and a damping ring with careful emittance and energy management. It also have to perform simultaneous top-up injections into four storage rings by pulse-to-pulse beam modulations not to interfare between three facilities of SuperKEKB, Photon Factory and PF-AR. This paper describes the injector design decisions and present status of the construction. | |||
TUPME014 | Coherent Synchrotron Radiation Predicted at the SuperKEKB Damping Ring | damping, vacuum, emittance, simulation | 1595 |
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The damping ring of SuperKEKB is under construction in order to inject low emittance positron beam into the main ring. We calculated the bunch lengthening and the energy spread caused by the longitudinal wake, which is dominated by the CSR wake field. The result was within the tolerance level. | |||
TUPME018 | Construction of New 90 MeV Injector Linac for the 1.2 GeV Booster Synchrotron at Tohoku University | gun, electron, synchrotron, quadrupole | 1607 |
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The Great East Japan Earthquake (March 11, 2011) has inflicted enormous damage on the accelerator facility of Research Center for Electron Photon Science, Tohoku University. A 300 MeV linac operated for 46 years as an accelerator for radioisotope production and also as an injector of the 1.2 GeV booster synchrotron for nuclear physics experiments. The accelerator will be rebuilt with all the recyclable components. New small linac is constructed as the injector for the booster synchrotron. The injector consists of thermionic rf-gun, two 3m-long accelerating structures, and transport line to the synchrotron. The maximum energy of injector is 90 MeV with beam loading. The detail of the injector linac is introduced in this conference. | |||
TUPME020 | Design of a TeV Beam Driven Plasma-wakefield Linear Collider | plasma, collider, acceleration, linear-collider | 1613 |
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Funding: This work is supported by the Research Council of Norway and U.S. Department of Energy under contract number DE-AC02-76SF00515. A novel design of a 500 GeV c.m. beam-driven PWFA linear collider with effective accelerating gradient on the order of 1 GV/m and extendable in the multi-TeV energy range is presented. The main bunches collide in CW mode at several kHz repetition frequency. They are accelerated and focused with several GV/m fields generated in plasma cells by drive bunches with very good transfer efficiency. The drive bunches are themselves accelerated by a CW superconducting rf recirculating linac. We consider the overall optimizations for the proposed design, compare the efficiency with similar collider designs like ILC and CLIC and we outline the major R&D challenges. |
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TUPME026 | Optimization on RF parameters of a Choke-Mode Structure for the Clic Main LINAC | wakefield, simulation, accelerating-gradient, cavity | 1628 |
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Funding: This work was support by the National Natural Science Foundation of China (Grant No. 11135004). A tapered choke-mode structure for the main linac of Compact Linear Collider (CLIC) had been designed. Wakefield suppression of this structure fits the beam dynamic requirements. But it has a lower RF performance compared to the baseline design of CLIC main linac. A genetic algorithm is used in the procedure to find the optimum solution. A new choke-mode structure with 24 regular cells working on 100MV/m has been design, which fits beam dynamic constraints and has higher RF efficiency and lower surface field. |
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TUPME039 | The Drive Beam Phase Stability in CTF3 and its Relation to the Bunch Compression Factor | acceleration, pick-up, klystron, linear-collider | 1655 |
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The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy needed to accelerate a low intensity "main" beam is provided by a high intensity, low energy "drive" beam. The precision and stability of the phase relation between two beams is crucial for the performance of the scheme. The tolerable phase jitter is 0.2 deg rms at 12GHz. For this reason it is fundamental to understand the main possible causes of the drive beam timing jitter. Experimental work aimed at such understanding was done in the CLIC Test Facility (CTF3) where a drive beam with characteristics similar to the CLIC one is produced. Several phase measurements allowed us to conclude that the main source of phase jitter is energy jitter of the beam transformed and amplified into phase jitter when passing through a magnetic chicane. This conclusion is supported by measurements done with different momentum compaction values in the chicane. In this paper the results of these several phase measurements will be presented and compared with expectations. | |||
TUPME048 | Imperfection Tolerances for On-line Dispersion Free Steering in the Main Linac of CLIC | wakefield, emittance, quadrupole, simulation | 1673 |
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Long-term ground motion misaligns the elements of the main linac of CLIC over time. Especially the misaligned quadrupoles create dispersion and hence the beam quality is decreased gradually due to an effect called chromatic dilution. Over longer time periods, orbit feedback systems are not capable to fully recover the beam quality and have to be supplemented by dispersion correction algorithms. In this paper, such and dispersion correction algorithm is presented, which is an extended version of the well-known dispersion free steering algorithm. This extended algorithm can recover the beam quality over long time scaled without stopping the accelerator operation (on-line). Tolerances for different imperfections of the system have been identified and a strong sensitivity to the resolution of the wake field monitors of the main linac accelerating structures has been identified. This problem can be mitigated by using a local excitation scheme as will be shown in this work. | |||
TUPME049 | Status of the Exploration of an Alternative CLIC First Energy Stage Based on Klystrons | klystron, luminosity, linear-collider, collider | 1676 |
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The Compact Linear Collider is based on a two-beam scheme to accelerate the main, colliding beams. This scheme allows to reach very high centre-of-mass energies. At low collision energies the main beams could be accelerated by powering the accelerating structures with X-band instead of a second beam. We explore this option and indicate the parameters and conceptual design. | |||
TUPME050 | Performance Comparison of Different System Identification Algorithms for FACET and ATF2 | kicker, emittance, simulation, alignment | 1679 |
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Good system knowledge is an essential ingredient for the operation of modern accelerator facilities. For example, beam-based alignment algorithms and orbit feedbacks rely strongly on a precise measurement of the orbit response matrix. The quality of the measurement of this matrix can be improved over time by statistically combining the effects of small system excitations with the help of system identification algorithms. These small excitations can be applied in a parasitic mode without stopping the accelerator operation (on-line). In this work, different system identification algorithms are used in simulation studies for the response matrix measurement at ATF2. The results for ATF2 are finally compared with the results for FACET, latter originating from an earlier work. | |||
TUPME053 | General Beam Loading Compensation in a Traveling Wave Structure | beam-loading, bunching, electron, storage-ring | 1688 |
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The well-known beam loading in a traveling wave structure is in fact a resistive beam loading which bunches travel on the crest. This type of beam loading could be compensated by increasing RF feed power. But generally, bunches could travel on each phase. General beam loading compensation is well-known for a single cell cavity and it is done by changing the RF feed power and detuning the structure together. In this paper, the concept of detuning for a TW structure will be shown and the evolution of fundamental mode beam-induced field will be derived and finally, it will be shown how to compensate beam loading by changing the phase velocity in comparison to the beam velocity. | |||
TUPME054 | Experimental Study of the Effect of Beam Loading on RF Breakdown Rate in CLIC High-gradient Accelerating Structures | beam-loading, optics, beam-losses, luminosity | 1691 |
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RF breakdown is a key issue for the multi-TeV high-luminosity e+e− Compact Linear Collider (CLIC). Breakdowns in the high-gradient accelerator structures can deflect the beam and decrease the desired luminosity. The limitations of the accelerating structures due to breakdowns have been studied so far without a beam present in the structure. The presence of the beam modifies the distribution of the electrical and magnetic field distributions, which determine the breakdown rate. Therefore an experiment has been designed for high power testing a CLIC prototype accelerating structure with a beam present in the CLIC Test Facility (CTF3). A special beam line allows extracting a beam with nominal CLIC beam current and duration from the CTF3 linac. The paper describes the beam optics design for this experimental beam line and the commissioning of the experiment with beam. | |||
TUPME055 | Strawman Optics Design for the CERN LHeC ERL Test Facility | optics, emittance, lattice, electron | 1694 |
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In preparation for a future Large Hadron electron Collider (LHeC) at CERN, an ERL test facility is foreseen as a test bed for SRF development, cryogenics, and advanced beam instrumentation, as well as for studies of ERL-specific beam dynamics. The CERN ERL test facility would comprise two linacs, each consisting of 4 superconducting 5-cell cavities at 802 MHz, and two return arcs on either side. With an RF voltage of 75 MeV per linac a final electron energy of about 300 MeV is reached. The average beam current should be above 6 mA to explore the parameter range of the future LHeC. In this paper we present a preliminary optics layout. | |||
TUPME062 | Simulation and Analysis of Microbunching Instability in a High Repetition rate FEL Beam Delivery System | electron, laser, simulation, FEL | 1709 |
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Funding: Work supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231. Microbunching instability in the accelerator beam delivery system of an FEL can significantly degrade the electron beam quality and limit performance of the X-ray radiation. In this paper, we present detailed numerical simulation and analytical analysis of the microbunching instability in a high repetition rate X-ray FEL beam delivery system that is being studied at Lawrence Berkeley National Laboratory. Our results suggest that by using a flexible accelerator design and a laser heater, the effects of microbunching instability can be suppressed without significantly sacrificing the final electron beam quality. |
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TUPWA004 | Advanced Considerations for Designing Very High-intensity Linacs through Novel Methods of Beam Analysis, Optimization, Measurement & Characterisation | emittance, space-charge, extraction, rfq | 1727 |
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Research in fundamental physics, nuclear physics or advanced materials, requires linear accelerators as irradiation sources with higher and higher beam intensity. In such machines, not only high beam power but also high space charge are the major challenges. This double concern often induces conflicting issues, which should be overcome from the accelerator design stage. It progressively appears that the usual methods are no more sufficient. Even new concepts are to be invented. With mega-watt beams, losses and also micro-losses must be minimised while with very strong space charge, few room can be reserved for beam diagnostics. New strategies for design and tuning are to be carried out. The beam itself can no more be described only by its classical values like emittance and Twiss parameters. Core and halo parts should be instead precisely defined and kept under surveillance. The beam phase space distribution itself becomes determinant, which is very far from waterbag or gaussian distributions. This paper aims at proposing new considerations for very high-intensity linacs while recalling the usual ones, from designing and tuning methods to beam definitions and characterisations. | |||
TUPWA013 | Study of the C-ADS Longitudinal Beam Instabilities Caused by HOMS | HOM, emittance, damping, simulation | 1751 |
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The C-ADS accelerator is a CW proton linac which accelerates the beam to 1.5GeV. It has the characteristics of being very high beam power and very high reliability that are not posed by any of the existing proton linacs. The accelerator uses two families (β=0.63 and β=0.82 ) of elliptical five cell superconducting cavities. High Order Modes can severely limit the operation of these cavities. Monopole modes are found by Microwave Studio CST. Then the longitudinal instability caused by these monopole modes are primarily investigated with code bbusim, taking into account of effects like High Order Modes frequency spread, beam input jitters and other beam and RF parameters of the beams and cavities. Preliminary simulation results show that monopole modes induced instability is not a problem if High Order Modes frequency spread is not less than 1MHz. However, further investigations are necessary in order to make a critical decision such as whether HOM damper will be adopted. Study on the transverse case is under way. | |||
TUPWA018 | Local Compensation-Rematch for Element Failures in the Low Energy Section of C-Ads Accelerator | solenoid, cavity, emittance, focusing | 1760 |
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Due to the requirement of high reliability and availability for the C-ADS accelerators, a fault tolerance design is pursued. The effects of transverse focusing element failures in different locations have been studied and the schemes of compensation by means of local compensation have been investigated. After one transverse element failure especially in the low energy section happens, some new methods have been purposed by which the new settings of the neighbouring solenoids and the cavities can be set, and the Twiss parameters and energy can be approximately recovered to that of the nominal ones at the matching point. We find that the normalized RMS emittance in transverse and longitudinal planes have no obvious growth after applying the compensation in each section of the main linac. When we make study on the compensation-rematch for the RF cavity failures, the TraceWin code has been used that doesn’t consider the phase change during the cavity resetting, so a code named LOCCOM, which is based on MATLAB, is developed and used to compensate the error on arrival-time at the matching point. | |||
TUPWA019 | Comparison of Tracking Simulation with Experiment on the GSI UNILAC | DTL, emittance, simulation, space-charge | 1763 |
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In the European framework “High Intensity Pulsed Proton Injector” (HIPPI), the 3D linac code comparison and benchmarking program with experiment have been initialed. PARMILA and HALODYN are involved in this work. Both of these codes have been developed and used for linac design and beam dynamics studies. In this paper, we compare the simulation results with experiment results which was carried out on the UNILAC Alvarez DTL. And discuss physics aspects of the different linac design and beam dynamics simulation codes. | |||
TUPWA020 | The Implementation of Equipartitioning in the Proton Linac Code PADSC | emittance, space-charge, lattice, quadrupole | 1766 |
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The high intensity accelerator projects place extremely stringent requirements on particle loss, since even very small losses can lead to unacceptably high levels of radioactivity that can hinder or prevent hands-on maintenance. Such losses are known to be associated with emittance growth and beam halo. Non-equipartitioning contributes a lot for emittance growth and beam halo. The present equipartitioning realization has assumed that the emittance and space charge force are keeping constant, which will induce errors. The implementation in the proton linac code PADSC does equipartitioning optimization according to the real space charge force and emittance in the quasi period lattice. | |||
TUPWA023 | Design of the Tuning System for the He+ Coupled RFQ-SFRFQ Cavity | cavity, rfq, simulation, impedance | 1775 |
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Funding: Supported by NSFC 10905003, 11079001, 91026012 Corresponding author: wangzhi@pku.edu.cn The CRS (coupled RFQ-SFRFQ) cavity is a new type linac that couples traditional RFQ (radio frequency quadrupole) and SFRFQ (separated function RFQ) electrodes into a single cavity. The overall design of the CRS cavity has been completed and the linac is being manufactured currently. In this paper, we aimed to design a frequency tuning system for the CRS cavity, which will be used to explore the electromagnetic field distribution between RFQ and SFRFQ sections in the cavity. The frequency range, variation of Q value, power consumption and electric field distribution were investigated. Based on the beam dynamic program SFRFQDYNv1.0, we analysed the beam transmission properties of the cavity under the unbalanced electric field distribution. The optimized parameters of the tuning system were obtained. |
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TUPWA025 | DESIGN STUDIES OF THE C-ADS MAIN LINAC WITH ONLY SPOKE CAVITIES | emittance, proton, simulation, space-charge | 1781 |
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The China ADS(C-ADS) project undertaken by the Chinese Academy of Science is based on superconducting proton linac. The design goal is to accelerate 10mA CW proton beam up to 1.5GeV. The accelerator includes an injector section and a main superconducting linac. Two injectors are under studying by IHEP and IMP respectively. In this paper, an alternative design of the main linac with full spoke cavity base on the beam characteristics from IMP injectorⅡis described. In addition, multi-particle beam dynamics simulations have been performed using TraceWin code to estimate the space charge effect. | |||
TUPWA034 | On the Choice of Linac Parameters for Minimal Beam Losses | space-charge, emittance, resonance, beam-losses | 1787 |
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In high intensity linear accelerators, the tune spreads induced by the space-charge forces in the radial and longitudinal planes are key parameters for halo formation and beam losses. For matched beams they are the parameters governing the number of resonances (including coupling resonances) which affect the beam and determine the respective sizes of the stable and halo areas in phase space. The number and strength of the resonances excited in mismatched beams leading to even higher amplitude halos are also directly linked to the tune spreads. In this paper, the equations making the link between the basic linac parameters (rf frequency, zero-current phase advances, beam intensity and emittances) and the tune spreads are given. A first analysis of the way these linac parameters can be chosen to minimize the tune spreads is presented. The parameters of ESS linac are used for this study. | |||
TUPWA059 | End-to-end Beam Simulations for the C-ADS Injector II | proton, rfq, simulation, diagnostics | 1838 |
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The Injector II for the proposed Chinese Accelerator Driven System (C-ADS) is designed to accelerate proton beam to ~ 10 MeV with beam current up to ~ 10 mA. The accelerator system will include a proton ECR ion source, a Low Energy Beam Transport System (LEBT), a room-temperature radio frequency quadrupole (RFQ), a Medium Energy Beam Transport System (MEBT), a Superconducting (SC) linac and a High Energy Beam Transport System (HEBT). Both RFQ and the SC linac will have a base frequency of 162.5 MHz. The accelerating cryomodules in the SC linac uses SC half-wave cavities for acceleration and SC solenoids with dipole correctors for transverse focusing and central orbit correction. End-to-end beam simulations starting with a realistic initial input beam from the ECR ion source were performed using DYNAC and IMPACT codes to evaluate the C-ADS Injector II accelerator system performance, code benchmarking with TRACK and explore system design options for future optimizations. The results of these beam dynamics studies will be presented in the paper. | |||
TUPWA067 | Beam Emittance Growth Effects in High-intensity RFQ | resonance, rfq, emittance, space-charge | 1859 |
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Beam dynamics in an RFQ are strongly affected by coupling between transverse and longitudinal particle oscillations. The adiabatic process of high-intensity bunched beam formation results in equipartitioning in the RFQ, which determines the longitudinal beam emittance. Avoiding parametric resonances is an important design criterion to prevent significant emittance growth of the beam. Manufacturing errors can result in beam emittance growth and reduction of beam transmission. This paper will present the results of a study where analytical and numerical evaluations were performed to determine the effect of the aforementioned factors on beam quality in a high-current RFQ. | |||
TUPWA068 | Model Independent Beam Tuning | simulation, quadrupole, beam-transport, drift-tube-linac | 1862 |
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This work presents a new model independent feedback control scheme for optimization and tuning of particle accelerator components, with a simulation demonstrating the method on a low energy, space-charge dominated beam. The scheme presented here does not depend on an accurate model of the system it is stabilizing, and may even be unaware of its control input direction (such as having rotated quadrupole magnets and alignment errors) and this direction may change with time (thermal cycling and hysteresis). Stability properties are demonstrated both analytically and through a simulation in which the current settings of twenty two quadrupole magnets are simultaneously tuned through the transport section of the Los Alamos Linear Proton Accelerator. The controller is unaware of the complex nonlinear beam dynamics, with its only input being the surviving beam current readings along the transport region. Starting with all magnet settings at zero, in which case all of the beam is lost by the end of the transport, the feedback control tunes the magnets resulting in successful transport to the first drift tube linac section. | |||
TUPWA069 | Longitudinal Phase Space Dynamics with Novel Diagnostic Techniques at FACET | wakefield, klystron, damping, radiation | 1865 |
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Funding: Work supported [optional: in part] by the U.S. Department of Energy under contract number DE-AC02-76SF00515. FACET produces high energy density electron beams for Plasma Wakefield Acceleration (PWFA) experiments. The high energy density beams are created by chirping the electron beam with accelerating sections and compressing the beam in magnetic chicanes. Precise control of the longitudinal beam profile is needed for the drive-witness bunch PWFA experiments currently underway at FACET. We discuss the simulations, controls, and diagnostics used to achieve FACET's unique longitudinal phase space. |
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TUPWO016 | Beam Dynamics Design of 3 MeV Medium Energy Beam Transport for Beam Intensity Upgrade of J-PARC Linac | emittance, DTL, simulation, cavity | 1916 |
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The J-PARC linac has a plan to upgrade its beam power in the summer 2013. This plan includes the replacement of the front-end components (ion source and 3 MeV RFQ) to increase the peak current from present 30 mA to 50 mA. Since it results in the different injection beam profile to medium energy beam transport (MEBT), which locates the RFQ downstream, we designed the beam dynamics of MEBT. In this presentation, we disscuss the new design of beam dynamics in MEBT. | |||
TUPWO019 | A Local Achromatic Design of C-ADS MEBT2 | emittance, bunching, controls, cavity | 1922 |
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The accelerator of China Accelerator Driven Sub-critical system consists of two injectors to ensure its high reliability. The Medium Energy Beam Transport line-2 is an essential part of the accelerator to transport and match the beam from either injector to the main linac. This paper presents a local achromatic design, which uses four bending magnets, for CADS MEBT2. It is found that both transverse and longitudinal emittance growths can be well controlled below 15% from MEBT2 entrance to the exit of the following superconducting spoke-021 section. The beam dynamics of MEBT2 will be discussed and the multi-particle tracking results will also be shown. | |||
TUPWO020 | Error Analysis for C-ADS MEBT2 | emittance, cavity, beam-transport, solenoid | 1925 |
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A local achromatic scheme has been developed for C-ADS MEBT2. This paper presents the error analysis results for this MEBT2 scheme. The effects of magnet and cavity misalignment, static and dynamic errors of electric and magnetic field, the displacement of the input beam as well as the initial mismatches of the incoming beam will be studied. Beam trajectory correction scheme will also be discussed. | |||
TUPWO022 | Space Charge Effects Study and Optimization in CSNS/LRBT | space-charge, emittance, lattice, injection | 1928 |
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The linac to ring beam transport line (LRBT) of China Spallation Neutron Source (CSNS) connecting the linac and the rapid cycling synchrotron (RCS) transports 80 MeV negative hydrogen ions (H−) beams for RCS injection. Space charge effect in LRBT is significant due to small emittance and high current density of the beam, which is a major cause of emittance growth and beam loss. An achromatic transverse optical matching was performed by TRACE 3D code. Emittance growths of beams with different initial distributions in different LRBT lattices were studied separately. Simulation results show that the LRBT design with triplet can mitigate the emittance growth by lattice optimization of the front matching section and no beam loss occurs at 15mA. The location and parameters of the debuncher in LRBT were also optimized to reduce the momentum spread and energy jitter. | |||
