IPAC2012 - List of Keywords (extraction)

Paper	Title	Other Keywords	Page
MOEPPB001	RF-breakdown Kicks at the CTF3 Two-beam Test Stand	linac, linear-collider, collider, acceleration	73
	A. Palaia, M. Jacewicz, T. Muranaka, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden W. Farabolini CEA/DSM/IRFU, France
	The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RF-breakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements.

MOPPC043	Injection/Extraction of Achromat-based 6D Ionization Cooling Rings for Muons	injection, solenoid, kicker, dipole	229
	X.P. Ding, D.B. Cline UCLA, Los Angeles, California, USA J.S. Berg, H.G. Kirk BNL, Upton, Long Island, New York, USA A.A. Garren, F.E. Mills Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: This work was supported in part by the US Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.). An achromat-based cooing ring using dipoles and solenoids is introduced and it can cool muons by large factors in six dimensions to achieve the necessary luminosity for a muon collider. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We estimate the parameters for the injection system into the solenoid-dipole ring cooler. We also present some simulations for injection/extraction system and discuss the injection/extraction requirements. Al Garren, J.S. Berg, D. Cline, X. Ding, H.G. Kirk, “Robust 6D μ± cooling using a solenoid-dipole ring cooler for a muon collider”, NIM A 654 (2011) 40-44.

MOPPC046	End-to-End G4Beamline Simulation of an Inverse Cyclotron for Muon Cooling	cyclotron, simulation, emittance, solenoid	238
	T.L. Hart, T.H. Luo, D.J. Summers UMiss, University, Mississippi, USA K. Paul Tech-X, Boulder, Colorado, USA
	An inverse cyclotron is a novel, intriguing idea for muon cooling necessary for proposed neutrino factories and muon colliders. We present the latest results of an end-to-end inverse cyclotron simulation that cools muons in the following sequence: single turn injection and initial cooling of 100 MeV kinetic energies to about 5 MeV with lithium hydrogen wedges; further substantial cooling to keV range kinetic energies and trapping with carbon foils and a rising electric field; and re-acceleration of the cooled, trapped muons back to 100 MeV. For neutrino factory and muon collider applications, the time of the entire cooling/trapping/re-acceleration process needs to be comparable to the muon lifetime so that decay losses are tolerable and the acceptance of the inverse cyclotron needs to be sufficiently large (on order 10 mm-rad normalized emittance). The latest progress toward these ends is presented.

MOPPC069	Quantitative Simulation of NIRS-930 Cyclotron	cyclotron, acceleration, simulation, electromagnetic-fields	292
	V.L. Smirnov, S.B. Vorozhtsov JINR/DLNP, Dubna, Moscow region, Russia A. Goto, S. Hojo, T. Honma, K. Katagiri NIRS, Chiba-shi, Japan
	The results of the computer modelling of the structural elements of the NIRS-930 cyclotron operational at the National Institute of Radiological Sciences (Chiba, Japan) are presented. The integrated approach to modelling of the cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics simulations is described. A computer model of the cyclotron was constructed. Electric and magnetic field distributions and mechanical structures were converted to the beam dynamics code for simulations, in which particle losses on the surfaces of the system elements were estimated. The existing data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron and beam parameter measurements are used for calibration of the simulations. New acceleration regimes could be formulated with the help of the constructed computer model of the machine.

MOPPD002	Ultra-low Energy Storage Ring at FLAIR	antiproton, storage-ring, ion, lattice	367
	C.P. Welsch, D. Newton, M.R.F. Siggel-King Cockcroft Institute, Warrington, Cheshire, United Kingdom O.E. Gorda, O. Karamyshev, G.A. Karamysheva, M. Panniello, A.I. Papash, A.V. Smirnov MPI-K, Heidelberg, Germany J. Harasimowicz, M. Putignano, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom
	Funding: The support of the HGF and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080, the Max Planck Institute for Nuclear Physics and the STFC Grant ST/G008248/1 is acknowledged. The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV. Based on the original design concept developed in 2005, the USR has been completely redesigned over the past few years. The ring structure is now based on a 'split achromat' lattice. This ensures compact ring dimensions of 10 x 10 m, whilst allowing both, in-ring experiments with gas jet targets and studies with extracted beams. In the USR, a wide range of beam parameters will be provided, ranging from very short pulses in the nanosecond regime to a coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Furthermore, studies into beam diagnostics methods for the monitoring of ultra-low energy ions at beam intensities less than 10⁶ were carried out. Here, we present the USR design with an emphasis on the expected beam parameters available to the experiments at FLAIR.

MOPPD020	A Model for a High-Power Scaling FFAG Ring	injection, dynamic-aperture, lattice, proton	409
	G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied. G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD023	Correction of the nu_r=3/2 Resonance in TRIUMF Cyclotron	resonance, cyclotron, TRIUMF, simulation	415
	T. Planche, R.A. Baartman, Y.-N. Rao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Imperfections in the TRIUMF cyclotron are a source of field errors which slightly violate the 6-fold symmetry of the ring. Among them, the third harmonic of the magnetic gradient errors drives the ν_r=3/2 resonance. This results in a modulation of the current density versus radius observed after the resonance crossing all the way to the extraction (480 MeV). The cyclotron has sets of harmonic correction coils at different radii, each set constituted of 6 pairs of coils placed in a 6-fold symmetrical manner. The 6-fold symmetry of this layout makes that a single set of harmonic coils cannot provide a full correction of third harmonic errors driving the ν_r=3/2 resonance. The last two sets of harmonic correction coils (number 12 and 13) are azimuthally displaced. In this study, we use this fact to achieve a full correction of the resonance. We also present experimental measurements that demonstrate the full correction.

MOPPD026	A Superconducting Ring Cyclotron for the DAEδALUS Experiment	cyclotron, proton, injection, focusing	421
	L. Calabretta INFN/LNS, Catania, Italy A. Calanna, D. Campo CSFNSM, Catania, Italy M.M. Maggiore, L.A.C. Piazza INFN/LNL, Legnaro (PD), Italy F. Méot BNL, Upton, Long Island, New York, USA
	Funding: Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud. The experiment DAEδALUS, proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector* and of a booster ring cyclotron has been proposed**. The booster Superconducting Ring Cyclotron is able to accelerate a H²⁺ molecule beam up to 800 MeV/n with a peak current of 10 mA and average power higher than 1.6 MW. To simplify the design of the superconducting magnetic coils, to minimize the radial force shift and to increase the room to host the RF cavities, the previous study has been updated increasing the injection energy of the H²⁺ and also the injection energy. The updated study on the magnetic sector configuration, on the superconducting coils and the magnetic forces are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too. J. Alonso et al., Jun2010 e-Print: arXiv:1006.0260 L. Calabretta, Proc. IPAC 2011, WEPS073 (2011). * L. Calabretta, Cyclotrons 2010, Lanzhou.

MOPPD027	A Compact High Intensity Cyclotron Injector for DAEδALUS Experiment	cyclotron, resonance, beam-losses, simulation	424
	L. Calabretta, D. Rifuggiato INFN/LNS, Catania, Italy A. Adelmann Paul Scherrer Institut, Villigen, Switzerland A. Calanna, D. Campo CSFNSM, Catania, Italy M.M. Maggiore, L.A.C. Piazza INFN/LNL, Legnaro (PD), Italy J.J. Yang CIAE, Beijing, People's Republic of China
	Funding: Istituto Nazionale di Fisica Nucleare - Laboratori Nazionale del Sud. The experiment DAEδALUS, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector and of a booster ring cyclotron has been proposed. The main characteristics of the new kind of separated sector cyclotron injector able to accelerate a H²⁺ molecule beam up to 60 MeV/n will be presented. Due to the low duty cycle, the peak current to be accelerated is 5 mA. The problem related to the injection of a H²⁺ beam, delivered by a compact ion source, and to the space charge effects will be discussed. To allow an easier injection in the booster Superconducting Ring Cyclotron the extraction energy has been increased up to 60 MeV/n. The pole gap was decreased to 60 mm to achieve a more efficient beam extraction. The updated configuration of the magnetic sectors, of the isochronous magnetic field and beam dynamics along extraction path and during the acceleration will be presented, too. J. Alonso et al., "Novel Search for CP Violation in the Neutrino Sector: DAEδALUS," Jun2010 e-Print: arXiv:1006.0260 ** L. Calabretta, Proc. of IPAC 2011, WEPS073, p. 2673 (2011).

MOPPD039	Status of the Design of the LBNE Neutrino Beamline	target, proton, status, shielding	451
	V. Papadimitriou, R. Andrews, M.R. Campbell, A.Z. Chen, S.C. Childress, C.D. Moore Fermilab, Batavia, USA
	Funding: DE-AC02-07CH11359 with the United States Department of Energy. The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota, about 1300 km away. The neutrinos are produced as follows: First, protons extracted from the MI-10 section of the Main Injector (60-120 GeV) hit a solid target above grade and produce mesons. Then, the charged mesons are focused by a set of focusing horns into a 250 m long decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the modeling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW in order to enable the facility to run with an upgraded accelerator complex. We discuss here the status of the design and the associated challenges.

MOPPD046	Lifetime of the Highly Efficient H⁻ Ion Sources	cathode, ion, plasma, electron	466
	V.G. Dudnikov Muons, Inc, Batavia, USA D.S. Bollinger Fermilab, Batavia, USA D.C. Faircloth, S.R. Lawrie STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531 Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

MOPPD051	Performance of Resonant Slow Extraction from J-PARC Main Ring	feedback, quadrupole, proton, septum	481
	M. Tomizawa, Y. Arakaki, T. Kimura, S. Murasugi, R. Muto, H. Nakagawa, K. Okamura, H. Sato, Y. Shirakabe, T. Toyama, E. Yanaoka, M. Yoshii KEK, Ibaraki, Japan D. Horikawa Sokendai, Ibaraki, Japan K. Mochiki Tokyo City University, Tokyo, Japan A. Schnase JAEA/J-PARC, Tokai-mura, Japan
	Proton beam accelerated by the J-PARC main ring (MR) with an imaginary transition lattice is slowly extracted by a third integer resonant extraction scheme and delivered to the hadron experimental hall. One of the critical issues in the slow extraction from a high intensity proton synchrotron is the inevitable beam loss caused by the extraction process at septum devices. A design with low beam loss (high extraction efficiency) is required to reduce machine damage and radiation exposure during hands-on maintenance. We have designed the slow extraction scheme to obtain high extraction efficiency for the MR lattice. The scheme has a large step size and a small angular spread enabling a hit rate of the beam on the developed thin septum device. Since the first 30 GeV proton beam was successfully delivered to the experimental hall in January 2009, an extremely high extraction efficiency of 99.5% has been achieved by an intensive beam tuning. In this paper, we report details of such performance. We will also describe some schemes to improve the serious spiky spill time structure due to large current ripples from the power supplies for the bending and quadrupole magnets.

MOPPD052	Study of Electrostatic Septum by Low-Z Material for High Intensity Proton Beam	septum, scattering, proton, beam-losses	484
	D. Horikawa Sokendai, Ibaraki, Japan Y. Arakaki, K. Okamura, Y. Shirakabe, M. Tomizawa KEK, Ibaraki, Japan I. Sakai University of Fukui, Faculty of Engineering, Fukui, Japan T. Shimogawa Saga University, Faculty of Science and Engineering, Saga, Japan
	In a high-intensity proton accelerator, the beam loss at the time of late beam extraction causes radioactivation of apparatus. It takes out and is a problem serious to that of upper about beam power. Its attention was paid to electric septum (ESS) of the equipment used for beam extraction for problem solving. The septum section of ESS which beam hits directly is usually used for tungsten. Therefore, it is low atomic number material to the septum section. Development of the new model ESS using the textile material carbon fiber of a certain carbon (CF) was started. Is it a problem in CF at processability? Is it using for the septum section of ESS for a certain reason? Difficult it was. Therefore, it succeeded in obtaining required form and intensity by developing the twisting thread technology of CF. Moreover, the tension strength test of CFwire and the pyrogenicity test by electric current were done. Is it the tension intensity and heat durability which exceed the existing tungsten wire? It was confirmed. In addition to the ESS development technique using these new materials, and a result, a future measure is reported.

MOPPD054	Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS	injection, septum, beam-transport, simulation	490
	P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPD059	Proposal of a Dummy Septum to Mitigate Ring Irradiation for the CERN PS Multi-Turn Extraction	septum, beam-losses, vacuum, shielding	499
	M. Giovannozzi, H. Bartosik, D. Bodart, J. Borburgh, R.J. Brown, S. Damjanovic, S.S. Gilardoni, B. Goddard, C. Hernalsteens, M. Hourican, M. Widorski CERN, Geneva, Switzerland
	High activation of the magnetic extraction septum of the CERN PS machine was observed due to the losses of the continuous beam extracted via the Multi-Turn Extraction (MTE) method. The resulting activation is however incompatible with safe operation so a mitigation measure was required and found, namely the installation of a passive dummy septum to protect the actual one seems to provide the required reduction in activation in the extraction area. The shielded dummy septum is intended to absorb particles during the rise time of the MTE extraction kickers, avoiding the beam impact on the blade of the active magnetic extraction septum. The principle of the proposed modifications of the PS layout will be presented together with the studies aimed at finalising the new configuration.

MOPPD060	Modified Extraction Scheme for the CERN PS Multi-Turn Extraction	septum, kicker, beam-losses, quadrupole	502
	M. Giovannozzi, S.S. Gilardoni, C. Hernalsteens, A. Lachaize, G. Métral CERN, Geneva, Switzerland
	High-activation of the extraction magnetic septum of the CERN PS machine was observed due to the losses of the continuous beam extracted via the Multi-Turn Extraction (MTE) method. A possible mitigation measure consists of using an existing electrostatic septum, located upstream of the extraction magnetic septum, to deflect the beam. This would highly decrease the beam losses, and hence the induced activation, during the rise time of the MTE kickers due to the reduced thickness of the electrostatic septum with respect to the magnetic one. The layout of this new extraction will be described in detail and the results of beam measurements presented.

MOPPD067	Novel Slow Extraction Scheme for Proton Accelerators Using Pulsed Dipole Correctors and Crystals	septum, proton, scattering, betatron	517
	V.D. Shiltsev Fermilab, Batavia, USA
	Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359 Slow extraction of protons beams from circular accelerators is currently widely used for a variety of beam-based experiments. The method has some deficiencies including limited efficiency of extraction, radiation induced due to scattering on the electrostatic septa and limited beam pipe aperture, beam dynamics effects of space charge forces and magnet power supplies ripple. Here we present a novel slow extraction scheme employing a number of non-standard accelerator elements, such as Silicone crystal strips and pulsed strip-line dipole correctors, and illustrate practicality of these examples at the 8 GeV proton Recycler Ring at Fermilab.

MOPPD069	Challenges for the SNS Ring Energy Upgrade	injection, electron, kicker, septum	520
	M.A. Plum, T.V. Gorlov, J.A. Holmes, T. Hunter, R.T. Roseberry, J. G. Wang ORNL, Oak Ridge, Tennessee, USA
	Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725. The Oak Ridge Spallation Neutron Source accumulator ring presently operates at a beam power of about 1 MW and a beam energy of 925 MeV. A power upgrade is planned to increase the beam energy to 1.3 GeV. For the accumulator ring this mostly involves modifications to the injection and extraction sections. A variety of modifications to the existing injection section were necessary to achieve 1 MW, and the tools developed and the lessons learned from this work are now being applied to the design of the new injection section. This paper will discuss the tools and the lessons learned, and also present the design and status of the upgrades to the accumulator ring.

