Paper | Title | Other Keywords | Page |
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MOODB101 | Manufacturing of the First of Series SIS100 Dipole Magnet | synchrotron, instrumentation, magnet-design, laser | 31 |
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Babcock Noell (Würzburg, Germany) manufactures the First of Series (FOS) SIS100 dipole magnet for the FAIR project. This contribution reports on the progress during the design-phase, performed together with GSI, and on the manufacturing- and assembly-processes. Special emphasis will be given on new or special techniques adopted to fulfill the stringent requirements demanded by such a magnet. The new tooling systems and machines which were developed and brought into operation for this FOS magnet will be discussed. | |||
MOODB102 | Multiple Function Magnet Systems for MAX IV | multipole, quadrupole, octupole, sextupole | 34 |
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Danfysik is currently producing 60 up to 3.3 m long magnet systems consisting of up to 12 multipole magnets integrated into each of the yokes for the bending achromats of the MAX IV 3 GeV storage ring and 12 similar systems for the MAX IV 1.5 GeV storage ring. Each magnet yoke contains combined function soft-end dipole and quadrupole elements which are machined out of one single iron block at tolerances of ± 0.02 mm. In addition, separate, higher order multipole magnets are kinematically mounted into the yokes. The integration of many magnetic elements into single yoke structures enables a compact, low emittance storage ring design. The dipole and quadrupole magnetic elements are magnetically field mapped with high precision on a 3D hall probe measuring bench. Higher order multipoles are measured on a slow rotating coil system developed for that purpose. Much effort has been put into automation in order to quickly perform the very comprehensive measurement program each girder will through. | |||
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Slides MOODB102 [2.701 MB] | ||
MOZB202 | The First Long Shutdown (LS1) for the LHC | ion, luminosity, vacuum, radiation | 44 |
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The LHC has been delivering data to the physics experiments since the first collisions in 2009. The first long shutdown (LS1), which started on 14 February 2013, was triggered by the need to consolidate the magnet interconnections so as to allow the LHC to operate at the design energy of 14 TeV in the centre-of-mass. It has now become a major shutdown which, in addition, includes other repairs, consolidation, upgrades and cabling across the whole accelerator complex and the associated experimental facilities. LS1 will see a massive programme of maintenance for the LHC and its injectors in the wake of more than three years of operation without the long winter shutdowns that were the norm in the past. The main driving effort will be the consolidation of the 10,170 high-current splices between the superconducting magnets. The presentation describes first the preparation phase with the prioritisation of the activities, the building of the teams and the detailed planning of the operation. Then, it gives the status after 3 months and the restart plans for all CERN accelerators. First lessons learnt for the 2nd long shutdown (LS2) will conclude the presentation. | |||
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Slides MOZB202 [13.675 MB] | ||
MOODB203 | vSTORM Facility Design and Simulation | injection, target, proton, optics | 55 |
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Funding: Fermi National Accelerator Laboratory A facility producing neutrinos from muons that decay in a storage ring can provide an extremely well understood neutrino beam for oscillation physics and the search for sterile neutrinos. The "neutrinos from STORed Muons"(nuSTORM) facility is based on this idea. The facility includes a target station with secondary particle collection, pion transfer line, pion injection, and a ~3.8 GeV/c muon storage ring. No muon cooling or RF sub-systems are required. The injection scenario for nuSTORM avoids the use of a separate pion decay channel and fast kickers. This paper reports a detailed description of the proposed injection scheme with full G4beamline simulations. We also present progresses on possible design options for a muon racetrack decay ring. |
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Slides MOODB203 [14.079 MB] | ||
MOPEA006 | Operation and Performance Upgrade of the SOLEIL Storage Ring | feedback, vacuum, power-supply, injection | 73 |
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SOLEIL delivers photons to 26 beamlines and 3 new ones are under construction together with the femtoslicing project. Up to 5 filling patterns are available for the users including a low alpha mode; all of them are in Top-up injection. The beam current for the users has been increased to 430 mA in the multibunch mode. The Storage Ring (SR) is running with a new optics incorporating an additional quadrupole triplet in one long straight section. The beam position stability remains excellent. Vertical positions from the dipole X-BPMs have been included in the orbit feedbacks loop with very encouraging results. A feedback loop maintaining the emittance coupling close to 1% for any Insertion Devices (IDs) configuration has been implemented. Up to 25 very diverse IDs are now installed on the SR, and several others are under design or construction. In house developments are being carried out in several domains such as construction of SR dipole power supply spare and of 70 kW-500 MHz solid state amplifiers, design of a pulsed multipole magnet for injection, and a Robinson wiggler, as well as a feasibility study of a local reduction of the emittance in one of the long straight sections. | |||
MOPEA007 | Study of Lower Emittance Optics Using Multi-Bend-Achromat Lattice at SOLEIL | emittance, optics, lattice, quadrupole | 76 |
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In the framework of a future upgrade of the SOLEIL 354 m long and 2.75 GeV storage ring, a series of lattice studies has been launched to aim at reducing by an order of magnitude the current 4 nm.rad horizontal emittance. In this exercise, the main constraint imposed is to leave all the existing 24 straight sections for insertion devices untouched. In the previous study (presented at IPAC 2012), the possibility of using superbends and exploiting their longitudinal dipole field variation was pursued in lowering the emittance, finding solutions with a horizontal emittance in the sub nanometer range. In the present study, the use of MBA (Multi-Bend-Achromat) lattice is explored, which is widely recognized today as the optimal lattice in reaching an ultra-low emittance. The study aims to clarify the adaptability of the MBA and the range of attainable emittance for the SOLEIL ring, in view particularly of the short straight sections existing in half of the original DBA cells in between the dipoles. The possibility of combining the previously obtained superbend solutions with the MBA lattice is also examined. | |||
MOPEA008 | A Low-Emittance Lattice for the ESRF | lattice, sextupole, emittance, injection | 79 |
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In the framework of its upgrade, the ESRF is looking at a new lattice for replacing the present Double Bend Achromat structure. This new lattice must have the same length and periodicity as the present one and keep the beamline source points unchanged. We will describe our design of an 844 m long lattice based on a 7-bend achromat. It is optimized for minimising the operation costs, in particular the wall-plug power, provides a large dynamic aperture allowing off-axis injection with the present ESRF injector, and gives an horizontal emittance of less than 200 pm at 6 GeV, thus considerably improving the brilliance and transverse coherence of the ESRF. | |||
MOPEA025 | Closed Orbit Correction in the High Field Lattice of ILSF Storage Ring | storage-ring, closed-orbit, lattice, sextupole | 127 |
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In the high intensity storage rings, there are many sources of errors which lead to closed orbit distortion (COD). To study effect of errors on closed orbit and to find optimum arrangement of beam position monitors (BPMs) and strength of corrector magnets, different types of expected misalignments and field errors were imposed randomly in the high field lattice of ILSF storage ring. This paper gives the results of closed orbit correction in the ILSF ring and stipulates the strength of correctors. | |||
MOPEA033 | Status of Upgrade Project of the 1.2 GeV Booster Synchrotron at Tohoku University | booster, quadrupole, alignment, synchrotron | 151 |
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The 1.2 GeV electron synchrotron has been operated for nuclear physics experiment since 1997 in Electron Light Science Centre, Tohoku University, in which the high energy gamma-rays via bremsstrahlung has been supplied for hadron physics. After the Great East Japan Earthquake in March 2011, recovery and reconstruction work of the accelerator complex is in progress vigorously. While the compact 90 MeV linac is newly constructed as the dedicated injector for the synchrotron, old power supplies of synchrotron magnets and also pulsed magnets for beam injection are going to be replaced in the synchrotron. Furthermore replacements of some quadrupole magnets to the combined function magnets with sextupole component are also on going. Modifying the ring optics so as to introduce the horizontal dispersion on the combined magnet position, this replacement work will make it possible to correct the chromaticity. At the present, power supplies and combined magnets have been manufactured and those installations will be completed soon. We will present the current status of upgrade project of the booster synchrotron. | |||
MOPEA047 | Ramping of the Solaris Storage Ring Achromat | quadrupole, optics, sextupole, lattice | 184 |
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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, The combined function magnets implemented for the MAX IV and Solaris 1.5 GeV storage ring double bend achromats (DBAs) represents a challenging task in magnetic design. The constituent magnets in the DBA block may be sensitive to saturation effects which must be accounted for, especially in the case of energy ramping, as is the case for Solaris and not for MAXIV, where injection will take place at a beam energy of 0.55-0.6 GeV. The magnetic field distribution was calculated as a function of energy in the range from 0.5 GeV up to 1.5 GeV for the gradient dipole and for the quadrupoles containing a sextupole component. Results show that for the dipole, which generates the strongest field, the relative change of quadrupole strength is lower than 4.10-3. For the quadrupoles the sextupole component is within the relative range of less than 0.7.10-4. The impact on linear and non-linear optics at low energies has been accordingly studied. This is on-going studies and only preliminary results are presented in this paper. |
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MOPEA053 | Status of NSLS-II Booster | booster, controls, vacuum, septum | 196 |
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The National Synchrotron Light Source II is a third generation light source under construction at Brookhaven National Laboratory. The project includes a highly optimized 3 GeV electron storage ring, linac pre-injector and full-energy injector-synchrotron. Budker Institute of Nuclear Physics build booster for NSLS-II. The booster should accelerate the electron beam continuously and reliably from a minimum 170 MeV injection energy to a maximum energy of 3.15 GeV and average beam current of 20 mA. The booster shall be capable of multi-bunch and single bunch operation. Pre-comissioning test results of booster components and system are reviewed. | |||
MOPEA054 | A Review of 14 Years of Operation of Helios2 at SSLS | controls, cryogenics, microtron, gun | 199 |
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In this paper, we present the current status of the superconducting Helios2 Synchrotron and review its major problems and their solutions over the last 14 years. We described how various breakdowns in the cryogenics system, the control system, the RF system, Dipole power supplies, Ring gate valves and helium compressor have all been overcome and what valuable lessons have been learned in operating this machine. | |||
MOPEA060 | Design of Low Momentum Compaction Lattices for the TPS Storage Ring | lattice, emittance, sextupole, injection | 217 |
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The nominal bunch length is around 10 ps rms in the Taiwan Photon Source (TPS), which is currently under construction. To further reduce bunch length to a few ps rms range, low momentum compaction factor configurations (low alpha), i.e., quasi-isochronous machines, are designed. The beam dynamics issues of the TPS low alpha lattices are reported. | |||
MOPEA062 | Metrology of the NESTOR Facility Equipment | target, storage-ring, quadrupole, survey | 222 |
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Development of X-ray generator NESTOR in the National Science Center Kharkov Institute of Physics&Technology will let significantly extend the scientific program of investigations that are carried out in NSC KIPT, will allow to increase an amount and improve quality of experimental researches in the field of physics and chemistry In this work tolerances for accuracy installation of the lattice elements of the complex are defined. The methods of lattice element position measurement were detected and ways of their realization were defined. These allow to realize the project parameters of NESTOR facility and, first of all, generated X-ray beam intensity. | |||
MOPEA063 | The First Results of the NESTOR Commissioning | injection, storage-ring, electron, focusing | 225 |
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In the paper the first results of the NESTOR facility are presented. 60 MeV electron linac injector has been tested and the first electron beam with project parameters was registered at the screen monitors. Electron beam was passed through the transportation channel and injection system. As a result, the first turn of the storage ring was closed. | |||
MOPEA067 | Ultra-low Emittance Upgrade Options for Third Generation Light Sources | emittance, lattice, resonance, dynamic-aperture | 237 |
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The increasing efforts in the synchrotron light sources community toward the design of a diffraction limited source at multi-keV photon energy have eventually stimulated the existing facilities to investigate possible upgrade paths to higher photon brightness and lower emittances to maintain their competitiveness within the users’ community. We present a possible option for upgrading 3rd generation light sources based on a rebiuld of the arcs with MBA cells, using diamond as an example. Emphasis is given to the AP desing issues with a view to minimal changes to the machine layout, contained cost and minimal downtime | |||
MOPEA068 | Novel Lattice Upgrade Studies for Diamond Light Source | lattice, vacuum, optics, quadrupole | 240 |
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Many synchrotron radiation facilities are studying lattice upgrades in order to lower the natural emittance and hence increase the radiation brightness. At Diamond we are pursuing a novel alternative, not targeting the minimum possible emittance but instead introducing additional insertion device (ID) straights and hence increasing the capacity of the facility, while still possibly achieving a more limited reduction in emittance. The new scheme involves converting some of the DBA lattice cells into a double-DBA or DDBA, with a new ID straight between the two achromats. This then allows existing or future bending magnet ports (which in Diamond are taken from near the entrance to the second dipole of the DBA lattice) to be served by a much more powerful insertion device. We present here the design concept and preliminary lattice design, and discuss the challenging magnet, vacuum and engineering issues. | |||