TUPWO034 | Focusing Magnetic Field Design for a FEL Linac | focusing, electron, space-charge, solenoid | 1949 |
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A linac-based Free Electron Laser is planned to be built in Huazhong University of Science and Technology (HUST). As an important part of the whole project, the focusing magnetic field is carefully designed. Space-charge force is calculated at first to give a rough evaluation about the focusing field. Start-to-end simulation shows that the magnetic field has only great effect on spot size and phase space. With the final designed field, 10-ps-length pulse containing 200pC electrons can be got and the corresponding RMS emittance and RMS radius are 7 πmm•mrad and 0.25 mm, respectively. Finally, a new idea (double-peak scheme) is discussed and excitation current is proposed as the evaluation index. | |||
TUPWO038 | Start-to-end Simulations for Heavy-ion Accelerator of RISP | rfq, emittance, simulation, proton | 1958 |
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RAON has been designed as a facility for rare isotope accelerator at Korea. The aceelerator consists of 28 GHz superconducting ion source, LEBT, RFQ, MEBT, superconducting linac and HEBT. The linac accelerates ion beams to 200 MeV/u with a beam power of 400 kW. Start-to-End simulations are performed from ECR-IS to HEBT and the detailed beam simulation results are presented. The beam dynamics issues are also discussed. | |||
TUPWO041 | Beam Size and Emittance Measurements during the ALBA Booster Ramp | booster, emittance, injection, dipole | 1964 |
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The beam emittance in the ALBA Booster is damped from 50·10-6 m*rad to 10-9 m*rad during the energy acceleration from 110 MeV to 3 GeV. The synchrotron radiation monitor installed in a dipole magnet provides the transverse beam size evolution along the energy ramp, which is then used to calculate the emittance evolution during the full booster cycle (from injection to extraction). In this report, we present the experimental set-up and technique of this measurement, and discuss the agreement between the measured parameters and theoretical values. | |||
TUPWO046 | The ESS Linac Simulator: A First Benchmark with TraceWin | space-charge, simulation, cavity, multipole | 1970 |
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The ESS Linac Simulator, ELS, will be the core of the online model used in the normal operations of the ESS linac. ESS Linac Simulator will operate through the eXtensible Accelerator Language, XAL, in order to provide an effective interface capable to simulate and predict the beam dynamics of the accelerator. The ELS is capable of simulating the dynamics of the beam envelope in both transverse and longitudinal planes in real time. In order to validate the effectiveness of the physics implemented, the ELS calculations are here benchmarked with TraceWin: the simulation code used for the design of the accelerator. | |||
TUPWO065 | Anomalously Long Bunches from the SLAC North Damping Ring | electron, simulation, klystron, damping | 2015 |
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The SLC damping ring provides emittance reduced beam to the beginning of the FACET accelerator. In measurements conducted during the 2012 FACET run, we find the bunch-length to be ~20% longer than canonical. A study is performed with longitudinal simulation code to determine the impact on the various stages of compression for FACET experimental running. | |||
TUPWO067 | Start-to-end Particle Tracking of the FACET Accelerator | emittance, klystron, wakefield, simulation | 2018 |
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Funding: Work supported by Department of Energy contract DE-AC02-76SF00515. The Facility for Advanced aCcelerator Experimental Tests (FACET) consists of the first two-thirds of the SLAC two-mile linac followed by a final focus and experimental end station. To date, wakefield-dominated emittance growth and dispersion in the linac, as well as dispersive and chromatic effects in the final focus have precluded regular reliable operation that meets the design parameters for final spot size. In this work, a 6-D particle tracking code (Lucretia) is used to simulate the complete machine, with input parameters taken directly from saved machine configurations. Sensitivities of various tuning parameters to the final spot sizes are compared with measurements taken from the real machine, and a set of tuning protocols is determined to improve regular machine operation. |
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TUPWO068 | Performance Improvements of the SLAC Linac for the FACET Beam | emittance, quadrupole, klystron, injection | 2021 |
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Funding: Work supported by U.S.Department of Energy, Contract DE-AC02-76SF00515. Two thirds of the SLAC Linac is used to generate a short, intense electron beam for the FACET experiments. The emittance growth along the Linac is a major concern to finally get small spot sizes for these experiments. There are two different approaches to get the required small emittances: a) lengthy iterative global tuning technique, and b) trying to identify locations of the main sources of the emittance growth and reducing their effect locally. How these approaches help to get good beam performances is discussed. |
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WEYB101 | Power Upgrade of J-PARC Linac | rfq, ion, ion-source, cavity | 2047 |
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A linac power upgrade program is now in progress after a successful recovery from the earthquake disaster. The power upgrade includes an ion source, an RFQ and a 400 MeV Annular-ring Coupled Structure (ACS) linac. We started a full-scale development of a cesium seeded RF-driven negative hydrogen ion source. The ion source extracted the beam of more than 60 mA with a duty factor of 2.5 %, which is satisfied with the requirement of the program. A new RFQ for 50 mA acceleration is under construction on the basis of a RFQ fabrication process, which was built as a backup for the present RFQ. Mass production of the ACS modules have almost completed. There is a plan to install these components and schedule the beam test in 2013. This presentation will cover the power upgrade status of the J-PARC linac. | |||
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Slides WEYB101 [4.205 MB] | ||
WEOBB101 | The KOMAC Accelerator Facility | DTL, proton, klystron, rfq | 2052 |
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Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government. The development of the Korea Multi-purpose Accelerator Complex (KOMAC) accelerator facility was finished and went into the operation period from 2013. The facility consists of an 100-MeV proton linac including a 50-keV ion source, a 3-MeV RFQ, and a 100-MeV DTL, and 20-MeV and 100-MeV beam lines. The linac and beam lines were developed by the Proton Engineering Frontier Project (PEFP), the first phase of KOMAC from 2002 to 2012. The goal of the beam commissioning is delivering 100-MeV 1-kW proton beams to a beam bump in a 100-MeV target room. After finishing the commissioning, the user beam service will start from spring 2013. The KOMAC user facility consists of 2 beam lines in the initial operation stage and it will be increased to 10 beam lines in future. The one beam line is for 20-MeV proton beams which are extracted after 20-MeV part of the DTL tanks. A medium energy beam transport (MEBT) is installed there for the 20-MeV beam extraction and the beam matching to the next DTL tank. The other beam line is for 100-MeV proton beams. This work summarized the status of the KOMAC accelerator and beam lines. |
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Slides WEOBB101 [6.038 MB] | ||
WEOBB102 | Design Integration of the FRIB Driver Linac | cryomodule, solenoid, SRF, ion | 2055 |
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Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 FRIB driver linac will deliver all stable heavy ion beams with beam energy more than 200 MeV/u, and beam power on target up to 400 kW. As the first SRF linac for high power heavy ion beams, there are many technical challenges, and integration of all the accelerator components is important. In this paper, major issues on integration of the FRIB drive linac are introduced and the corresponding studies are discussed, which include developments of accelerator online model, minimize uncontrolled beam loss in the SRF linac for high power heavy ion beams, beam diagnostic systems for beam tuning and for machine protection system (MPS), secondary collimators for charge selection of multi charge state ion beams, beam loading and stability of LLRF control, proper degauss process with superconducting (SC) solenoids when combined with SC dipole correctors, vacuum system, cryogenic and distribution system, helium pressure drop and stability of the cryomodules. |
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Slides WEOBB102 [3.557 MB] | ||
WEZB101 | Status of the European XFEL | undulator, photon, electron, gun | 2058 |
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The European XFEL is one of the world's largest accelerators presently under construction. The facility includes a 17.5 GeV superconducting linac with more than 3 km of electron beam transport lines and up to 5 FEL undulators. In mid-2013 the underground civil construction will finish. With most of the large scale production in full swing and first accelerator components installed, this talk should present the XFEL facility status and plans for accelerator commissioning including prospects for first XFEL experiments in Hamburg. | |||
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Slides WEZB101 [16.980 MB] | ||
WEOAB202 | JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs | electron, quadrupole, dipole, optics | 2085 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. We propose a demonstration experiment for a new concept of a ‘dogbone’ RLA with multi-pass return arcs – JEMMRLA (Jlab Electron Model of Muon RLA). Such an RLA with linear-field multi-pass arcs was introduced for rapid acceleration of muons for the next generation of Muon Facilities. It allows for efficient use of expensive RF while the multi-pass arc design based on linear combined-function magnets exhibits a number of advantages over separate-arc or pulsed-arc designs. Here we describe a test of this concept by scaling a GeV scale muon design for electrons. Scaling muon momenta by the muon-to-electron mass ratio leads to a scheme, in which a 4.5 MeV electron beam is injected in the middle of a 3 MeV/pass linac with two double-pass return arcs and is accelerated to 18 MeV in 4.5 passes. All spatial dimensions including the orbit distortion are scaled by a factor of 7.5, which arises from scaling the 200 MHz muon RF to a readily available 1.5 GHz. The hardware requirements are not very demanding making it straightforward to implement. Such an RLA may have applications going beyond muon acceleration: in medical isotope production, radiation cancer therapy and homeland security. |
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Slides WEOAB202 [1.485 MB] | ||
WEIB201 | Industrial Accelerators | electron, ion, neutron, radiation | 2100 |
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Particle accelerators, originally developed for basic science research, are increasingly being employed for industrial applications, with the production of these systems itself a worldwide business conducted by more than 70 companies and institutes. Collectively these entities ship more than 1000 systems per year. The industrial applications of these accelerators cover a broad range of business segments from low energy electron beam systems for welding, machining, and product irradiation to high energy cyclotrons and synchrotrons for radioisotope production and synchrotron radiation production. This talk is a review of these business segments and their impact on our lives and the economy. It will also cover new accelerator technology under development that will be used by industry in the future and the predicted growth in the various business segments. | |||
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Slides WEIB201 [3.937 MB] | ||
WEIB202 | Industrialization of the ILC Project | SRF, cavity, linear-collider, collider | 2105 |
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Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The International Linear Collider Global Design Effort (GDE) team completed the Technical Design Report (TDR) in early 2013. The TDR consists of a description of the machine design, a summary of the R&D program carried out in support of the design, a cost estimate and a project plan. The number of high technology components to be fabricated for ILC is large, similar to that built for the Large Hadron Collider*, and industrial partners have had an important role throughout the technical development and design period. It is recognized that transfer of new technology to industrial partners and subsequent collaborative development can be difficult**. To counter this, the ILC Technical Design Phase (TDP) team arranged a series of vendor visits, component development contracts, workshop satellite meetings and industrial production study contracts. The GDE collaboration provided the framework for development through an agreed-upon performance parameter set and project implementation scheme. The latter includes a ‘plug-compatibility’ policy that promotes innovation as long as specified interface conditions are met. In this paper we show the evolution of the technology from the labs where it was developed to the companies where high performance cavities are now routinely produced. * The longest journey: the LHC dipoles arrive on time. http://cerncourier.com/cws/article/cern/29723 ** Office of High Energy Physics Accelerator R&D Task Force Report http://www.acceleratorsamerica.org/report/acceleratortaskforcereport.pdf |
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Slides WEIB202 [5.181 MB] | ||
WEIB204 | Industry and Science, POSCO and POSTECH Case | site, FEL, klystron, storage-ring | 2115 |
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Funding: * Supported by MEST and POSTECH POSCO is a world-leading iron and steel company established in 1968 in Pohang, in the South East coast of Korea. Starting with 1.0 million ton size in 1973, the company made profits even in the first year. While its capacity has been increased to 40 million tons with another works in Gwangyang, POSCO paid attention on education to attract intellectuals to Pohang and Korea. It results in establishing a small-sized university, Pohang University of Science and Technology (POSTECH) in 1987. POSTECH immediately decided to construct a third generation synchrotron light source of 2.0 GeV, Pohang Light Source (PLS) on its campus in 1988, with support from POSCO and also Government. POSTECH achieved a high rank in the world, and PLS is upgraded to 3.0 GeV in 2011. A new PAL-XFEL of 10.0 GeV is now under construction. POSCO's consistent policy is the key of the success of POSTECH and Pohang Light Source. This is an unprecedented example of the relationship between industry and science. |
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Slides WEIB204 [4.759 MB] | ||
WEPWA004 | Multi-turn ERL Based Light Source: Analysis of Injection and Recovery Schemes | cryomodule, optics, injection, acceleration | 2129 |
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The optics simulation group at HZB is designing a multi-turn energy recovery linac -based light source. Using the superconducting Linac technology, the Femto-Science-Factory(FSF) will provide its users with ultra-bright photon beams of angstrom wavelength. The FSF is intended to be a multi-user facility and offer a variety of operation modes. The driver of the facility is a 6GeV multiturn energy recovery linac with a split linac. In this paper we compare different schemes of beam acceleration: a direct injection scheme with acceleration in a 6 GeV linac, a two-stage injection with acceleration in a 6 GeV linac, and a multi-turn (3-turn) scheme with a two-stage injection and two main 1 GeV linacs. The key points were costs and beam break up instability. | |||
WEPWA008 | Simulating the Bunch Structure in the THz Source FLUTE | simulation, space-charge, laser, dipole | 2141 |
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FLUTE is a planned THz source at KIT operating at a beam energy of 40 to 50 MeV in a wide bunch charge range. It consists of a laser driven rf-gun, a linac and a magnetic bunch compressor. The high current density combined with relatively low energy of FLUTE leads to complex strong self-field and beam-radiation field interactions, which are the limiting factors for the bunch compression efficiency. The results of numerical studies are presented in this paper. | |||
WEPWA009 | RF Bunch Compression Studies for FLUTE | cavity, simulation, gun, space-charge | 2144 |
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FLUTE is a planned 40 to 50 MeV accelerator test facility consisting, in the first phase, of an electron gun with an output energy of about 7 MeV, a traveling wave linac and a magnet chicane bunch compressor. The machine will serve as a source of intense THz radiation using coherent synchrotron radiation (CSR), coherent transition radiation (CTR), and coherent edge radiation (CER) as generation mechanisms. It is planned to operate the machine in the charge regime from a few pC up to several nC in order to study bunch compression schemes as well as the THz radiation generation. In this contribution the effect of velocity bunching by using a dedicated buncher cavity at low energy and operating the linac off-crest is studied in order to deliver RMS bunch lengths in the femtosecond range at low charge. | |||
WEPWA010 | FLUTE: A Versatile Linac-based THz Source Generating Ultra-short Pulses | radiation, laser, gun, electron | 2147 |
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FLUTE is a linac-based accelerator test facility and a THz source currently being constructed at KIT with an electron beam energy of ~41 MeV. It is designed to cover a large charge range from a few pC to ~3 nC. FLUTE is optimized to provide ultra-short electron bunches with an RMS length down to a few fs. In this contribution, we focus on the layout of the machine from the RF gun & gun laser over the linac and the compressor to the THz beamline for the generation of coherent synchrotron, transition and edge radiation (CSR, CTR, CER). | |||
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Poster WEPWA010 [0.802 MB] | ||
WEPWA011 | Injector Linac for the MESA Facility | booster, SRF, electron, target | 2150 |
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Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA" In this paper we present several possible configurations of an injector linac for the upcoming Mainz Energy-recovering Superconducting Accelerator (MESA)* and discuss their suitability for the project. *R. Heine, K. Aulenbacher, R. Eichhorn "MESA - Sketch of An Energy Recovery Linac For Nuclear Physics Experiments At Mainz" IPAC 12, New Orleans, USA, 2012, p.1993, TUPR073 |
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WEPWA012 | Preliminary Design of Transfer Lines for the ILSF Accelerator Complex | booster, storage-ring, synchrotron, electron | 2153 |
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There are two transfer lines (T-lines) which link the Iranian Light Source Facility (ILSF) accelerator complex to gather. Several criterias have been considered in design stage of the T-lines. This paper gives linear optimization results of the designed T-lines based on the first layout of the ILSF. | |||
WEPWA015 | Progress in Construction of the 35 MeV Compact Energy Recovery Linac at KEK | gun, cryomodule, shielding, laser | 2159 |
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The 35-MeV Compact Energy Recovery Linac (the Compact ERL or cERL) is under construction at the High Energy Accelerator Research Organization (KEK) in Japan. With the Compact ERL, we aim at establishing cutting-edge technologies for the GeV-class ERL-based synchrotron light source. To install the accelerator components of the cERL, we have constructed a shielding room having an area of about 60 m x 20 m. We have then installed a 500-kV DC photocathode gun, a 5-MV superconducting (SC) cryomodule for the injector, a 30-MV SC cryomodule for the main linac, and some of the other components. High-power test on the main SC cryomodule is underway in December, 2012. High-power or high-voltage tests on the injector cryomodule and on the DC gun are planned during January to March, 2013. An injector of the Compact ERL will be commissioned in April, 2013. We report the newest status of its construction. | |||
WEPWA017 | Development of Laser-Compton X-ray Source using Optical Storage Cavity | laser, electron, cavity, booster | 2165 |
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Funding: Work supported by the Quantum Beam Technology Program of MEXT and JSPS Grant-in-Aid for Young Scientists (B) 23740203 We have been developing a pulsed-laser storage technique in a super-cavity for a compact x-ray sources. The pulsed-laser super-cavity enables to make high peak power and small waist laser at the collision point with the electron beam. We already obtained a pulse-train x-rays through the laser-Compton scattering between a multi-bunch electron beam and an optical super-cavity. And also, we performed a X-ray imaging via laser-Compton X-ray. On these successful results, we decided to upgrade our system for increasing X-ray flux by 3-order of magnitudes for practical use. For an optical cavity, we designed 4-mirrors bow-tie cavity in order to increase the power. On the other hand, electron accelerator was also upgraded to increase the bunch number in the train. We use 3.6cells rf-gun and 12cell standing wave booster linac. As a result, 2-order increase of X-ray flux was achieved. Design of upgraded our laser-Compton X-ray source, the results of X-ray experiments and future prospective will be presented at the conference. |
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WEPWA023 | Design of 14 MeV LINAC for THz Source Based FEL | gun, FEL, quadrupole, emittance | 2181 |
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Abstract THz wave have many special performances, such as it can penetrate deep into many organic materials without the damage associated with ionizing radiation such as X-ray, it can be used to distinguish between materials with varying water content, because THz radiation is absorbed by water. In part researchers lacked reliable sources of THz, so develop new THz sources is important now. So far there were many kind of THz Source, one of them is THz source based a FEL that can produce high power (~kW). This paper will describe the design of a LINAC of 14MeV which is used for FEL to produce THz radiation. The LINAC is mainly composed of a novel EC-ITC RF gun, compensation coil, constant gradient accelerating structure, beam diagnostic system and so on. Main design parameters are as following: Energy 7~15MeV Beam current (macro pulse) 571mA (micro pulse) 30~40° Bunch length 5~7ps Charge per bunch 200~300pC Normalized emittance ≤10mm.mrad Energy spread(rms) ≤0.5% | |||
WEPWA047 | Longitudinal Stability of Multiturn ERL with Split Accelerating Structure | electron, simulation, cavity, resonance | 2226 |
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Some modern projects of the new generation light sources use the conception of multipass energy recovery linac with split (CEBAF-like) accelerating structures. One of the advantages of these light sources is the possibility to obtain a small longitudinal beam size. To help reduce it, the longitudinal dispersion should be non-zero in some arcs of the accelerator. However small deviations in voltages of the accelerating structures can be enhanced by induced fields from circulating bunches due to the dependence of the flight time on the energy spread and the high quality factor of the superconducting radio-frequency cavities. Therefore, instabilities related with interactions of the electron bunches and longitudinal modes of the cavities can develop in the installation. Stability conditions for the interactions with fundamental accelerating mode of the split accelerating system are discussed. Numerical simulations are made for two projects - MARS and FSF. | |||
WEPWA052 | A Gun to Linac Operation Analysis of the Taiwan Light Source Injector | electron, factory, gun, synchrotron | 2235 |
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A response surface methodology (RSM) was used to study the gun to linac optimization process of the Taiwan Light Source (TLS) injector at the National Synchrotron Radiation Research Center (NSRRC). A study model, based on artificial neural network (ANN) theory, which uses electron beam tuning knobs as variables, was constructed. An optimization procedure was developed by designating electron beam efficiency as the objective function and the selected beam tuning knobs as the variables. The theoretical model and optimization procedure were both implemented to evaluate the model. By properly applying the constructed optimization procedure, the beam efficiency was improved. This report outlines the details of the gun to linac optimization process experiment. | |||
WEPWA061 | ALICE ERL Intra-train Variation Investigation using Bunch-by-bunch BPMs | laser, FEL, cathode, gun | 2256 |
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The ALICE ERL is an energy recovery test facility based at Daresbury Laboratory. We present investigations of charge and transverse variations/oscillations in the ALICE trains (up to 1600 bunches, spacing 55.2ns, bunch charge up to 60pC), using turn-by-turn EMMA BPMs adjusted for bunch-by-bunch measurements*. A set-up was established which allows use of pickups immediately downstream of the DC Gun as well as in the Arcs. To analyse variations, a DFT was used. It was established that a previously observed prominent (~10%) 300kHz charge envelope variation is a feature of the Photoinjector Laser. A set of transverse variations at 300kHz and below that depended on steering was also observed in the Injection Line. Downstream of the Booster, it was discovered that the transverse spectra are different. Prevailing quite regular variations (in range of 50um) were observed around 100kHz, manifesting themselves in the horizontal plane, present in non-dispersive regions, and dependent on trajectory offset in the Booster. We discuss the results, and also present our plans to apply this technique to a new single bunch injector EBTF now under commissioning in Daresbury Laboratory.