MOPPD081	Upgrade of the LHC Beam Dumping Protection Elements	simulation, kicker, dumping, vacuum	556
	W.J.M. Weterings, T. Antonakakis, B. Balhan, J. Borburgh, B. Goddard, C. Maglioni, R. Versaci CERN, Geneva, Switzerland
	The Beam Dumping System for the Large Hadron Collider comprises for each ring a set of horizontally deflecting extraction kicker magnets, vertically deflecting steel septa, dilution kickers and finally, a couple of hundred meters further downstream, an absorber block. A mobile diluter (TCDQ) protects the superconducting quadrupole immediately downstream of the extraction as well as the arc at injection energy and the triplet aperture at top energy from bunches with small impact parameters, in case of a beam dump that is not synchronized with the particle free gap or a spontaneous firing of the extraction kickers. Simulations have shown that an asynchronous dump of a 7 TeV nominal beam into the TCDQ absorber blocks could damage it. This paper describes the proposed changes to this device in order to maintain the protection for the downstream elements while reducing the risk of damaging the TCDQ in case of such a beam loss.

MOPPP041	Effect of Roughness on Emittance of Potassium Cesium Antimonide Photocathodes	emittance, cathode, laser, electron	655
	T. Vecchione, J. Feng, H.A. Padmore, W. Wan LBNL, Berkeley, California, USA I. Ben-Zvi, M. Ruiz-Osés, L. Xue Stony Brook University, Stony Brook, USA D. Dowell SLAC, Menlo Park, California, USA T. Rao, J. Smedley BNL, Upton, Long Island, New York, USA
	Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the U. S. Department of Energy, under Contract DE-AC02-05CH11231, KC0407-ALSJNT-I0013, and DE-SC0005713 Here we present first measurements of the effect of roughness on the emittance of K2CsSb photocathodes under high fields. We show that for very thin cathodes the effect is negligible at up to 3 MV/m but for thicker and more efficient cathodes the effect becomes significant. We discuss ways to modify the deposition to circumvent this problem.

MOPPP052	Booster Synchrotron for SIRIUS Light Source	booster, injection, dipole, emittance	679
	F. H. de Sá, L. Liu, A.R.D. Rodrigues LNLS, Campinas, Brazil
	A full energy 3 GeV booster for the new Brazilian Synchrotron Light Laboratory (LNLS) third generation light source, SIRIUS, is proposed. The 144 m circumference magnetic lattice consists of two super-periods of FODO cells with defocusing dipoles and focusing quadrupoles. The optics provides a low emittance beam of 38 nm.rad at 3 GeV, high horizontal betatron and zero dispersion functions at straight sections. The top-up operation requires a cycling energy ramp from 150 MeV to 3 GeV with repetition rate of 1 Hz.

MOPPP060	Top-Off Mode of Operations: Setting Limits on the Extracted Beam Energy by Constraining Currents of Multiple Booster Dipole Power Supplies.	dipole, booster, lattice, injection	696
	T.V. Shaftan BNL, Upton, Long Island, New York, USA
	In preparation for top-off mode of the NSLS-II operations we have studied impact of errors in the dipole power supply current on the extracted beam energy, which has to be interlocked so to satisfy the safety requirements. The NSLS-II booster dipole circuits are combined into 3 independent PS circuits, which adds complexity to the analysis of the extracted beam energy limits.

MOPPR002	Overview of the Beam Diagnostics in the MedAustron Accelerator: Design Choices and Test Beam Commissioning	emittance, synchrotron, injection, proton	774
	F. Osmic, M. Feurstein, A. Gyorgy, A. Kerschbaum, M. Repovz, S.M. Schwarz EBG MedAustron, Wr. Neustadt, Austria G. Burtin CERN, Geneva, Switzerland
	The MedAustron center is a synchrotron based accelerator complex for cancer treatment and for clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study and its technical implementation by the Italian CNAO foundation in Pavia. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensity and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices, and reports the first beam commissioning results from the ITS.

MOPPR008	The Beam Loss Monitoring System at ELSA	injection, electron, booster, monitoring	786
	D. Proft, A. Balling, F. Frommberger, W. Hillert ELSA, Bonn, Germany
	A new diagnostic tool to monitor beam loss in the storage ring at the Electron Stretcher Facility ELSA has been set up. It enables the investigation of causes for electron loss in real time, providing an essential tool needed to achieve the planned beam current upgrade from 30 mA to 200 mA. The monitoring system consists of 32 pin-diode based radiation detectors spread around the storage ring. Therefore, individual electron loss can be localized after each quadrupole. The readout system was designed to allow an integration of single loss events within 70 μs in order to be able to correlate these events to machine state changes. The used monitoring hardware and readout system will be detailed. Furthermore first measurements of the beam loss during injection, the fast energy ramp during acceleration and the extraction phase will be presented.

MOPPR010	Simultaneous Measurement of Emittance at the Storage Ring and the External Beamlines of ELSA	emittance, quadrupole, synchrotron, diagnostics	792
	S. Zander, F. Frommberger, W. Hillert, D. Proft ELSA, Bonn, Germany
	Funding: Funded by the DFG within the SFB / TR 16. The Electron Stretcher Facility (ELSA) consists of several accelerator stages, the last one being a storage ring providing a beam of polarized electrons of up to 3.5 GeV. To ensure a high duty cycle, a slow extraction via a third integer resonance is applied at ELSA. The resonance extraction cause a variation of the emittance in the external beamline. A system for simultaneous measurement of emittance in the storage ring and the external beamlines has been installed. First results including a comparison of both emittances will be shown.

MOPPR013	Beam Loss and Transmission Control at FAIR	controls, ion, synchrotron, proton	801
	M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg, A. Reiter GSI, Darmstadt, Germany W. Vodel HIJ, Jena, Germany
	FAIR, the Facility for Antiproton and Ion Research, is presently entering the final layout phase at GSI. The injector chain consists of the existing linear accelerator UNILAC and synchrotron SIS18, plus a new dedicated 70 MeV high-intensity proton Linac. Along the injector chain to the main synchrotron SIS100 as well as in the beam transport lines, which connect synchrotrons, storage rings and experimental areas, beam transmission or vice versa beam loss have to be controlled very precisely. To supply a maximum intensity of 5·10¹¹ U²⁸⁺/spill to experiments and to prevent machine damages by intense beams, an integrated system for transmission and loss control is mandatory. While various kinds of beam current transformers control transmission online, intercepting Particle Detector Combinations (scintillators, ionization chambers, secondary electron monitors) are foreseen for optimization runs. External Beam Loss Monitors indirectly detect loss positions by measuring secondary particles. This contribution summarizes the requirements for the related detector systems and presents basic concepts for beam loss and transmission control at FAIR.

MOPPR028	Upgrade Plan of BLM System of J-PARC MR	injection, proton, ion, monitoring	837
	K. Satou, T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR042	Characterization Tests of a Stripline Beam Position Monitor for the CLIC Drive Beam	impedance, quadrupole, simulation, feedback	873
	A. Benot-Morell, A. Faus-Golfe, J.J. García-Garrigós IFIC, Valencia, Spain A. Benot-Morell, L. Søby CERN, Geneva, Switzerland J.M. Nappa, J. Tassan-Viol, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: FPA2010-21456-C02-01, SEIC-2010-00028 A prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics has been developed at CERN in collaboration with SLAC, LAPP and IFIC. In this paper, the design and simulations of the BPM with the analog readout chain and the BPM test bench are described, and the results of the first characterization tests are presented. The position resolution and accuracy parameters are expected to be below 2μm and 20μm respectively for a beam with a bunching frequency of 12GHz, an average current of 101A and a machine repetition rate of 50Hz.

MOPPR064	Development of a Turn-by-Turn Beam Position Monitoring System for Multiple Bunch Operation of the ATF Damping Ring	damping, synchrotron, feedback, monitoring	930
	P. Burrows, R. Apsimon, D.R. Bett, N. Blaskovic Kraljevic, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry JAI, Oxford, United Kingdom B. Constance CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	An FPGA-based monitoring system has been developed to study multi-bunch beam instabilities in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). The system utilises a stripline beam position monitor (BPM) and a single-stage down-mixing BPM processor. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR with c. 150ns bunch spacing, or the head bunch of up to three trains in a multi-bunch mode with bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software allow the recording of turn-by-turn data. An overview of the system and performance results will be presented.

MOPPR065	A Low-latency Sub-micron Resolution Stripline Beam Position Monitoring System for Single-pass Beamlines	monitoring, feedback, linear-collider, collider	933
	P. Burrows, D.R. Bett, N. Blaskovic Kraljevic, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry JAI, Oxford, United Kingdom R. Apsimon, B. Constance CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	A low-latency, sub-micron resolution stripline beam position monitoring system has been developed for use in single-pass beamlines. The fast analogue front-end signal processor is based on a single-stage RF down-mixer and is combined with an FPGA-based system for digitisation and further signal processing. The system has been deployed and tested with beam at the Accelerator Test Facility at KEK. Performance results are presented on the calibration, resolution and stability of the system. A detailed simulation has been developed that is able to account for the measured performance.

MOPPR066	Study of Transverse Pulse-to-Pulse Orbit Jitter at the KEK Accelerator Test Facility 2 (ATF2)	simulation, feedback, controls, linear-collider	936
	J. Resta-López, J. Alabau-Gonzalvo IFIC, Valencia, Spain R. Apsimon, B. Constance, A. Gerbershagen CERN, Geneva, Switzerland D.R. Bett, P. Burrows, G.B. Christian, M.R. Davis, C. Perry JAI, Oxford, United Kingdom
	Funding: FPA2010-21456-C02-01 For future linear colliders the precise control and mitigation of pulse-to-pulse orbit jitter will be very important to achieve the required luminosity. Diagnostic techniques for the orbit jitter measurement and correction for multi-bunch operation are being addressed at the KEK Accelerator Test Facility 2 (ATF2). In this paper we present recent studies on the vertical jitter propagation through the ATF2 extraction line and final focus system. For these studies the vertical pulse-to-pulse position and angle jitter have been measured using the available stripline beam position monitors in the beamline. The cases with and without intra-train orbit feedback correction in the ATF2 extraction line are compared.

TUXA01	Status of the J-PARC Facility	linac, neutron, hadron, synchrotron	1005
	S. Nagamiya JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	This presentation should provide a summary of the status and eventual re-commissioning of the J-PARC facility following the 2011 earth quake and tsunami.
	Slides TUXA01 [33.003 MB]

TUOBA01	Summary of Fermilab’s Recycler Electron Cooler Operation and Studies	electron, antiproton, emittance, ion	1068
	L.R. Prost, A.V. Shemyakin Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. Fermilab’s Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.
	Slides TUOBA01 [2.503 MB]

TUPPC005	Optimization of the SIS100 Nonlinear Magnet Scheme for Slow Extraction	sextupole, octupole, lattice, dynamic-aperture	1158
	A. Saa Hernandez, M.M. Kirk, D. Ondreka, N. Pyka, S. Sorge, P.J. Spiller GSI, Darmstadt, Germany
	The SIS100 superconducting synchrotron was initially planned mainly for fast extraction of protons and heavy ions. Due to the delay of the construction of the SIS300 synchrotron, SIS100 has to be able to provide slowly extracted heavy ion beams to the experiments. To improve the robustness of the slow extraction from SIS100, a lattice review was performed, resulting in an optimization of the nonlinear magnet scheme. In the original scheme the Hardt condition cannot be established due to a collapse of the dynamic aperture caused by the chromatic sextupoles. In the optimized scheme the positions of the chromatic sextupoles are modified and octupoles are employed to compensate the second order effects of these sextupoles. In addition, the number of resonance sextupole magnets is reduced. With the new scheme, the Hardt condition can be established, leading to higher extraction efficiency. The separatrix can be freely adjusted, and closed orbit control is improved.

TUPPC006	CW Energy Upgrade of the Superconducting Electron Accelerator S-DALINAC	recirculation, dipole, linac, simulation	1161
	M. Kleinmann, J. Conrad, R. Eichhorn, F. Hug, N. Pietralla TU Darmstadt, Darmstadt, Germany
	Funding: This work is supported by the DFG through SFB 634. The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected and to be finished by 2013. We review the design constraints related to the existing beam lines, report in detail on the magnet design (being the key issue) and the lattice calculations for the additional recirculation path.

TUPPC012	Optics of Extraction Lines at CNAO	proton, dipole, ion, septum	1179
	E. Bressi, L. Falbo, C. Priano, M. Pullia CNAO Foundation, Milan, Italy C. Biscari INFN/LNF, Frascati (Roma), Italy
	The CNAO (National Center for Oncological Hadrontherapy), is the first Italian center for deep hadrontherapy with proton and carbon ion beams, treating patients since fall 2011. The beam is delivered to the patient through a high energy transfer line (HEBT). The line is equipped with a horizontal switching dipole that carries the beam in three treatment rooms and a vertical switching dipole that allows a vertical delivery of the beam in the central treatment room. The CNAO HEBT commissioning has been carried out using proton and Carbon beams in the full range of energies: 60 to 250 MeV/u for protons, 120 to 400 MeV/u for Carbon ions. Optimization of the beam lines setup has been carried out for few energies, applying beam magnetic rigidity scaling for the full range in steps of the order of 1 MeV. The scaling has proven to be satisfactory for most elements, and only minor adjustments in the initial part of the line were needed to fulfill tolerances in all the range. Repeatability of magnetic settings is supported by measurements along the lines. Finally the results in terms of beam dimensions, beam transmission and beam position at the patient position are presented.

TUPPC030	Status of the Ion Sources at ESS-Bilbao	ion, controls, ion-source, plasma	1227
	J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz ESS Bilbao, Bilbao, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain R. Miracoli ESS-Bilbao, Zamudio, Spain
	Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

TUPPC059	Extraction of the Lie Map from Realistic 3D Magnetic Field Map	dipole, quadrupole, dynamic-aperture, lattice	1308
	Y. Li BNL, Upton, Long Island, New York, USA X. Huang SLAC, Menlo Park, California, USA
	Funding: Supported by Department of Energy Contract No. DE-AC02-98CH10886. We present a method to extract the Lie map of any arbitrary accelerator magnet from its actual 3D field map. After fitting a Taylor map from multi-particle tracking trajectories through the actual field, we factorize the map into a Lie map using Dragt-Finn's method. This method is validated by comparing with COSY-infinity for a soft-edge quadrupole model. Applications of extracting symplectic maps for the SPEAR and NSLS-II dipoles are shown as examples. A comparison of the map-tracking results against the direct field-integration-based method also is given.

TUPPC062	Transfer of Polarized 3He Ions in the AtR Beam Transfer Line	injection, ion, dipole, proton	1317
	N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US Department of Energy In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC077	Numerical Study of Beam Trapping in Stable Islands for Simple 2D Models of Betatronic Motion	emittance, simulation, resonance, octupole	1350
	M. Giovannozzi, C. Hernalsteens CERN, Geneva, Switzerland
	An essential ingredient for the proposed Multi-Turn Extraction (MTE) at the CERN PS is the beam trapping in stable islands. The control of the trapping process is essential for the quality of the final beam in terms of intensity sharing and emittance. In this paper, the splitting process is studied quantitatively by means of numerical simulations performed on 2D model representing the horizontal non-linear betatronic motion. The results are reviewed and discussed in details.

TUPPC082	Non-linear Beam Dynamics Tests at the CERN PS in the Framework of the Multi-turn Extraction	pick-up, synchrotron, coupling, betatron	1365
	M. Giovannozzi, G. Arduini, J.M. Belleman, S.S. Gilardoni, C. Hernalsteens, A. Lachaize, G. Métral, Y. Papaphilippou CERN, Geneva, Switzerland
	In the framework of the CERN PS Multi-Turn Extraction several campaigns of measurements probing the non-linear beam dynamics have been carried out. These measurements range from the measurement of non-linear chromaticity to phase space portraits, de-coherence and re-coherence measurements, secondary island tune etc. In this paper these measurements will be reviewed and the results presented and discussed in details.