MOPEA079 | Improving Emittances in Existing Storage Rings by Defocusing Dipoles | emittance, quadrupole, optics, lattice | 270 |
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Designs for ultimate storage rings typically employ two strategies to lower the emittances: 1) adding more bending magnets, and 2) using only focusing quadrupole magnets, with additional defocusing in the bending magnets. In an existing storage ring, the first strategy is precluded because the number of bends is typically fixed, but the second strategy could be used at modest expense. With the CESR storage ring as an example, we show how this is possible and propose an optics that reduces its emittance by more than a factor of 20. Furthermore, such an upgrade would could be installed incrementally without any long dark-time period. | |||
MOPFI007 | SIS-18 RF Knock-Out Optimization Studies | extraction, resonance, septum, synchrotron | 297 |
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The extraction efficiency and spill temporal-structure of the SIS-18 heavy ion synchrotron are part of the upgrades to the GSI accelerator complex. Losses to the extraction septum can be minimised through implementation of the Hardt condition resulting however in a poorer quality of the spill microstructure at resolutions of a few microseconds due to lowering of the horizontal chromaticity from its 'natural' value. Ways to improve the extraction efficiency and spill microstructure are investigated with a tracking code. One possibility for improvement may be to use an alternative RF modulation applied to the knock-out exciter. | |||
MOPFI031 | Progress on the Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source | linac, electron, neutron, controls | 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. | |||
MOPFI055 | Design Study of a 100 GeV Beam Transfer Line from the SPS for a Short Baseline Neutrino Facility | quadrupole, optics, target, extraction | 407 |
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A Short Baseline neutrino facility at CERN is presently under study. It is considered to extract a 100 GeV beam from the second long straight section of the SPS into the existing transfer channel TT20, which leads to the North Area experimental zone. A new transfer line would branch off the existing TT20 line around 600 m downstream of the extraction, followed by an S-shaped horizontal bending arc to direct the beam with the correct angle onto the defined target location. This paper describes the optimisation of the line geometry with respect to the switch regions in TT20, the integration into the existing facilities and the potential refurbishment of existing magnets. The optics design is shown, and the requirements for the magnets, power converters and instrumentation hardware are discussed. | |||
MOPFI059 | Design and Performance of the Beam Transfer Lines for the HIE-ISOLDE Project | target, emittance, simulation, optics | 416 |
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Beam design and beam optics studies for the HIE-ISOLDE transfer lines have been carried out in MadX, and benchmarked against Trace3D results. Magnet field errors and alignment imperfections leading to deviations from design parameters have been treated explicitly, and the sensitivity of the machine's lattice to different individual error sources was studied. As a result, the tolerances for the various error-contributions have been specified for the different equipment systems. The design choices for the expected magnet field and power supply quality, alignment tolerances, instrument resolution and physical aperture were validated. The methodology and results of the studies are presented. | |||
MOPFI063 | Progress on Designs for 180 MeV Injection into the ISIS Synchrotron | injection, septum, synchrotron, stripper | 428 |
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The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It operates at 50Hz accelerating beam via a 70 MeV H− linac and an 800 MeV proton synchrotron, delivering a mean beam power of 0.2 MW. As an initial step towards megawatt operations at ISIS, a study of replacement of the existing injector with a new 180 MeV H− linac has recently been completed. This could enable an increase in beam power to approximately 0.5 MW. The ISIS Facility at the Rutherford Appleton Laboratory in the UK produces intense neutron and muon beams for condensed matter research. It accelerates 3×1013 protons per pulse (ppp) at 50 Hz through a 70 MeV H− linac and an 800 MeV proton synchrotron, delivering a mean beam power of ~0.2 MW. A favoured first step to upgrade ISIS towards the megawatt regime is replacement of the linac with a new 180 MeV injector described in [1]. Studies of this upgrade, which aims to increase mean beam power up to 0.5 MW are outlined in [2]. This paper reports on recent development of the designs including the injection septum, dipole power supplies and detailed tracking of partially stripped foil products. | |||
MOPME012 | Single-bunch Longitudinal Phase Space Diagnostics in Multi-bunch Mode at the European XFEL | septum, simulation, diagnostics, electron | 494 |
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Dedicated longitudinal electron beam diagnostics is highly demanded for the control and optimization of modern X-ray free-electron lasers (XFEL). At the European XFEL, 3 transverse deflecting structures (TDS) will be installed at different locations of the accelerator for measurements of slice emittance and longitudinal profile. Operation of a TDS in combined use with an energy spectrometer, e.g. a dispersive section after a single dipole magnet, allows additionally for longitudinal phase space (LPS) measurements. However, utilization of a dipole magnet is not compatible with single-bunch measurements in multi-bunch operation mode, which will be the standard operation mode of the European XFEL. In this paper, we propose a LPS diagnostic beamline consisting of a TDS, fast kicker and septum magnet for the European XFEL. The layout of the accelerator lattice with optimized optics for LPS measurements will be presented. | |||
MOPME019 | Alignment Detection Study using Beam Induced HOM at STF | HOM, cavity, alignment, cryomodule | 509 |
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STF accelerator using L-band photocathode RF Gun and two superconducting cavities is under operation for R&D of ILC. Electron beam extracted from the RF Gun is accelerated to 40 MeV by two superconducting cavities. Cavity alignment requirements for ILC are less than 300um offset and 300urad tilt with respect to cryomodule. It is necessary to measure their offset and tilt inside of cryomodule. Cavity offset has been already measured by using beam induced HOM at FLASH in DESY. Cavity deformation during assembly and by cooling contraction has not been examined yet. We measured HOM signals to detect their tilt and bending. TE111-6 which has high impedance is used to estimate cavity offset. To find cavity tilt and bending, we selected pi over nine mode in the first dipole passband (TE111-1) and beam pipe modes. From information of TE111-1 which has maximum radial electric field in the middle cell, we can get electrical center of middle cell. At beam pipes, electrical center can be found by using beam pipe modes. Combinations of these electrical centers tell us cavity tilt and bending. We will present results of these TE111-1 and beam pipe mode together with beam trajectory information. | |||
MOPME020 | Development of the New Measurement Method for the Incoherent Tune Spread and the Tune Shift Caused by the Space Charge Effect | emittance, simulation, injection, space-charge | 512 |
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For the high intensity accelerator, the incoherent tune which is the frequency of the individual particles is shifted and decreases due to the space charge effect. In addition, the incoherent tune is formed into spread shape commonly. When the incoherent tune satisfies a resonance condition, it might be occurred the beam emittance growth and the beam loss. So it is necessary to reduce the incoherent tune spread and the tune shift as much as possible. To achieve this condition, it is desired to measure the incoherent tune spread and the tune shift directly. Therefore we are developing the new measurement method of the incoherent tune spread and the shift due to the space charge effect. From the simulation results, it was cleared that the beam distribution can be modified in the case of using the mono frequency dipole exciter because a particle which has the tune corresponding to the exciter can be resonated temporary. In addition, it was cleared that it is possible to evaluate the incoherent tune spread and the tune shift by the measurement of the distribution transition. We present the outline of this method and the developing plane at the J-PARC RCS. | |||
MOPME046 | Preliminary Experimental Results of Axial B-dot Measuring Beam Tilt | high-voltage, coupling, simulation, impedance | 577 |
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Funding: This work is under the support of NSFC project No. 11175166 Beam monitors sensitive to the beam's azimuthal B-dot field (sometimes referred as B-dots) are widly used to measure the displacement of beam centroid, as the beam generates a dipole term of the azimuthal magnetic field. The authors have pointd out that the similar B-dots sensitive to axial magnetic field can be used to measure the beam tilt directly in earlier work. A monitor which consists of four azimuthal B-dots and four axial B-dos is designed and fabricated. The monitor was tested on a coaxial calibration stand, which has a character resistance of 50 Ohm. Two position tuners are installed on the calibration stand, to adjust the position and the tilt of the inner conductor. Experiments show that the axial B-dot monitor can be successfully used to measure the tilt of the inner conductor directly. |
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MOPME047 | Simulation of a Beam Angel Monitor using the Axial B-dot Field | simulation, monitoring, coupling, induction | 580 |
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Funding: The National Natural Science Foundation of China A beam angel monitor using the axial B-dot field was presented recently while the one using azimuthal B-dot field had been widely employed to measure the beam positions for more than ten years. Basing on the principle of the proportionality between the deflection angel and the difference of axial B field with corresponding positions, the axial B-dot monitor has a potential use for beam deflection angle measurement directly. A test stand was built to test and improve the axial B-dot monitor, which is fabricated as a PCB structure. Meanwhile, simulations using the CST MWS code have been performed, demonstrating a good agreement to the test results and giving some advice to suppress the disturbance of position deviation of the beam. |
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MOPME058 | DEVELOPMENT OF A CAVITY-TYPE BEAM POSITION MONITORS WITH HIGH RESOLUTION FOR ATF2 | cavity, simulation, electron, extraction | 604 |
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We have developed a high resolution beam position monitors for ATF2 at KEK, which is an accelerator test facility for International Linear Collider(ILC). The main goals of ATF2 are achievement of 37nm beam size and 2nm beam position resolution for beam stabilization. For these goals, low-Q IP-BPM(Interaction Point Beam Position Monitor) with latency of 20 ns are being developed. In this paper, we will describe about design of Low-Q IP-BPM, the basics test results as RF test and BPM sensitivity test. Electronics for Low-Q IP-BPM will be also described. | |||
MOPWA025 | 2Hz Ramping Mode Dipole Power Supply for Testing the NSLSII Booster Dipole Magnets | power-supply, booster, controls, feedback | 714 |
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Budker Institute has designed and delivered Booster for NSLSII project including vacuum system, magnet system, diagnostics and power supplies. Dipole power supplies were directly delivered to BNL by sub-contractor (Danfysik, Denmark). To test dipole magnets on factory side, at BINP, it was decided to design and construct a high current ramping mode power supply. The designed power supply can operate with the reactive output power up to 150kVA and output current up to 900A at 2Hz ramping mode. The absolute accuracy achieved is better than 100ppm for the injection and extraction flats and better than 500ppm for the ramps. | |||
MOPWA038 | Flashbox Compact Beam Spectrometer and its Application to the High-gradient Acceleration Study | electron, ion, acceleration, accelerating-gradient | 753 |
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A Flashbox compact spectrometer has been developed for the Two-beam Test Stand (TBTS), which is a part of the CLIC test facility CTF3 at CERN. It is used to study limitations of high-gradient acceleration in X-band structures being prototyped in the TBTS. The Flashbox is built around the beam tube such that an electron beam can pass to be accelerated in the X-band structure while charged particles emitted from the accelerating structure can be intercepted on the spectrometer consisting of detector plates aligned along the beam axis in combination with magnetic and electric fields. The Flashbox has made it possible to identify electrons and ions emitted by the accelerating structure during RF breakdown. We describe the Flashbox and first results. | |||
MOPWA048 | The Cable Engineering Project for the TPS Power Supply | booster, power-supply, storage-ring, sextupole | 780 |
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The civil engineering of Taiwan Photon Source will soon be completed. The engineering of the power supply cabling should be done in advance of the schedule for the completion of the civil engineering. Using software (SolidWorks) to build a 3-D model, we obtain detailed cabling information because the model is made to scale 1 to 1. As all components are built into the model of the TPS accelerator, we can build accurately a model of the power supply cabling. For example, we can estimate every length and the total cable length for purchase and budget control. We can evaluate the conditions for every power cable to lay the cable tray from the power supply to the magnets, so we can lay every cable to follow the sequence in the cable tray. We thereby convert the drawing of the two-dimensional construction graph when we design the finished three-dimensional cabling model. The excellent and precise results are proved in this paper. | |||
MOPWA049 | Status Report of the FETS Photo Detachment Emittance Instrument at RAL | laser, ion, emittance, diagnostics | 783 |
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The Front End Test Stand at the Rutherford Appleton Laboratory (RAL) is being developed to demonstrate a chopped H− beam of 60 mA at 3 MeV with 10% duty cycle. Due to the high beam power it is advisable to use the technique of photo detachment to avoid intrusive methods. It is intended to apply this technique to perform emittance measurements at the output of the RFQ at full power. This requires a dedicated diagnostics dipole with a special-made vacuum chamber giving room for the different beam paths necessary to install a particle detector to measure the produced neutrals. Other aspects are the beam transport and influence of the dipole and its fringe field to the beam transport Other considerations are the installation of the laser, the optics and the particle detector itself. | |||
MOPWA055 | Status of Higher Order Mode Beam Position Monitors in 3.9 GHz Superconducting Accelerating Cavities at FLASH | HOM, cavity, wakefield, diagnostics | 798 |