* A. Kalinin et al, MOPA30, IBIC12, Tsukuba, Japan. |
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WEPWA063 | Longitudinal Beam Transport in the ALICE IR-FEL Facility | sextupole, FEL, quadrupole, dipole | 2262 |
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The ALICE facility at Daresbury Laboratory is an energy recovery test accelerator which includes an infra-red oscillator-type free electron laser (IR-FEL). The longitudinal transport functions (including R56 and T566) in the ALICE accelerator lattice are studied in this paper by use of precision time-of-arrival methods. The results allow characterisation of the triple bend achromat (TBA) arcs and compression chicane of the lattice. The relevance of the results to the operational performance of ALICE as a IR-FEL facility and a THz source is discussed. | |||
WEPWA064 | Simulations of the ALICE ERL | FEL, simulation, electron, space-charge | 2265 |
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ALICE is a low-energy Energy Recovery Linac operated at Daresbury Laboratory in Cheshire, UK. The ALICE injector is based around a 350 kV DC photo-cathode electron gun. With an operating voltage of 325 keV, electron dynamics in the ALICE injector are space-charge dominated and highly non-linear, and this complicates simulations of the beam dynamics in this region. With an intermediate energy of 6.5 MeV, and a final ring energy of 27.5 MeV, the space-charge effects in the rest of the machine can also not be ignored. In this paper we summarise some of the work that has been performed to understand and optimise the simulations of the ALICE ERL, in several different operating modes, and using several different modelling codes. | |||
WEPWA068 | Design Concepts for the NGLS Linac | cavity, cryomodule, cryogenics, HOM | 2271 |
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The Next Generation Light Source (NGLS) is a design concept for a multibeamline soft x-ray FEL array powered by a ~2.4 GeV CW superconducting linear accelerator, operating with a 1 MHz bunch repetition rate. This paper describes the concepts under development for a linac operating at 1.3 GHZ and based on minimal modifications to the design of ILC cryomodules in order to leverage the extensive R&D that resulted in the ILC design. Due to the different nature of the two applications, particular attention is given here to high loaded Q operation andμphonics control, as well as high reliability and expected up time. | |||
WEPWA070 | Design of a Collimation System for the Next Generation Light Source | collimation, gun, undulator, kicker | 2277 |
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Funding: This work is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Next Generation Light Source at LBNL will deliver MHz repetition rate electron beams to an array of free electron lasers. Because of the high beam power approaching one MW in such a facility, effective beam collimation is extremely important to minimize radiation damage, prevent quenches of superconducting cavities, limit dose rates outside of the accelerator tunnel and prevent equipment damage. This paper describes the conceptual design of a collimation system, including detailed simulations to verify its effectiveness. |
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WEPWA080 | Development of a Compact Insertion Device for Coherent Sub-mm Generation | radiation, laser, impedance, wakefield | 2295 |
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Funding: Department of Energy Contracts DE- SC-FOA-0000760 and DE-FG02-07ER84877 A novel design of resonant Cherenkov wakefield extractor that produced a ~0.9 mm wavelength radiation is presented. The experiment was performed at Idaho Accelerator Center (IAC) using specially upgraded 1.3 GHz 44 MeV linac facility. Specifics of the radiator performance and design are outlined including low-energy beam interaction with non-circular geometry. Some elements of the design may have certain potential for future compact mm-sub-mm-wave sources. |
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WEPWA083 | Results of NSLS-II Linac Commissioning | emittance, solenoid, dipole, quadrupole | 2301 |
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Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The NSLS-II linac is a 200 MeV normal conducting linac procured as a turn key system from Research Instruments. The linac and associated transport lines were installed at BNL in the winter of 2012. Commissioning activities started March 26 and lasted for 2.5 months. In this report we discuss the successful commissioning results of the linac, issues encountered, and the remaining work that needs to be accomplished for NSLS-II booster commissioning. |
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WEPWO016 | Construction of Main Linac Cryomodule for Compact ERL Project | HOM, cryomodule, cavity, radiation | 2349 |
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Compact ERL (cERL), which is a test facility of ERL, is under construction at KEK, in Japan. At the first stage of cERL project, electron beam will be accelerated by 30 MV at main linac region. We have developed a main linac cryomodule, which contains two L-band 9-cell superconducting cavities. Cavity assembly work was carefully done at a class-10 clean room and HOM absorbers and cold windows of input couplers were successfully mounted on the cavities. Next, the frequency tuners, thermal anchors, magnetic shields and temperature sensors and so on were assembled to the cryomodule. Then, using a clean-booth, warm windows of the input couplers are connected to the cold windows and gate valves were also attached to the both ends of the cryomodule. Finally, the cryomodule was installed into the beamline of cERL and connected to a 2K cryogenic system. Target of alignment precision of the cavities, after cooling down to 2K, are set to be within 1 mm against the beamline. The first cool-down test, followed by low power and high power measurements, is scheduled within the year 2012. | |||
WEPWO019 | Development of Frequency Measurement Setup for ADS 650MHz and 1.3GHz Superconducting RF Cavities at IHEP | cavity, SRF, simulation, controls | 2358 |
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The Accelerator Driven Sub-critical System (ADS) is under development in China, and the 650MHz β=0.82 superconducting RF cavity (SRF) has been chosen as a possible candidate to accelerate the proton bunches in the medium energy section from 360MeV to 1.5GeV [1]. In order to obtain quality management and quality assurance during fabrication, radio frequency measurements on parts and subassemblies of SRF cavities become a proper method [2]. In this paper, study on developing a new frequency measurement setup mainly for half cells, dumb-bells and end groups of ADS650MHz cavities at IHEP was reported. A digital pressure sense was assembled in the setup. Together with the simulation on the structural and frequency by ANSYS Workbench, a quantitative standard for the frequency measurement was built for the cavity fabrication. Since a 9-cell TESLA-Like cavity is also under study in the meantime, via a slight modification, the setup can be also used for it. | |||
WEPWO021 | ADS 650MHz β=0.82 Supercongducting Cavity Research Status | cavity, superconducting-cavity, proton, status | 2361 |
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IHEP is developing a 650MHz β=0.82 supercongducting cavity for the China ADS project. The cavity is for the energy range of from 367MeV to 1500Mev. We have chosen a five cell cavity and optimized the cavity with Epk/Eacc and Bpk/Eacc to reach high gradient. Two cavity parts were fabricated and the EB welding is in process. This paper will show the fabrication status and measurement results. | |||
WEPWO023 | High Current Superconducting Cavity Study and Design | cavity, superconducting-cavity, accelerating-gradient, electron | 2366 |
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Funding: Project 11275226 supported by NSFC IHEP is developing a new type of high current superconducting cavity called slotted cavity proposed in 2010. The cavity is suitable for accelerating high beam current in Energy Recovery Linac (ERL). The cavity can extremely dump high order modes (HOMs) in the cavity to keep a high beam current threshold in the linac. We have studied and designed a three cell cavity and the fabrication is under going. |
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WEPWO043 | IFMIF-EVEDA SRF Linac Couplers Test Bench | vacuum, SRF, controls, LLRF | 2396 |
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The IFMIF-EVEDA SRF Linac is a cryomodule equipped with eight superconducting HWR cavities, operating at the frequency of 175 MHz and powered by 200kW CW RF couplers. Before assembling the couplers to the cryomodule, it is necessary to process them using high levels of RF power. In order to perform this conditioning, the power couplers must be connected to a RF network which is fed by an RF source and ended with a load or a short-circuit, depending on the conditioning mode to be applied. A test bench has been designed for the conditioning of the SRF LINAC couplers. The main component is the “test box”, a resonant cavity where two couplers will be assembled to transmit the 200 kW from the RF source to the appropriate termination. The test box includes a large pumping port allowing an efficient pumping of the entire vacuum volume limited by the coupler ceramic windows. Several diagnostics as light detectors, vacuum gauges and thermal transducers will provide information on the relevant parameters for the control of the RF conditioning process. In addition, a support frame has been designed to maintain the whole assembly and reduce the mechanical stress on the couplers. | |||
WEPWO049 | A Proposal for an ERL Test Facility at CERN | cavity, electron, HOM, SRF | 2414 |
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An energy recovery linac at 300-400 MeV is proposed as a test facility using a two-pass two-cryomodule concept as a proof of principle for a future ERL based electron-ion collider. This facility will enable both the development and validation of the required SRF technology performance and ERL specific beam dynamics essential for the future collider. Furthermore, the test facility can be used as the injector to the main linac in future. The test facility proposal, its potential uses and some aspects of the RF system are presented. | |||
WEPWO053 | SRF Development for a MW Proton Source at Fermi National Accelerator Laboratory | cryomodule, cavity, SRF, HOM | 2423 |
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Funding: Work supported by the US Department of Energy Fermilab is planning a megawatt-level proton beam facility utilizing niobium superconducting RF (SRF) cavities. Project X at Fermilab will eventually provide high-intensity beams for research into the nature of matter at the "intensity frontier". Research and development in several areas will bring the SRF technology to the level needed for this application. Among developments in SRF being pursued with our national and international collaborators are 162.5 MHz half-wave resonators, 325 MHz single-spoke resonators, and two types of elliptical multi-cell 650 MHz cavities. Performance requirements for these cavities and cryomodules in continuous wave (CW) operation are extremely stringent in order to provide high accelerating gradients with acceptable total cryogenic load and overall accelerator capital and operating costs. This paper presents some highlights of the SRF R&D program and proton linac development work at Fermilab. |
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WEPWO055 | Fabrication and Testing of SSR1 Resonators for PXIE | cavity, cryomodule, vacuum, beam-transport | 2429 |
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Fermilab is in the process of constructing a proton linac to accelerate a 1 mA CW beam up to 30 MeV. It will be a test for the front end of Project X and known as the Project X Injector Experiment (PXIE). The major goal of PXIE is the validation of the Project X concept and mitigation of technical risks. It is expected to be constructed in the period of 2012-2016. The PXIE linac consists of a Ion source and LEBT, a 162.5 MHz RFQ, a MEBT, a 162.5 MHz HWR cryomodule (designed and built at ANL) and a 325 MHZ SSR1 cryomodule (designed and built at FNAL). In this paper we present the recent advances in the development of the SSR1 resonators at Fermilab. Several bare SSR1 resonators have been processed, heat-treated and tested successfully in the Fermilab Vertical Test Stand. The outfitting of helium vessels is in process and the coarse-fine frequency tuning system has been designed and is currently being procured and tested. Details of the power coupler are also discussed. | |||
WEPWO056 | Update of the Mechanical Design of the 650 MHZ β=0.9 Cavities for Project X | cavity, simulation, resonance, niobium | 2432 |
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Five-cell elliptical 650 MHz β=0.9 cavities to accelerate 1 mA of average H− beam current in the range 520-3000 MeV of the Project X Linac are currently planned. We will present the results of optimization of mechanical design of cavities with their Helium Vessel. We discuss the efforts to optimize the mechanical stability of the cavity versus the Helium bath pressure fluctuations, cavity tunability. We present also modal and thermal analysis; discuss tuner options and other issues. | |||
WEPWO057 | Update of SSR2 Cavities Design for Project X and RISP | cavity, cryomodule, simulation, heavy-ion | 2435 |
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Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. Single spoke resonators SSR2 (f=325 MHz) are under development at Fermilab. These cavities can meet requirements of Project X (FNAL) and RISP (Korea). The initial design of SSR2 cavities has been modified and optimized in order to satisfy the necessities of both projects. This paper will discuss the RF optimization for a single spoke resonator with a 50 mm beam pipe aperture and an optimal beta of 0.51. Further, the approach to the mechanical design of the cavity will be presented together with the proposed helium vessel. The latter is intended to guarantee a low He pressure sensitivity df/dp of the entire jacketed SSR2 and actively control the microphonics. |
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WEPWO059 | Cornell's HOM Beamline Absorbers | HOM, cavity, damping, cryomodule | 2441 |
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The proposed energy recovery linac at Cornell aims for high beam currents and short bunch lengths, the combination of which requires efficient damping of the higher order modes (HOMs) being present in the superconducting cavities. Numerical simulations show that the expected HOM power could be as high as 200 W per cavity with frequencies ranging to 40 GHz. Consequently, a beam line absorber approach was chosen. We will review the design, report on first results from a prototype and discuss further improvements. | |||
WEPWO060 | The CW Linac Cryo-module for Cornell’s ERL | cavity, HOM, damping, status | 2444 |
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Cornell University has proposed an energy-recovery linac (ERL) based synchrotron-light facility which can provide greatly improved X-ray beams due to the high electron-beam quality that is available from a linac. As part of the phase 1 R&D program, critical challenges in the design were addressed, one of them being a full linac cryo-module. It houses 6 superconducting cavities- operated at 1.8 K in cw mode- HOM absorbers and a magnet/ BPM section. We will present the design being finalized recently and report on the fabrication status that started in late 2012. | |||
WEPWO061 | Readiness for the Cornell ERL | emittance, cathode, cavity, laser | 2447 |
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Funding: Supported by NSF award DMR-0807731 and NY State Energy-Recovery Linacs (ERLs) are proposed as drivers for hard x-ray sources because of their ability to produce electron bunches with small, flexible cross sections and short lengths at high repetition rates. Cornell University has pioneered the design and hardware for ERL lightsources. This preparatory research for ERL-lightsource construction will be discussed. Important milestones have been achieved in Cornell's prototype ERL injector, including the production of a prototype SRF cavity that exceeds design specifications, the regular production of long-lived and low emittance cathodes, the acceleration of ultra-low emittance bunches, and the world-record of 65 mA current from a photoemission DC gun. We believe that demonstration of the practical feasibility of these technologies have progressed sufficiently to allow the construction of an ERL-based lightsource like that described in [erl.chess.cornell.edu/PDDR]. |
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WEPWO068 | Cornell ERL Main Linac 7-cell Cavity Performance in Horizontal Test Cryomodule Qualifications | cavity, cryomodule, higher-order-mode, HOM | 2459 |
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Funding: NSF DMR-0807731 Cornell has recently finished producing and testing the first prototype 7-cell main linac cavity for the Cornell Energy Recovery Linac, and completed the prototype cavity qualification program. This paper presents quality factor results from the horizontal test cryomodule (HTC) measurements, from the HTC-1 through HTC-3 experiments, reaching Q's up to 6 x 1010 at 1.6 K. We investigate the effect of thermal cycling on cavity quality factor and show that high quality factors can be preserved from initial mounting to fully outfitting the cavity with side-mounted input coupler and beam line absorbers. We also discuss the production of six additional main-linac cavities as we progress toward constructing a full 6-cavity cryomodule. |
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WEPWO069 | HOM Studies of the Cornell ERL Main Linac Cavity: HTC-1 Through HTC-3 | HOM, cavity, cryomodule, higher-order-mode | 2462 |
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Funding: Supported by NSF grant DMR-0807731 The Cornell energy recovery linac is designed to run a high energy (5 GeV), high current (100 mA), very low emittance beam (30 pm at 77 pC bunch charge). A major challenge to running such a large current continuously through the machine is the effect of strong higher-order modes(HOMs) that can lead to beam breakup. This paper presents the results of HOM studies for the prototype 7-cell cavity installed in a horizontal test cryomodule (HTC) from initial RF test, to being fully outfitted with side-mounted input coupler and beam line absorbers. We compare the simulated results of the optimized cavity geometry with measurements from all three HTC experiments. |
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WEPWO079 | Superconducting Single-spoke Cavities for High-velocity Applications | cavity, multipole, electron, higher-order-mode | 2480 |
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Spoke cavities have been investigated for particle acceleration in the high-velocity regime. As part of these efforts, single-spoke cavities for particles traveling at the speed of light are being designed and built for proof-of-principle demonstration. We report here on the results of electromagnetic properties, design optimization, multipacting analysis, field non-linearities and higher order mode spectrum for a single-spoke cavity operating at 325 MHz. | |||
WEPWO082 | Ferroelectric Based High Power Tuner for L-band Accelerator Applications | controls, cavity, vacuum, simulation | 2486 |
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Funding: US Department of Energy With this paper, we present our recent breakthrough with a new fast ferroelectric tuner development. The tuner is based on BST(M) ferroelectric elements (ε~150), which are designed to be used as the basis for L-band accelerator components intended for ERL, ILC, Project X and other applications. These new ferroelectric elements are to be fabricated for the new fast active tuner for SC cavities that can operate in air at low biasing DC fields. Note there were no reliable results on the long-term piezo actuators operations in CW regime. Specific features of ERL, ILC and Project X accelerator technology and challenges of the designs are high magnitude and phase stability of its operations. Mechanical vibrations, or microphonics affect the SRF resonator, while the ferroelectric tuners have shown extremely high tuning speed. We have demonstrated successful mitigation of the residual effects on the ferroelectric-metal interface along with the acceptable level of the overall loss factor of the tuner element. A new concepts of a tuning element based on low dielectric constant ferroelectrics along with fabrication technology of these new BST(M) ferroelectric elements will be presented. |
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WEPEA032 | Estimation and Correction of the Uncontrolled Beam Loss due to the Alignment Error in the Low-energy Linear Accelerator of RAON | alignment, ion, quadrupole, cavity | 2570 |
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RAON(Rare isotope Accelerator Of Newness) mainly consists of the front-end system, ISOL system , re-accelerator for ISOL system, charge stripper section and main linear accelerator(Linac) for ECR ion source. Since the beam energy at the down-stream of the front-end system is low, 0.3~0.5 MeV/u, the trajectories of the beam is very sensitive the alignment error of the magnets and cavities at the entrance of the main Linac. It can be caused the uncontrolled beam loss due to the large amplitude of the trajectory. The effect of the alignment errors of the magnets and cavities is estimated and corrected by using analytical model which is based on analytical model and code TRACK. The calculation result based on the analytical model agrees very well with the simulation by using the TRACK code. Using the analytical model, the position and number of the corrector and Beam Position Monitor(BPM) in low energy Linac was determined to compensate the amplification of the beam trajectory under 400 um. We will present the result of the estimation of the alignment error and the correction using steering magnet with strip-line Beam Position Monitor (BPM) in a low energy section. | |||
WEPEA034 | Study on the Beam Dynamics in the RISP Driver Linac | quadrupole, stripper, ion, resonance | 2576 |
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Abstract Rare Isotope Science Project (RISP) has been proposed as a multi-purpose accelerator facility for providing beams of exotic rare isotopes of various energies. The RISP driver linac which is used to accelerate the beam, for an example, Uranium ions from 0.3 MeV/u to 200 MeV/u consists of superconducting RF cavities and warm quadrupole magnets for focusing heavy ion beams. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the requirements of dynamic errors and correction schemes to minimize the beam centroid oscillation and preserve beam losses under control. | |||
WEPEA038 | Two and three Dimensional Models for Analytical and Numerical Space Charge Simulation | space-charge, controls, simulation, ion | 2585 |
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In this article there is described an analytical approach to describe the self-field of two- and three dimensional ellipsoidal presentation of space charge distribution. The corresponding results can be evaluated in both numerical and the analytic presentation for some model distributions of charge. The corresponding results can be embedded in the Lie formalism used to describe the map for the beam dynamics. The corresponding linear and nonlinear maps are evaluated in terms of the matrix representation of the evolution operator of the beam. Appropriate solutions for nonlinear differential equations are based on a prediction-correction method (the converging recursive procedure). These solutions are compared with the Vlasov equation solutions. A special software package for the described approach is presented. | |||
WEPEA040 | Space Charge and Cavity Modeling for the ESS Linac Simulator | space-charge, cavity, proton, simulation | 2588 |
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The proton linac of the European Spallation Source will operate at unprecedented beam power of 5 MW. Such power requires a precise modeling of the beam dynamics in order to protect its components from losses. The high peak current of 62.5 mA produces a space charge force that dominates the dynamics at low energy, while the high gradient required to accelerate up to 2 GeV in the 500 m of linac length is challenging for the dynamics in the RF cavities. This paper presents modelings of the space charge force and RF cavities used in the ESS Linac Simulator. The simulator is under development as part of the XAL on-line model, and it will be adopted for the ESS linac operations. | |||
WEPEA060 | Plans for the Upgrade of CERN's Heavy Ion Complex | ion, injection, luminosity, acceleration | 2645 |
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To reach a luminosity higher than 6×1027 Hz/cm2 for Pb-Pb collisions, as expected by the ALICE experiment after its upgrade during the 2nd Long LHC Shutdown (LS2), several upgrades will have to be performed in the CERN accelerator complex, from the source to the LHC itself. This paper first details the present limitations and then describes the strategy for the different machines in the ion injector chain. Both filling schemes and possible hardware upgrades are discussed. | |||
WEPEA069 | Review of the Drive Beam Stabilization in the CLIC Test Facility CTF3 | feedback, klystron, controls, low-level-rf | 2666 |
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CTF3 is a Test Facility focusing on beam-based studies of the key concepts of the Compact Linear Collider CLIC. Over the past several years many aspects the CLIC two-beam acceleration scheme were studied in CTF3, including the crucial issue of drive beam stability. The main sources of drifts and instabilities have been identified and mitigated, helping to improve the machine performance and showing significant progress towards the experimental demonstration of the very stringent requirements on current, energy and phase stability needed in CLIC. In this paper, the more effective techniques and feed-backs are summarized. The latest measurements on beam stability are reported and their relevance to CLIC is discussed. | |||
WEPFI002 | Acceptance Tests for the Spiral2 SC Linac RF Power Systems | cavity, impedance, insertion, controls | 2702 |
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Funding: This activity received founds from the EuCard RF Tech program The Spiral2 SC linac uses solid state amplifiers ranging from 2,5 to 19 kW and external circulators to drive normal and superconducting cavities at 88.0525 MHz. The project has no manpower for in house development and all power devices are ordered to commercial companies. Robust acceptance tests have therefore been defined to check reliability with respect to our application. The papers describes the tests procedure and results on our first units. |
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WEPFI003 | A New Timing System and Electron Gun Modulator | gun, electron, synchrotron, simulation | 2705 |
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In the last decade, Thales Communications & Security has manufactured turnkey linacs for the SOLEIL, ALBA and BESSY II synchrotrons. In the meanwhile, a new timing system and electron gun modulator was designed and a gun pulse length of 600 ps was measured. This paper will describe the system and will present the beam dynamics simulations results, comparing them with those obtained with the previous gun modulator *.