TUPPD001	The Mice Muon Beamline and Host Accelerator Beam Bump	target, proton, controls, injection	1404
	A.J. Dobbs, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom D.J. Adams STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom E. Overton, P.J. Smith Sheffield University, Sheffield, United Kingdom
	Funding: Science and Technology Facilities Council The international Muon Ionization Cooling Experiment (MICE) is designed provide a proof of principle of the technique of ionization cooling, that is the reduction of the phase space of a muon beam via ionization energy loss in absorbers. Subsequent reacceleration is then provided by RF cavities (‘‘sustainable cooling''). Ionization cooling represents an important step toward future facilities based on stored muons beams, such as a future Neutrino Factory or Muon Collider. The MICE Muon Beam begins with the decay of pions produced by a cylindrical titanium target dipped into the circulating proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. This generates a pion shower which is captured and subsequently decays producing the muon beam. A secondary effect of the MICE target is to cause an increase in the number of protons lost from the ISIS beam. It is important that this effect be minimized. An overview is presented here of the MICE Muon Beam, including the results of a study in to the effect of raising the vertical position of the ISIS beam (a ‘‘beam bump'') in the vicinity of the MICE target.

TUPPD020	An EMMA Racetrack	dipole, quadrupole, injection, electron	1452
	B.D. Muratori, J.K. Jones STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H.L. Owen UMAN, Manchester, United Kingdom
	EMMA (Electron Machine for Many Applications) is the world’s first prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. Alternative methods of injection and extraction into the EMMA ring are explored together with their feasibility and implications. The option of developing nested racetracks to achieve a particular desired energy is also explored.

TUPPD026	Study of the RFQ Beam Cooler for SPES project	ion, rfq, quadrupole, emittance	1467
	M.M. Maggiore, A.M. Porcellato, S. Stark INFN/LNL, Legnaro (PD), Italy
	The SPES project is the new Radioactive Ion Beam facility under construction at Laboratori Nazionali of Legnaro, Italy. In this framework in order to improve the beam quality in terms of emittance and energy spread, a study of a new RFQ beam cooler device is accomplishing. The electromagnetic design of the RFQ section and the electrostatic layout of the injection and extraction regions have been done. The study about the beam dynamic is going on by means of dedicated codes which allow to take into account the interaction of the ions with the buffer gas needed to cool the beams. The status of the project and the results will be shown in this report.

TUPPD039	Simulation Study of Space Charge Effects for a 100-keV, 150-mA Class Deuteron Source	emittance, simulation, plasma, focusing	1491
	M. Ichikawa, H. Suzuki Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan S. Maebara JAEA, Ibaraki-ken, Japan
	Ion sources providing high current beam with low emittance are required for accelerators to expand to apply them to fusion material science. A 100-keV, 150-mA class deuteron source with low emittance is required for an accelerator-based neutron irradiation facility to develop fusion materials, and the study for space charge effects in the range of a 20- to 150-mA deuteron beam is indispensable to extract the low beam emittance. For this purpose, each ion source to extract the beam current of 20, 50, 100, and 150 mA was designed by the Igun code, under the condition to extract a beam radius of 4 mm, a beam energy of 100 keV, and a normalized emittance of 0.2 PI mm mrad. In this article, these simulation results from the viewpoint of space charge effects will be presented in detail.

TUPPD046	Characterization of Li⁺ Alumino-Silicate Ion Source for Target Heating Experiments	ion, ion-source, space-charge, brightness	1506
	P.K. Roy, W.G. Greenway, J.W. Kwan, S.M. Lidia, P.A. Seidl, W.L. Waldron LBNL, Berkeley, California, USA D.P. Grote LLNL, Livermore, California, USA
	Funding: *This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231. The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li⁺ ion beam with energy 1.2–3 MeV to achieve uniform heating up to 0.1–1 eV. Experiments will be done using the Neutralized Drift Compression Experiment-II (NDCX-II) facility. The NDCX-II accelerator has been designed to use a large diameter (10.9 cm) Li⁺ doped alumino-silicate source to produce short pulses of ≈93 mA beam current. Fabrication of a lithium source is complex, it is necessary to apply a higher temperature (>1200-degC) for thermionic emission, and the beam current density of this source is ~1mA/cm² in the space-charge limited regime. Li⁺ emission is lower than the other alkaline ions sources (K⁺, Cs⁺). The lifetime of this source is roughly 50 hours, when pulsed. Characterization of an operational lithium alumino-silicate ion source, including beam emittance, is presented.

TUPPR016	Final Cross Section Design of the Stripline Kicker for the CLIC Damping Rings	impedance, damping, kicker, wakefield	1843
	C. Belver-Aguilar, A. Faus-Golfe IFIC, Valencia, Spain M.J. Barnes CERN, Geneva, Switzerland F. Toral CIEMAT, Madrid, Spain
	Funding: IDC-20101074 and FPA2010-21456-C02-01 The CLIC design relies on the presence of Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve, through synchrotron radiation, the very low emittance needed to fulfill the luminosity requirements. Kicker systems are required to inject and extract the beam from the Pre-Damping and Damping Rings. In order to achieve low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. In this paper the final design for the DR kicker is presented, including an optimization of the geometric parameters to achieve the requirements for both characteristic impedance and field homogeneity. In addition, a sensitivity analysis of characteristic impedance and field homogeneity to geometric parameters is reported.

TUPPR019	High Power Operation with Beam of a CLIC PETS Equipped with ON/OFF Mechanism	recirculation, simulation, controls, vacuum	1852
	I. Syratchev, R. Corsini, A. Dubrovskiy, P.K. Skowroński CERN, Geneva, Switzerland R.J.M.Y. Ruber Uppsala University, Uppsala, Sweden
	One of the feasibility issues of the CLIC two-beam scheme is the possibility of rapidly switching off the RF power production in individual Power Extraction and Transfer Structures (PETS) in case of breakdowns, either in the PETS or one of the main beam accelerating structures. The proposed solution is to use a variable external reflector connected to the PETS. When activated, this scheme allows us to manipulate gradually the RF power transfer to the accelerating structure and to reduce the RF power production in the PETS itself by a factor of 4. Recently the first operation of the Two Beam Test Stand (TBTS) PETS equipped with an on-off mechanism has been performed in CTF3. In this paper we will present the results of the PETS operation when powered by the drive beam up to high peak power levels (>100 MW) and compare them to expectations.

TUPPR031	Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3	quadrupole, alignment, lattice, linac	1885
	R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini CERN, Geneva, Switzerland E. Adli University of Oslo, Oslo, Norway
	The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

TUPPR060	Detection of Ground Motion Effects on the Beam Trajectory at ATF2	ground-motion, quadrupole, lattice, linear-collider	1954
	Y. Renier, J. Pfingstner, D. Schulte, R. Tomás CERN, Geneva, Switzerland
	The ATF2 experiment is currently demonstrating the feasibility of the beam delivery system for the future linear collider. The tunning is very critical to obtain the nanometer vertical beam size at the interaction point and in the case of CLIC, ground motion effects on the beam must be corrected. In this respect, as a proof of principle of a ground motion feed forward, the ground motion effects on the beam trajectory are extracted from the beam position monitor readings.

TUPPR086	Transport from the Recycler Ring to the Antiproton Source Beamlines	proton, kicker, antiproton, booster	2026
	M. Xiao Fermilab, Batavia, USA
	In the post-Nova era, the protons are directly transported from the Booster ring to the Recycler ring rather than the Main Injector. For Mu2e and g-2 project, the Debuncher ring will be modified into a Delivery ring to deliver the protons to both Mu2e and g-2 experiemnts. Therefore, It requires the transport of protons from the Recycler Ring to the Delivery ring. A new transfer line from the Recycler ring to the P1 beamline will be constructed to transport proton beam from the Recycler Ring to existing Antiproton Source beamlines. This new beamline provides a way to deliver 8 GeV kinetic energy protons from the Booster to the Delivery ring, via the Recycler, using existing beam transport lines, and without the need for new civil construction. This paper presents the Conceptual Design of this new beamline.

TUPPR087	Status of NSCL Cyclotron Gas Stopper	ion, cyclotron, injection, emittance	2029
	N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz NSCL, East Lansing, Michigan, USA
	A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

TUPPR093	Sources and Solutions for LHC Transfer Line Stability Issues	injection, kicker, septum, controls	2047
	L.N. Drosdal, W. Bartmann, C. Bracco, B. Goddard, V. Kain, G. Le Godec, M. Meddahi, J.A. Uythoven CERN, Geneva, Switzerland
	The LHC is filled through two 3km transfer lines from the last pre-injector, the SPS. Safe injection into the LHC requires stable trajectories in the transfer lines. During the LHC proton operations 2011 instabilities were observed. In particular shot-by-shot and bunch-by-bunch variations cause difficulties for steering of the beam and can potentially cause high beam losses at injection. The causes of these instabilities have been studied and will be presented in this paper. Based on the studies solutions will be proposed and finally the effects of the solutions will be studied.

WEOAA03	Development of the Beam Halo Monitor in the J-PARC 3-GeV RCS	injection, electron, beam-losses, gun	2122
	M. Yoshimoto, N. Hayashi, H. Hotchi, M. Kinsho, S.I. Meigo, K. Okabe, P.K. Saha, K. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. Transverse halo monitors, which are horizontal and vertical scanning aluminum plates type, has been installed in the extraction beam line. But the residual secondary electrons hindered the beam halo diagnostic. Thus we develop the new beam halo monitor with vibrating wire monitor.
	Slides WEOAA03 [6.701 MB]

WEPPC063	Superconducting RF Cavity for High-current Cyclotrons	cavity, cyclotron, focusing, injection	2354
	N. Pogue, P.M. McIntyre, A. Sattarov Texas A&M University, College Station, Texas, USA
	Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation. A novel superconducting cavity is presented for applications in cyclotrons. The cavity is in effect an extrusion of a 2-D double-quarter-wave structure, in which the ends of the extrusion are wrapped around and joined so that the cavity has no end perturbations. Power is applied to a linear array of input coupling loops, so that rf sheet current is launched in a laminar flow that matches the power coupled to the orbits of the cyclotron. Each loop is driven by an independent solid-state rf source. A strategy is presented for using to advantage the independent control of phase and amplitude to suppress transient phenomena. Longitudinal modes can be strongly suppressed. These provisions are of importance to suppress phenomena that can limit beam current.

WEPPP068	Latest Performance Results from the FONT5 Intra-train Beam Position and Angle Feedback System at ATF2	feedback, kicker, linear-collider, collider	2864
	D.R. Bett, R. Apsimon, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry JAI, Oxford, United Kingdom B. Constance CERN, Geneva, Switzerland J. Resta-López IFIC, Valencia, Spain
	A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch time scales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. The latest results from beam tests at ATF2 will be presented, including the system latency and correction performance.

WEPPP085	Study on the Realignment Plan for J-PARC 3 GeV RCS after the Tohoku Earthquake in Japan	injection, quadrupole, survey, alignment	2909
	N. Tani, H. Hotchi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	J-PARC 3GeV RCS suffered the big damage to its building and cooling and electric facilities by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. After the earthquake, RCS magnets were measured to confirm the state of accelerator beam line. As a result, it was found out that there was an alignment error of several millimeters in both horizontal and vertical directions that caused a deformation in the J-PARC 3GeV RCS tunnel. In this paper, we report the survey result in the accelerator tunnel after the earthquake and the realignment plan for J-PARC 3GeV RCS.

WEPPP090	Stable RF Distribution System for the S-band Linac	controls, linac, klystron, feedback	2924
	T. Naito, K. Ebihara, S. Nozawa, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan M. Amemiya AIST, Tsukuba, Japan
	The phase stabilization of the RF phase is key issue for the stable linac operation. An RF distribution system with femto-second stability has been developed for S-band linac using optic fiber links. The system uses a phase stabilized optical fiber (PSOF) and an active fiber length stabilization.* The phase stability is 0.1 degree (100f s) for 24 hours observation. In this paper, we present the test results of the system stability and evaluation of the existing RF reference line by using this system. * Naito et. al. IPAC10 MOPC146

WEPPR007	Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR	injection, beam-loading, acceleration, simulation	2949
	K. Hara, T. Koseki, C. Ohmori KEK, Tokai, Ibaraki, Japan Y. Sato J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR008	Simulation of Controlled Longitudinal Emittance Blow-up in J-PARC RCS	emittance, simulation, resonance, cavity	2952
	M. Yamamoto, M. Nomura, A. Schnase, T. Shimada, F. Tamura JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, A. Takagi, K. Takata, M. Toda, M. Yoshii KEK, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	In the J-PARC RCS, a high intensity beam is prepared for the MR. The longitudinal beam emittance at the RCS extraction should be optimized to avoid beam loss during and after MR injection. In order to match the longitudinal emittance shape between the RCS and the MR, it is desirable to enlarge the longitudinal emittance during the RCS acceleration. We have performed the particle tracking simulation for the controlled longitudinal emittance blow up in the RCS.

WEPPR010	Comparison between Electron Cloud Build-Up Measurements and Simulations at the CERN PS	electron, simulation, pick-up, vacuum	2955
	G. Iadarola Naples University Federico II, Science and Technology Pole, Napoli, Italy F. Caspers, S.S. Gilardoni, G. Iadarola, E. Mahner, G. Rumolo, C. Yin Vallgren CERN, Geneva, Switzerland
	The build up of an Electron Cloud (EC) has been observed at the CERN Proton Synchrotron (PS) during the last stages of the LHC high intensity beam preparation, especially after the bunch shortening before extraction. A dedicated EC experiment, equipped with two button pick-ups, a pressure gauge, a clearing electrode, and a small dipole magnet, is available in one of the straight sections of the machine. A measurement campaign has been carried out in order to scan the EC build-up of LHC-type beams with different bunch spacing, bunch intensity, and bunch length. Such information, combined with the results from build up simulations, is of relevance for the characterization in terms of Secondary Emission Yield (SEY) of the chamber inner surface. The interest is twofold: this will enable us to predict the EC build up distribution in the PS for higher intensity beams in the frame of the upgrade program, and it will provide validation of the EC simulation models and codes.

WEPPR013	Design of an Electrostatic Extraction Section for the University of Maryland Electron Ring	simulation, emittance, electron, lattice	2964
	K.J. Ruisard Rutgers University, The State University of New Jersey, Piscataway, New Jersey, USA B.L. Beaudoin, I. Haber, R.A. Kishek, T.W. Koeth UMD, College Park, Maryland, USA
	Funding: This work is supported by the US Dept. of Energy Office of High Energy Physics. The University of Maryland Electron Ring (UMER) is a 11.5 meter circumference, 10 keV, electron storage ring dedicated to the study of the physics space-charge-dominated beams transported over long path lengths. The intensity of the space charge in UMER can be varied by aperturing the injected beam current from 0.6 mA to 100 mA. Recently, the electron beam has been transported over one thousand turns. To fully characterize the transverse and longitudinal evolution of the beam on a turn-by-turn basis, extraction and transport to a diagnostic station is required. We present the design of a pulsed electric extraction system that satisfies the challenging constraint of fitting the hardware within the dense magnet lattice. The extraction system must universally accommodate the range beam intensities and minimize any disruption to the circulating beam

WEPPR028	An Estimate of Out of Time Beam Upon Extraction for Mu2e	septum, scattering, proton, background	2994
	N.J. Evans, S.E. Kopp The University of Texas at Austin, Austin, Texas, USA E. Prebys Fermilab, Batavia, USA
	Funding: U.S. Dept. of Energy. A bunched beam with specific structure is crucial to attaining the experimental sensitivity desired by the Mu2e collaboration. The final goal is a ratio of in-time to out-of-time beam, known as beam extinction, of 10^-10. An AC dipole system is in development to attain the final goal by sweeping out-of-time beam onto a collimation system, but it is still necessary to achieve something on the order of 10^-5 when beam is extracted from the Fermilab Debuncher ring to the experiment hall. Several sources of out-of-time beam in the Debuncher ring are analyzed, including: intrabeam scattering, RF noise, beam-gas interaction and scattering off of the extraction septum. Estimates are given for each source as well as a final estimate of total out-of-time beam expected upon extraction.