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Funding: This work was partially funded by the European Commission under the FP7 Research Infrastructures grant agreement No.227579. Higher order mode (HOM) beam position monitors (BPM) are being developed for the 3.9GHz third harmonic superconducting accelerating cavities at FLASH. The transverse beam position in a cavity can be determined utilizing beam-excited HOMs based on dipole components. The existing couplers used for HOM suppression provide the necessary signals. The diagnostics principle is similar to a cavity BPM, but requires no additional vacuum instruments on the linac. The challenges lie in the dense HOM spectrum arising from couplings of the majority HOMs amongst the four cavities in the cryo-module. HOMs with particularly promising diagnostics features were evaluated using various devices with various analysis methods. After careful theoretical and experimental assessment of HOMs, multi-cavity modes at ~5GHz were chosen to provide a global position over the complete module with superior resolution (~20μm) while trapped modes at ~9GHz provide local position in each cavity with comparable resolution (~50μm). A similar HOM-BPM system is planned for the European XFEL 3.9GHz module with 8 cavities. This paper reviews both the current status and the future prospects of HOM-BPMs in 3.9GHz cavities. |
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MOPWA072 | MODELING FOR TIME-RESOLVED RETARDING FIELD ANALYZER MEASUREMENTS OF ELECTRON CLOUD BUILDUP AT CesrTA | electron, vacuum, positron, pick-up | 846 |
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Funding: US National Science Foundation PHY-0734867, PHY-1002467, and the U.S. Department of Energy DE-FC02-08ER41538 The Cornell Electron Storage Ring Test Accelerator program includes investigations into electron cloud buildup mitigation techniques using custom vacuum chambers. Multibunch electron and positron beams of energies between 2.1 and 5.3 GeV with bunch spacings from 4 to 98 ns and bunch populations ranging from 1010 to 16·1010 provide highly differentiated sensitivity to the processes contributing to cloud buildup such as photoelectron production, cloud space-charge dynamics, and secondary electron emission. Measurements of the time dependence of cloud buildup using BPM-style shielded pickups have been shown to provide tight constraints on cloud buildup models. Recently, time-resolving retarding-field analyzers have been designed, installed and commissioned. These novel detectors combine the time-resolving feature of the shielded pickups with the fine transverse segmentation and cloud electron energy sensitivity of the time-integrating retarding-field analyzers used previously. We report on progress in modeling these measurements and quantify their sensitivity to various parameters describing the underlying physical processes contributing to cloud buildup. |
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MOPWO007 | Numerical Calculation of Electromagnetic Fields in Acceleration Cavities Under Precise Consideration of Coupler Structures | cavity, electromagnetic-fields, impedance, resonance | 897 |
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Funding: Work supported by BMBF under contract 05H12RD5 The acceleration with superconducting radio frequency cavities requires dedicated couplers to transfer energy from the radio frequency source to the beam. Simultaneously, higher order mode couplers are installed to effectively suppress parasitic modes. Therefore, the numerical eigenmode analysis based on real-valued variables is no longer suitable to describe the dissipative acceleration structure. At the Computational Electromagnetics Laboratory (TEMF) a robust parallel eigenmode solver to calculate the eigenmodes in the lossy acceleration structure is available. This eigenmode solver is based on complex-valued finite element analysis and utilizes basis functions up to the second order on curved tetrahedral elements to enable the high precision elliptical cavity simulations. The eigenmode solver has been applied to the TESLA 1.3 GHz accelerating cavity to determine the resonance frequency, the quality factor and the corresponding field distribution for all 192 eigenmodes up to the 5th dipole passband (3.12 GHz). |
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MOPWO033 | Analysis of LHC Transfer Line Trajectory Drifts | injection, optics, extraction, simulation | 960 |
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The LHC is filled from the SPS via two 3km long transfer lines. In the first years of LHC operation large trajectory variations were discovered. The sources of bunch-by-bunch and shot-by-shot trajectory variations had been identified and improved by the 2012 LHC run. The origins of the longer term drifts were however still unclear and significant time was spent correcting the trajectories. In the last part of the 2012 run the optics in the SPS was changed to lower transition energy. Trajectory stability and correction frequency will be compared between before and after the optics change in the SPS. The sources of the variations have now been identified and will be discussed in this paper. Remedies for operation after the long shutdown will be proposed. | |||
MOPWO041 | Simulations and Measurements of Physics Debris Losses at the 4 TeV LHC | simulation, luminosity, proton, background | 984 |
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Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. Simulations of energy deposition from the physics debris are normally done with shower simulation tools like FLUKA. Tracking tools like SixTrack allow faster simulations that open the possibility to study parametrically and optimize different layouts. In this paper, the results of FLUKA and SixTrack simulations are compared to beam measurements done for different collimator settings at 4 TeV, with p-p luminosities up to 7·1033 cm-2s−1. |
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MOPWO063 | LHeC IR Optics Design Integrated into the HL-LHC Lattice | optics, quadrupole, proton, radiation | 1034 |
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The two main drivers for the CDR LHeC IR design were chromaticy and synchrotron radiation. Recently it has been proposed that the LHeC IR proton optics could be integrated into the ATS scheme, which benefits from higher arc beta functions for the correction of chromaticity. In this scenario the distance between the IP and the protron triplet can be increased allowing for a reduction of the IR dipole field and the synchrotron radiation. First feasibility considerations and more in depth studies of the synchrotron radiation effects are presented in this paper. | |||
MOPWO073 | Design and Simulation of an Extraction Section for the University of Maryland Electron Ring | extraction, emittance, simulation, quadrupole | 1052 |
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Funding: Supported by the US Dept. of Energy, Office of High Energy Physics, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office. The University of Maryland Electron Ring (UMER) is a low-energy scaled facility for the study of intense beam dynamics, relevant to higher energy, high intensity accelerators. Many parameters crucial to understanding space charge dominated beam evolution, such as transverse emittance and longitudinal temperature, require the use of turn-by-turn interceptive diagnostics. To meet this need, we plan to implement an extraction section with a fast-pulsed electric-field kicker. This paper presents a suite of simulations used to guide the design process and predict extraction performance, using the WARP Particle-in-cell (PIC) code. Simulations in a transverse slice geometry predict beam trajectory and monitor beam evolution through extraction. After isolating a design based on centroid tracking, extraction acceptance is probed and an analysis proposed to estimate the error tolerances of the new ring elements. |
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TUOAB202 | ILSF, A Third Generation Light Source Laboratory in Iran | storage-ring, synchrotron, quadrupole, cavity | 1137 |
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The Iranian Light Source Facility (ILSF) project is a first large scale accelerator facility which is currently under planning in Iran. The circumference of the storage ring is 297.6 m with the energy of 3 GeV. The facility will be built on a land of 100 hectares area in the city of Qazvin, located 150 km West of Tehran. The city is surrounded by many universities, research centers and industrial companies. The design and construction of prototype items such as radio frequency solid state amplifier, dipole magnets, highly stable magnet power supplies and girders have already begun. A low field H-type dipole magnet with the central field of 0.5T at the gap of 34mm and length of 500mm was built and tested in site. Also a prototype storage ring quadrupole with a 18 T/m gradient and 233 iron length is in now in fabrication process. Site selection studies, including geotechnical and seismological measurements are being performed. Conceptual Design Report, CDR, as the first milestone of the project has been published on October 2012. | |||
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Slides TUOAB202 [5.173 MB] | ||
TUOCB201 | Recent Developments of Novel Beam Diagnostics at the ESRF | electron, vacuum, diagnostics, injection | 1143 |
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A number of rather novel and particular electron beam diagnostics have seen their development in 2012 for the ESRF Storage Ring. A vertical Beam Halo detector that measures the bunch population at millimetres, i.e. hundreds of σs of nominal beam size, away from the central core. This measurement is based on X-ray synchrotron radiation from a bending magnet and is totally non-destructive to the electron beam itself. Another diagnostic use of the very hard X-rays available from the bending magnets is the detection of electron beam energy fluctuations. The detector hardware is simple and in-expensive and has shown a resolution of energy fluctuations of less than 10ppm. Also a single orbit turn measurement of the injected beam shape and size is now possible through the use of visible synchrotron light combined with a fast gateable intensifier, which can be triggered on any of the desired orbit turns after injection. Detailed results of each of these new diagnostics will be presented. | |||
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Slides TUOCB201 [1.511 MB] | ||
TUPEA001 | Generation of Anomalous Intensive Transition Radiation for FEL | electron, radiation, lattice, polarization | 1161 |
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The 3D spin-glass system in the external standing electromagnetic field is considered. It is shown on an example of amorphous quartz, under the influence of a standing microwave field, at its certain parameters, superlattice is created in the medium where difference in values of dielectric constants of neighboring layers can be up to third order. Note that this superlattice exists during the nanosecond however it is sufficient for using it as a radiator for generation of transition radiation by relativistic electrons. | |||
TUPEA068 | Wake-field Reduction in Hybrid Photonic Crystal Accelerator Cavities | wakefield, lattice, cavity, simulation | 1289 |
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Funding: This work is supported by the U.S. Dept. of Energy, grant DE-FG02-04ER41317. Photonic crystals (PhCs) have attractive properties for manipulating electromagnetic radiation. In one application, PhCs are composed of a number of dielectric rods that can be arranged to make an accelerator cavity. These structures trap an accelerating mode and allow higher order modes to propagate out. Previous work showed that PhC structures allow excitation of unwanted transverse wake-fields that can disrupt the beam and limit luminosity levels. This work focuses on optimizing PhC cavities to reduce transverse wake-fields by minimizing the Q-factor of unwanted modes, while keeping the Q-factor of the accelerating mode high. The transverse wake-fields in the new optimized structures are compared with previously optimized structures and the CLIC cavity with HOM damping. |
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TUPEA074 | Protection of VUV FEL Mirrors using Soft Orbit Bump at Duke FEL/HIGS facility | FEL, radiation, wiggler, electron | 1301 |
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Funding: This work is supported in part by the US DoE grant # DE-FG02-97ER41033 The Duke FEL and High Intensity Gamma-ray Source (HIGS) facility is operated with an electron beam from 0.24 to 1.2 GeV and a photon beam from 190 to 1060 nm. Presently, the energy range of the gamma-beam is from 1 MeV to about 100 MeV, with the maximum total gamma-flux of more then 1010 gammas per second around 10 MeV. Production of high intensity, high energy gamma-beams of 60 to 100 MeV, using UV-VUV mirrors of 240 to 190 nm, requires high energy, high current electron beams of 0.9 to 1.05 GeV. Synchrotron radiation damage to the FEL mirrors becomes crucial for VUV FEL operation at or below 190 nm. The edge radiation (ER) from the End-of-Arc (EOA) bending magnet, instead of the radiation of FEL wigglers, is the dominant cause of a rapid degradation of the downstream FEL mirror. In this work, we describe a further development of the “soft” orbit bump concept to significantly reduce the radiation exposure to the mirror from the EOA dipole magnet. The bump uses designated "soft" orbit correctors with magnetic field limited to produce a radiation with a critical wavelength close or below the FEL wavelength. |
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TUPFI002 | Electron Cloud and Scrubbing Studies for the LHC | injection, electron, emittance, luminosity | 1331 |
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Electron cloud build-up resulting from beam-induced multipacting is one of the major limitations for the operation of the LHC with beams with close bunch spacing. Electron clouds induce unwanted pressure rise, heat loads on the beam screens of the superconducting magnets and beam instabilities. Operation with bunch spacing of 50 ns in 2011 and 2012 has required decreasing the Secondary Electron Yield of the beam screens below the multipacting threshold for beams with this bunch spacing. This was achieved by continuous electron bombardment induced by operating the machine with high intensity beams with 50 and 25 ns spacing during dedicated periods at injection energy (450 GeV) and at top energy (3.5 and 4 TeV). The evolution of the Secondary Electron Yield during these periods, at different sections of the machine, can be estimated by pressure, heat load and by bunch-by-bunch RF stable phase measurements. The experimental information on the scrubbing process will be discussed and a possible “scrubbing strategy” to allow the operation with 50ns and 25ns beams after the Long Shutdown in 2013-2014 will be presented. | |||
TUPFI010 | The LHCb Online Luminosity Control and Monitoring | luminosity, controls, target, proton | 1346 |
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The online luminosity control consists of an automatic slow real-time feedback system controlled by specific LHCb software, which communicates directly with a LHC software application. The LHC application drives a set of corrector magnets to adjust the transversal beam overlap at the LHCb interaction point in order to keep the instantaneous luminosity aligned to the target luminosity provided by the experiment. It was proposed and tested first in July 2010, and it has been in routine operation during the first two years of physics luminosity data taking, 2011 and 2012. This paper describes the operational performance of the LHCb experiment and the LHC accelerator during the luminosity control of the experiment, the accounting of the recorded luminosity and dead time of the detector, and analyses the beam stability during the adjustment of the transverse beam overlap at the interaction point. | |||
TUPFI011 | Study and Operational Implementation of a Tilted Crossing Angle in LHCb | luminosity, beam-losses, controls, monitoring | 1349 |