* A. Setty, "Beam dynamics of the 100 MeV preinjector for the Spanish synchrotron ALBA", PAC07, Albuquerque, USA, June 2007. |
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WEPFI009 | RF Measurement during CW Operation of an RFQ Prototype | rfq, simulation, cavity, proton | 2720 |
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A 17 MeV MHz proton linac is being developed as a front end of the driver accelerator for the MYRRHA facility in Mol. As a part of the MAX (MYRRHA Accelerator Experiment and Development) project a 4-rod Test-RFQ with a resonance frequency of 176 MHz has been designed and built for the MAX-Project. The RFQ has been modified to solve the cooling problem at cw-operation, the geometrical precision had to be improved as well as the rf-contacts. The developments led to a new layout and a sophisticated production procedure of the stems and the electrodes. Calculations show an improved Rp-value leading to power losses less than 30 kW/m, which is about 60 % of the power losses which could be achieved safely at cw-operation of the similar Saraf-RFQ. Thermal measurements and simulations with the single components has been completed. During cw-operation the temperature distribution will be measured and the rf-performance checked. | |||
WEPFI013 | The Damped C-band RF Structures for the European ELI-NP Proposal | damping, beam-loading, dipole, photon | 2726 |
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The gamma beam system of the European ELI-NP proposal foresees the use of a multi-bunch train colliding with a high intensity recirculated laser pulse. The linac energy booster is composed of 14 travelling wave C-Band structures, 1.8 m long with a field phase advance per cell of 2π/3 and a repetition rate of 100 Hz. Because of the multi-bunch operation, the structures have been designed with a damping of the HOM dipoles modes in order to avoid beam break-up (BBU). In the paper we discuss the design criteria of the structures also illustrating the effectiveness of the damping in the control of the BBU. Prototype activity is finally illustrated. | |||
WEPFI014 | Present Status and Progresses of RFQ of IFMIF/EVEDA | rfq, coupling, vacuum, quadrupole | 2729 |
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The RFQ of IFMIF/EVEDA is designed to accelerate a 125 mA D+ beam from 0.1 MeV to 5 MeV at a frequency of 175 MHz. The production of the modules 16, 17 and 18 necessary has been completed. In this paper the progress and improvements on the production of the modules, as well the development of the brazing procedure design will be described. | |||
WEPFI015 | Design and Field Measurements of a Linear Accelerator Endowed with Single Feed with Movable Short Coupler | emittance, dipole, electron, simulation | 2732 |
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The free electron laser performances strongly depend on the beam quality. The dipolar field present in the linac coupler causes the beam emittance degradation. This paper studies an alternative solution for reducing the dipolar field, by using a symmetrical coupler with single feed input and a movable short circuit placed on the opposite waveguide. The structure has been simulated and optimized with the Ansys HFSS simulation code. An aluminum prototype has been machined in the workshop of “Elettra - Sincrotrone Trieste S.C.p.A.”. After matching and tuning the accelerating structure, the phase advance and the coupler field asymmetries have been measured by means of the bead-pull method and have been compared with the simulation results. | |||
WEPFI016 | Upgrade of Power Supply System for RF-Chopper At J-PARC Linac | pick-up, cavity, LLRF, simulation | 2735 |
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In the J-PARC Linac, the radio frequency deflector was adopted as a chopper to capture the particles into the RF-bucket in the next synchrotron. The chopper, consists of two deflectors, was installed on the medium-energy beam-transport line. In the operation of the RF-chopper, the fast rise/fall time of the pulse is a fundamental requirement to minimize the beam loss due to insufficient deflection to some beam bunches. In the previous system, the two series-connected chopper deflectors were driven by one solid- state amplifier. However, the fall time indicated a poor result to effect the ringing into each cavity. Therefore, the additional solid-state amplifier and low level RF system were installed in the summer 2012 and the connection changed to the parallel system from the series using two amplifiers. The rise/fall time of the chopped beam, is defined as the step height of 10% and 90%, was about 20 nsec in the beam current of 15 mA and the effect of the ringing was decreased. We would like to introduce the performance of the new chopper system. | |||
WEPFI017 | Performance of Cavity Phase Monitor at J-PARC Linac | cavity, pick-up, DTL, LLRF | 2738 |
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The amplitude and the phase stabilities of the RF system play an important role for the cavity of a high intensity proton accelerator. For the J-PARC Linac, the accelerating field ambiguity must be maintained within ±1% in amplitude and ±1 degree in phase due to the momentum acceptance of the next synchrotron. To realize the requirement, a digital feedback (FB) control is used in the low level RF (LLRF) control system, and a feed-forward (FF) technique is combined with the FB control for the beam loading compensation. The stability of ±0.2% in amplitude and ±0.2 degree in phase of the cavity was achieved including the beam loading in a macro pulse. Additionally, the cavity phase monitors, which can measure the phase difference between any two cavities, were installed in summer, 2011. The monitor has the three different types, which are for the present 324-MHz RF system, the 972-MHz RF system and the combined system of 324-MHz RF and 972-MHz RF. The phase monitor for the 324-MHz RF has been in operated since Dec. 2011. We would like to introduce the phase monitor and indicate the phase stability at the J-PARC linac. | |||
WEPFI037 | Recent Status of a C-band 2MeV Accelerator | electron, target, laser, status | 2783 |
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In order to carry out engineering research on miniaturization of accelerator, we performs effort to develop C-band 2MeV standing wave accelerator. At present , the important progress has been achieved on the accelerator development. The accelerating tube has been fully sealed, and the hot test platform of the accelerator has been built. In condition of repetition rate of 200Hz, preliminary power test has been got through. Using ionization chamber dose monitor, we tested the dose rate of X-ray at 1m before the target. And by means of steel absorption method, we tested the energy of the electron beam. The preliminary test results are: beam energy about 2.0MeV, dose rate about 2Gy/min•m. | |||
WEPFI038 | R&D of New C-band Accelerating Structure for SXFEL Facility | FEL, cavity, impedance, wakefield | 2785 |
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C-band high gradient accelerating structure is crucial technology for Shanghai Soft X-ray FEL facility. Based on the prototype, the optimized C-band accelerating structure is proposed, and the experimental model is ready for high power test. In this paper, optimization design and some experiment results are presented, also design, fabrication and cold test of experimental model are introduced. | |||
WEPFI042 | Installation and Operation of the RF System for the 100 MeV Proton Linac | klystron, controls, LLRF, proton | 2797 |
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Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government. The RF system of the 100MeV proton linac for 1st phase of KOMAC has been installed at the Gyeong-ju site. Nine sets of LLRF control system and the HPRF system including 1MW klystrons, circulators and waveguide components have been installed at the klystron gallery, and four high voltage converter modulators has been installed at the modulator room. A RF reference system distributing 300MHz LO signal to each RF control system has also been installed with a temperature control system. The requirement of RF field control is within ± 1% in RF amplitude and ± 1 degree in RF phase, and the operation of RF system will start at the end of this year after installation. The installation and operation of the RF system for the 100MeV proton linac are presented in this paper. |
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WEPFI045 | PAL-XFEL Accelerating Structures | klystron, electron, emittance, impedance | 2806 |
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We need 172 accelerating structures for the PAL-XFEL 10 GeV main linac. It takes long time for these structures to be delivered. So we are trying to find suppliers of the accelerating structures. First, we made an order of 40 accelerating structures to Mitsubishi Heavy Industry (MHI), which have Quasi-type couplers to reduce the quadruple and sextuple components of the electric field in the coupling cavity. And Research Instruments (RI) has fabricated a 3m long race type accelerating structure for PAL-XFEL. Also, Vitzrotech which is a domestic company and IHEP in China are under developing accelerating structures for PAL-XFEL respectively. We will describe the current status of accelerating structures and high power test results of the newly developed structures in this paper. | |||
WEPFI056 | Study of the Thermo-Mechanical Behavior of the CLIC Two-Beam Modules | alignment, RF-structure, controls, collider | 2818 |
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The final luminosity target of the Compact LInear Collider (CLIC) imposes a micron-level stability of the two-meter repetitive two-beam modules constituting the main linacs. Two-beam prototype modules have been assembled to extensively study their thermo-mechanical behaviour under different operation modes. The power dissipation occurring in the modules will be reproduced and the efficiency of the corresponding cooling systems validated. At the same time, the real environmental conditions present in the CLIC tunnel will be studied. Air conditioning and ventilation systems will be installed in the dedicated laboratory. Air temperature will be varied from 20 to 40 °C, while air flow rate will be regulated up to 0.8 m/s. During all experimental tests, the alignment of the RF structures will be monitored to investigate the influence of power dissipation and air temperature on the overall thermo-mechanical behaviour. This test program will allow for better understanding the behaviour of CLIC modules and the results will be propagated back to both numerical modelling and engineering design. | |||
WEPFI057 | Longitudinal Design and RF Stability Requirements for the SwissFEL Facility | wakefield, emittance, booster, undulator | 2821 |
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The SwissFEL facility will produce coherent, bright, and short photon pulses covering a wavelength range down to an angstrom, requiring an emittance between 0.18 to 0.43 mm mrad at bunch charges between 10 pC and 200 pC. In nominal operation continuous changes in this range will be offered to the users to allow an individual tradeoff between photon power and pulse length. The facility consists of a S-band RF-gun, booster, and a C-band main linac, which accelerates the beam up to 5.8 GeV. Two compression chicanes will provide a nominal peak current of about 1 to 3 kA depending on the charge. The stability of RF systems is a key design issue for stable compression schemes at reliable user facilies. In this paper different operation modes are presented and discussed in terms of machine stability requirements. | |||
WEPFI058 | Breakdown Localization Studies on the SwissFEL C-band Test Structures | background, coupling, factory, impedance | 2824 |
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The SwissFEL main linac will consist of 104 C-band structures with a nominal accelerating gradient of 28MV/m. First power tests were performed on short constant impedance test-structures composed of eleven double-rounded cups. In order to localize breakdowns, two or three acoustic emission sensors were installed on the test-structures. In order to localize breakdowns we have analyzed, in addition to acoustic measurements, the delay and phase of the rf power signals. Parasitic, acoustic noise emitted from the loads of the structure complicated the data interpretation and necessitated appropriate processing of the acoustic signals. The Goals of the experiments were to identify design and manufacturing errors of the structures. The results indicate that breakdowns occur mostly at the input power coupler, as also confirmed by vacuum-events at the same location. The experiments show that the linac test-structures fulfill the requirements in breakdown probability. Moreover developing a detection system based on acoustic emission sensors for breakdown localization for our C-band structure seems reasonable given the results obtained. | |||
WEPFI066 | The RF System for the MICE Experiment | cavity, controls, LLRF, diagnostics | 2848 |
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The International Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate the effectiveness of ionisation cooling to reduce the phase space footprint of a muon beam, principally to allow the subsequent acceleration of muons for next generation colliders and/or neutrino factories. The experiment (and indeed any subsequent accelerator cooling channel based on the same principles) poses certain unusual requirements on its RF system, whilst the precision measurement of the ionisation cooling process demands special diagnostics. This paper shall outline the key features of the RF system, including the LLRF control, the power amplifier chain, distribution network, cavities, tuners and couplers, all of which must operate in a high magnetic field environment. The RF diagnostics which, in conjunction with the other MICE diagnostics, shall allow detailed knowledge of the amplitude and phase of the acceleration field during the transit of each individual Muon shall also be outlined. | |||
WEPFI075 | Design of the FRIB RFQ | rfq, vacuum, ion, dipole | 2866 |
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Funding: This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 FRIB linac driver includes a front end and a SRF linac for all stable ion beams with energy more than 200 MeV/u, and beam power on target up to 400 kW. A 80.5 MHz FRQ at the front end accelerates heavy ion beams from 12 keV/u to 0.5 MeV/u, in CW mode. Design of the RFQ is introduced and several important technical issues are discussed in this paper. |
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WEPFI076 | Experience with a 5 kW, 1.3 GHz Solid State Amplifier | status, SRF, cryomodule, factory | 2869 |
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This study describes the experience with and performance of a commercially available 1.3 GHz 5kW Solid State Amplifier in various experiments at Cornell University. This paper focuses on several key factors in testing the performance of the amplifier. Among those are phase and amplitude stability, gain linearity, and phase shift vs. power. High power amplifiers are usually built with multiple RF power modules and the individual output signals are then combined in a power combiner. Therefore, the phases of the individual RF output power signals have to be adjusted within tight tolerances. The relative phases can be affected by different lengths cables and also affect the overall gain performance of the amplifier. | |||
WEPFI080 | Waveguide Component R&D for the ILC | klystron, cavity, coupling, linear-collider | 2881 |
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Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515. Several years of effort have gone into refining the design of the International Linear Collider. The direction the design has evolved in response to driving considerations has resulted in a more sophisticated waveguide system for delivering RF power to the cavities. In particular, the desire to eliminate parallel service tunnels along the main linacs led to the proposal of the Klystron Cluster Scheme (KCS)*, involving plumbing the combined power from groups of klystrons down from the surface at several locations in overmoded waveguide. Additionally, to increase superconducting cavity yield, the acceptance criteria were relaxed to encompass a ±20% range in sustainable operating gradient, which must be accommodated by tailoring of the RF power distribution. Designs and prototype testing of some of the novel waveguide components developed to allow these changes are described here. * Christopher Nantista and Chris Adolphsen, “Klystron Cluster Scheme for ILC High Power RF Distribution,” presented at the 2009 Particle Accel. Conf., Vancouver, B.C., Canada, May 2009. |
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WEPFI081 | High Power Tests of Overmoded Waveguide for the ILC Klystron Cluster Scheme | resonance, klystron, simulation, coupling | 2884 |
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A Klystron Cluster Scheme has been proposed for the ILC Main Linacs in which the output power of up to thirty, 10 MW, 1.3 GHz klystrons are combined in a single, 0.5 m diameter circular waveguide in a surface building and transported down to and along the accelerator tunnel where it is periodically tapped-off to power strings of cavities. This schemes eliminates the need for a separate linac service tunnel and simplifies the linac electric and cooling distribution systems. Recently, a 40 meter long circular waveguide with a coaxial input coupler and a 90 degree rf bend were assembled and run in a resonant configuration to test the concept. With the pipe pressurized with up to 30 psig of N2 to raise the rf breakdown threshold, it was demonstrated that field levels equal to those for the 300 MW transmission required for ILC could be sustained reliably. We report on these and other test results from this program. | |||
WEPFI084 | High Power S-band RF Window Optimized to Minimize Electric and Magnetic Field on the Surface | klystron, vacuum, simulation, positron | 2893 |
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Funding: * Work Supported by Doe Contract No. DE-AC02-76SF00515 RF windows are used to separate vacuum from atmosphere in high power microwave systems, such as klystrons. RF breakdowns in these megawatt power environments are frequent and problematic. And S-band RF window was designed to have reduced electric and magnetic field in the ceramic and waveguide joints. Specifically the normal component of the electric field on the ceramic is minimized and a traveling wave is created inside the ceramic by optimizing the shape of the window and the geometry of the joint between the circular waveguide to the rectangular waveguide. A prototype of this window in the process of being made at SLAC for high power tests. |
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WEPFI088 | High-power Tests of an Ultra-high Gradient Compact S-band (HGS) Accelerating Structure | vacuum, klystron, coupling, monitoring | 2902 |
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RadiaBeam Technologies reports on the RF design, fabrication and high-power tests of a ultra-high gradient S-Band accelerating structure (HGS) operating in the pi-mode at 2.856 GHz. The compact HGS structure offers a drop-in replacement for conventional S-Band linacs in research and industrial applications such as drivers for compact light sources, medical and security systems. The electromagnetic design (optimization of the cell shape in order to maximize RF efficiency and minimize surface fields at very high accelerating gradients) has been carried out with the codes HFSS and SuperFish while the thermal analysis has been performed by using the code ANSYS. The high-power conditioning was carried out at Lawrence Livermore National Laboratory (LLNL). | |||
WEPME005 | Pulsed RF Control for the P-Linac Test Stand at FAIR | controls, cavity, proton, antiproton | 2929 |
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Funding: Supported through BMBF contract no. 06DA9024I The p-linac will be a dedicated proton injector for antiproton production at FAIR (GSI Darmstadt). It will provide a 70 MeV/70 mA pulsed proton beam with a duty cycle of about 10-4. Therefore the RF of the normal conducting, coupled CH cavities* will be pulsed, too. In order to test the operation of those cavities, a test stand is under construction at GSI. The RF control hard- and software for the test stand is developed at TU Darmstadt. It is based on the digital low level RF control system, which is operational at the S-DALINAC**. Hardware as well as software had to be customized, in order to achieve pulsed operation within the given limits. These customizations as well as measurements from pulsed operation will be presented. *R. Brodhage et al. Development and Measurements on a Coupled CH Proton Linac for FAIR, IPAC'10 **M. Konrad et al. Digital base band rf control system for the… , PRL ST Accel. & Beams 15 |
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WEPME007 | Commissioning of the Upgraded Superconducting CW Linac ELBE | cavity, klystron, vacuum, SRF | 2935 |
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With the expansion of the radiation source ELBE a center for high power radiation sources is being built at the Helmholtz Zentrum Dresden-Rossendorf (HZDR). In a first step (January 2012) the available CW RF-power (1.3 GHz) per superconducting 9-cell TESLA cavity at ELBE had been increased from 8.5 kW to 20 kW (CW) using solid state amplifiers. In a second step the performance of several machine components of ELBE must be redesigned to enable full power operation without risks. The poster gives an overview how these problems have been solved at ELBE and reports on the commissioning. | |||
WEPME015 | Evaluation of the Superconducting LLRF system at cERL in KEK | LLRF, cavity, controls, coupling | 2956 |
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A low level RF (LLRF) design is being currently developed within the compact Energy Recover Linac (cERL) at KEK. One challenging task is to achieve the high amplitude and high phase stability required by the accelerating fields of up to 0.1% and 0.1°, respectively. To improve the performance of the LLRF system, a gain scanning experiment for determining the optimal controller gain was carried out on the cERL. Furthermore, as a substitute for the traditional PI controller, a more robust H∞-based multiple input multiple output (MIMO) controller was realized. This controller requires more detailed system information (transfer function or state equation), which can be acquired by using modern system identification methods. In this paper, we describe the current status of these experiments on the cERL. | |||
WEPME016 | Recent Progress of a Laser-based Alignment System at the KEKB Injector Linac | laser, alignment, controls, feedback | 2959 |
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A new laser-based alignment system is under development in order to precisely align accelerator components with a precision level of ±0.1 mm along an ideal straight line at the KEKB injector linac. The high-precision alignment system is strongly required for the Super B-factory at KEK. The laser-based alignment system comprises a He-Ne laser source and optical components for delivering the laser beam, and silicon photodetectors. The laser-based alignment system aligns a misalignment of a girder unit for accelerating structures while accelerator components on the girder unit are aligned with another laser tracker system with a similar precision level. A new PC-based feedback system for the laser pointing stability has been introduced in order to stabilize the transverse laser positions at the photodetector. The experimental results show that although the laser pointing stability is easily disturbed by environmental factors without the feedback system, it has been successfully applied to control the laser pointing stability within a few ten-micron-meter. In this report, the experimental investigations in the new feedback system are reported. | |||
WEPME017 | Development and Application of the Trigger Timing Watchdog System in KEK Electron/Positron Linac | controls, klystron, EPICS, electron | 2962 |
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The KEK injector linac provides electrons and positrons to several accelerator facilities. A 50 Hz beam-mode switching system has been constructed to realize simultaneous top-up injections for Photon Factory and the KEKB high- and low-energy rings, which require different beam characteristics. An event-based timing and control system was built to change the parameters of various accelerator components within 20 ms. The components are spread over a 600-m-long linac and require changes to a total of 100 timing and control parameters. The system has been operated successfully since the autumn of 2008 and has been improved upon as beam operation experience has been accumulated. The timing watchdog and alert system are indispensable for the stable and high quality beam operation. For this purpose, we developed and utilized several timing watchdog system. We will present the detail of timing signal watchdog system for the KEK injector linac. | |||