WEPPR038	Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring	betatron, linac, injection, coupling	3018
	J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang LANL, Los Alamos, New Mexico, USA
	Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

WEPPR072	Increasing Instability Thresholds in the SPS by Lowering Transition Energy	optics, emittance, injection, coupling	3096
	H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, S. Cettour-Cave, K. Cornelis, J. Esteban Muller, W. Höfle, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova CERN, Geneva, Switzerland
	A new optics for the SPS with lower transition energy was tested experimentally during 2010-2011, showing a significant increase of the single bunch instability thresholds at injection, due to the 3-fold increase of the slip factor. This paper summarizes the series of performed machine studies for different LHC bunch structures and intensities. In particular, the search of the TMCI threshold in the new optics is presented. Observations on the longitudinal multi-bunch stability are compared between the nominal and the low-transition optics. Finally, optics variants with higher vertical tunes are discussed, which can allow to further increase the TMCI and vertical instability thresholds by reducing the vertical beta function.

THXA01	Producing Medical Isotopes using X-rays	linac, target, electron, neutron	3177
	M.S. de Jong CLS, Saskatoon, Saskatchewan, Canada
	Funding: Natural Resources Canada Non-reactor-based Isotope Supply Program Contribution Agreement Saskatchewan Crown Investment Corporation Contribution Agreement In recent years, there has been frequent shortages of Mo-99 and its daughter isotope, Tc-99m, which are the most heavily used medical diagnostic radio-isotopes. The Canadian Light Source is leading a project to demonstrate large-scale photo-neutron production of Mo-99 using a high-power 35 MeV electron linac as an alternative to production of Mo-99 from fission of highly enriched U-235 in research reactors. This talk will present the results that have been obtained to date and discuss the commercial potential for this alternative production scheme.
	Slides THXA01 [6.482 MB]

THXA02	Operation and Patient Treatments at CNAO Facility	proton, ion, synchrotron, acceleration	3180
	E. Bressi CNAO Foundation, Milan, Italy
	The CNAO (National Centre for Oncological Hadrontherapy) has been realized in Pavia. It is a clinical facility created and financed by the Italian Ministry of Health and conceived to supply hadrontherapy treatments to patients recruited all over the Country. A qualified network of clinical and research Institutes, the CNAO Collaboration, has been created to build and to run the centre. Three treatment rooms (three horizontal and one vertical) are installed. Beams of protons with kinetic energies up to 250 MeV and beams of carbon ions with maximum kinetic energy of 400 MeV/u are transported and delivered by active scanning systems. CNAO commissioning concerning the high technology started in 2009. First patient was treated with Proton beam in September 2011, the 22nd. This presentation presents the features of the system, together with the results of the first treatments.
	Slides THXA02 [14.843 MB]

THEPPB006	Improving the Synchrotron Performance of the Heidelberg Ionbeam Therapy Center	ion, synchrotron, controls, dipole	3243
	Th. Haberer HIT, Heidelberg, Germany
	The HIT linac-synchrotron-system routinely delivers pencil beams to the dose delivering rasterscanning devices at 3 treatment rooms, including the worldwide first scanning ion gantry, and 1 experimental cave. At HIT the quality-assured library of pencil beam parameters covers roughly 100.000 combinations of the ion, energy, intensity and beam size. Each patient-specific treatment plan defines a subset of these pencil beams being subsequently requested during the dose delivery. Aiming at shortened irradiation times an upgrade program making heavy use of feed-back mechanisms is under way. Driven by patient-specific data out of the scanning beam dose delivery process central synchrotron components are coupled to the therapy control system in order to tailor the beam characteristics in real-time to the clinical requirements. The paper will discuss the functional upgrades and report about the impact on the medical application at HIT.

THPPC012	Impedance Computation of Main Components in CSNS/RCS	impedance, cavity, simulation, vacuum	3299
	Y. Li, L. Huang, Z.P. Li, Y.D. Liu, N. Wang, S. Wang IHEP, Beijing, People's Republic of China
	The rapid cycling synchrotron (RCS) of the China spallation neutron source (CSNS) is a high intensity proton accelerator. The study on the coupling impedance in the ring plays an important role in the stability of the beam. The impedance of the main vacuum components in the RCS ring, such as RF cavities, bellows, ports of vacuum pumps, collimator etc, was calculated by using numerical methods. Meantime, RF shielding of bellows, collimators and ports of vacuum pumps are considered. The impact of the busbar configuration on RF cavities and beams was estimated by impedance calculation.

THPPC030	Multi-physics Analysis of the Fermilab Booster RF Cavity	cavity, booster, proton, injection	3347
	M.H. Awida, M.S. Champion, T.N. Khabiboulline, V.A. Lebedev, J. Reid, V.P. Yakovlev Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

THPPC066	Adjustable High Power Coax RF Coupler without Moving Parts	coupling, cavity, solenoid	3443
	M.L. Neubauer, A. Dudas, R. Sah Muons, Inc, Batavia, USA A. Nassiri ANL, Argonne, USA
	A high power fundamental RF power coupler (FPC) with an adjustable in situ coupling factor would be highly desirable for a number of applications; for example, the 352 MHz light source at APS and Project X. A Phase I project has been completed with a prototype constructed and modeled. The prototype includes a coaxial TEE with two windows a quarter wavelength apart, and a ferrite tuner. Two materials were tested and their characteristics measured in terms of loss and magnetic field requirements to produce the desired change in coupling. A VSWR of better than 1.05:1 and a bandwidth of at least 8% at 1.15:1 was measured. The tradeoffs of a final design are proposed based upon these results.

THPPC074	High Frequency High Power RF Generation using a Relativistic Electron Beam	wakefield, electron, damping, impedance	3458
	C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow Euclid TechLabs, LLC, Solon, Ohio, USA H. Chen, Y. Yang TUB, Beijing, People's Republic of China M.E. Conde, W. Gai, J.G. Power ANL, Argonne, USA
	High frequency, high power rf sources are required for many applications. Benefiting from the ~10 GW beam power provided by the high current linac at the Argonne Wakefield Accelerator facility, we propose to develop a series of high power rf sources based on the extraction of coherent Cherenkov radiation from the relativistic electron beam. The frequencies cover from C-band up to W-band with different structures. Simulations show that ~1 GW 20 ns rf pulse can be generated for an 11.7 GHz structure, ~400 MW for a 26 GHz structure, and ~14 MW for a 91 GHz structure.

THPPD002	The First Magnetic Field Control (B-Train) to Optimize the Duty Cycle of a Synchrotron in Clinical Operation	controls, synchrotron, feedback, pick-up	3503
	E. Feldmeier, R. Cee, M. Galonska, Th. Haberer, A. Peters, S. Scheloske HIT, Heidelberg, Germany
	In December 2011 the Heidelberg Ion Therapy Center started to use the magnetic field feedback control for its clinical operation. Therewith the magnetic field deviation of the ramped magnets in the synchrotron depending on eddy currents and hysteresis are no longer in effect. Waiting times on the flattop and the "chimney" in the recovery phase of the synchrotron cycle are no longer necessary. The efficiency of the accelerator is increased by more than 20\% and the treatment time shortens accordingly. The core of the magnetic feedback system is a real time measuring system of the magnetic field with extremely high precision.

THPPD049	Conceptual Design of a Superconducting Septum for FFAGs	septum, ion, proton, simulation	3620
	H. Witte BNL, Upton, Long Island, New York, USA M. Aslaninejad, J. Pasternak Imperial College of Science and Technology, Department of Physics, London, United Kingdom K.J. Peach, T. Yokoi JAI, Oxford, United Kingdom
	Funding: This work was supported by STFC grant ST/G008531/1 and EPSRC Grant EP/E032869/1. The fixed magnetic field in FFAG (Fixed Field Alternating Gradient) accelerators means that particles can be accelerated very rapidly. This makes them attractive candidates for many applications, for example for accelerating muons for a neutrino factory or for charged particle therapy (CPT). To benefit fully from this the particles have to be extracted at the same rate. In combination with the high magnetic rigidity of the particles this represents a significant challenge, especially where variable energy extraction is required, which implies extraction at variable radius. This paper presents a conceptual design of a 4T superconducting septum for the PAMELA accelerator, which is an FFAG for a combined proton/carbon ion therapy facility. The field in the septum is varied as a function of the horizontal position, which allows variable energy extraction without the need for sweeping of the magnetic field.

THPPD052	Operation and Current Status of Injection, Extraction, Kicker Magnet and the Power Supply for J-PARC 3 GeV RCS	kicker, impedance, power-supply, injection	3629
	M. Watanabe, N. Hayashi, Y. Shobuda, K. Suganuma, T. Takayanagi, T. Togashi JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	3-GeV RCS (Rapid Cycling Synchrotron) at High Intensity Proton Accelerator Facility (J-PARC) have started for 24-hour operation with repetition rate of 25 pps in February, 2009. Kicker power supply system which uses thyratrons switches is used for extraction of the proton beam. There were many troubles for unstable operation of the thyratrons just after beam commissioning started. Recently, however, the operations were improved and the failure rate was reduced to approximately 0.1 % in October 2010. After the earthquake on March 11, 2011, the injection and extraction magnets, power supplies, the cables and the bus-duct have been checked. Insulation resistance test, impedance test were performed. Reflected wave measurements by the low-level and high-power pulse of the kicker magnets were performed. Visual checks by a fiber endoscope were also performed in the kicker magnets. The results of the measurements and the checks were all not in the problem.

THPPD069	Adjustable Pulse Duration Fast Kicker for the CRYRING Storage Ring	kicker, injection, high-voltage, controls	3671
	J.-P. Lavieville, P. Lebasque SOLEIL, Gif-sur-Yvette, France W. Beeckman, O. Cosson Sigmaphi, Vannes, France
	The CRYRING storage ring of the Manne Siegbahn Laboratory (MSL, Stockholm) shall be moved to become part of FLAIR accelerators complex in Darmstadt to be used for deceleration of antiprotons and charged ions. That needs an upgrade to adapt it to the full energy range (30MeV – 0.13 MeV) of its future exploitation. SIGMAPHI, in close collaboration with SOLEIL light Source, is in charge of new fast injection and extraction magnets kickers and their pulsed power supplies. The injection will be done at maximum energy (30 MeV) while the extraction need to cover the full energy range (30 MeV – 0.13 MeV) that requires a continuous adjustment capability on the pulse duration and on the deviation amplitude. The development made specifically for the CRYRING kickers is based on a new design involving two different pulsed power supplies, each one managing either the fast rise time or the current flat top. Using solid state switches allows adapting simultaneously the pulse duration and its amplitude. This contribution presents the specific scheme and the development of a kicker system working up to 20 kV with pulse duration from 1.62 μs to 16.3 μs with transient times less than 300 ns.

THPPD078	Cold Cathode Thyratron Based High-voltage Kicker Generators at the Duke Accelerators: Six Year Experience	kicker, power-supply, cathode, high-voltage	3698
	V. Popov, S.F. Mikhailov, P.W. Wallace, Y.K. Wu FEL/Duke University, Durham, North Carolina, USA
	Funding: This work is supported in part by the US DOE grant #DE-FG02-97ER41033. The performance of the Duke storage ring based light sources, the Duke storage ring FEL and High Intensity Gamma-ray Source (HIGS), has been greatly improved since 2007 as the result of operating a new full-energy, top-off booster injector (0.18 - 1.2 GeV), allowing fixed energy operation of the storage ring (0.25 - 1.2 GeV). The injection/extraction kicker system is one of the key components of the accelerator facility which determines efficiency and reliability of the light source operation. Pseudo-Spark Switches(PSS), also known as cold cathode thyratrons, are the critical components of the high voltage pulse generators for kickers. More than six years of operation has allowed us to study the lifetime issue for the 10 kA class devices. Recently, we have tested the next generation cold cathode thyratron, with one installed in one of our storage ring kicker high voltage generators. In the present paper we will also present preliminary test results of this new thyratron and the required modifications of its triggering driver to improve its performance.

THPPP008	The ELENA Project: Progress in the Design	electron, vacuum, antiproton, emittance	3740
	T. Eriksson, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, R. Kersevan, M. Martini, S. Maury, S. Pasinelli, G. Tranquille CERN, Geneva, Switzerland W. Oelert Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich, Germany
	The Extra Low ENergy Antiproton ring (ELENA) project started in June 2011 and is aimed at substantially increasing the number of antiprotons delivered to the Antiproton Decelerator (AD) physics community. ELENA will be a small machine that receives antiprotons from AD at 5.3 MeV kinetic energy and decelerates them further down to 100 keV. It will be equipped with an electron cooler to avoid beam losses during deceleration and to reduce beam phase space at extraction. Design work is progressing with emphasis on machine parameters and design as well as infrastructure, ring, transfer lines and vital subsystem design.

THPPP016	Upgrade Strategies for the Proton Synchrotron Booster Dump at CERN	proton, booster, cavity, synchrotron	3761
	A. Sarrió Martínez, F. Loprete, C. Maglioni CERN, Geneva, Switzerland
	CERN’s LHC Injection chain Upgrade (LIU) involves a revision of the Proton Synchrotron Booster dump, which was designed in the 1960’s to cope with beam energies reaching 800 MeV and intensities of 10⁺¹³ particles per pulse. Thermo-mechanical studies highlighted the need for an upgrade of the dump, so that it is capable of withstanding energies in the order of 2 GeV and intensities up to 10⁺¹⁴ particles per pulse. This paper proposes a new design of the dump in the light of various constraints and choices such as the geometry, materials and the integration of the required cooling system. Further topics discussed include the strategy for dismantling the old device, which has been continuously irradiated for almost 40 years and presents a difficult access. Therefore, a detailed ALARA procedure is being prepared in order to carry out the upgrade works in the area.

THPPP017	ELENA: From the First Ideas to the Project	antiproton, electron, rfq, vacuum	3764
	G. Tranquille, P. Belochitskii, T. Eriksson, S. Maury CERN, Geneva, Switzerland W. Oelert Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich, Germany
	Successful commissioning of the CERN Antiproton Decelerator (AD) in 2000 was followed by significant progress in the creation of antihydrogen atoms. The extraction energy of the decelerated antiprotons is nevertheless very high compared to that required by experiments and results in a trapping efficiency of only 0.1% to 3%. To improve this value by an order of magnitude the study of an Extra Low ENergy Antiproton ring (ELENA) started in 2003 and was approved as a CERN construction project in 2011. During these years the choice of the main machine parameters such as the beam extraction energy, emittance and bunch length were defined, taking into account requests from the physics community. The main challenges were also identified, such as dealing with the large space charge tune, the ultra high vacuum required and the tight requirements for the electron cooler. Housing the ELENA ring within the AD hall significantly reduced the project cost as well as simplifying the beam transfer from AD to ELENA and from ELENA to the existing experimental areas. This contribution will follow ELENA from its beginnings to the final, approved project proposal.

THPPP020	Project X with Superconducting Rapid Cycling Synchrotron	synchrotron, proton, beam-losses, FEL	3773
	H. Piekarz Fermilab, Batavia, USA
	A synchrotron-based upgrade of Fermilab accelerator complex for high intensity physics with Project X is described. It consists of: 1 GeV pulse linac, 1-8 GeV superconducting rapid cycling synchrotron (SRCS), dual 8 GeV storage ring (SR1,2), and 60 GeV Main Injector(MI). Pulse linac and SRCS operate at 10 Hz while SR1, SR2, and MI operate at 1.33 Hz. SR1 stores 3 and SR2 4 SRCS pulses making physics cycle 0.7 s. SR1 batch is extracted in 0.5 s at 3 locations of its ring providing beams to kaon and 2 muon experiments. SR2 batch is transferred to MI, accelerated to 60 GeV, and extracted to 3 neutrino production targets for Minos, Nova, and LBNE experiments. Main synchrotron parameters are listed and magnet systems described. Projected beam power is compared to expectations with linac-only based upgrade as well as with current and planned similar accelerator facilities elsewhere.