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The current crossing angle scheme at LHCb interaction point (horizontal crossing angle and vertical beam separation) prohibits the use of the LHCb dipole positive polarity for 25 ns bunch spacing operation since the beam separation at the first parasitic encounter is very small inducing unwanted beam encounters. To overcome this limitation a different crossing angle scheme was proposed in 2007 by W. Herr and Y. Papaphilippou. The new schema implies a vertical external crossing angle that together with the horizontal internal crossing angle, from the LHCb dipole and its three compensator magnets, defines a new tilted crossing and separation plane providing enough beam separation at the parasitic encounters. This paper summarizes the feasibility study of the new crossing scheme, the implementation in routine operation and analyzes the beam stability during the building up of the tilted crossing plane. | |||
TUPFI017 | Evaluation of Field Quality for Separation Dipoles and Matching Section Quadrupoles for the LHC High Luminosity Lattice at Collision Energy | quadrupole, lattice, simulation, dynamic-aperture | 1367 |
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Funding: Work supported by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404; and by the US DOE contract DE-AC02-76SF00515. The high luminosity upgrade of the LHC (HL-LHC) lattice requires new larger aperture magnets to be installed in the low-beta interaction regions (IRs). These include Nb3Sn superconducting (SC) triplet quadrupoles, Nb-Ti SC separation dipoles D1 and D2, and SC Q4 quadrupoles. The upgrade significantly reduces the beta functions at these IRs, producing higher beta functions and larger beam size in these magnets, and requiring a larger aperture. The high beta functions also increase the impact of high order field errors in these new magnets on dynamic aperture (DA). Therefore, to maintain an acceptable DA, new specifications for the magnet field quality are required. Since the IR error effects at collision are dominated by the triplets, their field quality has been studied and specified first*. As a next step, the field errors were added to the D1 and D2 dipoles and Q4 quadrupoles while maintaining the triplet errors to specifications. The impact of the errors on DA has been determined in long term tracking simulations using SixTrack. The optimized field error specifications for the D1, D2 and Q4 magnets are presented. * Y. Nosochkov, Y. Cai, M-H. Wang, S. Fartoukh, M. Giovannozzi, R. de Maria, E. McIntosh, “Optimization of Triplet Field Quality for the LHC High Luminosity Lattice at Collision Energy”, IPAC 2013. |
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TUPFI022 | Power Load from Collision Debris on the LHC Point 8 Insertion Magnets Implied by the LHCb Luminosity Increase | luminosity, quadrupole, proton, optics | 1382 |
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LHCb is aiming to upgrade its goal peak luminosity up to a value of 2 1033 cm-2 s−1 after LS2. We investigate the collision debris impact on the machine elements by extensive FLUKA simulations, showing that the present machine layout is substantially compatible with such a luminosity goal. In particular the installation of a TAS (Target Absorber ofSecondaries, installed in front of the final focus Q1-Q3 quadrupole triplet in the LHC high luminosity insertions) turns out not to be necessary on the basis of the expected peak power deposition in the Q1 superconducting coils. A warm protection may be desirable to further reduce heat load and dose on the D2 recombination dipole, due to the absence of the TAN (Target Absorber of Neutrals, present in Point 1 and 5). | |||
TUPFI044 | LHC Optics with Crab-waist Collisions and Local Chromatic Correction | optics, sextupole, luminosity, quadrupole | 1448 |
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Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579. We report the status of the optics design for a local chromatic correction with extremely-flat beams at the LHC. Together with a Large Piwinski angle, this optics opens up the possibility of crab-waist collisions at the LHC, for which a new layout of the LHC insertion region (IR) is needed. We present a complete optics and discuss the parameters of the final "double-half" quadrupole. |
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TUPFI045 | Electron-cloud Maps for LHC Scrubbing Optimization | electron, injection, simulation, beam-losses | 1451 |
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Electron-cloud maps as alternative to detailed build-up simulations have already been applied in the past for a few accelerators, e.g. RHIC and the LHC at 7 TeV. We here report a first application of maps to optimize the "beam scrubbing" of the LHC arcs at injection energy: Maps are used to efficiently determine the optimum bunch filling pattern which maximizes the electron flux on the chamber wall, while respecting constraints on the central cloud density to ensure beam stability. In addition, new features have been explored, e.g. by introducing thresholds which divide regions where either linear maps or cubic maps best describe the build-up and the decay of an electron cloud. In the near future we plan to extend the map formalism to individual slices in a dipole file in order to represent the vertical "stripes". | |||
TUPFI060 | Complete Muon Cooling Channel Design and Simulations | emittance, beam-cooling, factory, simulation | 1484 |
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Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittance required for an Energy-Frontier Muon Collider, but lacks an end-to-end design. Meanwhile, the recent discovery of a Higgs-like boson has created interest in the High Energy physics community for a Higgs Factory to investigate its properties and verify whether it is Standard Model or beyond. We present principles and tools to match emittances between and within muon beam cooling subsystems that may have different characteristics. The Helical Cooling Channel (HCC), which combines helical dipoles and a solenoid field, allows a general analytic approach to guide designs of transitions from one set of cooling channel parameters to another. These principles and tools will be applied to design a complete cooling channel that would be applicable to a Higgs Factory and an Energy Frontier Muon Collider. | |||
TUPFI061 | Preliminary Design of a Higgs Factory μ+μ- Storage Ring | quadrupole, collider, factory, storage-ring | 1487 |
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Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, and by the US Department of Energy through the Muon Accelerator Program (MAP). A Muon Collider offers unique possibilities for studying the recently found Higgs boson. Higgs bosons can be produced in reasonable amounts in the s-channel, so that the colliding muon beam energy of just 62.5GeV is required. Precision direct measurements of the Higgs boson mass and width is possible due to absence of brems- and beam-strahlung. At the same time, there are difficulties specific to muon colliders: relatively large beam emittance which necessitates quite small beta-function values (~ a few cm) at the interaction point in order to obtain sufficiently high luminosity, as well as superconducting magnet and detector protection from showers generated by muon decay products. Due to these factors, the required aperture of the final focus quadrupoles is very large (up to 0.5 m) posing challenging engineering constraints as well as beam dynamics issues with fringe fields. The first results of a complex approach to these problems in the Higgs Factory collider design are presented which promise luminosities in excess of 1031 cm-2s−1 with a 4 MW proton driver. |
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TUPFI076 | First RHIC Collider Test Operation at 2.5GeV Beam Energy | ion, multipole, injection, luminosity | 1523 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. To search for the critical point in the QCD phase diagram, RHIC needs to operate at a set of low gold beam energies between 2.5 and 20 GeV per nucleon. During run 12, first successful collider operation at the lowest energy of 2.5 GeV per nucleon was achieved. We present the challenges and achieved results, and discuss possible future upgrades and improvements. |
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TUPFI079 | A Proposed “Delay Line” for Hadron Beams in RHIC | quadrupole, optics, hadron, interaction-region | 1532 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. A “delay line” has been proposed to be installed in the Blue ring of the RHIC to accommodate collisions of asymmetric nuclei. The delay line can also be used in the e-RHIC accelerator to accommodate electron hadron collisions at various energies. We will present the layout and the optics of the delay line and we will discuss the energy range that asymmetric collisions can be performed in the RHIC collider. |
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TUPME004 | Spin Tracking at the International Linear Collider | resonance, polarization, positron, damping | 1565 |
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Funding: This work is supported by the German Federal Ministry of Education and Research, Joint Research Project R&D Accelerator "Spin Optimization", contract number 19XL7Ic4 In the baseline design for the International Linear collider an helical undulator-based positron source has been chosen that can provide positrons with a polarization of 60% as an upgrade option motivated by physics reasons. But even the baseline configuration would already provide about 30%. In order to match the high precision requirements from physics and to optimize the physics outcome one has to control systematic uncertainties to a very high level. Therefore it is needed to run both beams polarized but provide also an unpolarized set-up for control reasons. In our study we present results on precise spin tracking and propose also an minimal machine set-up to run in an unpolarized mode within the baseline design. |
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TUPWA021 | Multi-Pass, Multi-Bunch Beam Breakup of ERLs with 9-cell Tesla Cavities | HOM, cavity, betatron, simulation | 1769 |
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Funding: Supported by the Major State Basic Research Development Program of China under Grant No. 2011CB808303 and No. 2011CB808304 In this paper, multi-pass, multi-bunch beam break-up of some small-scale Energy Recovery Linac(ERL) configuration using 9-cell Tesla cavity is discussed. The threshold currents of different cases are investigated and some factors that influence the threshold currents are discussed. |
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TUPWA061 | Observation at CesrTA of the Reduction of the Vertical Beam Size of the Lead Bunch in a Train Due to the Presence of a Precursor Bunch | electron, positron, feedback, simulation | 1841 |
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Funding: Work supported by DOE Award DE-FC02-08ER41538, NSF Award PHY-0734867, PHY-1068662 and the Lepton Collider R&D Coop Agreement: NSF Award PHY-1002467. Electron cloud-induced beam dynamics is being studied at CesrTA under various conditions. These measurements make use of instrumentation for the detection of the coherent self-excited spectrum for each bunch within the train and bunch-by-bunch vertical beam size. In the position spectrum coherent betatron dipole and head-tail motion is detectable for each individual bunch within the train. These techniques are utilized to study the electron cloud-related interactions, which cause the growth of coherent motion and beam size along the train. We report on the observations of the vertical enlargement of the first bunch(es) in 30 bunch-long trains. We also report that the addition of a precursor bunch following the train of bunches and before the start of the next train can counteract the vertical enlargement of the first bunch(es) in the train. Results from these observations will be presented. |
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TUPWA062 | Dependence of Beam Instabilities Caused by Electron Clouds at CesrTA on Variations in Bunch Spacing and Chromaticity | electron, damping, positron, resonance | 1844 |
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Funding: Work supported by DOE Award DE-FC02-08ER41538, NSF Award PHY-0734867 and the Lepton Collider R&D Coop Agreement: NSF Award PHY-1002467 Experiments have been performed at the Cornell Electron-Positron Storage Ring Test Accelerator (CesrTA) to probe the interaction of the electron cloud with a 2.1 Gev stored positron beam. The purpose of these experiments was to characterize the dependence of beam–electron cloud interactions on the bunch spacing and the vertical chromaticity. These experiments were performed on a 30-bunch positron train, at a fixed current of 0.75mA/bunch. The bunch spacing was varied between 4 and 28 ns at three different vertical chromaticity settings. The beam dynamics of the stored beam, in the presence of the electron cloud, was quantified using: 1) a gated Beam Position Monitor (BPM) and spectrum analyzer to measure the bunch-by-bunch frequency spectrum of the bunch trains; 2) an x-ray beam size monitor to record the bunch-by-bunch, turn-by-turn vertical size of each bunch within the trains. In this paper we report on the observations from these experiments and analyze the effects of the electron cloud on the stability of bunches within these different trains. |
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TUPWO001 | A New 5BA Low Emittance Lattice for Sirius | emittance, lattice, sextupole, coupling | 1874 |
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Sirius is a third-generation low emittance synchrotron light source under construction at LNLS, the Brazilian Synchrotron Light Laboratory. A new 5BA lattice was designed in replacement for the previous TBA lattice with the aim to reduce the emittance to sub-nm.rad values. The new design has a circumference of 518 m with 20 achromatic straight sections and a natural emittance of 0.28 nm.rad at 3 GeV for the bare lattice (without IDs). The dipoles combine low 0.58 T field magnets for the main beam deflection with a 2 T short superbend magnet sandwiched in the center dipole. This creates a longitudinal dipole gradient that is used both to lower the emittance and to provide hard X-ray dipole sources. | |||
TUPWO003 | CLIC 3 TeV Beam Size Optimization with Radiation Effects | radiation, quadrupole, lattice, photon | 1877 |
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Horizontal beamsize contribution due to radiation on bending magnets is calculated using theoretical results and recent improvements in mapclass (Mapclass2). In order to verify the code and validity of its approximations, a simple lattice with no geometrical nor chromatic aberrations, one dipole and a final drift has been used to compare Mapclass2 calculations and Placet tracking results. CLIC 3TeV lattice is optimized including the radiation effects. Current results show that correction of chromatic aberrations impose constraints in radiation improvement. | |||
TUPWO004 | Preliminary Design of a 4 MW Proton Beam Switchyard for a Neutrino Super Beam Production Facility | target, proton, kicker, quadrupole | 1880 |
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Funding: European Commission Framework Programme 7 Design Study: EUROnu, Project Number 212372. The feasibility of the distribution of 4 MW proton beam power onto a 4-targets horn system for neutrino super-beams production is discussed. A preliminary solution using a pair of bipolar kickers to route the beam onto the targets at a repetition rate of 50 Hz (12.5 Hz per beam line) is proposed. Compensating dipoles would apply symmetry in the system. Magnetic fields induced by these optical elements would not exceed 0.96 T. Studies of the beam envelopes with the code TRANSPORT suggest the use of three quadrupoles per beam line located after the dipoles to focus the 4 mm σ beam onto each target. The length of this switchyard system is estimated to be 29.9 m and 3 m radius. |