WEPME018 | Ytterbium Laser Development of DAW RF Gun for SuperKEKB | laser, gun, extraction, emittance | 2965 |
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For obtaining higher luminosity in the SuperKEKB, the photocathode RF electron gun with strong electric focusing field for high-current, low-emittance beams will be employed in the injector linac. The electron beams with a charge of 5 nC and a normalized emittance of 10 μm are expected to be generated in the photocathode RF gun by using the laser source with a center wavelength of 260 nm and a pulse width of 30 ps. Furthermore, for reducing the emittance, the laser pulse width should be reshaped from Gaussian to rectangle structure. Therefore, Ytterbium (Yb)-doped laser system that provides broader bandwidth, higher amplify efficiency and higher output power is employed. The laser system starts with a large mode-area Yb-doped fiber-based amplifier system, which consists of a passively mode-locked femtosecond Yb-fiber oscillator and two steps Yb-fiber amplifier. To obtain the several 10mJ-class pulse energy, a Yb:YAG thin-disk regenerative solid-state amplifier is employed. Deep UV pulses for the photocathode are generated by using two frequency-doubling stages. High pulse energy and good stability would be expected. | |||
WEPME032 | Development Status of SINAP Timing System | PLC, status, controls, background | 2992 |
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After successful implementation of SINAP timing solution at Pohang Light Source in 2011, the development of SINAP timing system version-II was finished by the end of 2012. The hardware of version-II is based on Virtex-6 FPGA chip, and bidirectional event frame transfer is realized in a 2.5Gbps fiber network. In event frame, data transfer functionality substitutes for distributed bus. The structure of timing system is also modified, where a new versatile EVO could be configured as EVG, FANOUT and EVR with optical outputs. Besides standard VME modules, we designed PLC-EVR as well, which is compatible with Yokogawa F3RP61 series. Based on brand new hardware architecture, the jitter performance of SINAP timing system version-II is improved remarkably. | |||
WEPME035 | Overview of the RF Synchronization System for the European XFEL | laser, LLRF, booster, undulator | 3001 |
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One of the most important requirements for the European XFEL RF system is to assure a very precise RF field stability within the accelerating cavities. The required amplitude and phase stability equals respectively dA/A <3·10-5, dphi<0.01 deg @ 1.3GHz in the injector and dA/A<10-3, dphi <0.1 deg @1.3GHz in the main LINAC section. Fulfilling such requirements for the 3.4 km long facility is a very challenging task. Thousands of electronic and RF devices must be precisely phase synchronized by means of harmonic RF signals. We describe the proposed architecture of the RF Master Oscillator and the Phase Reference Distribution System designed to assure high precision and reliability. A system of RF cable based interferometers supported by femtosecond-stable optical links will be used to distribute RF reference signals with required short and long term phase stability. We also present test results of prototype devices performed to validate our concept. | |||
WEPME045 | Development and Validation of a Multipoint Based Laser Alignment System for CLIC | laser, alignment, target, linear-collider | 3028 |
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Alignment is one of the major challenges within CLIC study, since all accelerator components have to be aligned with accuracy up to 10 μm over sliding windows of 200 m. So far, the straight line reference concept has been based on stretched wires coupled with Wire Positioning Sensors. This concept should be validated through inter-comparison with an alternative solution. This paper proposes an alternative concept where laser beam acts as straight line reference and optical shutters coupled with cameras visualise the beam. The principle was first validated by a series of tests using low-cost components. Yet, in order to further decrease measurement uncertainty in this validation step, a high-precision automatised micrometric table and reference targets have been added to the setup. The paper presents the results obtained with this new equipment, in terms of measurement precision. In addition, the paper gives an overview of first tests done at long distance (up to 53 m), having emphasis on beam divergence. | |||
WEPME046 | Alignment Challenges for a Future Linear Collider | alignment, collider, linear-collider, laser | 3031 |
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The preservation of ultra-low emittances in the main linac and Beam Delivery System area is one of the main challenges for linear colliders. This requires alignment tolerances never achieved before at that scale, down to the micrometre level. As a matter of fact, in the LHC, the goal for the smoothing of the components was to obtain a 1σ deviation with respect to a smooth curve of 0.15 mm in a 150 m long sliding window, while for the CLIC project for example, it corresponds to 10 micrometres over a sliding window of 200m in the Beam Delivery System area. Two complementary strategies are being studied to fulfill these requirements: the development and validation of long range alignment systems to propagate precision and accuracy over a few hundreds of metres and short range alignment systems over a few metres. The studies undertaken, with associated test setups and the latest results will be detailed, as well as their application for the alignment of both CLIC and ILC colliders. | |||
THOAB101 | Laser Wire Based Parallel Profile Scan of H− Beam at the Superconducting Linac of Spallation Neutron Source | laser, ion, neutron, pick-up | 3090 |
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Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. We report on the world’s first experiment of a parallel profile scan of the hydrogen ion (H−) beam using a laser wire system. The system was developed at the superconducting linac (SCL) of the Spallation Neutron Source (SNS) accelerator complex. The laser wire profile scanner is based on a photo-detachment process and therefore can be conducted on an operational H− beam in a nonintrusive manner. The parallel profile scanning system makes it possible to simultaneously measure profiles of the 1-MW neutron production H− beam at 9 different locations (corresponding to energy levels of 400 – 950 MeV) of the superconducting linac using a single light source. The entire measurement process takes less than 5 minutes to complete. Together with the hardware modification, we have also upgraded our user interface to visualize the 9-pairs of H− beam profiles in a real-time fashion, which presents a highly intuitive and informative picture of the H− beam propagation along the acceleration path. The laser wire based parallel profile scanning system provides a powerful tool for accelerator operators and physicists to study the SCL modelling, monitor and/or tune the beam parameters. |
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Slides THOAB101 [2.277 MB] | ||
THYB201 | Where Next with SRF? | SRF, cavity, cryomodule, proton | 3124 |
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Funding: This manuscript has been authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. RF superconductivity (SRF) has become, over the last ~20 years, the technology of choice to produce RF cavities for particle accelerators. This occurred because of improvements in material and processing techniques as well as the understanding and remediation of practical limitations in SRF cavities. This development effort span ~40 years and Nb has been the material of choice for SRF cavity production. As the performances of SRF Nb cavities are approaching what are considered to be theoretical limits of the material, it is legitimate to ask what will be the future of SRF. In this article we will attempt to answer such question on the basis of near-future demands for SRF-based accelerators and the basic SRF properties of the available materials. Clearly, Nb will continue to play a major role in SRF cavities in the coming years but the use of superconductors with higher critical temperature than Nb is also likely to occur. |
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Slides THYB201 [1.549 MB] | ||
THPPA02 | Features and Applications of the Program ELEGANT | simulation, electron, FEL, lattice | 3139 |
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Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. ELEGANT is an open-source accelerator design and simulation code that has been in use and development for nearly two decades. In that time, it has evolved into a fairly general code for the design and modeling of linacs and storage rings, due in no small measure to suggestions and feedback from users world-wide. The code is best known for modeling of linacs for free electron lasers and particularly its relatively fast and straightforward modeling of coherent synchrotron radiation in magnetic bunch compression systems. This capability led to the discovery of a microbunching instability in such systems, thus helping to seed a new field of research. ELEGANT's capabilities are enhanced by the use of self-describing data files and the Self-Describing Data Sets (SDDS) toolkit. In this paper, we briefly review the features and capabilities of the code, then give a series of application examples from simulation of linear accelerators and storage rings. |
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Slides THPPA02 [0.477 MB] | ||
THPPA03 | The Development of China’s Accelerators I Have Experienced | proton, synchrotron, luminosity, radiation | 3144 |
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The development of China’s high energy accelerator for half a century falls into two stages, namely the first 20 hovering years (1958-1978) and the later 30 years of rapid development (from 1978 till now). I was lucky enough to have experienced the whole process, witnessed, and to some extent, joined in the decision-making, the projects approval, the designing, the development and construction of China's five large scientific facilities undertaken by the Institute of High Energy Physics in Beijing. A brief review is given of the previous stage of history regarding the consideration of China’s high energy accelerators in the first 20 years. A short presentation is also given of the later 30 years concerning the rapid development of the Beijing Electron-Positron Collider (BEPC and BEPCII), the completed BEPC-based Shanghai Synchrotron Radiation Facility (SSRF), the Chinese Spallation Neutron Source (CSNS) under construction, the high-intensity proton accelerator (ADS) used for nuclear waste transmutation and the proton therapy machine in the R&D stage. | |||
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Slides THPPA03 [6.015 MB] | ||
THPEA007 | Upgrade of Safety Interlock System of e+/e− Linac for SuperKEKB Project | gun, PLC, laser, status | 3161 |
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The upgrade of e+/e− Injector Linac is going on for SuperKEKB project. The personal interlock system of the Linac has been upgrading several times according to the upgrade phase. One of the biggest changes has been made when the Linac was divided into two areas: upstream and downstream linacs, which allows us to work out the upgrade even during injection to Photon Factories at lower energies using the downstream linac. Most of the interlock system devices were duplicated to start the 'half' accelerator operation. Another remarkable update is to adopt an RF-Gun as a new electron source. We programmed a specific strong logic for the RF-Gun operation. These upgrades will be reported with the introduction of the whole interlock system. | |||
THPEA011 | WPF Based EPICS Server and its Application in CSNS | EPICS, controls, LLRF, PLC | 3170 |
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The control system of China Spallation Neutron Source(CSNS) is under construction based on EPICS. The Linac low level RF(LLRF) local control program running on a local control PC uses Windows Presentation Foundation( WPF) as its development tool and uses the C# codes to implement the functionality. The Linac LLRF control system is non-EPICS, so the Linac LLRF local variables can’t be accessed directly from EPICS. Therefore we need to port the Linac LLRF local control system to EPICS. This paper presents the WPF base EPICS server and its application in CSNS. | |||
THPEA015 | Induced Radioactivity Research for Scraper | electron, radioactivity, radiation, synchrotron | 3173 |
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The 200MeV electron linac of NSRL is one of the earliest high-energy electron linear accelerators in China. The electrons are accelerated to 200MeV by five accelerating tubes and collimated by the scraper followed each accelerating tube. The scraper aperture is smaller than the accelerating tube,so some electrons will hit on the structure materials when they pass through them. These lost electrons will cause induced radioactivity due to bremsstrahlung, cascade shower and photo-nuclear reaction. This paper gives the simulation to different energy electrons lost at the corresponding scraper by EGSnrc. The results showed that electrons were lost mainly at the scraper during the accelerating period,and the actual measurement confirmed this. Meanwhile,the induced radionuclide types have been studied. Recently,the linac mentioned above has been retired because of upgrading. The equipments and materials removed are used to study induced radioactivity generated in different materials. The research will provide the theoretical basis for the similar accelerator decommissioning plan,and is also significant for accelerator structure design,material selection and radiation protection programs design. | |||
THPEA017 | Based on Channel Archiver of EPICS to Realize SSC-LINAC System Efficiently Beam Tuning | controls, EPICS, ion, status | 3179 |
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In order to improve running efficiency of accelerator, shorten the time of changing accelerator beam is key link and it should be considered how to accelerate the ion to specific energy quickly and accurately. We will discuss how to use years of heavy ion accelerator operation data to generate a set of virtual accelerator equipment data for specific ion and energy, load to all the accelerator equipment fast. EPICS provide Channel Archiver tools that can achieve and store data from the IOC equipment operation information. In this study, we use Archive Engine tool and Oracle to combine data acquisition function and data management function. Firstly store the Archive Engine acquisition data into Oracle database, and then according to the data to create accelerator system operation snapshot as the basis for beam tuning. The snapshot data includes all equipment state and parameters at special time in accelerator operating. When the ion is to be changed, related snapshot in Oracle database will be retrieved and loaded to all the equipment and to realize efficiently beam tuning. | |||
THPEA018 | Design of an Integrated Platform based on CSS and MATLAB for SSC-LINAC System Controlling and Data Analysis | controls, EPICS, power-supply, vacuum | 3182 |
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CSS is the abbreviation of Control System Studio and is widely used in particle accelerator experiments area. Based on Eclipse, it is a collection of tools which can display details of the PV, show alarm state, as well as the function of data browsers, archive engine and so on. CSS offers an integrated approach to build a control system. We have recently developed a control and monitor system for the SSC-LINAC system to control and monitor power supply, vacuum, high frequency, and other accelerator equipments. In the area of accelerator controlling, we often need to do some mathematical operations like Fourier transform of the monitored data to get some accuracy performances of interested equipments. Unfortunately, CSS cannot satisfy this requirement. It is well known that MATLAB plays very well in data process and provides many mathematical tools. If we can combine these two tools together, we can get better control strategy. In the presentation, we will discuss the design of this integrated platform to implement the display, control and data process. | |||
THPEA038 | ESS Naming Convention | target, controls, neutron, vacuum | 3222 |
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The European Spallation Source is an intergovernmental project building a multidisciplinary research laboratory based upon thermal neutrons. The main facility will be built in Lund, Sweden. Construction is expected to start 2013 and the first neutrons will be produced in 2019. The ESS linac will deliver 5 MW of power to the target at 2.5 GeV, with a nominal current of 50 mA. The ESS Naming Convention is based on a standard, originally developed for the Super Superconducting Collider (SSC) and later adopted by other large research facilities, e.g. the Spallation Neutron Source (SNS), Facility for Rare Isotope Beams (FRIB), International Thermonuclear Experimental Reactor (ITER), and the Continuous Electron Beam Accelerator Facility (CEBAF). The ESS Naming Convention was agreed upon and approved at a very early stage of the ESS project in order to establish a standard before names started to evolve. The main scope was to standardise meaningful, yet short and mnemonic signal and device names. The present paper describes the naming convention, the site wide implementation at ESS and associated web based tools. | |||
THPEA039 | Radiation Protection Study for the Shielding Design of the LINAC 4 Beam Dump at CERN | shielding, radiation, neutron, simulation | 3225 |
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Linac4, a new 160 MeV H− accelerator, is currently being constructed at CERN. The accelerator is terminated by a dump collecting beam which is not intended for further utilization. The aim of this study is to determine an optimal shielding of the beam dump fulfilling the radio-protection requirements. The proposed shielding must take into account different accelerator operational phases, the space constraints inside the accelerator vault as well as the decommissioning of the installation at the end of its lifetime. Therefore a detailed Monte-Carlo calculation using FLUKA particle transport and interaction code has been performed and the relevant physics quantities have been evaluated for different irradiation profiles and shielding material. Moreover, the residual dose rate and induced activation have been calculated for several cooling times in order to optimize the choice of the shielding material following the ALARA principle. Finally the airborne radioactivity induced by particles escaping the shielding as well as the activation of the beam dump cooling water have been also calculated using FLUKA and simplified laminar flow models. | |||
THPEA052 | TLS Operation Information Management: Automatic Logging Tools | kicker, booster, injection, klystron | 3261 |
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The Taiwan Light Source (TLS) has been operated in the Top-up mode since October 2005 and has maintained a beam current of 360mA since 2010. Several essential parameters and waveforms are constantly recorded as routine accelerator operation reference. Therefore, five LabVIEW-based data and waveform logging software programs have been developed for the purpose of preliminary diagnose at the TLS. In this report, certain actual cases in regular operation are presented. | |||
THPEA060 | LLRF System for LCLS-II at SLAC | LLRF, controls, klystron, feedback | 3276 |
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Funding: Work supported by US Department of Energy Contract DE AC03 76SF00515 After LCLS-I successfully delivering the full operation for users, SLAC has been approved to build the second Linac Coherent Light Source, LCLS-II, which makes use of another third of the 2-mile long Linac from Sector 10 to Sector20. The LLRF System will use mTCA (Micro Telecommunication Computing Architecture) to replace the VME system for LCLS-II injector and some key stations along the LINAC. The faster data acquisition and more powerful FPGA and CPU in the mTCA system enable the LLRF system to extend its control ability to a 2.5 μsec beam pulse rate of 360Hz. The new LLRF system is more compact and has the capability of low latency intra-pulse feedback to reduce fast phase and amplitude jitter during a single pulse. The prototype of the mTCA based LLRF control system has been operating at RF station 28-2 in LCLS-I. Detailed design structure and the prototype experimental results will be presented that demonstrate the system meets the exacting phase and amplitude stability requirements for LCLS-II. |
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THPEA061 | EPICS Accelerator Control System for the IAC-RadiaBeam THz Project | controls, EPICS, power-supply, HOM | 3279 |
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The Idaho Accelerator Center (IAC) of Idaho State University has been operating a 44 MeV L-band linac for various nuclear physics related applications. However, for the past several years, this research has been done without the aid of a modern computer based control system. To obtain a better reproducibility and stability in operation, the EPICS accelerator control system has been applied to control various components of this linac. This has been done for the purpose of a joint THz research project between IAC and RadiaBeam that was performed in November 2012. This paper describes the development of the EPICS accelerator control system used during this joint THz research experiment. | |||
THPEA063 | NSLS II Injector Integrated Testing | controls, target, booster, diagnostics | 3285 |
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The NSLS-II is a state of the art 3 GeV synchrotron light source under construction at Brookhaven National Laboratory. Since 2012, the injector system gradually moves to the commissioning stage. It occurs after group people efforts on optics design, equipment specifications, construction and tests, assembly, installation and alignment. It is very important and exciting. To make the commissioning smooth and efficient, an important effort was put on the sub-system integration test to make sure the device function along with utility, timing system and control system, to calibrate diagnostics system and to debug high level application with simulated beam signals and required hardware. In this paper, we report our integration test experience and related control system software development. | |||
THPFI003 | Vacuum Study of the Cavity String for the IFMIF - LIPAc Cryomodule | vacuum, cryomodule, cavity, pick-up | 3291 |
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In the framework of the International Fusion Materials Irradiation Facility (IFMIF), a superconducting option has been chosen for the 5 MeV RF Linac of the first phase of the project (EVEDA), based on a cryomodule composed of 8 HWRs, 8 RF couplers and 8 Solenoid packages. This paper will focus on the beam vacuum of the cryomodule. The cryomodule beam line is made of the pattern solenoid package / cavity-coupler, and a valve on each side of the cryomodule. During the installation of the cryomodule on the accelerator system, the cavity string has to be pumped down with the beam valves closed. Thereby a manifold is connected to the cavities during the assembly of the beam line components in the clean room. In previous conferences, the cryomodule was presented with a vacuum manifold connected to each cavity. A study realized on this complex vacuum configuration with Molflow, a test-particle Monte-Carlo simulator for ultra-high vacuum, permitted to reduce the number of cavities connected to the manifold and by consequence to reduce the risk of pollution during the clean room assembly. | |||
THPFI004 | Progress on the SRF Linac Developments for the IFMIF-LIPAC Project | cryomodule, solenoid, vacuum, SRF | 3294 |
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In the framework of the International Fusion Materials Irradiation Facility (IFMIF), which consists of two high power accelerator drivers, each delivering a 125 mA deuteron beam at 40 MeV in CW, an accelerator prototype is presently under design and realization for the first phase of the project. This accelerator includes a SRF Linac, which is designed for the transportation and focalization of the deuteron beam up to 9 MeV. This SRF Linac is a large cryomodule of ~6 m long, working at 4.4 K and at the frequency of 175 MHz in continuous wave. It is mainly composed of 8 low-beta HWRs, 8 Solenoid Packages and 8 RF Power Couplers. This paper focuses on the recent developments and changes made on the SRF Linac design: following the abandon of the HWR frequency tuning system, initially based on a plunger located inside the central region of the resonator, a new external tuning system has been designed, implying a complete redesign of the resonator and consequently impacting the cryomodule lattice. The recent changes in the design are presented in this paper. In addition, cold tests were performed on a HWR prototype and cold tests results of the magnets prototypes are also presented. | |||