THPPP023	Momentum Cogging at the Fermilab Booster	booster, dipole, injection, controls	3782
	K. Seiya, C.C. Drennan, W. Pellico, A.K. Triplett, A.M. Waller Fermilab, Batavia, USA
	The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2·10¹⁷ protons/hour which is almost double the current operation at 1.10¹⁷ protons/hour. The beam loss in the machine is going to be an issue. The booster accelerates beam from 400 MeV to 8GeV and extracts to The Main Injector (MI). Cogging is the process that synchronizes the extraction kicker gap to the MI by changing radial position of the beam during the cycle. The gap creation occurs at about 700MeV which is 6msec into the cycle. The variation of the revolution frequency from cycle to cycle is larger at lower energy and it is hard to control by changing the radial position because of aperture limitations. Momentum cogging is able to move the gap creation earlier by using dipole correctors and radial position feedback, and controlling the revolution frequency and radial position at the same time. The new cogging is going to save energy loss and aperture. The progress of the momentum cogging system development is going to be discussed in this paper.

THPPP065	The FNAL Injector Upgrade Status	rfq, emittance, beam-transport, vacuum	3886
	C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.

THPPP079	Status of J-PARC Main Ring After Recovery from the Great East Japan Earthquake Damage	kicker, injection, proton, status	3915
	T. Koseki KEK, Ibaraki, Japan
	The J-PARC facility was heavily damaged by the Great East Japan Earthquake on March 11, 2011. For the Main Ring synchrotron (MR), a few tens of cracks were found in the tunnel and many of them leaked groundwater. Displacements of magnet positions after the earthquake were larger than ±15 mm in horizontal and ±5 mm in vertical. Re-alignment of all the magnets and monitors in the MR were carried out in the autumn 2011. Accelerator study and users operation are plan to resume in December 2011 and January 2012, respectively. During the long shutdown period from March to December of 2011, we made work not only for the recovery from the earthquake damages but also for improvements to increase beam power as follows; replacement of injection kickers, upgrade of the ring collimator section, installation of a new collimator system in the slow extraction sections, two rf-systems, four skew-quadrupoles and three octupoles. In this paper, the recovery work and the improvements made in the shutdown periods are reported. Status of high power beam operation after the long shutdown is also presented in details.

THPPP080	Beam Halo Reduction in the J-PARC 3-GeV RCS	emittance, injection, bunching, linac	3918
	H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata KEK, Ibaraki, Japan K. Satou J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.

THPPP083	Status of J-PARC 3 GeV RCS	injection, beam-losses, beam-transport, vacuum	3927
	M. Kinsho JAEA/J-PARC, Tokai-mura, Japan
	J-PARC RCS have delivered beam progressively since 2008. The RCS ramped up the beam power, and delivered beam of 300kW equivalent and 220kW to MR and MLF, respectively, before the earthquake disaster. The RCS was heavily affected by the last Great East Japan Earthquake. At the RCS, the circulating road went wavy and the yard area for electricity and cooling water devices was heavily distorted. We have investigated damages of each device and also have tried to restore beam operation. From middle of December last year we could start beam test and also would start to deliver beam to MR and MLF for user operation from this January. We have been performed not only recovery works but also improvement of the RCS for realizing high power stable operation with low beam losses. I report status of beam operation and near future plan for the RCS.

THPPR009	Optimization of the Electron Beam Extraction Efficiency in a Booster for TLS	electron, booster, factory, kicker	3981
	H.C. Chen, H.-P. Chang, H.H. Chen, S. Fann, S.J. Huang, J.A. Li, C.C. Liang, Y.K. Lin, Y.-C. Liu NSRRC, Hsinchu, Taiwan
	The Response Surface Methodology (RSM), is used to study the optimization process of the electron beam extraction efficiency for Taiwan Light Source (TLS) in NSRRC. A study model was constructed based on the Artificial Neural Network (ANN) theory by using selected beam extraction tuning knobs as the variables. An optimization procedure is developed by taking extraction efficiency as the objective function and the selected beam tuning knobs as the variables. Furthermore, this theoretical model and optimization procedure have been put into practice in verifying how effectively the model can accomplish. By properly applying the constructed optimization procedure for electron beam extraction study, the efficiency has been improved effectively. The details of the study will be reported in this paper.

THPPR030	High Power Test of RF Separator For 12 GeV Upgrade of CEBAF at Jefferson Lab	cavity, vacuum, ion, coupling	4032
	S. Ahmed, C. Hovater, G.A. Krafft, J.D. Mammosser, M. Spata, M.J. Wissmann JLAB, Newport News, Virginia, USA J.R. Delayen ODU, Norfolk, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. CEBAF at JLab is in the process of an energy upgrade from 6 GeV to 12 GeV. The existing setup of the RF separator cavities in the 5th pass will not be adequate enough to extract the highest energy (11 GeV) beam to any two existing halls (A, B or C) while simultaneously delivering to the new hall D in the case of the proposed 12 GeV upgrade of the machine. To restore this capability, several options including the extension of existing normal conducting (NC) and a potential 499 MHz TEM-type superconducting (SC) cavity design have been investigated using computer simulations. Detailed numerical studies suggest that six 2-cell normal conducting structures meet the requirements; each 2-cell structure will require up to 4 kW RF input power in contrast with the current nominal operating power of 1.0 to 2.0 kW. A high power test to 4 kW is required to confirm the cavity’s operate-ability at these elevated gradient and power levels. We have assembled a 2-cell cavity, pumped down to 2.0·10^-9 torr using ion pump and confirmed the low level RF performance. A high power test is in progress and will be completed soon. The detailed numerical and experimental results will be discussed in the paper.

THPPR038	Failure Studies at the Compact Linear Collider: Main Linac and Beam Delivery System	linac, quadrupole, betatron, wakefield	4056
	C.O. Maidana, M. Jonker, A. Latina CERN, Geneva, Switzerland
	The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy of two high-intensity, low-energy drive beams is extracted and transferred to two low-intensity, high-energy main beams. The machine protection and electrical integrity group has the mission to protect the various machine components from damage caused by ill controlled beams. Various failure scenarios were studied and the potential damage these failures could cause to the machine structures were estimated. In this paper, first results of the beam response to correctors and/or quadrupole kick failures in the main linac and in the beam delivery system (BDS) sections are presented as well as possible collimator damage scenarios. The use of the code PLACET for machine protection analysis is described as well.

THPPR053	A CW FFAG for Proton Computed Tomography	cyclotron, proton, lattice, acceleration	4094
	C. Johnstone, D.V. Neuffer Fermilab, Batavia, USA H.L. Owen STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom P. Snopok IIT, Chicago, Illinois, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy An advantage of the cyclotron in proton therapy is the continuous (CW) beam output which reduces complexity and response time in the dosimetry requirements and beam controls. A CW accelerator requires isochronous particle orbits at all energies through the acceleration cycle and present compact isochronous cyclotrons for proton therapy reach only 250 MeV (kinetic energy) which is required for patient treatment, but low for full Proton Computed Tomography (PCT) capability. PCT specifications need 300-330 MeV in order for protons to transit the human body. Recent innovations in nonscaling FFAG design have achieved isochronous performance in a compact (~3 m radius) design at these higher energies. Preliminary isochronous designs are presented here. Lower energy beams can be efficiently extracted for patient treatment without changes to the acceleration cycle and magnet currents.

THPPR063	1 GeV CW Nonscaling FFAG for ADS, and Magnet Parameters	lattice, cyclotron, simulation, proton	4118
	F. Méot, W.-T. Weng BNL, Upton, Long Island, New York, USA C. Johnstone Fermilab, Batavia, USA P. Snopok Illinois Institute of Technology, Chicago, IL, USA
	Multi-MW proton driver capability remains a challenging, critical technology for many core HEP programs, particularly the neutrino ones such as the Muon Collider and Neutrino factory, and for next generation energy applications such as Accelerator Driven Subcritical Reactors (ADS) and Accelerator Transmutation of Waste for nuclear power and waste management. Work is focused almost exclusively on an SRF linac, as, to date, no re-circulating accelerator can attain the 10^-20 MW capability necessary for the nuclear applications. Recently, the concept of isochronous orbits has been explored and developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. The FFAG can remain isochronous beyond the energy reach of cyclotrons and with fixed magnetic fields and strong focusing coupled to recent advances in tune stability, dynamic aperture, and footprint, serious study is underway on a potential application to the ADS problem. Work is progressing on a stable, high intensity, 0.25-1GeV isochronous FFAG. Development and studies of novel magnets with the nonlinear radial fields required to support isochronous operation are reported here.

THPPR064	MW-class 800 MeV/n H²⁺ SC-Cyclotron for ADC application, Design Study and Goals	cyclotron, injection, target, closed-orbit	4121
	F. Méot, T. Roser, W.-T. Weng BNL, Upton, Long Island, New York, USA L. Calabretta INFN/LNS, Catania, Italy A. Calanna CSFNSM, Catania, Italy
	A megawatt class isochronous cyclotron is a potential candidate for accelerator driven systems, as in the subcritical-fission molten-salt reactor application. A scheme for a 800 MeV/nucleon cyclotron accelerating molecular H₂⁺ has been derived from on-going proton driver design studies for neutrino beam production. The present paper reports on beam dynamics studies regarding that cyclotron, exploiting its superconducting coil magnetic sector OPERA field map. These studies are aimed at assessing lattice properties as accelerated orbit, phase oscillations, tunes, beam envelopes and other resonance effects.

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MOEPPB001

RF-breakdown Kicks at the CTF3 Two-beam Test Stand

linac, linear-collider, collider, acceleration

73

A. Palaia, M. Jacewicz, T. Muranaka, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
W. Farabolini
CEA/DSM/IRFU, France

The measurement of the effects of RF-breakdown on the beam in CLIC prototype accelerator structures is one of the key aspects of the CLIC two-beam acceleration scheme being addressed at the Two-beam Test Stand (TBTS) at CTF3. RF-breakdown can randomly cause energy loss and transverse kicks to the beam. Transverse kicks have been measured by means of a screen intercepting the beam after the accelerator structure. In correspondence of a RF-breakdown we detect a double beam spot which we interpret as a sudden change of the beam trajectory within a single beam pulse. To time-resolve such effect, the TBTS has been equipped with five inductive Beam Position Monitors (BPMs) and a spectrometer line to measure both relative changes of the beam trajectory and energy losses. Here we discuss the methodology used and we present the latest results of such measurements.

MOPPC043

Injection/Extraction of Achromat-based 6D Ionization Cooling Rings for Muons

injection, solenoid, kicker, dipole

229

X.P. Ding, D.B. Cline
UCLA, Los Angeles, California, USA
J.S. Berg, H.G. Kirk
BNL, Upton, Long Island, New York, USA
A.A. Garren, F.E. Mills
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: This work was supported in part by the US Department of Energy in part under award numbers DE-FG02-92ER40695 (UCLA), DE-AC02-98CH10886 (BNL) and DE-FG02-07ER84855 (Particle Beam Lasers, Inc.).
An achromat-based cooing ring using dipoles and solenoids is introduced and it can cool muons by large factors in six dimensions to achieve the necessary luminosity for a muon collider. The ring is designed with sufficient space in each superperiod for injection and extraction magnets. We estimate the parameters for the injection system into the solenoid-dipole ring cooler. We also present some simulations for injection/extraction system and discuss the injection/extraction requirements*.
* Al Garren, J.S. Berg, D. Cline, X. Ding, H.G. Kirk, “Robust 6D μ± cooling using a solenoid-dipole ring cooler for a muon collider”, NIM A 654 (2011) 40-44.

MOPPC046

End-to-End G4Beamline Simulation of an Inverse Cyclotron for Muon Cooling

cyclotron, simulation, emittance, solenoid

238

T.L. Hart, T.H. Luo, D.J. Summers
UMiss, University, Mississippi, USA
K. Paul
Tech-X, Boulder, Colorado, USA

An inverse cyclotron is a novel, intriguing idea for muon cooling necessary for proposed neutrino factories and muon colliders. We present the latest results of an end-to-end inverse cyclotron simulation that cools muons in the following sequence: single turn injection and initial cooling of 100 MeV kinetic energies to about 5 MeV with lithium hydrogen wedges; further substantial cooling to keV range kinetic energies and trapping with carbon foils and a rising electric field; and re-acceleration of the cooled, trapped muons back to 100 MeV. For neutrino factory and muon collider applications, the time of the entire cooling/trapping/re-acceleration process needs to be comparable to the muon lifetime so that decay losses are tolerable and the acceptance of the inverse cyclotron needs to be sufficiently large (on order 10 mm-rad normalized emittance). The latest progress toward these ends is presented.

MOPPC069

Quantitative Simulation of NIRS-930 Cyclotron

cyclotron, acceleration, simulation, electromagnetic-fields

292

V.L. Smirnov, S.B. Vorozhtsov
JINR/DLNP, Dubna, Moscow region, Russia
A. Goto, S. Hojo, T. Honma, K. Katagiri
NIRS, Chiba-shi, Japan

The results of the computer modelling of the structural elements of the NIRS-930 cyclotron operational at the National Institute of Radiological Sciences (Chiba, Japan) are presented. The integrated approach to modelling of the cyclotron, including calculation of electromagnetic fields of the structural elements and beam dynamics simulations is described. A computer model of the cyclotron was constructed. Electric and magnetic field distributions and mechanical structures were converted to the beam dynamics code for simulations, in which particle losses on the surfaces of the system elements were estimated. The existing data on the axial injection, magnetic, acceleration and extraction systems of the cyclotron and beam parameter measurements are used for calibration of the simulations. New acceleration regimes could be formulated with the help of the constructed computer model of the machine.

MOPPD002

Ultra-low Energy Storage Ring at FLAIR

antiproton, storage-ring, ion, lattice

367

C.P. Welsch, D. Newton, M.R.F. Siggel-King
Cockcroft Institute, Warrington, Cheshire, United Kingdom
O.E. Gorda, O. Karamyshev, G.A. Karamysheva, M. Panniello, A.I. Papash, A.V. Smirnov
MPI-K, Heidelberg, Germany
J. Harasimowicz, M. Putignano, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom

Funding: The support of the HGF and GSI under contract VH-NG-328, the EU under contract PITN-GA-2008-215080, the Max Planck Institute for Nuclear Physics and the STFC Grant ST/G008248/1 is acknowledged.
The Ultra-low energy electrostatic Storage Ring (USR) at the future Facility for Low-energy Antiproton and Ion Research (FLAIR) will provide cooled beams of antiprotons in the energy range between 300 keV down to 20 keV. Based on the original design concept developed in 2005, the USR has been completely redesigned over the past few years. The ring structure is now based on a 'split achromat' lattice. This ensures compact ring dimensions of 10 x 10 m, whilst allowing both, in-ring experiments with gas jet targets and studies with extracted beams. In the USR, a wide range of beam parameters will be provided, ranging from very short pulses in the nanosecond regime to a coasting beam. In addition, a combined fast and slow extraction scheme was developed that allows for providing external experiments with cooled beams of different time structure. Furthermore, studies into beam diagnostics methods for the monitoring of ultra-low energy ions at beam intensities less than 10⁶ were carried out. Here, we present the USR design with an emphasis on the expected beam parameters available to the experiments at FLAIR.

MOPPD020

A Model for a High-Power Scaling FFAG Ring

injection, dynamic-aperture, lattice, proton

409

G.H. Rees, D.J. Kelliher, S. Machida, C.R. Prior, S.L. Sheehy
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

High-power FFAG rings are under study to serve as drivers for neutron spallation, muon production, and accelerator-driven reactor systems. In this paper, which follows on from earlier work*, a 20 - 70 MeV model for a high-power FFAG driver is described. This model would serve as a test bed to study topics such as space charge and injection in such rings. The design incorporates a long straight to facilitate H^- charge exchange injection. The dynamic aperture is calculated in order to optimize the working point in tune space. The injection scheme is also described. A separate design for an ISIS injector, featuring a novel modification to the scaling law, was also studied.
*G.H. Rees and D.J. Kelliher, “New, high power, scaling, FFAG driver ring designs” HB2010, Morschach, September 2010, MOPD07, p. 54, http://www. JACoW.org

MOPPD023

Correction of the nu_r=3/2 Resonance in TRIUMF Cyclotron

resonance, cyclotron, TRIUMF, simulation

415

T. Planche, R.A. Baartman, Y.-N. Rao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Imperfections in the TRIUMF cyclotron are a source of field errors which slightly violate the 6-fold symmetry of the ring. Among them, the third harmonic of the magnetic gradient errors drives the ν_r=3/2 resonance. This results in a modulation of the current density versus radius observed after the resonance crossing all the way to the extraction (480 MeV). The cyclotron has sets of harmonic correction coils at different radii, each set constituted of 6 pairs of coils placed in a 6-fold symmetrical manner. The 6-fold symmetry of this layout makes that a single set of harmonic coils cannot provide a full correction of third harmonic errors driving the ν_r=3/2 resonance. The last two sets of harmonic correction coils (number 12 and 13) are azimuthally displaced. In this study, we use this fact to achieve a full correction of the resonance. We also present experimental measurements that demonstrate the full correction.