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TUPWO006 | Orbit Correction System at the Collector Ring | sextupole, closed-orbit, quadrupole, optics | 1886 |
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The CR is dedicated ring for cooling of hot beam coming either from the antiproton separator or SFRS. It is anticipated that the understanding and control of the beam orbits will be important for achieving low beam losses. We describe our plans for measuring and correcting the COD of the CR. The closed orbit of the CR, which is distorted due to magnets misalignments, can reduce the ring acceptance by factor of 2, if a special correction system is not applied. The system, which is developed for the CR should be periodically or manually invoked to correct the global closed orbit and used to adjust the orbit position at some point using local bump. BPM and corrector magnets, which are planned to be used at the CR, are described in this paper. SVD method is used to obtain the corrector strength or corrector factors in global or local orbit correction. | |||
TUPWO014 | Downscaling the Energy of the MAMI-B Cascade Towards 100 MeV | injection, microtron, extraction, electron | 1910 |
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Funding: Work supported by DFG (CRC 443/1044) and the German federal state of Rheinland-Pfalz New experiments could benefit from energies of ~100 MeV, significantly lower than 180 MeV which is the lowest energy routinely available with the microtron cascade of MAMI-B. This article describes the difficulties which arise due to the drastically reduced injection energy of the first microtron (RTM-1) and presents the results of the beam tests which have been performed. We suggest a new beam extraction system from RTM-2 which will avoid these problems. |
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TUPWO040 | Asymmetric Energy Colliding Ion Beams in the EDM Storage Ring | ion, storage-ring, proton, controls | 1961 |
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A possibility to bent equally two counter rotating ion beams by the crossed electric and magnetic fields is investigated. The first beam is polarized and its spin precession is adjusted to be synchronous with the velocity vector precession (a frozen spin method). The counter rotating unpolarized ion beam travels along the same orbit but with different velocity. Sensitive SQUID-type BPMs measure the vertical orbit difference of two beams. Later on this information is used to distinguish the EDM signal from the magnetic moment precession. Application of this approach to search of the EDM for proton, deuteron and helion is discussed. | |||
TUPWO041 | Beam Size and Emittance Measurements during the ALBA Booster Ramp | booster, emittance, linac, injection | 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. | |||
TUPWO042 | Modeling Results from Magnetic and Beam Based Measurements of the ALBA Gradient Dipoles | focusing, lattice, quadrupole, storage-ring | 1967 |
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The ALBA lattice is a DBA-like structure where most of vertical focusing is provided by gradient dipoles. In the first year of machine operation, the model parameters describing the focusing strength of the 32 dipoles have been calibrated by fitting the measured closed orbit response matrix. The mean k-value obtained from this analysis differs by -0.3% with respect to the value taken from the magnetic measurements previous to the magnet installation, while the k variation within the 32 dipoles is of the same order of magnitude. The optics results (tunes, beta beating, dispersion) obtained with the beam based model are compared with the predicted ones from the magnetic measurement model. | |||
TUPWO047 | Preliminary Results of Linear Optics From Orbit Response in the CERN PSB | quadrupole, optics, booster, coupling | 1973 |
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Funding: This research project is supported by a Marie Curie Early Initial Training Network Fellowship of the European Community's Seventh Framework Programme under contract number (PITN-GA-2011-289485-OPAC) Future operations for the CERN accelerator complex will require the PS Booster to deliver higher intensity beam without increasing emittances, and having an accurate knowledge of the machine’s lattice imperfections will be necessary. We present preliminary results of the analysis of orbit response measurements in the PS Booster to determine the linear optics and to identify field errors in each of the machine’s four rings. |
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TUPWO073 | Precision Tune, Phase and Beta Function Measurement by Frequency Analysis in RHIC | optics, betatron, kicker, booster | 2027 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. The high quality of the RHIC turn-by-turn (TbT) data obtained from the beam position monitor (BPM) system was fully exploited by using two analysis approaches. One is a time domain least square fitting technique and the other one is a frequency domain interpolated Fourier Transform technique. Both methods were applied to 1024-turn data from kicked beam and from continuous coherent excitation experiments. The betatron phase precisions obtained with both methods were ~0.1 degree for the continuous excitation and ~0.2 degree for the impulse excitation. The algorithms of these two analyses and comparison of their results will be presented in this report. |
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WEOAB202 | JEMMRLA - Electron Model of a Muon RLA with Multi-pass Arcs | linac, electron, quadrupole, 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] | ||
WEPWA008 | Simulating the Bunch Structure in the THz Source FLUTE | simulation, space-charge, laser, linac | 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. | |||
WEPWA049 | Top-up Safety Simulations for the ALBA Storage Ring | quadrupole, sextupole, simulation, storage-ring | 2229 |
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The potential hazards introduced by injecting into the ALBA storage ring with front end shutters open are determined through particle tracking simulations. The method is based on the possible overlap between phase space of forwards and backwards tracking between the straight section downstream the front end and the beamline. Realistic magnetic field, trajectory, aperture and energy errors are taken into account. Scenarios that could bring an injected beam of electrons passing through an open beamline front end are identified. The interlocks required to prevent such situations from arising are stated. | |||
WEPWA063 | Longitudinal Beam Transport in the ALICE IR-FEL Facility | sextupole, FEL, quadrupole, linac | 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. | |||
WEPWA069 | Design Concepts for an RF Deflecting Cavity-Based Beam Spreader for a Next Generation FEL | cavity, FEL, gun, septum | 2274 |
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Funding: Work supported by the Director, Office of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The Lawrence Berkeley National Laboratory (LBNL) is developing design concepts for a multi-beamline soft x-ray FEL array powered by a superconducting linear accelerator, operating with a high bunch repetition rate of approximately one MHz. Electron bunches supplied by a high-brightness, high-repetition-rate photocathode electron gun are distributed by a beam spreader, designed to deliver individual bunches from a CW linac to an array of independently configurable FEL beamlines with nominal bunch rates up to 100 kHz in each FEL, and with even pulse spacing. We describe recent developments in the technical choices, design and parameters of the spreader system and its main components. |
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WEPWA072 | Design and Commissioning of Chasman-Green Double Bend Achromatic Lattice Linear Transport Line at the University of Hawai'i MkV Accelerator Facility | quadrupole, electron, focusing, diagnostics | 2280 |
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The design of the Double Bend Achromat (DBA) lattice was originally motivated by the desire to increase the brightness of a synchrotron ring by storing a low emittance electron beam*. Alternating the direction of the bends in the DBA lattice turns the ring into a linear transport line, which has advantages over the straight transport lines typically used in linac FEL's. The dipoles in the DBA cells provide synchrotron images of the electron beam, a real-time non-destructive diagnostic during operation. As in circular machines, sections between DBA cells provide a low-emittance dispersion free beam for insertion devices such as FEL's and inverse Compton backscattering sources. This paper describes an example linear DBA, which has been designed and commissioned as part of the MkV 40 MeV electron accelerator facility at the University of Hawaii.
* Renate Chasman and G. Kenneth Green "Preliminary Design of a Dedicated Synchrotron Radiation Facility", IEEE Transactions on Nuclear Science, NS22(3):1765-1767, June 1975 |
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WEPWA083 | Results of NSLS-II Linac Commissioning | linac, emittance, solenoid, 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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WEPWA086 | Characterization of PrFeB Permanent Magnet Blocks with Helmholtz Coils at NSLS-II | undulator, cryogenics, permanent-magnet, insertion | 2304 |
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For investigatation to build the cryogenic undulator using bake-able Praseodymium-Iron-Boron(PrFeB) magnet blocks, a short period(16.8mm) and fixed gap(5mm) hybrid undulator prototype has been fabricated at BNL. For this undulator, 36 PrFeB magnet blocks(28 type A, 4 type B, 4 type C) are used. The magnetic field characteristics of the undulator heavily depend on the directional uniformity of the magnetization of block sets. The strength and direction of magnetization of the PrFeB magnet blocks are measured using a Helmholtz coil system. The data include the three vector components of the total magnetic dipole moment of the blocks and also compare with vendor measuremeant results. | |||
WEPWA091 | Simulation Design of a Low Energy Bunch Compressor with Space Charge Effect | space-charge, gun, electron, cathode | 2307 |
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Funding: Department of Energy, USA Following the proposal of electron beam slicing method to generate short x-ray pulses in storage ring, we studied the feasibility of the crucial technique required by electron beam slicing, i.e., the generation of very low energy electron beam with very small beam size (30 μm) and very short bunch length (100 fs). Based on one of the BNL RF gun, 5 MeV beam energy and 50 pC bunch charge was assumed in the study. The beam ‘natural’ energy-time negative chirp, due to space charge effect, was used and the bunch length is compressed from from 0.8 ps to ~150 fs with a chicane structure. The system is in the space charge dominated regime. We use the code PARMELA and Generic optimization method for parameters optimization with various strategies to overcome the damaging from the space charge effect. After optimization, the beam transverse size is 50 micron and the bunch length is 150 fs, close to our original specification. In this paper we describe the design and the physical process in the compressor and focus section. The study confirmed the possibility to generate strong focused and compressed very low energy beam in the space charge dominated regime. |
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WEPWO026 | HOM Parameters Simulation and Measurement Result of the IHEP02 Low-loss Cavity | HOM, cavity, damping, wakefield | 2372 |
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In cavities , there exists not only the fundamental mode which is used to accelerate the beam but also higher order modes(HOMs). The higher order modes excited by beam can seriously affect beam quality, especially for the higher R/Q mode. This paper reports on recent measurements of higher order modes in the IHEP-2 low-loss SRF cavity. Using different methods, the Qext of the dangerous modes passband are got. This result is compared with TESLA result. R/Q of the first three passbands are also got by CST and compared with the results of TESLA cavity and STFBaseline cavity. | |||
WEPWO045 | RF Multipolar Characterization of the Latest LHC Deflecting Cavities | cavity, multipole, luminosity, extraction | 2402 |
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Funding: The HiLumi LHC Design Study (a sub-system of HL-LHC) is cofunded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. Deflecting cavity geometries considered for the Large Hadron Collider (LHC)crab scheme lack axial symmetry resulting in non-zero higher-order components of the deflecting field. A formalism to express the higher-order multipoles was developed and applied on previous cavity designs to characterize their influence on the beam stability. In this paper, the radio frequency (RF) multipoles are numerically estimated for the latest cavity geometries and compared to the older versions. A sensitivity study is carried to understand the numerical error levels and define mechanical tolerances. |
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WEPWO072 | HOM Damping Coupler Design for the 400-MHz RF Dipole Compact Crab Cavity for the LHC HiLumi Upgrade | HOM, cavity, damping, coupling | 2468 |
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Funding: Work partially supported by the US DOE through the US LHC Accelerator Research Program (LARP), and by US DOE under contract number DE-AC02-76SF00515. Crab cavities are adapted as the baseline design for the LHC HiLumi upgrade to achieve head-on beam-beam collisions for further improvement in luminosity. A 400-MHz compact RF dipole crab cavity design was developed by a joint effort between Old Dominion University and SLAC under the support of US LARP program. This design has shown very favorable RF parameters and can fit into the available beamline spacing for either vertical and horizontal crabbing schemes. A niobium prototype cavity based on such a design has been manufactured for vertical test. In addition, there are stringent wakefield requirements that needed to be met for such a cavity in order to preserve the quality of the circulating beams. In this paper, we will discuss different damping schemes for such a compact design and present the HOM coupler designs to meet the damping requirements. |
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WEPWO080 | Compact Superconducting RF-dipole Cavity Designs for Deflecting and Crabbing Applications | cavity, multipole, HOM, higher-order-mode | 2483 |
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Over the years the superconducting parallel-bar design has evolved into an rf-dipole cavity with improved properties. The new rf-dipole design is considered for number of deflecting and crabbing applications. Some of those applications are the 499 MHz rf separator system for the Jefferson Lab 12 GeV upgrade, 400 MHz crabbing cavity system for the proposed LHC high luminosity upgrade, and 750 MHz crabbing cavity for the medium energy electron-ion collider in Jefferson Lab. In this paper we present the optimized rf design in terms of rf performance including rf properties, higher order mode properties, multipacting, multipole expansion for the above mentioned applications. | |||
WEPWO084 | Improvement of the Q-factor Measurement in RF Cavities | cavity, coupling, pick-up, HOM | 2489 |