THPFI007 | Increasing the Stability of the Electron Beam of the S-DALINAC | electron, feedback, acceleration, dipole | 3303 |
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Funding: Funded by DFG through SFB 634 The S-DALINAC is a superconducting recirculating electron accelerator with a final energy of 130 MeV. It operates in cw at 3 GHz. It accelerates beams of either unpolarized or polarized electrons and is used as a source for nuclear- and astrophysical experiments at the university of Darmstadt since 1987. We will report on two future upgrade plans for increasing the operation stability of the accelerator: A high energy scraper system for collimating the beam before it is delivered to the experiments and a rf feedback system to fix the rf phase of the beam leaving the injector linac by measurements on a rf monitor. |
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THPFI008 | Experience and Benefits from PLM-based Parts Management at European XFEL | cavity, controls, factory, undulator | 3306 |
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DESY has developed a parts management solution, which is used in the series fabrication of accelerator components for the European XFEL. The parts management solution stores assembly instructions and drawings for each component, and it tracks the assembly progress of each individual component. It offers procedures for quality inspections, for handling non-conformities and for managing changes, and it tracks the current whereabouts and the entire history of each part. The solution is based on DESY's Product Lifecycle Management (PLM) System and integrates several laboratories and suppliers. The poster shows how parts management is used at the European XFEL in the production of the super-conducting rf cavities, in the assembly of the cryomodules and in the assembly of the undulators, and discusses experience and benefits. | |||
THPFI010 | High Energy RF Deflectors for the FERMI@Elettra project | electron, FEL, vacuum, wakefield | 3309 |
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Measuring and controlling the longitudinal phase space and the time-slice emittance of the electron bunch at 1.2 GeV entering in the undulator beam-lines, is crucial to obtain high FEL performances. In the FERMI@Elettra machine, two RF deflecting cavities have been installed at the end of the linac, in order to stretch the electron bunch horizontally and vertically, respectively. The two cavities are individually powered by the same klystron and a switch system is used to choose the deflection plane. This paper reports the RF measurements carried out during the acceptance test, the RF conditioning including the breakdown rate measurements. Finally, the commissioning with electron beam of the deflecting structure and a comparison of the measured electron bunch length evaluated by using the two deflectors are also reported. | |||
THPFI012 | Design of the cERL Vacuum System | vacuum, electron, diagnostics, gun | 3315 |
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The compact Energy Recovery Linac (cERL) is being constructed as a test accelerator for the ERL-based future light source at KEK. In the design of the cERL, electron beams with low normalized emittance (0.1 mm·mrad) and high average current (10 mA) are generated at a 500-kV gun, and accelerated up to 125 MeV at superconducting (SC) cavities that make energy recovery. The vacuum system should accommodate such high intensity, ultrashort bunch (0.1 ~ 3 ps) electron beams, and be designed so as to minimize its loss factor. Therefore, low impedance vacuum components, such as zero-gap flanges and rf-shielded screen monitors, have been developed. Extra high and clean vacuum is required in the vicinity of the SC cavities to maintain their high gradient operation, and those beam tubes are coated by Non-Evaporable Getter (NEG) films. Because of the low beam energy, photon absorbers are not necessary and the beam tubes can be made of stainless steel. However, the photon scrubbing effect is so limited that the beam tubes should be ready for in-situ bakeout and are wrapped with thin Kapton heaters, which are also useful for the NEG-coating activation. | |||
THPFI035 | Design of A 4-cavities Collinear Load Coated with FeSiAl Alloy for 14 MeV LINAC | cavity, simulation, target, instrumentation | 3370 |
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Collinear load is a substitute for waveguide load to miniaturize linear accelerator and make the beam quality better. Coating with a kind of high efficient microwave-absorbing material FeSiAl alloy, a collinear load section composed of 4 cavities (at 2 /3 mode) with different coating dimensions is designed to absorb 4kW remnant power. Cavity dimensions are adjusted to compensate the frequency shift from 2856 MHz respectively. Simulation shows the loss material FeSiAl only need to be coated on the inner surface of the ring. This makes the design and construction of the cooling system for the load segment easier. Coming with a specific water cooling system can makes the working frequency of the accelerator and the collinear load more close to the supposed. Eventually, based on optimized uniform power absorption principle concluded from the simulation of temperature field, a four-cavity collinear load is designed with one-way attenuation of 76.1 dB, while the largest shift from operation frequency is 35 kHz. | |||
THPFI041 | Installation and Operation of the Beamlines for the 100-MeV Proton Linac | proton, DTL, alignment, site | 3376 |
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Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government. Beamlines and 100-MeV proton linac have been developed for 1st phase of KOMAC(Korea Multi-purpose Accelerator Complex) at the Gyeong-ju site. The linac supply either 20-MeV or 100-MeV proton beams for beam applications. Each proton beam can be transported to 2 beamlines for industrial purpose and 3 beamlines for various researches. At the first phase, 2 beamlines were installed and under test. A detailed description of the installation and the preliminary test results will be presented in this paper. |
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THPFI042 | Design Considerations for Phase Reference Distribution System at ESS | controls, LLRF, cavity, radiation | 3379 |
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PRDS (Phase Reference Distribution System) will be serving as the phase alignment line for all cavities with high phase stability. With the current design of individually RF source powering for most cavities at ESS, phase reference distribution system should provide the reference signals for totally 34 LLRF systems at 100 meters long low-frequency section (for all 352.21MHz cavities, including RFQ, DTL, bunching cavities and spokes), and for totally 180 LLRF systems at 342 meters long high-frequency section (for all 704.42MHz cavities, including medium beta and high beta elliptical cavities). Coaxial cable based solution and optical fibre based solution are discussed in this note for PRDS (Phase reference distribution system) at ESS. Some possible schemes in each of these two distribution solutions are introduced and comparisons among these schemes are made. Some effort is made as well to find out a reasonable design for PRDS at ESS. | |||
THPFI045 | Reliability Approach for Machine Protection Design in Particle Accelerators | controls, proton, beam-losses, booster | 3388 |
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Particle accelerators require Machine Protection Systems (MPS) to prevent beam induced damage of equipment in case of failures. This becomes increasingly important for proton colliders with large energy stored in the beam such as LHC, for high power accelerators with a beam power of up to 10 MW, such as the European Spallation Source (ESS), and for linear colliders with high beam power and very small beam size. The reliability of Machine Protection Systems is crucial for safe machine operation; all possible sources of risk need to be taken into account in the early design stage. This paper presents a systematic approach to classify failures and to assess the associated risk, and discusses the impact of such considerations on the design of Machine Protection Systems. The application of this approach will be illustrated using the new design of the MPS for LINAC 4, a linear accelerator under construction at CERN. | |||
THPFI083 | Radiation Damage Study of Graphite and Carbon-carbon Composite Target Materials | target, proton, radiation, isotope-production | 3487 |
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Funding: Operated by Fermi Research Alliance, LLC, under Contract No. DE-AC02- 07CH11359 with the U.S. Department of Energy. Use of graphite and carbon-carbon composite materials as high intensity proton targets for neutrino production is currently thought to be limited by thermal and structural material properties degraded by exposure to high energy proton beam. Identification of these limits for various irradiation and thermal environments is critical to high intensity targets for future facilities and experiments. To this end, several types of amorphous graphite and one type of carbon-carbon (3D weave) composite were exposed to 180 MeV proton beam at the BNL BLIP facility. Irradiated samples were then thermally, ultra-sonic, and structurally tested and compared to un-irradiated samples. Results show significant changes in material properties even at very low damage levels (<0.09 DPA) and that significant interstitial annealing of these properties occurs at annealing temperatures only slightly above irradiation temperature. This points the way to optimizing target operating temperature to increase target lifetime. A description of the plan to explore radiation damage in target materials through the new RaDIATE collaboration (Radiation Damage In Accelerator Target Environments) is also presented. |
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THPFI091 | Simultaneous Four-hall Operation for 12 GeV CEBAF | extraction, recirculation, laser, electron | 3502 |
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Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The CEBAF accelerator at Jefferson lab will have a new experimental hall, Hall D, added to its existing three halls as a part of the ongoing 12 GeV upgrade. Under the present CEBAF design, there is no option for sending beam to all four halls simultaneously. At least one hall has to stay down during the machine operation. A new pattern for interleaving the beam bunches is introduced that allows simultaneous operation of all four halls and provide opportunity for additional future experimental beams. The new configuration presents only a minimal change to the existing CEBAF extraction system. In fact all the lower pass extractions will stay as they are and only the frequency of 5th-pass horizontal RF separator will change. In order to make room for the new Hall D beam among the existing three beams, the beam repetition rate is reduced only for the halls taking beam at the highest pass. This and other details of the new configuration and beam pattern will be presented and discussed. A separate paper in this conference will cover the implementation choices including changes to the beam source and extraction region.* * "Source and Extraction for simultaneous Four-Hall beam delivery system at CEBAF", proceedings of this conference. |
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THPME012 | Measuring the Direction of Permanent Magnet Easy Axis by Helmholtz Coil | quadrupole, permanent-magnet, DTL, multipole | 3534 |
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Permanent magnets for quadrupole focusing was used in drift-tube linac of the Compact Pulsed Hadron Sources(CPHS) in Tsinghua university. In order to ensure the accuracy of the quadrupole field can meet the design requirement, we need measure the strength and direction of remanence and choose the suit magnet. This paper proposed an easy way to get the direction of permanent magnet easy axis by Helmholtz coil without knowing the angle between magnet and the axis of the coil: the magnet rotational angle data was measured by rotary encoder and encoder would send trigger signal every turn at the same direction. First we started to record data when trigger signal was appeared. Then measured the magnet in three perpendicular directions (x,y,z). Last, caculated the remanence in three directions. We had measured some magnet by the new method and obtained satisfactory results. | |||
THPME025 | Design of Cryomodules for RAON | cryomodule, cryogenics, cavity, vacuum | 3558 |
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The RAON linac utilizes four types of superconducting cavities such as QWR, HWR, SSR1, and SSR2 which are operating at 2 K in order to accelerate the various ion beams. The main role of the cryomodules is to maintain the cryogenic temperature for the superconducting cavity operation. Five types of cryomodules will be necessary since one QWR cavity, three and six HWR cavities, four SSR1 cavities, and eight SSR2 cavities will be installed in the dedicated cryomdoules. Total number of the cryomodule is 147, 48 for QWR, 60 for HWR, 22 for SSR1, 17 for SSR2. The cryomodules of RAON does not include focusing magnets but includes the cavities operating at 2 K. This paper describes the current status of the RAON cryomodule design. The issues included in the paper are the thermal load estimation, design of the components such as thermal shield and intercept of the cryomodules, and cryogenic flow circulation system according to the cryomodule operation. | |||
THPME036 | Design and Measurement of the Transfer Line Magnets for the Taiwan Photon Source | quadrupole, dipole, simulation, booster | 3591 |
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The Taiwan photon source (TPS) transfer line from the linac to the booster (LTB) is made of 1 bending magnet, 11 quadrupoles and the booster to the storage ring (BTS) is include of 2 bending magnets, 7 quadrupoles. LTB bending magnet is provided for 11 degrees defection from the linac to the booster and 31 degrees from the linac to the beam dumper with two operating currents. The BTS quadrupoles are included four 0.3m and three 0.4m magnets which cross sections are the same with booster quadrupole give different integral quadrupole field strengths and cooling systems are redesign from 2 circuits to 4. The magnetic fields were simulated with Opera 2D and 3D; optimum processes are discussed. All of the magnets have been constructed by Danfysik, scanditronix and Gongin. This paper discusses the features, the design concept and the results of field measurements of these transfer line magnets. | |||
THPWA001 | Design of X-Band Medical Linear Accelerator with Multiple RF Feeds and RF Phase Focusing | focusing, cavity, impedance, bunching | 3627 |
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Funding: Work supported by the Egyptian Science and Technology Development Fund (STDF) No. 953. A design of 6 MeV X-band 9.3 GHz medical linear accelerator is presented. It is composed of four separate clusters of accelerating cavities, where a coherent RF excitation is provided separately to each cluster. The use of multiple accelerating sections with multiple RF feeds permits the use of inexpensive RF sources. The first cluster is Alternate Phase Focusing (APF) RF cavities, providing radial and longitudinal beam focusing without the use of heavy and bulky magnets or solenoids. The three other clusters used for acceleration are composed of multiple standing wave sections operating in the Pi-mode. Each section has been designed and optimized for high shunt impedance by means of 2D SUPERFISH code and 3D CST code. A two dimensional code, named PTCC, was developed to facilitate design and analysis of the different parts of the accelerating structure. |
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THPWA005 | The HIT Accelerator as Part of a Medical Product: Impacts on the Maintenance Strategy | ion, controls, ion-source, proton | 3639 |
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The HIT accelerator produces protons and carbon beams with a large variety of parameters: 255 different energies, four foci and ten intensity steps per ion are independently available at 5 iso-centres to be requested by the dose delivery system for tumor treatment. Thus the whole accelerator chain is part of a medical product, in case of HIT an in-house manufactured device. The overall risk and quality management has deep influences on the maintenance process. Not only the huge volume of necessary documentation reflects this impact but also the organizational process before, along and after the services at HIT. Especially, the comprehensive testing after the maintenance procedures follows sophisticated checklists (e.g. the ion source service). On the other hand, a high operational availability of the accelerator in a hospital is mandatory. To realize 8250 hours of accelerator uptime per year in case of HIT, a maintenance strategy is necessary, which interleaves the regular service of the building infrastructure, e.g. air conditioning, with the periodic maintenance of the accelerator components. In detail, this approach will be discussed along the magnets and the gantry structure. | |||
THPWA008 | Design of a Fast-cycling High-gradient Rotating Linac for Protontherapy | cyclotron, proton, klystron, simulation | 3642 |
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General interest has been shown over the last years for the development of single room facilities serving a population of about 2 million people for proton cancer therapy. Compact machines are needed to accelerate proton beams of few nanoamperes up to 230 MeV. In this framework the project TULIP (Turning LInac for Protontherapy), patented by TERA Foundation, foresees a linac mounted on a rotating gantry used as a booster for protons previously accelerated by a cyclotron. The linac is composed of modular units powered by independently controlled klystrons. The RF power transmission is made possible by high power rotating joints developed in collaboration with CLIC group. The final beam energy can be varied in steps of few MeV from pulse to pulse by amplitude and/or phase modulation of the klystron signals, making possible the implementation of active spot scanning technique with tumor multi-painting. The present paper provides the main characteristics of TULIP, describing the different choices for the linac design parameters together with the structural design of the supporting gantry and of the final beam line. | |||
THPWA010 | Application of X-band 30 MeV Linac Neutron Source to Nuclear Material Analysis for Fukushima Nuclear Plant Accident | neutron, electron, target, scattering | 3648 |
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We plan to use our X-band (11.424GHz) electron linac as a neutron source for the nuclear analysis for the Fukushima nuclear plant accident. Quantitative material analysis and forensics for nuclear security will start several years later after the safe settlement of the accident is established. For the purpose, we should now accumulate more precise nuclear data of U, Pu, TRU and MA especially in epithermal (0.1-10 eV) neutrons. Therefore, we have decided to move the linac into the core of the experimental nuclear reactor “Yayoi” which is now under the decommission procedure. First we plan to perform the TOF (Time Of Flight) transmission measurement of the total cross sections of the nuclei for 0.1-10 eV neutrons. Electron energy, macro-pulse length, power and neutron yield are ~30 MeV, 100 ns – 1 micros, <0.5 kW and <1012 n/s, respectively. Optimization of the design of a neutron target (Ta, W, U), TOF line and neutron detector (Ce:LiCAF) of high sensitivity and fast response is underway. Installation, commissioning and measurement starts in 2014. Detailed design and way how to contribute to the analysis of the Fukushima nuclear plant accident will be presented. | |||
THPWA014 | Development of Photon-induced Positron Annihilation Lifetime Spectroscopy using an S-band Compact Electron Linac | positron, photon, electron, laser | 3660 |
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Funding: This work was supported by Grants-in-Aid for Scientific Research (22360297) Positron annihilation lifetime spectroscopy (PALS) is a very sensitive tool to characterize materials and study defects at the nanometer scale. However, the application of PALS has been restricted to thin samples because of the limited range of positrons in materials. PALS for thick samples is possible by using high energy photons to create positrons inside the sample via pair production. This technique is called photon-induced positron annihilation lifetime spectroscopy (PiPALS). We have developed a novel PiPALS system using ultra-short photon pulses based on bremsstrahlung radiation to carry out in-situ measurement of structural materials under special conditions (piping for supercritical water and nuclear reactor materials). Intense, ultra-short photon pulses with energies up to 40 MeV can be generated by using an electron linear accelerator with photocathode rf gun system at AIST. In this conference, we will present the experimental result of the positron annihilation lifetime spectrum of a metal target by using ultra-short photon pulses*. *Y. Taira et al., Rad. Phys. and Chem., accepted for publication 2012. |
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THPWA034 | Overview of CERN Technology Transfer Strategy and Accelerator-related Activities | vacuum, target, proton, electron | 3702 |
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CERN, the European Organization for Nuclear Research, is actively engaged in identifying technologies developed for its accelerator complex that could be profitably used by partner research organizations or commercial companies in applications with potentially high socio-economic impact beyond pure fundamental physics research. In the first part of the paper, an overview of CERN current strategy in the field of Technology Transfer and Intellectual Property Management will be presented, with details on the most effective models, implementation tools and processes developed to achieve satisfactory dissemination and valorisation of the knowledge generated within the Organization. In the second part, CERN currently available technology portfolio will be described with focus on cases originated from the Accelerator and Technology Sector. A selection of promising on-going projects embracing a variety of technology fields and application areas will be detailed to showcase technical challenges and possible benefits of initiatives driven by (but not limited to) the needs of CERN scientific programme. | |||
THPWA046 | Accelerator Optimization within the oPAC Project | cryogenics, radiation, simulation, electron | 3735 |
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Funding: Work supported by the EU under Grant Agreement 289485. Many of the today’s most advanced research infrastructures rely on the use of particle accelerators. This includes for example synchrotron light sources and FELs, high intensity hadron accelerators for the generation of exotic beams and spallation sources, as well as much smaller accelerator facilities for precision experiments and fundamental studies. Moreover, accelerators are very important for many commercial applications, such as for example medical applications, material studies and treatment, lithography, or security applications, such as scanners at airports or cargo stations. The full potential of any accelerator can only be exploited if the performance of all its parts are continuously optimized, if numerical tools are made available that allow for developing and improving advanced machine designs, if methods are developed in partnership between the academic and industry sectors to monitor beams with ever higher intensities and brightness, shorter pulse lengths or smaller dimensions. This contribution presents the R&D program of the oPAC project that optimizes existing and future accelerators. |
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THPWA047 | GEM*STAR - New Nuclear Technology to Produce Inexpensive Diesel Fuel from Natural Gas and Carbon | neutron, controls, proton, target | 3738 |
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The 75,000 tons of US stored spent nuclear fuel (SNF) from conventional nuclear reactors is a resource that could provide 125 years of all US electrical power. Or it could also provide a great amount of process heat for many applications like producing green diesel fuel from natural gas and renewable carbon. An accelerator system like the SNS at ORNL can provide neutrons to convert SNF into fissile isotopes to provide high temperature heat using technology developed at the ORNL Molten Salt Reactor Experiment. In the GEM*STAR accelerator-driven subcritical reactor that we wish to build, the accelerator allows subcritical operation (no Chernobyls), the molten salt fuel allows volatiles to be continuously removed (no Fukushimas), and the SNF does not need to be enriched or reprocessed (to minimize weapons proliferation concerns). The molten salt fuel and the relaxed availability requirements of process heat applications imply that the required accelerator technology is available now. A new opportunity has arisen to use GEM*STAR to reduce the world’s inventory of weapons-grade plutonium leaving only remnants that are permanently unusable for nuclear weapons.