MOPPD026

A Superconducting Ring Cyclotron for the DAEδALUS Experiment

cyclotron, proton, injection, focusing

421

L. Calabretta
INFN/LNS, Catania, Italy
A. Calanna, D. Campo
CSFNSM, Catania, Italy
M.M. Maggiore, L.A.C. Piazza
INFN/LNL, Legnaro (PD), Italy
F. Méot
BNL, Upton, Long Island, New York, USA

Funding: Istituto Nazionale Fisica Nucleare - Laboratori Nazionali del Sud.
The experiment DAEδALUS*, proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector** and of a booster ring cyclotron has been proposed***. The booster Superconducting Ring Cyclotron is able to accelerate a H²⁺ molecule beam up to 800 MeV/n with a peak current of 10 mA and average power higher than 1.6 MW. To simplify the design of the superconducting magnetic coils, to minimize the radial force shift and to increase the room to host the RF cavities, the previous study has been updated increasing the injection energy of the H²⁺ and also the injection energy. The updated study on the magnetic sector configuration, on the superconducting coils and the magnetic forces are presented. The isochronous magnetic field, the beam dynamics along the injection and extraction path and during the acceleration are presented, too.
* J. Alonso et al., Jun2010 e-Print: arXiv:1006.0260
** L. Calabretta, Proc. IPAC 2011, WEPS073 (2011).
*** L. Calabretta, Cyclotrons 2010, Lanzhou.

MOPPD027

A Compact High Intensity Cyclotron Injector for DAEδALUS Experiment

cyclotron, resonance, beam-losses, simulation

424

L. Calabretta, D. Rifuggiato
INFN/LNS, Catania, Italy
A. Adelmann
Paul Scherrer Institut, Villigen, Switzerland
A. Calanna, D. Campo
CSFNSM, Catania, Italy
M.M. Maggiore, L.A.C. Piazza
INFN/LNL, Legnaro (PD), Italy
J.J. Yang
CIAE, Beijing, People's Republic of China

Funding: Istituto Nazionale di Fisica Nucleare - Laboratori Nazionale del Sud.
The experiment DAEδALUS*, recently proposed by MIT scientist to search for CP violation in the neutrino sector, needs three accelerator with energy of about 800 MeV, average power of some MW and duty cycle of 20%. To reduce the cost of the accelerators a cyclotron complex consisting of an injector and of a booster ring cyclotron has been proposed**. The main characteristics of the new kind of separated sector cyclotron injector able to accelerate a H²⁺ molecule beam up to 60 MeV/n will be presented. Due to the low duty cycle, the peak current to be accelerated is 5 mA. The problem related to the injection of a H²⁺ beam, delivered by a compact ion source, and to the space charge effects will be discussed. To allow an easier injection in the booster Superconducting Ring Cyclotron the extraction energy has been increased up to 60 MeV/n. The pole gap was decreased to 60 mm to achieve a more efficient beam extraction. The updated configuration of the magnetic sectors, of the isochronous magnetic field and beam dynamics along extraction path and during the acceleration will be presented, too.
* J. Alonso et al., "Novel Search for CP Violation in the Neutrino Sector: DAEδALUS," Jun2010 e-Print: arXiv:1006.0260
** L. Calabretta, Proc. of IPAC 2011, WEPS073, p. 2673 (2011).

MOPPD039

Status of the Design of the LBNE Neutrino Beamline

target, proton, status, shielding

451

V. Papadimitriou, R. Andrews, M.R. Campbell, A.Z. Chen, S.C. Childress, C.D. Moore
Fermilab, Batavia, USA

Funding: DE-AC02-07CH11359 with the United States Department of Energy.
The Long Baseline Neutrino Experiment (LBNE) will utilize a neutrino beamline facility located at Fermilab to carry out a compelling research program in neutrino physics. The facility will aim a beam of neutrinos toward a detector placed at the Homestake Mine in South Dakota, about 1300 km away. The neutrinos are produced as follows: First, protons extracted from the MI-10 section of the Main Injector (60-120 GeV) hit a solid target above grade and produce mesons. Then, the charged mesons are focused by a set of focusing horns into a 250 m long decay pipe, towards the far detector. Finally, the mesons that enter the decay pipe decay into neutrinos. The parameters of the facility were determined taking into account several factors including the physics goals, the modeling of the facility, spacial and radiological constraints and the experience gained by operating the NuMI facility at Fermilab. The initial beam power is expected to be ~700 kW, however some of the parameters were chosen to be able to deal with a beam power of 2.3 MW in order to enable the facility to run with an upgraded accelerator complex. We discuss here the status of the design and the associated challenges.

MOPPD046

Lifetime of the Highly Efficient H⁻ Ion Sources

cathode, ion, plasma, electron

466

V.G. Dudnikov
Muons, Inc, Batavia, USA
D.S. Bollinger
Fermilab, Batavia, USA
D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531
Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

MOPPD051

Performance of Resonant Slow Extraction from J-PARC Main Ring

feedback, quadrupole, proton, septum

481

M. Tomizawa, Y. Arakaki, T. Kimura, S. Murasugi, R. Muto, H. Nakagawa, K. Okamura, H. Sato, Y. Shirakabe, T. Toyama, E. Yanaoka, M. Yoshii
KEK, Ibaraki, Japan
D. Horikawa
Sokendai, Ibaraki, Japan
K. Mochiki
Tokyo City University, Tokyo, Japan
A. Schnase
JAEA/J-PARC, Tokai-mura, Japan

Proton beam accelerated by the J-PARC main ring (MR) with an imaginary transition lattice is slowly extracted by a third integer resonant extraction scheme and delivered to the hadron experimental hall. One of the critical issues in the slow extraction from a high intensity proton synchrotron is the inevitable beam loss caused by the extraction process at septum devices. A design with low beam loss (high extraction efficiency) is required to reduce machine damage and radiation exposure during hands-on maintenance. We have designed the slow extraction scheme to obtain high extraction efficiency for the MR lattice. The scheme has a large step size and a small angular spread enabling a hit rate of the beam on the developed thin septum device. Since the first 30 GeV proton beam was successfully delivered to the experimental hall in January 2009, an extremely high extraction efficiency of 99.5% has been achieved by an intensive beam tuning. In this paper, we report details of such performance. We will also describe some schemes to improve the serious spiky spill time structure due to large current ripples from the power supplies for the bending and quadrupole magnets.

MOPPD052

Study of Electrostatic Septum by Low-Z Material for High Intensity Proton Beam

septum, scattering, proton, beam-losses

484

D. Horikawa
Sokendai, Ibaraki, Japan
Y. Arakaki, K. Okamura, Y. Shirakabe, M. Tomizawa
KEK, Ibaraki, Japan
I. Sakai
University of Fukui, Faculty of Engineering, Fukui, Japan
T. Shimogawa
Saga University, Faculty of Science and Engineering, Saga, Japan

In a high-intensity proton accelerator, the beam loss at the time of late beam extraction causes radioactivation of apparatus. It takes out and is a problem serious to that of upper about beam power. Its attention was paid to electric septum (ESS) of the equipment used for beam extraction for problem solving. The septum section of ESS which beam hits directly is usually used for tungsten. Therefore, it is low atomic number material to the septum section. Development of the new model ESS using the textile material carbon fiber of a certain carbon (CF) was started. Is it a problem in CF at processability? Is it using for the septum section of ESS for a certain reason? Difficult it was. Therefore, it succeeded in obtaining required form and intensity by developing the twisting thread technology of CF. Moreover, the tension strength test of CFwire and the pyrogenicity test by electric current were done. Is it the tension intensity and heat durability which exceed the existing tungsten wire? It was confirmed. In addition to the ESS development technique using these new materials, and a result, a future measure is reported.

MOPPD054

Effect of the 2011 Great East Japan Earthquake in the Injection and Extraction of the J-PARC 3-GeV RCS

injection, septum, beam-transport, simulation

490

P.K. Saha, H. Harada, H. Hotchi, S.I. Meigo, N. Tani, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

In the 3-GeV rapid cycling synchrotron (RCS) of the Japan Proton Accelerator Research Complex (J-PARC), the injection and extraction systems play important roles for the beam injection and extraction, respectively. Unfortunately, the 2011 great east Japan earthquake had a serious impact on the ongoing schedule due to the big damage of the whole accelerator facility and the infrastructure as well. The injection and extraction including the beam transport lines magnets suffered a noticeable displacement resulting with alignment errors. As realignment of the RCS magnets can not be done in this year, then based on the post earthquake measured alignment data, we have estimated the effect as well as possible solutions on the injected and extracted beam for as usual operation. Fortunately, the simulation results shows that there would not be any serious impact on both injected as well as extracted beam with present alignment errors and thus user operation can be resume as expected. The simulation result together with some experimental results will be presented.

MOPPD059

Proposal of a Dummy Septum to Mitigate Ring Irradiation for the CERN PS Multi-Turn Extraction

septum, beam-losses, vacuum, shielding

499

M. Giovannozzi, H. Bartosik, D. Bodart, J. Borburgh, R.J. Brown, S. Damjanovic, S.S. Gilardoni, B. Goddard, C. Hernalsteens, M. Hourican, M. Widorski
CERN, Geneva, Switzerland

High activation of the magnetic extraction septum of the CERN PS machine was observed due to the losses of the continuous beam extracted via the Multi-Turn Extraction (MTE) method. The resulting activation is however incompatible with safe operation so a mitigation measure was required and found, namely the installation of a passive dummy septum to protect the actual one seems to provide the required reduction in activation in the extraction area. The shielded dummy septum is intended to absorb particles during the rise time of the MTE extraction kickers, avoiding the beam impact on the blade of the active magnetic extraction septum. The principle of the proposed modifications of the PS layout will be presented together with the studies aimed at finalising the new configuration.

MOPPD060

Modified Extraction Scheme for the CERN PS Multi-Turn Extraction

septum, kicker, beam-losses, quadrupole

502

M. Giovannozzi, S.S. Gilardoni, C. Hernalsteens, A. Lachaize, G. Métral
CERN, Geneva, Switzerland

High-activation of the extraction magnetic septum of the CERN PS machine was observed due to the losses of the continuous beam extracted via the Multi-Turn Extraction (MTE) method. A possible mitigation measure consists of using an existing electrostatic septum, located upstream of the extraction magnetic septum, to deflect the beam. This would highly decrease the beam losses, and hence the induced activation, during the rise time of the MTE kickers due to the reduced thickness of the electrostatic septum with respect to the magnetic one. The layout of this new extraction will be described in detail and the results of beam measurements presented.

MOPPD067

Novel Slow Extraction Scheme for Proton Accelerators Using Pulsed Dipole Correctors and Crystals

septum, proton, scattering, betatron

517

V.D. Shiltsev
Fermilab, Batavia, USA

Funding: Work supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359
Slow extraction of protons beams from circular accelerators is currently widely used for a variety of beam-based experiments. The method has some deficiencies including limited efficiency of extraction, radiation induced due to scattering on the electrostatic septa and limited beam pipe aperture, beam dynamics effects of space charge forces and magnet power supplies ripple. Here we present a novel slow extraction scheme employing a number of non-standard accelerator elements, such as Silicone crystal strips and pulsed strip-line dipole correctors, and illustrate practicality of these examples at the 8 GeV proton Recycler Ring at Fermilab.

MOPPD069

Challenges for the SNS Ring Energy Upgrade

injection, electron, kicker, septum

520

M.A. Plum, T.V. Gorlov, J.A. Holmes, T. Hunter, R.T. Roseberry, J. G. Wang
ORNL, Oak Ridge, Tennessee, USA

Funding: ORNL/SNS is managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.
The Oak Ridge Spallation Neutron Source accumulator ring presently operates at a beam power of about 1 MW and a beam energy of 925 MeV. A power upgrade is planned to increase the beam energy to 1.3 GeV. For the accumulator ring this mostly involves modifications to the injection and extraction sections. A variety of modifications to the existing injection section were necessary to achieve 1 MW, and the tools developed and the lessons learned from this work are now being applied to the design of the new injection section. This paper will discuss the tools and the lessons learned, and also present the design and status of the upgrades to the accumulator ring.

MOPPD081

Upgrade of the LHC Beam Dumping Protection Elements

simulation, kicker, dumping, vacuum

556

W.J.M. Weterings, T. Antonakakis, B. Balhan, J. Borburgh, B. Goddard, C. Maglioni, R. Versaci
CERN, Geneva, Switzerland

The Beam Dumping System for the Large Hadron Collider comprises for each ring a set of horizontally deflecting extraction kicker magnets, vertically deflecting steel septa, dilution kickers and finally, a couple of hundred meters further downstream, an absorber block. A mobile diluter (TCDQ) protects the superconducting quadrupole immediately downstream of the extraction as well as the arc at injection energy and the triplet aperture at top energy from bunches with small impact parameters, in case of a beam dump that is not synchronized with the particle free gap or a spontaneous firing of the extraction kickers. Simulations have shown that an asynchronous dump of a 7 TeV nominal beam into the TCDQ absorber blocks could damage it. This paper describes the proposed changes to this device in order to maintain the protection for the downstream elements while reducing the risk of damaging the TCDQ in case of such a beam loss.

MOPPP041

Effect of Roughness on Emittance of Potassium Cesium Antimonide Photocathodes

emittance, cathode, laser, electron

655

T. Vecchione, J. Feng, H.A. Padmore, W. Wan
LBNL, Berkeley, California, USA
I. Ben-Zvi, M. Ruiz-Osés, L. Xue
Stony Brook University, Stony Brook, USA
D. Dowell
SLAC, Menlo Park, California, USA
T. Rao, J. Smedley
BNL, Upton, Long Island, New York, USA

Funding: This work was supported by the Director, Office of Science, Office of Basic Energy Sciences of the U. S. Department of Energy, under Contract DE-AC02-05CH11231, KC0407-ALSJNT-I0013, and DE-SC0005713
Here we present first measurements of the effect of roughness on the emittance of K2CsSb photocathodes under high fields. We show that for very thin cathodes the effect is negligible at up to 3 MV/m but for thicker and more efficient cathodes the effect becomes significant. We discuss ways to modify the deposition to circumvent this problem.

MOPPP052

Booster Synchrotron for SIRIUS Light Source

booster, injection, dipole, emittance

679

F. H. de Sá, L. Liu, A.R.D. Rodrigues
LNLS, Campinas, Brazil

A full energy 3 GeV booster for the new Brazilian Synchrotron Light Laboratory (LNLS) third generation light source, SIRIUS, is proposed. The 144 m circumference magnetic lattice consists of two super-periods of FODO cells with defocusing dipoles and focusing quadrupoles. The optics provides a low emittance beam of 38 nm.rad at 3 GeV, high horizontal betatron and zero dispersion functions at straight sections. The top-up operation requires a cycling energy ramp from 150 MeV to 3 GeV with repetition rate of 1 Hz.

MOPPP060

Top-Off Mode of Operations: Setting Limits on the Extracted Beam Energy by Constraining Currents of Multiple Booster Dipole Power Supplies.

dipole, booster, lattice, injection

696

T.V. Shaftan
BNL, Upton, Long Island, New York, USA

In preparation for top-off mode of the NSLS-II operations we have studied impact of errors in the dipole power supply current on the extracted beam energy, which has to be interlocked so to satisfy the safety requirements. The NSLS-II booster dipole circuits are combined into 3 independent PS circuits, which adds complexity to the analysis of the extracted beam energy limits.