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Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. The Q values of Higher-order-modes (HOMs) in RF cavities are measured at room temperature with the 3 dB bandwidth reading by a network analyzer. The resonant curve distortion is created by the resonance splitting due to the ellipticity caused by manufacture tolerance and RF ports. Therefore, the measured Q values are usually lower than the simulated or theoretical Q values. In some cases, even only one mode’s Q can be measured with the 3 dB method. There may be two reasons for this happening. One is that only one mode was excited and the neighbor splitmode was close to 90° polarized; the other reason is that the resonant curve of one mode was distorted by the other mode too much to measure the 3dB range. In this paper, we resolve this issue by looking into the RF measurement setup, including cavity, input coupler and pick-up coupler, from the equivalent circuit and wave point of view. Based on the BNL3 copper prototype cavity, we compared these results from measurement and simulation. |
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WEPWO086 | Split Higher Order Modes in Superconducting Cavities | resonance, cavity, HOM, higher-order-mode | 2495 |
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Funding: This work was supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE and award no. DE-SC0002496 to Stony Brook University with the US DOE. Split resonances are a common appearance in superconducting cavities and were studied here on the specific example of the TE11 dipole resonance in five-cell copper models of the ERL and BNL3. The BNL3 cavity was designed to be suitable for the envisioned electron-hadron collider eRHIC. Achieving the required high-current performance depends on avoiding beam break-up instabilities by minimizing the Higher Order Modes (HOM) Q-values. This was attempted in the design phase and will be done with appropriate mode dampers in operation. The availability of a copper model provided a convenient opportunity to confirm the design and to study potentially nefarious high-Q resonances. The appearance of split resonances impeded the HOM identification and the theoretical interpretation as elipticity deformation is presented in this report. |
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WEPEA003 | Dipole Fringe Field Effects in the ThomX Ring | quadrupole, sextupole, closed-orbit, betatron | 2504 |
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Thom-X is a 50 MeV compact ring based on the Compton back-scattering which is being built in LAL, France. With a very short bend radius of 0.352 m, the nonlinear effects of the dipole fringe fields become critical to the beam dynamic . This paper compares the modelings of the dipole fringe field using four popular codes: MadX, Elegant, BETA, and Tracy3, and then discuss the proper model to have consistent results between the analytical calculation and the symplectic tracking of the Thom-X ring. | |||
WEPEA009 | Effects of Field Imperfections in the Isochronous Mode of the CR Storage Ring at FAIR | quadrupole, octupole, sextupole, simulation | 2510 |
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Today the challenge is to measure masses of exotic nuclei up to the limits of nuclear existence which are characterized by low production cross-sections and short half-lives. The large acceptance Collector Ring (CR) at FAIR tuned in the isochronous ion-optical mode offers unique possibilities for such measurements. Nonlinear field errors as well as fringe fields of the wide aperture quadrupoles and dipoles strongly excite the high-order aberrations which negatively affect the time resolution of the isochronous ring. Their influence is investigated here and a possible correction scheme is shown. | |||
WEPEA048 | Specification of a System of Correctors for the Triplets and Separation Dipoles of the LHC Upgrade | multipole, simulation, optics, insertion | 2612 |
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Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The luminosity upgrade of the LHC aims at reducing β* from 55 cm to 15 cm or beyond. This can be achieved by the ATS* scheme and means of new large aperture superconducting triplet (IT) quadrupoles (150 mm), preferably using the Nb3Sn technology in order to keep the gradient reasonably high (140 T/m). The field quality requires careful specification in order to ensure a large enough dynamic aperture. In this context, dedicated corrector magnets are foreseen to provide semi-local corrections of specific multipole components and find the best possible compromise between the demand and what can be realistically achieved by the magnet manufacturer. In this paper the layout and main parameters of the IT corrector package are presented together with the correction strategy. Moreover, the foreseen performance is discussed in detail. * S. Fartoukh, ‘’An Achromatic Telescopic Squeezing (ATS) Scheme for LHC Upgrade’’, in proceedings of IPAC11, p. 2088. |
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WEPEA049 | Analysis of the Non-linear Fringe Effects of Large Aperture Triplets for the HL LHC Project | quadrupole, simulation, optics, luminosity | 2615 |
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Funding: The HiLumi LHC Design Study is included in the HL-LHC project and is partly funded by the European Commission within the Framework Programme 7 Capacities Specific Programme, Grant Agreement 284404. The HL-LHC project relies on large aperture quadrupoles which are compatible with the very large beam sizes in the inner triplets resulting from the strong reduction of β*. As a result the beam is much more sensitive to non-linear perturbations in this region, such as those induced by the fringe fields of the low-beta quadrupoles. The spatial extension of these fringe fields increases as well more or less linearly with the coil aperture, which is an additional motivation to analyse this aspect in detail in the framework of the High Luminosity LHC design study. This paper will quantify this effect both by direct analytical estimates using first order Hamiltonian perturbation theory, and via numerical studies thanks to the dedicated implementation of a fringe field symplectic integrator in SixTrack. |
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WEPEA072 | Experimental Studies of Resonance Crossing in Linear Non-scaling FFAGs With the S-POD Plasma Trap | resonance, ion, focusing, betatron | 2675 |
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In a linear non-scaling FFAG the betatron tunes vary over a wide range during acceleration. This naturally leads to resonance crossing including first order integer resonances. The S-POD (Simulator for Particle Orbit Dynamics) plasma trap apparatus at Hiroshima University represents a physically equivalent system to a charged particle beam travelling in a strong focusing accelerator lattice. The S-POD system can be used as an ‘experimental simulation’ to investigate the effects of resonance crossing and its dependence on dipole errors, tune crossing speed and other factors. Recent developments and experiments are discussed. | |||
WEPEA074 | Optimisation of the Beam Line for COMET Phase-I | electron, solenoid, background, target | 2681 |
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The COMET experiment will search for very rare muon processes that will give us an insight into particle physics beyond the Standard Model. COMET requires an intense beam of muons with a momentum less than 70 MeV/c. This is achieved using an 8 GeV proton beam; a heavy metal target to primarily produce pions; a solenoid capture system; and a curved solenoid to perform charge and momentum selection. It was recently proposed to build COMET is two phases with physics measurements being made in both phases. This requires re-optimising the beam line for a shorter curved solenoid. This will affect the pion and muon yield; the momentum distributions at the detector; and the collimator scheme required. This paper will present the beam line design for COMET Phase-I, which aims to maximise the yield for low momentum muons suppressing sources of backgrounds in the beam. | |||
WEPEA077 | Applying the 'Simple Accelerator Modelling in Matlab' (SAMM) Code to High Luminosity LHC Upgrade | proton, kicker, dynamic-aperture, quadrupole | 2690 |
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The "Simple Accelerator Modelling in Matlab" (SAMM) code is a set of Matlab routines for modelling beam dynamics in high energy particle accelerators. It includes a set of CUDA codes that can be run on a Graphics Processor Unit. These can be called from SAMM and can speed up tracking simulations by 100 times. To make use of this potential for the computationally intensive LHC upgrade simulations, we have developed additional Matlab and CUDA routines to simulate the full set of elements that are present in the Large Hadron Collider. We present the results of applying these codes to dynamic aperture calculations. These results are benchmarked against PTC and MADX. | |||
WEPFI013 | The Damped C-band RF Structures for the European ELI-NP Proposal | damping, linac, beam-loading, 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. | |||
WEPFI015 | Design and Field Measurements of a Linear Accelerator Endowed with Single Feed with Movable Short Coupler | emittance, linac, 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. | |||
WEPFI075 | Design of the FRIB RFQ | rfq, vacuum, linac, ion | 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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WEPFI089 | High Gradient Normal Conducting Radio-frequency Photoinjector System for Sincrotrone Trieste | gun, cathode, coupling, quadrupole | 2905 |
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Radiabeam Technologies, in collaboration with UCLA, presents the development of a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system for the Sincrotrone Trieste facility. Designed to operate with a 120MV/m accelerating gradient, this single feed, fat lipped racetrack coupler design is modeled after the LCLS photoinjector with a novel demountable cathode which permits cost effective cathode exchange. Full overview of the project to date and installation at Sincrotrone Trieste will be discussed along with basic, design, engineering and manufacturing. | |||
WEPFI091 | Design of a Normal-conducting RF-dipole Deflecting Cavity | cavity, simulation, luminosity, extraction | 2911 |
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In this paper we present a novel design of a CW normal conducting RF deflecting cavity. The cavity is designed into a dipole-like structure, resulting a high (R/Q)transverse. The geometry at high H field is optimized to lower the surface peak power. We will show the design of a 325 MHz and 163 MHz cavity based on this structure and compare their performances with their superconducting counterparts. | |||
WEPME004 | A Digital Beam-Phase Control System for a Heavy-Ion Synchrotron with a Double-Harmonic Cavity System | controls, cavity, synchrotron, feedback | 2926 |
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Funding: Funded by GSI Helmholtzzentrum für Schwerionenforschung GmbH For the new Facility for Antiproton and Ion Research (FAIR) at GSI Helmholtzzentrum für Schwerionenforschung GmbH, the heavy-ion synchrotron SIS18 will be operated with a double-harmonic cavity system*. The second cavity, running at twice the fundamental RF frequency, is used to lengthen the bucket which introduces nonlinearities to the control system. To damp longitudinal rigid dipole oscillations a digital feedback system consisting of a filter and an integrator is used. For the existing single-harmonic setup an FIR-filter is implemented which realizes a multiple bandpass filter with the first passband close to the synchrotron frequency. Both, the feedback gain and the passband frequency of the filter depend on the actual value of the synchrotron frequency**. It was shown by simulations and in an experiment that this setup can be transferred to a double-harmonic cavity system obtaining similar results for the region of stable feedback parameters, if the oscillation frequency of the bunch barycenter*** is considered instead of the synchrotron frequency of a linearized bucket. In this contribution the results of the simulation and the experiment are presented and compared. *Klingbeil et al.: Phys. Rev. Special Topics - Accelerators and Beams 14, 102802, 2011 **Klingbeil et al.: IEEE Trans. on Nucl. Science, Vol. 54, No. 6, 2007 ***Grieser et al.: Proc. 3rd IPAC, 2012 |
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WEPME020 | Alignment Plan and Survey Results of the Equipment for J-PARC 3 GeV RCS | alignment, quadrupole, injection, emittance | 2971 |
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Misalignment of several millimeters of the magnets of J-PARC 3GeV RCS in both horizontal and vertical directions was caused by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. As the result of orbit calculation showed that the beam loss was acceptable for beam operation at 300kW, beam operation with the current placement has been implemented. Realignment of the equipment will be carried out from August to December in 2013. Survey carried out in the summer of 2013 found out misalignment of ceramic vacuum ducts therefore their positioning is necessary. In this paper, these measurement result and latest alignment plan for J-PARC 3GeV RCS are reported. | |||
WEPME023 | Study of the Vibration of the AC Dipole and Magnetic Measurement Girder for CSNS/RCS | acceleration, resonance, damping, synchrotron | 2980 |
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The dipole magnet of the China Spallation Neutron Source Rapid-cycling Synchrotron (RCS) will be operated at a 25Hz sinusoidal alternating current which causes severe vibration. The vibration will influence the long-term safety and reliable operation of the magnet. By taking the magnet and magnetic measurement girder as a specific model system, a method for analyzing and studying the dynamic characteristic of the system is put forward by combining theoretical calculation with experimental testing. And the ctive vibration of magnet is different with passive vibration which was causes by ground vibration, so a new isolator was designed to decrease the vibratory force and avoid the resonance phenomenon. | |||
WEPME049 | An Application of Laser Position Sensing Detector for Magnet Centralizing System | quadrupole, laser, alignment, electron | 3040 |
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Taiwan Photon Source (TPS) project has been proposed to create a 3GeV synchrotron light source. The designated ultra-low emittance of this new light source requires high precision positioning of storage ring magnets. The alignment of all magnets is very importance since it directly affects the closed orbit of electron beams. Previously, conventional on-site alignment of the magnets was mainly relying on the theodolite performance. The cumulated errors could be in the order of 0.1mm. In this paper, a new alignment scheme is proposed to enhance the on-site alignment of magnets for TPS project. To achieve the high precision requirements, a device possessing the advantages of expansion mandrel in conjunction with Position Sensing Detector (PSD) is proposed. The development of this alignment device is anticipated to provide a better mechanism to properly align the centers of the both quadrupole and sextupole magnets on girder with less than 30μm positioning errors. | |||
WEPME055 | Investigation of Source Point Instabilities in Dipole Magnet Based Beamlines | synchrotron, feedback, optics, radiation | 3055 |
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At Diamond the source point in the second dipole of the Double Bend Achromats can vary due the lack of adjacent BPMs constraining angle and position of the electron beam at the dipole. We have implemented a code based on our AT model to predict the effects of a corrector strength change and compared our predictions to data both from a beamline and from our pinhole cameras. We discuss the possibility of interfacing the code to a ray tracing routine in order to infer beam spot changes in the downstream beamline and suggest a procedure to restore the original source point. | |||
WEPME064 | Recent Development on Beam-based Alignment in RHIC | quadrupole, alignment, controls, power-supply | 3082 |