* Charles D. Bowman et al., “GEM*STAR: The Alternative Reactor Technology Comprising Graphite, Molten Salt, and Accelerators,” Handbook of Nuclear Engineering, Springer (2010). |
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THPWA048 | New Generation X-band Linacs for Medical and Industrial Appplications | electron, RF-structure, radiation, beam-losses | 3741 |
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The proposed designs of the new X-band linear accelerators for industrial and medical applications are based on a well-known side-coupled RF structure. The immediate applications envisioned for the new linear accelerators are security screening and intraoperative radiotherapy (IORT). The new design has promising features and presents cost reduction potential for electron beam and X-ray systems used in medical, industrial, and security screening applications. | |||
THPWA051 | Compact, Inexpensive X-band Linacs as Radioactive Isotope Source Replacements | gun, electron, simulation, radiation | 3746 |
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Funding: Work supported by DNDO Phase II SBIR HSHQDC-10-C-00148 and DOE Phase II SBIR DE- SC0000865. Radioisotope sources are commonly used in a variety of industrial and medical applications. The US National Research Council has identified as a priority the replacement of high-activity sources with alternative technologies, due to the risk of accidents and diversion by terrorists for use in Radiological Dispersal Devices (“dirty bombs”). RadiaBeam Technologies is developing novel, compact, inexpensive linear accelerators for use in a variety of such applications as cost-effective replacements. The technology is based on the MicroLinac (originally developed at SLAC), an X-band linear accelerator powered by an inexpensive and commonly available magnetron. Prototypes are currently under construction. This paper will describe the design, engineering, fabrication and testing of these linacs at RadiaBeam. Future development plans will also be discussed. |
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THPWA052 | Proposal for a muSR Facility at BNL | target, proton, booster, extraction | 3749 |
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Funding: Work supported by U.S. DOE under contract No DE-AC02-98CH10886 with the U.S. Department of Energy. By implanting positive muons in a substance (either gas, liquid or solid), their magnetic moments can be used to sample the magnetic properties of the material. The precession rate can give the magnetic field strength, and the field direction is given away after the muons decay into positrons that are detected. The information obtained from muSR can be complementary to that from other methods such as NMR, ESR, and neutron scattering. A low energy muon surface source is particularly interesting for studying thin films. To date, only four user facilities exist in the world but none in the US. We explore the possibility of using the AGS complex at BNL for a muSR facility for the production of positive surface muons. |
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THPWO001 | Assembling, Testing and Installing the SPIRAL2 Superconducting Linac | cryomodule, vacuum, cavity, alignment | 3752 |
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Assembly and tests of the SPIRAL2 superconducting linac's components are now proceeding smoothly. Cryomodules are being processed in CEA Saclay and IPN Orsay, inter-cryomodules "warm" sections in GANIL. While installation of the accelerators components is going on in the new SPIRAL2 building in Caen, installation of the cryomodules will begin during the last quarter of 2013. The latest results of the cryomodules tests as well as the installation strategy are depicted in this paper. | |||
THPWO002 | Progress of Construction and Installation of the SPIRAL2 Accelerator | ion, rfq, controls, vacuum | 3755 |
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Officially approved in May 2005, the SPIRAL2 project was launched in July 2005 at GANIL, with the active participation of French laboratories (CEA, CNRS) and international partners. This new facility is composed of a linear accelerator producing deuteron, proton and heavy ion beams in a wide range of energies and intensities, with two dedicated experimental areas in the fields of Neutron for Science (NFS) and very heavy and super heavy element production (S3). In a second step, the facility will also produce Rare elements serving a low energy RIB experimental hall, or post-accelerated by means of the existing cyclotron CIME. This paper presents the performances of the main accelerator components, and the installation process into the SPIRAL2 building. | |||
THPWO004 | RF Tuning of the LINAC4 RFQ | rfq, coupling, quadrupole, dipole | 3761 |
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The construction of Linac4, the new 160 MeV CERN H− injector, has started with the goal of improving the LHC injection chain with a new higher energy linac. The low energy front end of Linac4 is based on a 352 MHz, 3-m long Radiofrequency Quadrupole (RFQ) which accelerates the 70 mA, 45 keV H− beam from the ion source to the energy of 3 MeV. The RFQ, made of three modules, one meter each, is of the four-vane type and it has been designed in collaboration between CERN and CEA. Construction has started in 2009 and all the steps of machining and assembly have been done at CERN. The RFQ is equipped with 35 fixed tuners and one waveguide RF port located in the second module. This paper describes the procedure used to tune the accelerating field and the power coupler of the LINAC4 RFQ in order to achieve the nominal voltage profile within ±1% accuracy. | |||
THPWO007 | Advanced Superconducting CW Heavy Ion Linac R&D | solenoid, cavity, ion, heavy-ion | 3770 |
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An advanced upgrade program has to be realized in the next years, such that enhanced primary beam intensities are available. For this a new sc 28 GHz full performance ECR ion source has to be established. Via a new low energy beam line an already installed new RFQ and an IH-DTL will provide for cw-heavy ion beams with high average beam intensity. It is foreseen to build a new cw-heavy ion-linac behind this high charge state injector. In preparation an advanced R&D program is defined: The first linac section comprising a sc CH-cavity embedded by two sc solenoids (financed by HIM and partly by HGF-ARD-initiative) as a demonstrator will be tested in 2014). After successfull testing an advanced cryomodule comprising up to 4 rf cavities is foreseen. First layout scenarios of this advanced test bench will be presented. | |||
THPWO008 | Status of the 70 MeV FAIR Proton Injector | proton, DTL, rfq, cavity | 3773 |
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Funding: BMBF The FAIR project requires a dedicated proton injector for the creation of high intensity secondary antiproton beams. This machine will be the first high intensity linear accelerator based on CH-DTL. The status of the project, with particular emphasis on the construction of the first RF prototype is presented. |
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THPWO009 | Beam Dynamics Error and Loss Investigation of the FAIR Proton Injector | rfq, DTL, proton, quadrupole | 3776 |
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The FAIR Proton Linac is a 70mA, 70 MeV. 325 MHz linear accelerator based on CH cavities. The focusing scheme is provided by an asynchronous KONUS lattice period. Random misalignment and rotation errors of the quadrupoles, together with phase and RF settings of the power source plays a major role in beam losses. Those effects are investigated and the beam dynamics results, including several source of errors, are presented and discussed. | |||
THPWO012 | High Gradient Room Temperature Cavity Development for 10 – 100 AMeV Beams | cavity, focusing, ion, DTL | 3785 |
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Funding: BMBF, 05P12RFRB9 These linac activities are aimed to increase the accelerating field gradient. In IAP – Frankfurt, a CH – design was proposed to post-accelerate a proton bunch, generated by an intense laser, from 10 – 15.2 MeV. The accelerating field gradient is expected to reach > 10 MV/m. Within a funded project, this cavity will be further developed towards a high gradient cavity. The availability of the GSI 3 MW klystron test stand will be very important for these investigations. The results will influence the rebuilt of the Unilac - Alvarez section, where the existing linac tunnel with 1 m thick concrete walls should house a powerful pulsed heavy ion linac, optimized for achieving finally the beam intensities specified for the GSI-FAIR project. The status of the cavity design will be presented. |
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THPWO015 | First Coupled CH Power Cavity for the FAIR Proton Injector | cavity, coupling, proton, alignment | 3791 |
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For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In Summer 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. Before Spring 2013 the final drift tube structure will be welded inside the main tanks and the preparation for copper plating will take place. This paper will report on the main tuning and commissioning steps towards that novel type of DTL and it will show the latest results measured on a fully operational CH proton cavity. | |||
THPWO016 | Superconducting CH Cavities for Heavy Ion Acceleration | cavity, solenoid, cryomodule, status | 3794 |
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Funding: Work supported by HIM, GSI and BMBF Contr. No. 06FY7102 To demonstrate the operation ability of superconducting (sc) Crossbar-H-mode (CH) cavity technology a 217 MHz structure of this type is under development at the Institute for Applied Physics (IAP) of Frankfurt University. The cavity has 15 accelerating cells and a design beta of 0.059. It will be equipped with all necessary auxiliaries like a 10 kW power coupler and a tuning system. Currently, the cavity is under construction. Furthermore, this cavity will serve as demonstrator for a sc continuous wave (cw) LINAC at GSI. The proposed cw LINAC is highly requested to fulfil the requirements of nuclear chemistry and especially for a competitive production of new Super Heavy Elements (SHE) in the future. A full performance test by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is planned in 2014. The current status of the sc CH cavity and the demonstrator project is presented. |
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THPWO017 | A Coupled RFQ-IH Cavity for the Neutron Source FRANZ | rfq, DTL, simulation, cavity | 3797 |
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The Frankfurt neutron Source at the Stern-Gerlach-Zentrum (FRANZ) delivers neutrons in the energy range from 1 to 300 keV at high intensities. The neutrons are produced using the the 7Li(p,n)7Be reaction with 2 MeV protons. The linac accelerator cavities consists of a 4-rod-RFQ coupled with an 8 gap interdigital H-type drift tube section with a total cavity length of 2.3 m. It accelerates the 120 keV beam to 2.03 MeV at a frequency of 175 MHz. The combined cavity will be powered by one RF amplifier to reduce investment and operation costs. The inductive power coupler will be located at the RFQ part. The coupling into the IH – section is provided by direct inductive coupling within the cavity. The coupled RFQ-IH combination is investigated with CST-MWS-simulations and by an RF model. The linac combination has to match the resonance frequency, flatness along the RFQ and the voltage ratio between both cavity sections. Beam operation will be cw (a few mA) and pulsed 250 kHz, 50 ns (up to 50 mA and beyond). The thermal cavity losses are about 200 kW and the cooling is the challenging topic. | |||
THPWO022 | Beam Dynamics Design, Simulation and Benchmarking for the C-ADS Injector-II RFQ | rfq, simulation, emittance, quadrupole | 3809 |
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The planned Chinese Accelerator Driven System (C-ADS) will use two 10 MeV, up to 10 mA, and CW (Continuous Wave) proton linacs in parallel as injectors. Two versions of the injectors with different resonant frequencies as well as different cavity configurations are under development. This paper will focus on the beam dynamics design, simulation and benchmarking performed for the 162.5 MHz, 2.1 MeV Injector-II RFQ (Radio-Frequency Quadrupole). | |||
THPWO023 | The New RFQ as RIB Injector of the ALPI Linac | rfq, emittance, injection, ion | 3812 |
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At the Legnaro National Laboratories it is operating a Super Conducting linac for nuclear studies named ALPI. A new project SPES is under study to provide neutron-rich rare nuclear beams (RIB) of final energies in the order of 10 MeV/A for nuclei in the A= 9-160 mass region. The radioactive ions will be produced with the ISOL technique using the proton induced fission on a Direct Target of UCx and subsequently reaccelerated using a new injector for the ALPI accelerator complex. In this paper the new RFQ injector and the transport line to ALPI will be describe. | |||
THPWO024 | PROGRESS ON DTL DESIGN FOR ESS | DTL, multipole, emittance, simulation | 3815 |
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In the European Spallation Source (ESS) accelerator, the Drift Tube Linac (DTL) will accelerate a proton beam of 50 mA pulse peak current from 3 to ~80 MeV. In this paper the engineering design of DTL tanks with the beam dynamics errors studies and the RF design are shown. | |||
THPWO027 | Lattice and Error Studies for J-PARC Linac Upgrade to 50mA/400MeV | emittance, simulation, lattice, focusing | 3818 |
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Equi-partitioning (EP) setting is applied as base-line design for the J-PARC linac upgrade from present 15mA/181MeVto 50mA/400MeV H− beam. We also studied the possibility of mitigating the intra-beam stripping (IBSt) with constant-envelop setting for the frequency jump from 324MHz to the 972MHz ACS section. Since the constant-envelop setting here for the frequency jump is away from equi-partitioning and close to the resonances kz=3kx, kz=2kx and so on, considerable emittance exchange and mismatch were found in the simulation. It is natural to continue the work to explore the parameter space around the above two typical settings. Three key points are to be checked. The first is the tradeoff between the envelopes big enough to suppress the IBSt and tunes not to be too depressed to the space charge region. The second point is the sensitivity of these lattices vs. errors. The third is about the criterion of mismatch in the presence of emittance exchange. When emittance exchange is serious the mismatch can be unavoidable. So it is crucial to ensure the settings are in the safe region free from un-controlled mismatch. | |||
THPWO028 | Commissioning Plan for Energy Upgrade of J-PARC Linac | acceleration, injection, quadrupole, DTL | 3821 |
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In J-PARC linac, we plan to have an energy and intensity upgrade in summer 2013. The upgrade involves replacement of the ion source and RFQ (Radio Frequency Quadrupole linac), and addition of ACS (Annular Coupled Structure linac) cavities after existing SDTL (Separate Drift Tube Linac) section. With this upgrade, the design peak current will be increased from the present 30 mA to 50 mA, and the energy from 181 MeV to 400 MeV. This significant upgrade will be followed by a full-scale beam commissioning campaign. In this paper, we present the plan for the commissioning with outlining the assumed commissioning schemes. | |||
THPWO029 | Beam Loss Monitoring and Mitigation at J-PARC DTL | DTL, radiation, injection, vacuum | 3824 |
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Close radiation survey at the cavity outer surface has indicated a significant beam loss in the first tank of J-PARC DTL (Drift Tube Linac) which has been localized at a certain drift tube. It has motivated us to measure the beam loss at the DTL, and we have installed beam loss monitors of scintillator type at the cavity surface. It is challenging to monitor the beam loss due to low energy of lost particles and shielding by the thick cavity wall. In this paper, we report the results of beam loss measurement and beam loss mitigation tuning using the beam loss monitors. | |||
THPWO030 | Recent Progress in Beam Commissioning of J-PARC Linac | DTL, resonance, simulation, radiation | 3827 |
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The beam operation of J-PARC linac has been restored from the earthquake, and started to pursue higher beam power operation. We have also started to prepare for coming energy and intensity upgrade. In this paper, we review recent progress in beam commissioning of J-PARC linac with emphasis on the beam loss mitigation and preparation for the upgrade. | |||
THPWO031 | Status of J-PARC Accelerators | extraction, vacuum, injection, power-supply | 3830 |
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After nine-months of beam shutdown by the Great Earthquake in March 2011, the J-PARC facility resumed beam operation. In December 2011, operations were carried out at low duty such as single-shots or 1 to 2.5 Hz for beam tuning. At the beginning of January 2012, we started beam tuning at the full repetition rate of 25 Hz at the linac and the 3 GeV Rapid Cycling Synchrotron (RCS). After the tuning, user programs of the Materials and Life Science Experiment Facility (MLF), the Neutrino facility and the Hadron facility started. The beam power was increased from 100 to 300 kW to the MLF users, from 3.3 kW to 6 kW to the Hadron users, and from 140 to 200 kW to the Neutrino users. The beam availability went lower to 73 % in JFY 2011 due to the trouble of the linac klystron power supply in March, but it has got back to 90-94 % as of November in JFY2012. We have also much upgrade work during the shutdown period or in parallel to the operation. We’ve demonstrated new record power beyond 500kW from the RCS. The status and progress of the J-PARC accelerators are presented. | |||
THPWO032 | Progress of Injection Energy Upgrade Project for J-PARC RCS | injection, power-supply, impedance, septum | 3833 |
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The injection energy of the J-PARC RCS will be upgraded in 2013. New power supplies for the shift bump magnet system will be installed. Some of other systems, upgrade of the painting bump power supplies and pulse steering systems, are already installed and tested or used for the nominal operation. The paper reports the progress of injection energy upgrade project. | |||
THPWO033 | High Intensity Beam Trial of up to 540 kW in J-PARC RCS | injection, simulation, resonance, proton | 3836 |
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Recently we have performed a high intensity beam trial of up to 540 kW. In this paper, beam intensity dependece and injection painting parameter dependence of beam loss, observed in this beam experiment, will be discussed with the corresponding numerical simulation results. | |||
THPWO034 | Fabrication of the RFQ III for the J-PARC Linac Current Upgrade | rfq, cavity, dipole, quadrupole | 3839 |
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The J-PARC accelerator comprises an injector linac, a 3-GeV Rapid-Cycling Synchrotron and a 50-GeV Main Ring. The J-PARC linac has been operating for users with the beam energy of 181 MeV. The energy (to 400MeV) and current (to 50mA) upgrade of the linac is scheduled for 1MW operation at RCS. For the current upgrade, the RFQ III, which is designed for 50mA beam acceleration, has been fabricated. The engineering design and the fabrication technologies are basically the same as the RFQ II in J-PARC linac. Some engineering methods are improved for the dimension accuracy, the reliability, and the period of fabrication. In the RFQ II fabrication, there was a leakage trouble at the electron-beam-welding spot by the thermal stress at the brazing only occasionally. Then, we changed to all-brazing design. Also, there was a vane deformation after the final machining. This was corrected by changing the method of fixation at the brazing. As a result, a dimension error was in a tolerable range. Currently, the fabrication is in a final process and the high-power test is scheduled at the second quarter of 2012. | |||
THPWO035 | Numerical Study on the Effect of Magnetic Shield of a Bunch Shape Monitor in J-PARC Linac | electron, simulation, beam-transport, quadrupole | 3842 |
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In the annual shutdown period of 2012, three bunch shape monitors (BSMs) have been installed to the J-PARC linac beam transport line at the downstream of the 181-MeV separated DTL. To measure the longitudinal micro-bunch shape, the BSM detects the electrons produced by the accelerated protons hitting the negatively energized wire. Due to the space limitation, the each BSM is installed at the center of the quadrupole doublet, where the fringe field from the quadrupole magnets exists. It has been observed that the fringe field significantly affects the orbit of the emitted electrons. To shield the magnetic field, iron plates have been inserted to the spaces between the quadrupole magnets and BSM. This causes changes of the total magnetic flux density (GL) and the amount of quadrupole component of the fringe field. In this paper, numerical estimation of the shield effect is presented. | |||
THPWO036 | Annular-Ring Coupled Structure Linac for the J-PARC Linac Energy Upgrade | vacuum, ion, cavity, proton | 3845 |
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The linac of Japan Proton Accelerator Research Complex (J-PARC) is the injector to the 3-GeV rapid cycle synchrotron. In order to increase the beam power of the synchrotron, the task of the 400-MeV energy upgrade of the linac started from March 2009. Following the 191-MeV Separated-type DTL, the 25 modules of the Annular-ring Coupled Structure (ACS) linac will be added from August 2013. The operating frequency and the accelerating field E0 of the ACS are 972 MHz and 4.2 MV/m, respectively. The cavity fabrication of the ACS has been almost finished, and then the completed cavities are stored in the J-PARC site. Currently, pumps and vacuum components are being installed on the cavities for the test of vacuum condition. For the pulsed beam of J-PARC, the vacuum pressure have to be less than 10-6 Pa in order not to exceed 0.1 W/m beam loss. In this paper, we present the R&D results to reduce the vacuum pressure using the stored ACS cavity and the current status of the energy upgrade. | |||
THPWO040 | Progress of Injector-1 and Main Linac of Chinese ADS Proton Accelerator | cavity, rfq, proton, solenoid | 3854 |
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China ADS study program was Supported by the "Strategic Priority Research Program " of the Chinese Academy of Sciences at 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in about twenty years. The driver Linac is defined to be1.5 GeV in energy, 10mA in current and in CW operation mode. To meet the extremely high reliability and availability of ADS, the Linac is designed with much installed margin and fault tolerance. ADS accelerator is composed of two parallel 10MeV injectors and a main Linac. The superconducting acceleration structures are employed except the RFQs. This paper will present design of the China ADS accelerator and related key technology developments. | |||
THPWO043 | Progress on the Physics Design of the C-ADS Injector Scheme I | rfq, focusing, cavity, ion-source | 3863 |
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Funding: Surported by China ADS Project The China ADS (C-ADS) driver linac is composed of two parallel 10 MeV injectors and a main linac which boosts the beam further to 1.5 MeV. There are two design schemes for the injectors based on different working frequency and superconducting cavity structures and are under developing at the same time on IHEP and IMP. The Injector Scheme I, which is proposed by IHEP, works at 325 MHz, the same frequency of the main linac, and superconducting Spoke cavities with geometry beta of 0.12, the same type of cavity as the main linac too, are applied after the RFQ. In this paper, the latest progress on physics design will be presented. |