MOPPR002

Overview of the Beam Diagnostics in the MedAustron Accelerator: Design Choices and Test Beam Commissioning

emittance, synchrotron, injection, proton

774

F. Osmic, M. Feurstein, A. Gyorgy, A. Kerschbaum, M. Repovz, S.M. Schwarz
EBG MedAustron, Wr. Neustadt, Austria
G. Burtin
CERN, Geneva, Switzerland

The MedAustron center is a synchrotron based accelerator complex for cancer treatment and for clinical and non-clinical research with protons and light ions, currently under construction in Wiener Neustadt, Austria. The accelerator complex is based on the CERN-PIMMS study and its technical implementation by the Italian CNAO foundation in Pavia. The MedAustron beam diagnostics system is based on sixteen different monitor types (153 devices in total) and will allow measuring all relevant beam parameters from the source to the irradiation rooms. The monitors will have to cope with large intensity and energy ranges. Currently, one ion source, the low energy beam transfer line and the RFQ are being commissioned in the Injector Test Stand (ITS) at CERN. This paper gives an overview of all beam monitors foreseen for the MedAustron accelerator, elaborates some of the design choices, and reports the first beam commissioning results from the ITS.

MOPPR008

The Beam Loss Monitoring System at ELSA

injection, electron, booster, monitoring

786

D. Proft, A. Balling, F. Frommberger, W. Hillert
ELSA, Bonn, Germany

A new diagnostic tool to monitor beam loss in the storage ring at the Electron Stretcher Facility ELSA has been set up. It enables the investigation of causes for electron loss in real time, providing an essential tool needed to achieve the planned beam current upgrade from 30 mA to 200 mA. The monitoring system consists of 32 pin-diode based radiation detectors spread around the storage ring. Therefore, individual electron loss can be localized after each quadrupole. The readout system was designed to allow an integration of single loss events within 70 μs in order to be able to correlate these events to machine state changes. The used monitoring hardware and readout system will be detailed. Furthermore first measurements of the beam loss during injection, the fast energy ramp during acceleration and the extraction phase will be presented.

MOPPR010

Simultaneous Measurement of Emittance at the Storage Ring and the External Beamlines of ELSA

emittance, quadrupole, synchrotron, diagnostics

792

S. Zander, F. Frommberger, W. Hillert, D. Proft
ELSA, Bonn, Germany

Funding: Funded by the DFG within the SFB / TR 16.
The Electron Stretcher Facility (ELSA) consists of several accelerator stages, the last one being a storage ring providing a beam of polarized electrons of up to 3.5 GeV. To ensure a high duty cycle, a slow extraction via a third integer resonance is applied at ELSA. The resonance extraction cause a variation of the emittance in the external beamline. A system for simultaneous measurement of emittance in the storage ring and the external beamlines has been installed. First results including a comparison of both emittances will be shown.

MOPPR013

Beam Loss and Transmission Control at FAIR

controls, ion, synchrotron, proton

801

M. Schwickert, T. Hoffmann, F. Kurian, H. Reeg, A. Reiter
GSI, Darmstadt, Germany
W. Vodel
HIJ, Jena, Germany

FAIR, the Facility for Antiproton and Ion Research, is presently entering the final layout phase at GSI. The injector chain consists of the existing linear accelerator UNILAC and synchrotron SIS18, plus a new dedicated 70 MeV high-intensity proton Linac. Along the injector chain to the main synchrotron SIS100 as well as in the beam transport lines, which connect synchrotrons, storage rings and experimental areas, beam transmission or vice versa beam loss have to be controlled very precisely. To supply a maximum intensity of 5·10¹¹ U²⁸⁺/spill to experiments and to prevent machine damages by intense beams, an integrated system for transmission and loss control is mandatory. While various kinds of beam current transformers control transmission online, intercepting Particle Detector Combinations (scintillators, ionization chambers, secondary electron monitors) are foreseen for optimization runs. External Beam Loss Monitors indirectly detect loss positions by measuring secondary particles. This contribution summarizes the requirements for the related detector systems and presents basic concepts for beam loss and transmission control at FAIR.

MOPPR028

Upgrade Plan of BLM System of J-PARC MR

injection, proton, ion, monitoring

837

K. Satou, T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The upgrade plan of BLM system of J-PARC Main Ring synchrotron (MR) will be described. Existing proportional chamber beam loss monitors (P-BLMs) have fast signal rise time of about 100ns and high gas gain of about 2·10⁴ at the maximum. These abilities were quite advantageous for the early beam commissioning stage. On the other hand, the gas gain is degraded with increasing output current. The P-BLM is suitable for a measurement of a low level beam loss event, however, vulnerable to a measurement of an accidental beam loss event (fast loss) causing high radiation. To enhance the dynamic range of the system, 1m long Air Ionization Chambers (AICs) will be installed and operated with the P-BLM. Experiments using the real beam loss at collimator area and at the Co60 radiation facility have demonstrated the stable operations up to the radiation level activated by the maximum beam loss power of the collimator area. A new data taking system is now under development, and its performances will also be presented.

MOPPR042

Characterization Tests of a Stripline Beam Position Monitor for the CLIC Drive Beam

impedance, quadrupole, simulation, feedback

873

A. Benot-Morell, A. Faus-Golfe, J.J. García-Garrigós
IFIC, Valencia, Spain
A. Benot-Morell, L. Søby
CERN, Geneva, Switzerland
J.M. Nappa, J. Tassan-Viol, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: FPA2010-21456-C02-01, SEIC-2010-00028
A prototype of a stripline Beam Position Monitor (BPM) with its associated readout electronics has been developed at CERN in collaboration with SLAC, LAPP and IFIC. In this paper, the design and simulations of the BPM with the analog readout chain and the BPM test bench are described, and the results of the first characterization tests are presented. The position resolution and accuracy parameters are expected to be below 2μm and 20μm respectively for a beam with a bunching frequency of 12GHz, an average current of 101A and a machine repetition rate of 50Hz.

MOPPR064

Development of a Turn-by-Turn Beam Position Monitoring System for Multiple Bunch Operation of the ATF Damping Ring

damping, synchrotron, feedback, monitoring

930

P. Burrows, R. Apsimon, D.R. Bett, N. Blaskovic Kraljevic, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry
JAI, Oxford, United Kingdom
B. Constance
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

An FPGA-based monitoring system has been developed to study multi-bunch beam instabilities in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). The system utilises a stripline beam position monitor (BPM) and a single-stage down-mixing BPM processor. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR with c. 150ns bunch spacing, or the head bunch of up to three trains in a multi-bunch mode with bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software allow the recording of turn-by-turn data. An overview of the system and performance results will be presented.

MOPPR065

A Low-latency Sub-micron Resolution Stripline Beam Position Monitoring System for Single-pass Beamlines

monitoring, feedback, linear-collider, collider

933

P. Burrows, D.R. Bett, N. Blaskovic Kraljevic, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry
JAI, Oxford, United Kingdom
R. Apsimon, B. Constance
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

A low-latency, sub-micron resolution stripline beam position monitoring system has been developed for use in single-pass beamlines. The fast analogue front-end signal processor is based on a single-stage RF down-mixer and is combined with an FPGA-based system for digitisation and further signal processing. The system has been deployed and tested with beam at the Accelerator Test Facility at KEK. Performance results are presented on the calibration, resolution and stability of the system. A detailed simulation has been developed that is able to account for the measured performance.

MOPPR066

Study of Transverse Pulse-to-Pulse Orbit Jitter at the KEK Accelerator Test Facility 2 (ATF2)

simulation, feedback, controls, linear-collider

936

J. Resta-López, J. Alabau-Gonzalvo
IFIC, Valencia, Spain
R. Apsimon, B. Constance, A. Gerbershagen
CERN, Geneva, Switzerland
D.R. Bett, P. Burrows, G.B. Christian, M.R. Davis, C. Perry
JAI, Oxford, United Kingdom

Funding: FPA2010-21456-C02-01
For future linear colliders the precise control and mitigation of pulse-to-pulse orbit jitter will be very important to achieve the required luminosity. Diagnostic techniques for the orbit jitter measurement and correction for multi-bunch operation are being addressed at the KEK Accelerator Test Facility 2 (ATF2). In this paper we present recent studies on the vertical jitter propagation through the ATF2 extraction line and final focus system. For these studies the vertical pulse-to-pulse position and angle jitter have been measured using the available stripline beam position monitors in the beamline. The cases with and without intra-train orbit feedback correction in the ATF2 extraction line are compared.

TUXA01

Status of the J-PARC Facility

linac, neutron, hadron, synchrotron

1005

S. Nagamiya
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

This presentation should provide a summary of the status and eventual re-commissioning of the J-PARC facility following the 2011 earth quake and tsunami.

Slides TUXA01 [33.003 MB]

TUOBA01

Summary of Fermilab’s Recycler Electron Cooler Operation and Studies

electron, antiproton, emittance, ion

1068

L.R. Prost, A.V. Shemyakin
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
Fermilab’s Recycler ring was used as a storage ring for accumulation and subsequent manipulations of 8 GeV antiprotons destined for the Tevatron collider. To satisfy these missions, a unique electron cooling system was designed, developed and successfully implemented. The most important features that distinguish the Recycler cooler from other existing electron coolers are its relativistic energy (it employs a 4.3 MeV, 0.1 A DC electron beam), a weak continuous longitudinal magnetic field in the cooling section (~100 G), and lumped focusing elsewhere. With the termination of the collider operation at Fermilab, the cooler operation was also terminated. In this article, we will summarize the experience of commissioning, optimizing and running this unique machine over the 6 years of its existence.

Slides TUOBA01 [2.503 MB]

TUPPC005

Optimization of the SIS100 Nonlinear Magnet Scheme for Slow Extraction

sextupole, octupole, lattice, dynamic-aperture

1158

A. Saa Hernandez, M.M. Kirk, D. Ondreka, N. Pyka, S. Sorge, P.J. Spiller
GSI, Darmstadt, Germany

The SIS100 superconducting synchrotron was initially planned mainly for fast extraction of protons and heavy ions. Due to the delay of the construction of the SIS300 synchrotron, SIS100 has to be able to provide slowly extracted heavy ion beams to the experiments. To improve the robustness of the slow extraction from SIS100, a lattice review was performed, resulting in an optimization of the nonlinear magnet scheme. In the original scheme the Hardt condition cannot be established due to a collapse of the dynamic aperture caused by the chromatic sextupoles. In the optimized scheme the positions of the chromatic sextupoles are modified and octupoles are employed to compensate the second order effects of these sextupoles. In addition, the number of resonance sextupole magnets is reduced. With the new scheme, the Hardt condition can be established, leading to higher extraction efficiency. The separatrix can be freely adjusted, and closed orbit control is improved.

TUPPC006

CW Energy Upgrade of the Superconducting Electron Accelerator S-DALINAC

recirculation, dipole, linac, simulation

1161

M. Kleinmann, J. Conrad, R. Eichhorn, F. Hug, N. Pietralla
TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by the DFG through SFB 634.
The S-DALINAC is a superconducting recirculating electron accelerator with maximum design energy of 130 MeV operating in cw at 3 GHz. Even so the gradients of the superconducting cavities are well above design, their design quality factor of 3*10⁹ have not been reached so far. Due to the limited cooling power of the cryo-plant being 120 W, the final energy achievable in cw operation is around 85 MeV, currently. In order to provide a cw beam with the designed final energy in the future, the installation of an additional recirculation path is projected and to be finished by 2013. We review the design constraints related to the existing beam lines, report in detail on the magnet design (being the key issue) and the lattice calculations for the additional recirculation path.

TUPPC012

Optics of Extraction Lines at CNAO

proton, dipole, ion, septum

1179

E. Bressi, L. Falbo, C. Priano, M. Pullia
CNAO Foundation, Milan, Italy
C. Biscari
INFN/LNF, Frascati (Roma), Italy

The CNAO (National Center for Oncological Hadrontherapy), is the first Italian center for deep hadrontherapy with proton and carbon ion beams, treating patients since fall 2011. The beam is delivered to the patient through a high energy transfer line (HEBT). The line is equipped with a horizontal switching dipole that carries the beam in three treatment rooms and a vertical switching dipole that allows a vertical delivery of the beam in the central treatment room. The CNAO HEBT commissioning has been carried out using proton and Carbon beams in the full range of energies: 60 to 250 MeV/u for protons, 120 to 400 MeV/u for Carbon ions. Optimization of the beam lines setup has been carried out for few energies, applying beam magnetic rigidity scaling for the full range in steps of the order of 1 MeV. The scaling has proven to be satisfactory for most elements, and only minor adjustments in the initial part of the line were needed to fulfill tolerances in all the range. Repeatability of magnetic settings is supported by measurements along the lines. Finally the results in terms of beam dimensions, beam transmission and beam position at the patient position are presented.

TUPPC030

Status of the Ion Sources at ESS-Bilbao

ion, controls, ion-source, plasma

1227

J. Feuchtwanger, I. Arredondo, F.J. Bermejo, I. Bustinduy, J. Corres, M. Eguiraun, P.J. González, J.L. Muñoz
ESS Bilbao, Bilbao, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
R. Miracoli
ESS-Bilbao, Zamudio, Spain

Currently there are two types of ion sources under development and testing at ESS-Bilbao, the first one is a Penning type source based on the ISIS/RAL source, modified to use permanent magnets to generate the Penning field. The second source is an off-resonance ECR source that is being developed in-house. The Penning source is in the late stages of commissioning, and a beam has been extracted from it. Currently the main work on that source is in the optimization of the operating parameters. The ECR source on the other hand is in the early stages of the commissioning, all parts have been fabricated, and Vacuum tests are underway. Testing of the RF and control systems will follow, and finally the whole system will be tested. The control system for both ion sources was developed under LabView, and runs on a real time system. While for testing the timing sequences run locally, the system is being developed so that it can run using a central timing system.

TUPPC059

Extraction of the Lie Map from Realistic 3D Magnetic Field Map

dipole, quadrupole, dynamic-aperture, lattice

1308

Y. Li
BNL, Upton, Long Island, New York, USA
X. Huang
SLAC, Menlo Park, California, USA

Funding: Supported by Department of Energy Contract No. DE-AC02-98CH10886.
We present a method to extract the Lie map of any arbitrary accelerator magnet from its actual 3D field map. After fitting a Taylor map from multi-particle tracking trajectories through the actual field, we factorize the map into a Lie map using Dragt-Finn's method. This method is validated by comparing with COSY-infinity for a soft-edge quadrupole model. Applications of extracting symplectic maps for the SPEAR and NSLS-II dipoles are shown as examples. A comparison of the map-tracking results against the direct field-integration-based method also is given.

TUPPC062

Transfer of Polarized 3He Ions in the AtR Beam Transfer Line

injection, ion, dipole, proton

1317

N. Tsoupas, W.W. MacKay, F. Méot, T. Roser, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US Department of Energy
In addition to collisions of electrons with various unpolarized ion species as well as polarized protons, the proposed electron-hadron collider (eRHIC) will also facilitate the collisions of electrons with polarized 3He ions. The AGS is the last acceleration stage of ions before injection into one RHIC for final acceleration. The AtR (AGS to RHIC) transfer line will be utilized to transport the polarized 3He ions from AGS into one of the RHIC’s collider rings. In this paper we investigate the extraction energy of the polarized 3He ions from the AGS which will optimize the polarization of 3He ions injected into RHIC. Some of the peculiarities (interleaved horizontal and vertical bends) of the AtR line's layout may degrade this spin matching of the polarized 3He ions. We will also discuss possible simple modifications of the AtR line to accomplish a perfect “spin matching” of the injected 3He beam with that of the stable spin direction at the injection point of the RHIC ring.