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Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. During the 2012 polarized proton and heavy ion runs, we continued the efforts on beam-based alignment (BBA) of quadrupoles in RHIC. A complete set of BBA data of triplet quadrupoles in all interaction regions of RHIC was obtained. In addition, the measurement procedures and data analysis were improved and the corresponding codes were developed. Here we report on the results of BBA measurements, analysis, and corrections. The model sensitivity, the measurement repeatability, and the BBA accuracy limitations are also discussed. As a continuing effort, we also present application code that is under development for future BBA operations in RHIC. |
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THOAB201 | Development of the Dielectric Wall Accelerator | proton, simulation, radiation, shielding | 3115 |
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The Compact Particle Accelerator Corporation has developed an architecture to produce pulsed proton bunches that will be suitable for proton beam therapy. The Dielectric Wall Accelerator engineering prototype includes a RFQ injection system with a pulsed kicker to select the desired proton bunches and a linear accelerator incorporating a High Gradient Insulator with stacked transmission to produce the required voltage. The transmission lines are switched with solid state laser driven optical switches. A computational model has been developed that is in very good agreement with the experimental results. The system is presently achieving accelerating gradients of approximately 15 MeV/m. The computational model has been used to design the next generation system that will achieve 25 MeV/m by early 2013. This paper will discuss the status of the apparatus, the basic elements of the computational model, experimental results and comparison to the model predictions. In addition, the paper will present concepts for proton therapy systems that incorporate the Dielectric Wall Accelerator and fully leverage its features to achieve clinical requirements. | |||
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Slides THOAB201 [1.650 MB] | ||
THPEA026 | Radiation Safety Interlock System for DCLS | radiation, controls, electron, monitoring | 3198 |
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Dalian Coherent Light Source (DCLS) is in the design phase currently and will be constructed in Dalian from 2013. It is a seeded HGHG-FEL, mainly consisting of one 300 MeV electron linear accelerator and one undulator. Radiation safety is one of the most important tasks for Dalian FEL. Radiation safety interlock system (RSIS) is designed to prevent personnel exposure to high radiation levels, based on the As Low As Reasonably Achievable (ALARA) principle. RSIS controls access to the radiation protection areas and monitors safety devices. Only if all the radiation safety conditions are satisfied, then the facility will be permitted to operate. Once any condition is broken, RSIS will send a signal to stop the electron beam immediately to guarantee radiation safety. The core component of RSIS utilizes Programmable Logic Controller (PLC), which is a proven and reliable technology in the field of industrial automatic control. All safety-relevant functions of RSIS are implemented with fail-safe components. The hard wiring cable of the peripheral signals for the safety-relevant functions is redundant. The safety interlock signals are sent via a fail-proof protocol and transferred redundantly. | |||
THPEA062 | Magnetic Field Measurements for the IAC-RadiaBeam THz Project | quadrupole, radiation, electron, FEL | 3282 |
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At the Idaho Accelerator Center (IAC) of Idaho State University, recently, a new chicane with four dipoles and quadrupole triplet magnets were installed in a 44 MeV linac to perform the IAC-RadiaBeam Terahertz (THz) project. To generate high power THz radiation, a THz radiator with numerous periodic gratings was also installed downstream of the quadrupole triplet. However, the electron beam shape at the radiator has to be horizontally focused strip-like one due to a tiny radiator gap with a width of 1.2 mm, and electron bunch length should be about a few picosecond (ps) to generate high power THz radiation in the radiator. By using the quadrupole triplet and chicane dipoles, we can control the transverse beam profile and bunch length freely. In this paper, we report the measured field maps of the dipole and quadrupole magnets, their effective lengths, and field strength or gradient as a function of the magnet power supply current. | |||
THPFI006 | A New External Beamline for Detector Tests | quadrupole, simulation, electron, extraction | 3300 |
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At the electron accelerator ELSA, a new external beamline is under construction, whose task is to provide a primary electron beam for detector tests. In the future, the accelerator facility will not only be offering an electron beam to the currently installed double polarization experiments for baryon spectroscopy, but to the new "Research and Technology Center Detector Physics" as well. This institution will be established near the accelerator in Bonn and is charged with the development of detectors for particle and astroparticle physics. The requirement for the new beamline is to be able to vary the beam parameters such as beam current and width over a wide range. With the resonance extraction method, it is possible to extract electrons with a maximum energy of 3.2 GeV slowly to the test area. A quasi-continuous external beam current of 1 fA to 100 pA can be offered. A further reduction of the beam current can be realized by utilizing the single-pulse operation mode at ELSA. The beam width can be changed in both transverse directions from 1 mm to 8 mm. | |||
THPFI007 | Increasing the Stability of the Electron Beam of the S-DALINAC | linac, electron, feedback, acceleration | 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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THPFI017 | Development of Harmonic Field Measurement System with Higher Resolution ADC | background, multipole, quadrupole, focusing | 3330 |
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Quadrupole magnets for ILC final focus should be enough strong with the limitation on the external radius, while the vibration of the magnetic center has to be highly avoided to keep the nm sized beam focusing stable at the interaction point a few m downstream from the lens. Gluckstern's 5-ring PMQ singlet seems a good candidate for the purpose, which is under investigation. The precise magnetic harmonic field measurement system is also under development for adjusting each magnet ring and evaluation of the assembled singlet. A rotating magnet system and a rotating coil system are prepared for the former and the latter purposes, respectively. Both systems have 24-bit ADC's for higher resolution. For the rotation coil, a flexible print circuit sheet, where a pair of one turn coils is printed on, is glued on a quartz rod. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. The two digitized signals are integrated digitally. | |||
THPFI043 | The Status of the Vacuum System of the MAX IV Laboratory | vacuum, storage-ring, injection, status | 3382 |
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All the vacuum chambers of the 3 GeV storage ring of MAX IV laboratory are under production. NEG coating R&D has been done to validate technical solutions for the coating process. The standard vacuum chambers for the 1.5 GeV ring of MAX IV and Solaris are designed and they are in the procurement process. We present an update in the technical design of the vacuum chambers following the interaction with the manufacture, the implications on the production due to NEG coating and the design of the vacuum chambers of the 1.5 GeV storage ring. | |||
THPFI051 | Radio-Frequency Multipacting as Quality Control of Coatings for e-Cloud Suppression | coupling, electron, resonance, vacuum | 3403 |
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To mitigate electron clouds in particle accelerators, a carbon coating with low SEY has been developed. In the case of the SPS (Super Proton Synchrotron), which belongs to the LHC injector chain, testing the performance of coated beam pipes directly in the accelerator must cope with the schedule of the regular machine operation. For this reason an alternative instrument based on RF induced multipacting in a coaxial configuration has been designed for ex-situ characterization of the main bending dipoles of the SPS. In this contribution we report the results obtained before and after coating for two 6.4 meter dipoles with different cross sections of the vacuum chambers. The multipacting is monitored by measuring the pressure rise and the RF reflected power. After coating, the power threshold to induce multipacting is strongly reduced indicating a lower propensity for electron cloud. The impact of the RF coupling on the sensitivity of the technique is discussed. | |||
THPME001 | Permanent Magnets in Accelerators can save Energy, Space, and Cost | permanent-magnet, quadrupole, synchrotron, vacuum | 3511 |
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Green Magnet technology with close to zero electrical power consumption without the need for cooling water saves costs, space and hence spares natural resources. A compact dipole based on permanent magnets has been developed at Danfysik in collaboration with Sintex and Aarhus University. This first Green Magnet has been delivered to ETH Zurich for testing in a compact accelerator mass spectrometer facility. Permanent NdFeB magnets generate a fixed magnetic field of 0.43 T at a gap of 38.5 mm without using electrical power in the H-type 90° bending magnet with a bending radius of 250 mm. Thermal drift of the permanent magnets is passively compensated. Small air cooled trim coils permit fine tuning of the magnetic field. Magnetic field measurements and thermal stability tests show that the Green Magnet fully meets the magnetic requirements of the previously used electromagnet. The use of Green Magnet technology in other accelerator systems like synchrotron light sources is discussed. | |||
THPME003 | Standard Sextupole Magnets for NSLS-II Synchrotron | sextupole, synchrotron, booster, target | 3517 |
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Danfysik received the order to design, manufacture and test 169 Standard Sextupole Magnets for the NSLS-2 synchrotron. Extraordinary tight tolerances were specified for the mechanical and magnetic properties. We present a re-optimized magnetic pole profile to make a more mechanically robust design, suitable for large-scale manufacture. Due to a well-controlled wire erosion process during the manufacturing stage, the mechanical tolerances were kept on the 10 micron level, even after assembly/disassembly cycles. A major challenge of the project was to verify the magnetic performance of the magnets. This was done using our in-house harmonic measurement bench. We present magnetic measurements of the magnet series, measured over more than 24 months, which show high stability, both in terms of magnetic roll angle, error field terms, and integrated strength. | |||
THPME005 | Status of the Super FRS Magnet Development for FAIR | quadrupole, status, octupole, sextupole | 3519 |
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The Super-FRS is a new two stage in flight separator to be built on the site of GSI, Darmstadt, Germany as part of the FAIR (Facility for Anti-proton and Ion Research). It will be able to create and spatially separate rare isotopes from all elements up to Uranium. Also very short lived nuclei will be observed efficiently. The Super-FRS has three branches, so a wide variety of experiments can be carried out in frame of the NUSTAR collaboration. The large acceptance needed leads to large apertures of the magnets and therefore only a superconducting solution is feasible. The magnets of the Super-FRS are of the so called superferric type. These magnets use superconducting coils but the field is shaped by magnetic iron yoke. In this contribution the actual status of the designs of the dipole and multipole magnets will be presented. | |||
THPME007 | HTS Magnet to Polarize Ultra Cold Neutrons | neutron, simulation | 3522 |
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We have developed magnets using High Temperature Superconductor (HTS) wires for this decade. A HTS magnet was designed and fabricated to polarize ultra cold neutrons (UCN). It consists of 10 double pancakes and the number of the total winding is 2,800 turns. The inner diameter of the coil is 131.5 mm and the coil is 105 mm long. The coil is conduction cooled by a pulse tube cryocooler and the operating temperature is expected to be 20 K. The maximum rated current is 200 A and the magnetic field is higher than 3.5 T at the center. Results of cooling tests and field measurements are presented. | |||
THPME013 | MAGNET SUBSYSTEM OF HLS II | storage-ring, electron, quadrupole, beam-transport | 3537 |
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Funding: Work supported by Natural Science Foundation of China 11005106 To improve the performance of the Hefei Light Source (HLS), in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices, NSRL is now upgrading HLS to HLS II. Most of the magnets had to be replaced in this project. To measure the magnets, set of the magnetic measurement equipment in NSRL are also re-built. New magnets are sample measured, the discreteness and uniformity of integrated magnetic field all meet the requirements. Piecewise fitting and electron tracking of bending magnets for injector and beam transport line were performed and the results showed that the electron trajectory fitted the physical design well. |
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THPME018 | Design of Dipole and Quadrupole for THz-FEL at CAEP | quadrupole, FEL, beam-transport, magnet-design | 3540 |
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The high average power terahertz free electronic laser (THz-FEL) is being constructed at CAEP (China Academy of Engineering Physics), which is designed for lasing between 100-300 μm. The magnets of THz-FEL include 3 dipoles and 6 quadrupoles, and their fields and field quality were required by 6-9 MeV operation. This proceeding introduced the design and the main parameters of these magnets. The higher harmonic content of the magnetic field was also analyzed. All the design of magnets achieved the goal. | |||
THPME023 | A NEW HARMONIC COIL BENCH AT SINAP FOR THE ALS COMBINED FUNCTION SEXTUPOLE MAGNETS | multipole, sextupole, controls, quadrupole | 3552 |
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A new harmonic coil bench has been developed at Shanghai Institute of Applied Physics (SINAP) to measure the ALS combined function sextupole magnets. The measurement system has been designed with the aim to perform precise, fast and reliable measurements of series of magnets. It determines the strength, and the multipole content of the field as well as the magnetic axis for precise positioning of alignment targets on top of the multipoles. The multipole, while supported on a marble platform, can be moved with regard to the rotating coil using multi-dimensional adjustment plate. The resolution of the movement is read out by micrometer with a few μm resolutions. This article introduces the measurement system constitutes. | |||
THPME024 | Magnet Designs of the In-flight Fragment Separator for the RISP | quadrupole, radiation, sextupole, target | 3555 |