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THPWO044 | Error Analysis and Beam Loss Control in C-ADS Main Linac | simulation, emittance, cavity, solenoid | 3866 |
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The China ADS (C-ADS) driver linac is defined to deliver a CW proton beam of 1.5 GeV in energy and 10 mA in current. To meet the extremely high reliability and availability, it is very important and imperative to perform detailed error analysis to simulate the real machine, where the errors always exist. The error studies are by very intense macro-particle simulations by both Trace-Win and TRACK codes with space charge effects included. Through error analysis the proper closed-orbit correction scheme and the maximum tolerable hardware and alignment errors can be found. This paper presents the method to optimize the apertures of elements in the C-ADS main linac. According to the detailed sensitivity analysis of different errors, the static and dynamic errors for the main linac are proposed. The basic lattice scheme has also been re-optimized based on the error studies. The correction scheme is also described, and with the correction scheme the residual orbit can be controlled very well. The influence of the correctors and BPM failures on the correction scheme is also studied. | |||
THPWO045 | Commissioning Plan for the CSNS Linac | DTL, emittance, diagnostics, quadrupole | 3869 |
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The linac of the China Spallation Neutron Source(CSNS) will be commissioned from October 2013. The linac will be commissioned in three phases. The delivery of beam to the RCS is planned for October 2015. This paper describes the commissioning plans for the MEBT and DTL parts of the linac. Techniques for finding the RF set-point, matching and steering are presented, as well as codes to assist in the beam commissioning. | |||
THPWO046 | The Preparation for the Commissioning of CSNS Accelerators | injection, DTL, optics, target | 3872 |
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The China Spallation Neutron Source (CSNS) is now under construction, and the beam commissioning of ion source will start from the end of 2013, and will last several years for whole accelerators. The commissioning plan for the CSNS accelerators will be presented, including the commissioning correlated parameters, beam instrumentation in used commissioning, the goal at different commissioning stages. The development of high level application software will also be presented. | |||
THPWO047 | The LLRF Measurement and Analysis of the SSC-LINAC RFQ | rfq, cavity, LLRF, simulation | 3875 |
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Funding: Supported by NSFC(11079001) The manufacturing process of the SSC-LINAC RFQ went to end and the LLRF measurement has been done. The frequency of the RFQ is 53.557 MHz without tuning, which is not far from the design value 53.667 MHz. The unflatness of the field along the beam axis is less than ±4%, which meets the simulation results. The dipole field is in the acceptable margin as well. The frequency will be adjusted by tuning plungers in operation. In this paper, the field distribution along the cavity has been measured and compared with the modulated electrodes simulation. The difference and its influences on the beam transmission have been analyzed. |
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THPWO049 | Preliminary Beam Dynamics and Structure Design of One 50mA/CW RFQ with Ramped Inter-vane Voltage | rfq, simulation, radio-frequency, quadrupole | 3881 |
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Funding: Work supported by National Natural Scienccontracte Foundation of China (Major Research Plan Grant No. 91126003 and Project 11175096). The beam dynamics and structure design of a ramped-voltage CW RFQ (Radio Frequency Quadrupole) accelerator for a NSFC (National Natural Science Foundation of China) Project at Tsinghua University is presented in this paper. The ramped-voltage RFQ, in which the inter-vane voltage increases from the low-energy end to the high-energy end, is compact and efficient. The RFQ, with the operating frequency of 325 MHz, will capture a 50 mA/CW, 50 keV proton beam from the RF source and accelerate it to 3 MeV, an energy suitable for chopping and injecting the beam in a conventional Drift Tube Linac. After optimization, the total length is as short as 2.9 m and the transmission rate is above 97%. The design of RFQ structure including the undercuts will also be shown. |
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THPWO051 | Status of CPHS Project | neutron, proton, target, rfq | 3887 |
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CPHS (Compact Pulsed Hadron Source) project was initiated in Tsinghua University at 2009. It consists of a 13 MeV proton Linac (RFQ+DTL), a neutron target station and some neutron stations. The construction of 3 MeV Linac (RFQ only) and target station will be finished at the end of 2012. And initial commissioning will be started at the early of year 2013. The progress and results of early commissioning will be presented at this paper. Then we will report the next plan also. | |||
THPWO059 | Beam Dynamics Design of the Main Accelerating Section with KONUS in the CSR-LINAC Proposal | emittance, DTL, rfq, heavy-ion | 3895 |
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The CSR-LINAC as the injector of the Cooling Storage Ring (CSR) has been proposed in Heavy Ion Research Facility in Lanzhou (HIRFL). The injection linac mainly consists of two Linacs, the Radio Frequency Quadrupole linac (RFQ) and the Drift Tube Linac (DTL). The KONUS (Kombinierte Null Grad Struktur) concept has been introduced to the drift tube linac section. In this paper, the re-matching of the main accelerating section will be finished in the 3.7MeV/u scheme and the new beam dynamics design updating to 7MeV/u will be shown. Through the beam re-matching, the relative emittance growth has been suppressed greatly along the linac. The KONUS structure is also adopted in the beam dynamics design that update from 3.7MeV/u to 7MeV/u and the good beam quality and transmission is shown. | |||
THPWO062 | Status of the RAON Accelerator Systems | target, cavity, ion, ISOL | 3898 |
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Funding: This work is made possible by the support of the Ministry of Science, ICT and Future Planning (MSIP) and the National Research Foundation (NRF) of the Republic of Korea. The RAON is the heavy ion accelerator being built in Korea to build the In-flight Fragment (IF) and Isotope Separation On-Line (ISOL) facilities to support cutting-edge researches in various science fields. Superconducting linac with 200 MeV/u, 400 kW is the driver for the IF facility and the 70 MeV, 70 kW H− cyclotron is the driver for the ISOL facility. These facilities are to provide high intensity stable beams and rare isotope beams for the users domestic and abroad. The design and prototyping efforts are under way such as superconducting cavities and magnets. Status of the RAON accelerator systems is presented. |
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THPWO063 | The Early Stage of the Cavity Fabrication Process (ECT and furnace) for RAON | cavity, niobium, vacuum, superconducting-cavity | 3901 |
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RAON is consist of three part about the acceleration line. These are SCL1, SCL2 and SCL3. SCL1 and SCL3 will be made from QWR (Qarter Wave Resonator) and HWR (Half Wave Resonator). And SCL2 will be made from SSR1 (Single Spoke Resonator) and SSR2 (Single Spoke Resonator). Accordingly, The RAON needs 48 QWR, 276 HWR, 88 SSR1 and 136 SSR2 to get the performance that we want. To accelerate the particle using lots of cavity, we have to make a process of cavity fabrication for RAON. We will compare to each process made from the other laboratories and to make the optimal process for RAON to get the performance that we want. And that process will consider the type of cavity and the purpose of the accelerator. I will introduce the early stage of the cavity fabrication process for RAON in this paper. | |||
THPWO064 | Superconducting Linac for the Rare Isotope Science Project | cryomodule, cavity, ion, quadrupole | 3903 |
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Abstract The RISP (Rare Isotope Science Project) accelerator has been planned to study heavy ion of nuclear, material and medical science at the Institute for Basic Science (IBS). It can deliver ions from proton to Uranium. The facility consists of three superconducting linacs of which superconducting cavities are independently phased and operating at three different frequencies, namely 81.25, 162.5 and 325 MHz. Requirement of the linac design is especially high for acceleration of multiple charge beams. In this paper, we present the RISP linac design, the superconducting cavity and the requirements of beam diagnosics. | |||
THPWO066 | Beam Commissioning of KOMAC Linac | DTL, proton, rfq, simulation | 3909 |
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Funding: This work was supported by the Ministry of Education, Science and Technology of the Korean Government. The proton engineering frontier project (PEFP), which is the first phase of Korea multi-purpose accelerator complex (KOMAC), developed a 100-MeV proton linac which consists of a 50 keV injector, a 3-MeV radio frequency quadrupole (RFQ) and a 100-MeV drift tube linac (DTL). The installation of the linac was finished in 2012. The goal of the beam commissioning in spring 2013 is accelerating 100-MeV proton beams with the beam power of 1 kW to the beam dump which is located downstream of the linac. This work summarized the beam commissioning result for the linac. |
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THPWO068 | Resonance Frequency Control Characteristics of the 100-MeV Drift Tube Linac | controls, DTL, resonance, proton | 3912 |
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Funding: This work was supported by the Ministry of Science and Technology of the Korean Government. A 100-MeV, 20mA proton accelerator has been developed by KAERI (Korea Atomic Energy Institute). Total 11 DTL (Drift Tube Linac) tanks are used to accelerator the proton beam from 3-MeV to 100-MeV. A RCCS (Resonance frequency Control Cooling System) has been developed to control the resonance frequency of each DTL tank. The coolant for the drift tube and quadrupole magnets are supplied by the RCCS, whereas the wall coolant temperature maintains constant at 27 degree C by using the DI water supplied from the utility. In this paper, the resonance frequency control schemes are summarized and the control characteristics of the DTL tank by using the RCCS are discussed. |
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THPWO069 | Development of the NICA Injection Facility | ion, ion-source, rfq, injection | 3915 |
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The new accelerator complex Nuclotron-based Ion Collider fAcility (NICA) is assumed to operate using two injectors: the Alvarez-type linac LU-20 as injector for light ions, polarized protons and deuterons and a new linac HILac for heavy ions. The main features of ion sources and both linacs are presented. Upgrade for pre-accelerator of LU-20 is described. | |||
THPWO070 | ESS DTL RF MODELIZATION: FIELD TUNING AND STABILIZATION | DTL, cavity, target, quadrupole | 3918 |
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The Radio Frequency (RF) design of Drift Tube Linac (DTL) of the European Spallation Source, ESS, has been defined in order to satisfy the accelerating field requirements of beam dynamic studies and to reduce peak field levels in the critical areas. The electro-magnetic field is stabilized with post-couplers. The cells geometries of the DTL are optimized to accommodate permanent magnet quadrupoles (PMQ), to get maximum shunt impedance, to meet the Moretti criterion at the low energy part and to facilitate the mechanical construction. | |||
THPWO072 | Design Options of the ESS Linac | emittance, target, cryomodule, proton | 3921 |
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The European Spallation Source, ESS, uses a linear accelerator to deliver the high intensity proton beam to the target station. The nominal average beam power is 5~MW with a peak beam power at target of 125~MW. During last year the ESS linac was costed, and to meet the budget a few modifications were introduced to the linac design, namely the final energy was decreased from 2.5~GeV to 2.0~GeV and the beam current was increased accordingly to compensate the lower final energy. As a result the linac is designed to meet the cost objective by taking a higher risk. This paper focuses on the new design options, beam dynamics requirements of the design and finally on the beam dynamics performance of the linac. | |||
THPWO073 | European Spallation Source Afterburner Concept | neutron, proton, target, kicker | 3924 |
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The European Spallation Source (ESS) is a long pulsed source based on a high power superconducting linac. The long pulse concept is an excellent strategy of maximizing high beam power while minimizing peak power on the target. Chopping in the long pulse concept provides the necessary resolution for many neutron physics applications. However, there are some neutron physics applications in which both peak neutron flux and high resolution are desired. The peak flux of the ESS can be enhanced by placing an accumulator ring at the end of the linac. A bunch by bunch extraction scheme can be used to optimize the proton pulse time profile that maximizes peak neutron flux while minimizing instantaneous beam power on the target. | |||
THPWO074 | Technical Design of the ESS Facility | DTL, target, rfq, proton | 3927 |
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The 5 MW European Spallation Source is entering a construction phase for the entire facility. This paper surveys the unique features, challenges and open issues that exist, from ion source to target, and from moderator to instruments. It is consistent with the ESS-wide Technical Design Report, published in April 2013.
The paper is presented on behalf of the ESS consortium, and all the contributors to the ESS TDR. |
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THPWO075 | Beam Loss Limits in High Power Proton Linear Accelerators | proton, rfq, DTL, radiation | 3930 |
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High power hadron linear accelerators are designed based on 1 W/m loss limit criteria. The loss limit originates from the hands-on-maintenance allowance of the accelerators and limits average dose rate level to less than 0.1 - 1 mSv/hr at 30 cm from a machine after 100 days of continuous operation and 4 hours of down time. However, machine activation and thus beam loss limit depends on incident particle energy and 1 W/m is only a good approximation for energies 100-200 MeV and higher (in H-/H+ accelerators). At lower energies though, one could allow much higher than 1 W/m without excess activation. A careful analysis of energy dependent loss limits was performed for proton linacs as part of the study for the European Spallation Source (ESS) linac, for energy ranges 5 MeV – 2.5 GeV. ESS linac is to be built in Lund, Sweden and will deliver 5 MW proton beam to the target. MARS code was used for calculations and beam loss limits were derived as a function of energy. | |||
THPWO076 | Design Study for 10 MHz Beam Frequency of Post-accelerated RIBs at HIE-ISOLDE | rfq, emittance, bunching, solenoid | 3933 |
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An increased bunch spacing of approximately 100 ns is requested by several research groups targeting experimental physics at HIE-ISOLDE. A design study testing the feasibility of retrofitting the existing 101.28 MHz REX (Radioactive ion beam EXperiment) RFQ with a sub-harmonic external pre-buncher at the ISOLDE radioactive nuclear beam facility has been carried out as a means of decreasing the beam frequency by a factor of 10. The proposed scheme for the 10 MHz bunch repetition frequency is presented and its performance assessed with beam dynamics simulations. The opportunity to reduce the longitudinal emittance formed in the RFQ is discussed along with the options for chopping the satellite bunches populated in the bunching process. | |||
THPWO077 | Status and Plans for the Upgrade of the LHC Injectors | injection, ion, extraction, luminosity | 3936 |
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The plans for preparing the LHC injectors to fulfill the needs of the LHC during the next decade have significantly progressed in 2012. Linac4 construction has passed major steps of pre-series fabrication. Hardware developments and beam studies have allowed refining the baseline actions to implement and the beam characteristics achievable at injection into the collider for protons as well as for Lead ions. These achievements are described in this paper, together with the updated project planning matched to the new schedule of the LHC. | |||
THPWO078 | Status of the Upgrade of the CERN PS Booster | injection, booster, extraction, dipole | 3939 |
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The CERN PS Booster (PSB) is presently undergoing an ambitious consolidation and upgrade program within the frame of the LHC Injectors Upgrade (LIU) project. This program comprises a new injection scheme for H− ions from CERN’s new Linac4, the replacement of the main RF systems and an energy upgrade of the PSB rings from 1.4 to 2.0 GeV which includes the replacement of the main magnet power supply as well as the upgrade of the extraction equipment. This paper describes the status and plans of this work program. | |||
THPWO082 | Commissioning of the Linac4 RFQ at the 3 MeV Test Stand | rfq, diagnostics, solenoid, emittance | 3951 |
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Linac4, the future 160MeV H− injector to the CERN Proton Synchrotron Booster, is presently under construction at CERN as a first step of the planned upgrade of the LHC injectors. The low energy section of LINAC4, consisting of an ion source, a 352.2 MHz Radio Frequency Quadrupole (RFQ) and a chopper line is being commissioned in a dedicated test stand before installation in its final position in the tunnel. The RFQ is designed to accelerate a 45 keV, 70 mA, H− beam to 3 MeV, with an efficiency of 95% while preserving the transverse emittance. The RFQ, a four-vane structure 3 m in length, has been designed in collaboration with CEA/IRFU and it has been built at the CERN workshop. The precise fabrication has allowed to achieve a field flatness of 1%. The completion of the accelerating structure in September 2012 was followed by a complete series of bead-pull measurements and by high-power conditioning to the nominal power of 0.39 MW corresponding to a voltage of 78 kV across the 3 meters. Measurements with beam are foreseen during the first half of 2013. This paper reports the results of the low-power and high power RF commissioning as well as the status of beam measurements. | |||
THPWO087 | Measurement of Resonant Space Charge Effects in the J-PARC Linac | emittance, resonance, simulation, space-charge | 3966 |
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Traditionally, high intensity linac designs follow the “equipartitioning condition”, a strict control of the transverse and longitudinal tune ratios throughout the linac that ensures space-charge driven emittance exchange between the longitudinal and transverse planes is minimised. However, equipartitioning imposes strict rules on the linac design, thus limiting the design options and increasing the overall construction cost. More recently, practical tools have been developed that offer guidelines in designing non-equipartitioned linacs, by charting the stable regions in a tune ratio diagram (Hofmann’s Charts). While these stability diagrams have been backed by extensive multiparticle simulations and some experimental evidence, questions still remain regarding the practical consequences of crossing the resonances. In this paper preliminary results are presented from an experimental study conducted in the J-PARC linac, where for the first time we measured both the transverse and longitudinal emittance for different linac working points. A detailed analysis will be presented as well as a discussion on the wider implications of this experiment. | |||
THPWO091 | Staging Scenarios for Project-X | emittance, lattice, rfq, acceleration | 3972 |
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Funding: US DOE under contract DE-AC02-76CH03000. Project-X is a high intensity proton source in development at Fermilab. At its heart is a linac based on superconducting technology comprising two distinct sections. The first one operates in CW mode and delivers beam with a flexible time structure to simultaneous experimental programs at 1 and 3 GeV. The second one operates in pulsed mode and accelerates a modest fraction (5%) of the beam from 3 GeV to 8 GeV for accumulation in the existing Main Injector complex. In an era of constrained budgets, construction in stages -with each stage capable of supporting worthy scientific programs - may be advantageous. Requirements for each program, coupled to the physical constraints imposed by the Fermilab site have led to a few possible scenarios, which are discussed in this contribution. In particular, we examine the implications of introducing bends in the linac at 1 and 3 GeV in terms of overall performance, flexibility and cost. |
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THPWO092 | Update of Beam Optics and SRF Cavities for Project X | cavity, cryomodule, solenoid, optics | 3975 |
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The Project X staging [1] requires reconsideration of the beam optics and thus, the SRF system for the 3 GeV CW linac of the Project X. The revised beam optics is presented in the paper as well as revised cavity design for SSR2 section and a new concept of the linac segmentation. The new versions for the Project X cryo-modules for the SSR2 section, low-beta 650 MHz section and high-beta 650 MHz section are discussed. The beam extraction scheme at 1 GeV is discussed also. [1] S. Holmes, “Project X News, Strategy, Meeting Goals,” 2012 Fall Project X Collaboration Meeting, 27-28 November 2012, Fermilab. | |||
FRXAB201 | Status of CSNS Project | target, quadrupole, cavity, dipole | 3995 |
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The China Spallation Neutron Source (CSNS) accelerator is designed to accelerate proton beam pulses to 1.6 GeV at 25 Hz repetition rate, striking a solid metal target to produce spallation neutrons. The accelerator provides a beam power of 100 kW on the target in the first phase and then 500 kW in the second phase by increasing the average beam intensity 5 times while raising the linac output energy. The project construction has been formally launched in 2011 and it is planed to complete the project in March 2018. It is one of the high intensity proton accelerator projects in the world and it imposes a great challenge to Chinese accelerator community. This presentation will cover the status and challenges of the CSNS project. | |||
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Slides FRXAB201 [4.320 MB] | ||
FRXCB201 | Overview of the World-wide RIB Facilities | ion, target, cyclotron, heavy-ion | 4000 |
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This presentation will cover the latest development, status and challenges of the world-wide RIB beam facilities. | |||
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Slides FRXCB201 [7.665 MB] | ||
FRYAA01 | An Overview of Light Source Development in Asia | synchrotron, FEL, radiation, electron | 4005 |
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This talk should cover the history of light sources that have been constructed, are now in operation or planned for the future in Asia. Advances in accelerator physics and technological innovations leading to steadily increasing machine performance and photon beam properties should be discussed. | |||
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Slides FRYAA01 [7.342 MB] | ||