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Magnets to be used for the in-flight fragment separator of the rare isotope science project (RISP) have been designed. The dipole magnets have a gap width of 150 mm and a magnetic rigidity of 10 Tm. The superferric quadrupole magnets have a pole tip radius of 170 mm and a maximum field gradient of 14 T/m. In addition, superconducting multiple coils will be wound around the cold bore tube of the quadrupole magnet to make high-order magnetic field corrections. In the high radiation region near the production target, warm iron dipole and quadrupole magnets employing high temperature superconductor (HTS) coils will be used in order to reduce the cold mass and to remove large radiation heat loads effectively at the temperature of 30-50 K. The design of dipole and quadrupole magnets has been optimized considering technical constraints and the manufacturing of the prototype of superferric quadrupole magnets is in progress. Simulation results using OPERA-3D and some results of prototyping will be presented. | |||
THPME028 | Prototype Superconducting Magnets for the NICA Accelerator Complex | booster, quadrupole, collider, ion | 3567 |
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NICA is a new accelerator complex being under design and construction at the Joint Institute for Nuclear Research (JINR) in Dubna. Full-size prototype dipole and quadrupole magnets for the booster synchrotron and the NICA collider have been designed, manufactured and tested. The magnets are based on a cold window frame iron yoke and a saddle-shaped superconducting winding made from a hollow NbTi composite superconducting cable cooled with a forced two-phase helium flow at T = 4.5 K. The maximal operating magnetic field in the aperture is 1.8 T. The magnetic field ramp rate of 1.2 T/s should be achievable. The quench history, AC losses as a function of the magnetic field ramp rate and pressure drop in the cooling channels of the magnets at different pulsed operation modes are presented. | |||
THPME029 | Design of NSLS-II Booster Dipoles with Combined-function Magnetic Field | booster, sextupole, extraction, injection | 3570 |
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Focusing and defocusing dipoles magnets of NSLS-II 3 GeV booster are designed, manufactured and measured in BINP, Russia. The magnets should provide the booster operation at energy from 170 MeV to 3.15 GeV with a 2 Hz frequency. Because of booster compactness the dipoles have quadrupole and sextupole components and should create high quality of field of ± 2·10-4 in region of ± 2 cm. In this paper the design and results of 2D and 3D simulation are presented. | |||
THPME030 | Magnetic Measurement Results of the NSLS-II Booster Dipole Magnets | booster, alignment, sextupole, extraction | 3573 |
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Focusing and defocusing dipole magnets for NSLS-II 3 GeV booster are designed, manufactured and measured in BINP, Russia. Magnetic measurements of 32 BD and 28 BF magnets are made by BINP. In this paper the results of magnetic measurements of dipoles magnets in the field area of 0.638 – 11.829 kGs for BD type and 0.260 - 4.829 kGs for BF type are given. Analysis and comparison with magnetic field simulation are made. | |||
THPME031 | Ramped Magnetic Measurement of NSLS-II Booster Dipoles | vacuum, booster, quadrupole, sextupole | 3576 |
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13. The magnetic system of NSLS II Booster are designed, manufactured and tested in BINP, Russia. The dipoles of the Booster have quadrupole and sextupole components and should create high quality of field ± 2·10-4 in region ± 2 cm. Magnets should provide performance of booster for energy from 170 MeV to 3.15 GeV with 2 Hz frequency. This report considers ramped magnetic measurement of NSLS-II Booster Dipoles. | |||
THPME032 | Magnetic Measurement of the NSLS-II Booster Dipole with Combine Functions | booster, extraction, quadrupole, sextupole | 3579 |
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The magnetic system of NSLS II Booster are designed, manufactured and tested in BINP, Russia. The dipoles of the Booster have quadrupole and sextupole components and should create high quality of field ± 2·10-4 in region ± 2 cm. Magnets should provide performance of booster for energy from 170 MeV to 3.15 GeV with 2 Hz frequency. To measure multipole field components one need to know accurate position of the probes in 3D coordinates. This report considers description of the magnetic measurement stand and achived accuracy for DC case. | |||
THPME036 | Design and Measurement of the Transfer Line Magnets for the Taiwan Photon Source | quadrupole, simulation, booster, linac | 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. | |||
THPME037 | Magnetic Field Character of TPS Booster Magnets | quadrupole, sextupole, multipole, booster | 3594 |
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The Taiwan Photon Source (TPS) is a 3-GeV synchrotron radiation facility operated in top-up injection mode. The booster ring of TPS shares the same tunnel, concentric with the storage ring. The lattice of the booster is a 24-cell DBA of circumference 496.8 m. The energy of the electron beam is ramped from 150 MeV to 3 GeV at repetition rate 3 Hz in the booster ring. The trajectory of the electron beam is controlled with complicated combined-function magnets including combined dipole magnet, combined quadrupole magnet, pure quadrupole magnet, sextupole magnet and corrector magnet. The measurement and performance of these magnets are discussed in this letter. | |||
THPME041 | Configurable Field Magnets for a Proton Beam Dynamics R&D Ring | multipole, injection, proton, space-charge | 3603 |
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Magnets with many independently-powered coils can provide nearly arbitrary combinations of multipoles up to a certain order. This paper gives examples of field quality in such an "omni-magnet", which is normal-conducting and simulated with Poisson. Since the magnets also have quite large apertures they may be used to make a general-purpose FFAG and synchrotron test ring for beam dynamics studies. This could use the 3MeV H− beam from the RAL proton Front End Test Stand (FETS) and outline ring parameters are given for that situation. | |||
THPME044 | Fabrication and Test of a 1 M Long Single-aperture 11 T Nb3Sn Dipole for LHC Upgrades | sextupole, luminosity, interaction-region, magnet-design | 3609 |
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Funding: Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy and European Commission under FP7 project HiLumi LHC, GA no.284404 The planned upgrade of the LHC collimation system includes two additional collimators to be installed in the dispersion suppressor areas around points 2, 3 and 7, and high luminosity interaction regions in points 1 and 5. The necessary longitudinal space for the collimators could be provided by replacing some 8.33 T NbTi LHC main dipoles with 11 T dipoles based on Nb3Sn superconductor and compatible with the LHC lattice and main systems. To demonstrate this possibility Fermilab and CERN have started in 2011 a joint R&D program with the goal of building by 2015 a 5.5-m long twin-aperture dipole prototype suitable for installation in the LHC. An important part of the program is the development and test a series of short single-aperture demonstration dipoles with the nominal field of 11 T at the LHC nominal current of ~11.85 kA and ~20% margin. This paper describes the design features and test results of a 1-m long single-aperture Nb3Sn demonstrator dipole for the LHC collimation system upgrade. |
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THPME045 | TEST RESULTS OF A NB3SN QUADRUPOLE COIL IMPREGNATED WITH RADIATION-RESISTANT MATRIMID 5292 | quadrupole, radiation, collider, controls | 3612 |
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Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. FNAL is developing advanced Nb3Sn magnets for present and future accelerators. Insulation is one of the primary elements of magnet design, essential for maintaining its electrical, mechanical and thermal performance. The Nb3Sn magnet fabrication process involves coil reaction at high temperature and then impregnation with epoxy to restore the insulation electrical and mechanical properties. The traditional epoxy offers adequate structural and electrical properties, but has a low radiation strength which limits the lifetime of accelerator magnets operating in severe radiation environments. Studies to replace epoxy as impregnation material for Nb3Sn coils with high radiation-resistant material have started at FNAL ten years ago. The studies concentrated on the Matrimid® 5292, a bismaleimide based material, which has appropriate viscosity and potlife as well as provides excellent mechanical, electrical and thermal coil properties. A 1 m long Nb3Sn quadrupole coil was recently fabricated, impregnated with Matrimid and tested in a quadrupole magnetic mirror at 4.2 and 1.9 K. Coil test results are presented and compared to the results for similar coils impregnated with epoxy. |
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THPME046 | A Summary of the Quality of the ALS Combined Function Sextupole Magnets | sextupole, multipole, quadrupole, controls | 3615 |
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Funding: This work was supported by the Office of Science, U.S. Department of Energy under DOE contract number DE-AC02-05CH11231. A total of 51 combined function magnets is required to upgrade the Advanced Light Source (ALS) Storage Ring at LBNL. These magnets will provide 4 types of magnetic fields: sextupole, horizontal and vertical dipoles, and skew quadrupole and will enable an emittance reduction and upgrade of the beam quality in the ALS ring. A relatively new procedure using EDM cut poles after core assembly that was first used by Buckley System Ltd, NZ was adopted during the production of these magnets. Also, a new 3D CAD modeling was used for the coil design. A total of 57 magnets (including prototypes and spare magnets) were built by the Shanghai Institute of Applied Physics (SINAP) in China. These magnets have achieved extraordinarily high pole profile accuracies and exhibit excellent coil performance characteristics: resistances and water flows reached a high degree of consistency. Consequently, the system errors of the magnetic field of these magnets all meet the LBNL specifications. This paper will summarize the mechanical quality and magnetic field properties of these magnets. The interrelationship between the qualities of coil and the magnet field will be described as well. |
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THPME052 | Analysis of the NSLS-II Magnet Measurement Data | quadrupole, sextupole, storage-ring, multipole | 3624 |
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Funding: Work supported by U.S. DOE, Contract No. DE-AC02-98CH10886 NSLS-II is a third generation 3GeV light source that is under-construction at the Brookhaven National Laboratory. The 30-DBA-cell storage ring will provide micron size beam resulting from the 1nm emittance. Recently the last magnet was received and the completion of girder installation in the tunnel is foreseeable in a few months. In this paper we will briefly review the physics considerations for the magnet specifications, the major field quality related issues that arose during the fabrication process. Our emphasis will be on the statistical analysis of the magnet measurement results and comparison with the design tolerances. |
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THPWA004 | The HIT Gantry: From Commissioning to Operation | ion, proton, optics, diagnostics | 3636 |
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The patient treatment at the first 360° raster scanning heavy ion gantry of the Heidelberg Ion Therapy Facility (HIT) started in October 2012 using proton and carbon ion beams. HIT is the first dedicated proton and carbon cancer therapy facility in Europe. It uses full 3D intensity controlled raster scanning dose delivering method of pencil beams. The ion energy ranges from ~50 up to 430 MeV/u (ion penetration depths of 20 to 300 mm in water). Beams are provided by a linac-synchrotron-system to four high energy beam lines: 2 horizontal patient treatment rooms; 1 horizontal experimental cave for quality assurance, development, and research work; and the heavy ion gantry. From the first commissioning the libraries of carbon and proton pencil beams at the gantry had been offered with the whole variety of ion beam properties: 255 energy steps, 4 beam foci, 360°, and 10 intensities (106-1010/spill) regarding the central beam. This paper reflects the impact of the subsequent preclinical testing including beam size/position, and dose measurements within the irradiation field of 20x20 cm2 on the further improvement of the ion optical settings of the gantry high energy transfer line. | |||
THPWO004 | RF Tuning of the LINAC4 RFQ | rfq, linac, coupling, quadrupole | 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. | |||
THPWO011 | Status of the SIS100 Heavy Ion Synchrotron Project at FAIR | cryogenics, quadrupole, ion, extraction | 3782 |
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SIS100 is a unique superconducting heavy ion synchrotron, optimized for the acceleration of intense beams of intermediate charge state heavy ions. The operation with such beams has required new synchrotron design features and new technical concepts aiming for minimized ionization beam loss and vacuum dynamics. SIS100 is a superconducting synchrotron because of the required vacuum conditions and pumping power to achieve stable XHV conditions at high intensity operation. The project and procurement status will be presented. | |||
THPWO014 | Design Study of a High Frequency Proton Ladder RFQ | rfq, cavity, proton, antiproton | 3788 |
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For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. In the low energy section, between the Ion Source and the main linac an RFQ has to be designed. Accelerating protons from 95 keV to 3.0 MeV the RFQ will oscillate at 325 MHz. This particular high frequency for an RFQ creates difficulties which are challenging in developing this cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with an ladder type RFQ, especially concerning the dipole component of the accelerating fields, which is almost not noticeable. This paper will show 3D simulations of the general layout and a whole cavity demonstrating the power of a ladder type RFQ. It will outline a possible layout for the RFQ within the new FAIR proton injector. | |||
THPWO034 | Fabrication of the RFQ III for the J-PARC Linac Current Upgrade | rfq, linac, cavity, 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. | |||
THPWO078 | Status of the Upgrade of the CERN PS Booster | injection, booster, extraction, linac | 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. | |||
THPWO079 | A Possible Scheme to Deliver 2 GeV Beams from the CERN PS Booster to the ISOLDE Facility | target, proton, booster, ion | 3942 |
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The CERN PS Booster (PSB) is presently undergoing an upgrade program to increase its beam energy from 1.4 GeV to 2.0 GeV. While this energy upgrade is targeted at LHC-type beams, the option of delivering 2 GeV beams to the ISOLDE facility has also been investigated. In this paper we present a preliminary study for delivering 2 GeV beams to ISOLDE including the physics motivation and the implications on the accelerator hardware. | |||
THPWO081 | Design Options of a High-power Proton Synchrotron for LAGUNA-LBNO | space-charge, proton, emittance, optics | 3948 |
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Design studies have been initiated at CERN, exploring the prospects of future high-power proton beams for producing neutrinos, within the LAGUNA-LBNO project. These studies include the design of a 2 MW high-power proton synchrotron (HP-PS) using the LP-SPL as injector. This paper resumes the design options under study in order to reach this high power, and their implications regarding layout, magnet technology beam loss control and RF considerations. Optics optimization studies are also presented including beam transfer and collimation considerations. | |||
FRXAB201 | Status of CSNS Project | target, quadrupole, linac, cavity | 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] | ||