TUPPC077

Numerical Study of Beam Trapping in Stable Islands for Simple 2D Models of Betatronic Motion

emittance, simulation, resonance, octupole

1350

M. Giovannozzi, C. Hernalsteens
CERN, Geneva, Switzerland

An essential ingredient for the proposed Multi-Turn Extraction (MTE) at the CERN PS is the beam trapping in stable islands. The control of the trapping process is essential for the quality of the final beam in terms of intensity sharing and emittance. In this paper, the splitting process is studied quantitatively by means of numerical simulations performed on 2D model representing the horizontal non-linear betatronic motion. The results are reviewed and discussed in details.

TUPPC082

Non-linear Beam Dynamics Tests at the CERN PS in the Framework of the Multi-turn Extraction

pick-up, synchrotron, coupling, betatron

1365

M. Giovannozzi, G. Arduini, J.M. Belleman, S.S. Gilardoni, C. Hernalsteens, A. Lachaize, G. Métral, Y. Papaphilippou
CERN, Geneva, Switzerland

In the framework of the CERN PS Multi-Turn Extraction several campaigns of measurements probing the non-linear beam dynamics have been carried out. These measurements range from the measurement of non-linear chromaticity to phase space portraits, de-coherence and re-coherence measurements, secondary island tune etc. In this paper these measurements will be reviewed and the results presented and discussed in details.

TUPPD001

The Mice Muon Beamline and Host Accelerator Beam Bump

target, proton, controls, injection

1404

A.J. Dobbs, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
D.J. Adams
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
E. Overton, P.J. Smith
Sheffield University, Sheffield, United Kingdom

Funding: Science and Technology Facilities Council
The international Muon Ionization Cooling Experiment (MICE) is designed provide a proof of principle of the technique of ionization cooling, that is the reduction of the phase space of a muon beam via ionization energy loss in absorbers. Subsequent reacceleration is then provided by RF cavities (‘‘sustainable cooling''). Ionization cooling represents an important step toward future facilities based on stored muons beams, such as a future Neutrino Factory or Muon Collider. The MICE Muon Beam begins with the decay of pions produced by a cylindrical titanium target dipped into the circulating proton beam of the 800 MeV ISIS synchrotron at the Rutherford Appleton Laboratory, U.K. This generates a pion shower which is captured and subsequently decays producing the muon beam. A secondary effect of the MICE target is to cause an increase in the number of protons lost from the ISIS beam. It is important that this effect be minimized. An overview is presented here of the MICE Muon Beam, including the results of a study in to the effect of raising the vertical position of the ISIS beam (a ‘‘beam bump'') in the vicinity of the MICE target.

TUPPD020

An EMMA Racetrack

dipole, quadrupole, injection, electron

1452

B.D. Muratori, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H.L. Owen
UMAN, Manchester, United Kingdom

EMMA (Electron Machine for Many Applications) is the world’s first prototype non-scaling electron FFAG hosted at Daresbury Laboratory. Several upgrade possibilities for EMMA are explored, from creating a dispersion-free region in the ring to facilitate injection and extraction to making an insertion in EMMA by turning it into a racetrack-style machine. Alternative methods of injection and extraction into the EMMA ring are explored together with their feasibility and implications. The option of developing nested racetracks to achieve a particular desired energy is also explored.

TUPPD026

Study of the RFQ Beam Cooler for SPES project

ion, rfq, quadrupole, emittance

1467

M.M. Maggiore, A.M. Porcellato, S. Stark
INFN/LNL, Legnaro (PD), Italy

The SPES project is the new Radioactive Ion Beam facility under construction at Laboratori Nazionali of Legnaro, Italy. In this framework in order to improve the beam quality in terms of emittance and energy spread, a study of a new RFQ beam cooler device is accomplishing. The electromagnetic design of the RFQ section and the electrostatic layout of the injection and extraction regions have been done. The study about the beam dynamic is going on by means of dedicated codes which allow to take into account the interaction of the ions with the buffer gas needed to cool the beams. The status of the project and the results will be shown in this report.

TUPPD039

Simulation Study of Space Charge Effects for a 100-keV, 150-mA Class Deuteron Source

emittance, simulation, plasma, focusing

1491

M. Ichikawa, H. Suzuki
Japan Atomic Energy Agency (JAEA), International Fusion Energy Research Center (IFERC), Rokkasho, Kamikita, Aomori, Japan
S. Maebara
JAEA, Ibaraki-ken, Japan

Ion sources providing high current beam with low emittance are required for accelerators to expand to apply them to fusion material science. A 100-keV, 150-mA class deuteron source with low emittance is required for an accelerator-based neutron irradiation facility to develop fusion materials, and the study for space charge effects in the range of a 20- to 150-mA deuteron beam is indispensable to extract the low beam emittance. For this purpose, each ion source to extract the beam current of 20, 50, 100, and 150 mA was designed by the Igun code, under the condition to extract a beam radius of 4 mm, a beam energy of 100 keV, and a normalized emittance of 0.2 PI mm mrad. In this article, these simulation results from the viewpoint of space charge effects will be presented in detail.

TUPPD046

Characterization of Li⁺ Alumino-Silicate Ion Source for Target Heating Experiments

ion, ion-source, space-charge, brightness

1506

P.K. Roy, W.G. Greenway, J.W. Kwan, S.M. Lidia, P.A. Seidl, W.L. Waldron
LBNL, Berkeley, California, USA
D.P. Grote
LLNL, Livermore, California, USA

Funding: *This work was performed under the auspices of the U.S Department of Energy by LLNL under contract DE AC52 07NA27344, and by LBNL under contract. DE-AC02-05CH11231.
The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li⁺ ion beam with energy 1.2–3 MeV to achieve uniform heating up to 0.1–1 eV. Experiments will be done using the Neutralized Drift Compression Experiment-II (NDCX-II) facility. The NDCX-II accelerator has been designed to use a large diameter (10.9 cm) Li⁺ doped alumino-silicate source to produce short pulses of ≈93 mA beam current. Fabrication of a lithium source is complex, it is necessary to apply a higher temperature (>1200-degC) for thermionic emission, and the beam current density of this source is ~1mA/cm² in the space-charge limited regime. Li⁺ emission is lower than the other alkaline ions sources (K⁺, Cs⁺). The lifetime of this source is roughly 50 hours, when pulsed. Characterization of an operational lithium alumino-silicate ion source, including beam emittance, is presented.

TUPPR016

Final Cross Section Design of the Stripline Kicker for the CLIC Damping Rings

impedance, damping, kicker, wakefield

1843

C. Belver-Aguilar, A. Faus-Golfe
IFIC, Valencia, Spain
M.J. Barnes
CERN, Geneva, Switzerland
F. Toral
CIEMAT, Madrid, Spain

Funding: IDC-20101074 and FPA2010-21456-C02-01
The CLIC design relies on the presence of Pre-Damping Rings (PDR) and Damping Rings (DR) to achieve, through synchrotron radiation, the very low emittance needed to fulfill the luminosity requirements. Kicker systems are required to inject and extract the beam from the Pre-Damping and Damping Rings. In order to achieve low beam coupling impedance and reasonable broadband impedance matching to the electrical circuit, striplines have been chosen for the kicker elements. In this paper the final design for the DR kicker is presented, including an optimization of the geometric parameters to achieve the requirements for both characteristic impedance and field homogeneity. In addition, a sensitivity analysis of characteristic impedance and field homogeneity to geometric parameters is reported.

TUPPR019

High Power Operation with Beam of a CLIC PETS Equipped with ON/OFF Mechanism

recirculation, simulation, controls, vacuum

1852

I. Syratchev, R. Corsini, A. Dubrovskiy, P.K. Skowroński
CERN, Geneva, Switzerland
R.J.M.Y. Ruber
Uppsala University, Uppsala, Sweden

One of the feasibility issues of the CLIC two-beam scheme is the possibility of rapidly switching off the RF power production in individual Power Extraction and Transfer Structures (PETS) in case of breakdowns, either in the PETS or one of the main beam accelerating structures. The proposed solution is to use a variable external reflector connected to the PETS. When activated, this scheme allows us to manipulate gradually the RF power transfer to the accelerating structure and to reduce the RF power production in the PETS itself by a factor of 4. Recently the first operation of the Two Beam Test Stand (TBTS) PETS equipped with an on-off mechanism has been performed in CTF3. In this paper we will present the results of the PETS operation when powered by the drive beam up to high peak power levels (>100 MW) and compare them to expectations.

TUPPR031

Experimental Verification of the CLIC Decelerator with theTest Beam Line in the CLIC Test Facility 3

quadrupole, alignment, lattice, linac

1885

R.L. Lillestøl, S. Döbert, M. Olvegård, A. Rabiller, G. Sterbini
CERN, Geneva, Switzerland
E. Adli
University of Oslo, Oslo, Norway

The Test Beam Line in the CLIC Test Facility 3 is the first prototype of the CLIC drive beam decelerator. The main purpose of the experiment is to demonstrate efficient 12 GHz rf power production and stable transport of an electron drive beam during deceleration. The Test Beam Line consists of a FODO structure with high precision BPMs and quadrupoles mounted on mechanical movers for precise beam alignment. Nine out of the planned 16 Power Extraction and Transfer Structures have currently been installed and commissioned. We correlate rf power production measurements with the drive beam deceleration measurements, and compare the two measurements to the theoretical predictions. We also discuss the impact of the drive beam bunch length and bunch combination on the measurements.

TUPPR060

Detection of Ground Motion Effects on the Beam Trajectory at ATF2

ground-motion, quadrupole, lattice, linear-collider

1954

Y. Renier, J. Pfingstner, D. Schulte, R. Tomás
CERN, Geneva, Switzerland

The ATF2 experiment is currently demonstrating the feasibility of the beam delivery system for the future linear collider. The tunning is very critical to obtain the nanometer vertical beam size at the interaction point and in the case of CLIC, ground motion effects on the beam must be corrected. In this respect, as a proof of principle of a ground motion feed forward, the ground motion effects on the beam trajectory are extracted from the beam position monitor readings.

TUPPR086

Transport from the Recycler Ring to the Antiproton Source Beamlines

proton, kicker, antiproton, booster

2026

M. Xiao
Fermilab, Batavia, USA

In the post-Nova era, the protons are directly transported from the Booster ring to the Recycler ring rather than the Main Injector. For Mu2e and g-2 project, the Debuncher ring will be modified into a Delivery ring to deliver the protons to both Mu2e and g-2 experiemnts. Therefore, It requires the transport of protons from the Recycler Ring to the Delivery ring. A new transfer line from the Recycler ring to the P1 beamline will be constructed to transport proton beam from the Recycler Ring to existing Antiproton Source beamlines. This new beamline provides a way to deliver 8 GeV kinetic energy protons from the Booster to the Delivery ring, via the Recycler, using existing beam transport lines, and without the need for new civil construction. This paper presents the Conceptual Design of this new beamline.

TUPPR087

Status of NSCL Cyclotron Gas Stopper

ion, cyclotron, injection, emittance

2029

N.S. Joshi, G. Bollen, M. Brodeur, D.J. Morrissey, S. Schwarz
NSCL, East Lansing, Michigan, USA

A gas-filled reverse cyclotron for the thermalization of energetic beams is under construction at NSCL/MSU. Rare isotopes produced via projectile fragmentation after in-flight separation will be injected into the device and converted into low-energy beams through buffer gas interactions as they spiral towards the center of the device. The extracted thermal beams will be used for low energy experiments such as precision mass measurements with traps or laser spectroscopy, and further transport for reacceleration. Detailed calculations have been performed to optimize the magnetic field design as well as the transport and stopping of ions inside the gas. An RF-carpet will be used to transport the thermal ions to the axial extraction point. The calculations indicate that the cyclotron gas stopper will be much more efficient for the thermalization of light and medium mass ions compared to linear gas cells. In this contribution we will discuss simulations of the overall performance and acceptance of machine, the beam matching calculations to the fragment separator emittance, and the construction status.

TUPPR093

Sources and Solutions for LHC Transfer Line Stability Issues

injection, kicker, septum, controls

2047

L.N. Drosdal, W. Bartmann, C. Bracco, B. Goddard, V. Kain, G. Le Godec, M. Meddahi, J.A. Uythoven
CERN, Geneva, Switzerland

The LHC is filled through two 3km transfer lines from the last pre-injector, the SPS. Safe injection into the LHC requires stable trajectories in the transfer lines. During the LHC proton operations 2011 instabilities were observed. In particular shot-by-shot and bunch-by-bunch variations cause difficulties for steering of the beam and can potentially cause high beam losses at injection. The causes of these instabilities have been studied and will be presented in this paper. Based on the studies solutions will be proposed and finally the effects of the solutions will be studied.

WEOAA03

Development of the Beam Halo Monitor in the J-PARC 3-GeV RCS

injection, electron, beam-losses, gun

2122

M. Yoshimoto, N. Hayashi, H. Hotchi, M. Kinsho, S.I. Meigo, K. Okabe, P.K. Saha, K. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

Transverse beam halo is one of the most important beam parameters due to limit the performance of the high intensity beam accelerator. Therefore the transverse beam halo measurement is required to increase the beam power of the J-PARC 3-GeV RCS. Transverse halo monitors, which are horizontal and vertical scanning aluminum plates type, has been installed in the extraction beam line. But the residual secondary electrons hindered the beam halo diagnostic. Thus we develop the new beam halo monitor with vibrating wire monitor.

Slides WEOAA03 [6.701 MB]

WEPPC063

Superconducting RF Cavity for High-current Cyclotrons

cavity, cyclotron, focusing, injection

2354

N. Pogue, P.M. McIntyre, A. Sattarov
Texas A&M University, College Station, Texas, USA

Funding: This work is supported by grants from the State of Texas (ASE) and the Mitchell Family Foundation.
A novel superconducting cavity is presented for applications in cyclotrons. The cavity is in effect an extrusion of a 2-D double-quarter-wave structure, in which the ends of the extrusion are wrapped around and joined so that the cavity has no end perturbations. Power is applied to a linear array of input coupling loops, so that rf sheet current is launched in a laminar flow that matches the power coupled to the orbits of the cyclotron. Each loop is driven by an independent solid-state rf source. A strategy is presented for using to advantage the independent control of phase and amplitude to suppress transient phenomena. Longitudinal modes can be strongly suppressed. These provisions are of importance to suppress phenomena that can limit beam current.

WEPPP068

Latest Performance Results from the FONT5 Intra-train Beam Position and Angle Feedback System at ATF2

feedback, kicker, linear-collider, collider

2864

D.R. Bett, R. Apsimon, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, M.R. Davis, A. Gerbershagen, C. Perry
JAI, Oxford, United Kingdom
B. Constance
CERN, Geneva, Switzerland
J. Resta-López
IFIC, Valencia, Spain

A prototype Interaction Point beam-based feedback system for future electron-positron colliders, such as the International Linear Collider, has been designed and tested on the extraction line of the KEK Accelerator Test Facility (ATF). The FONT5 intra-train feedback system aims to stabilize the beam orbit by correcting both the position and angle jitter in the vertical plane on bunch-to-bunch time scales, providing micron-level stability at the entrance to the ATF2 final-focus system. The system comprises three stripline beam position monitors (BPMs) and two stripline kickers, custom low-latency analogue front-end BPM processors, a custom FPGA-based digital processing board with fast ADCs, and custom kicker-drive amplifiers. The latest results from beam tests at ATF2 will be presented, including the system latency and correction performance.

WEPPP085

Study on the Realignment Plan for J-PARC 3 GeV RCS after the Tohoku Earthquake in Japan

injection, quadrupole, survey, alignment

2909

N. Tani, H. Hotchi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

J-PARC 3GeV RCS suffered the big damage to its building and cooling and electric facilities by the Tohoku Region Pacific Coast Earthquake on March 11, 2011. After the earthquake, RCS magnets were measured to confirm the state of accelerator beam line. As a result, it was found out that there was an alignment error of several millimeters in both horizontal and vertical directions that caused a deformation in the J-PARC 3GeV RCS tunnel. In this paper, we report the survey result in the accelerator tunnel after the earthquake and the realignment plan for J-PARC 3GeV RCS.

WEPPP090

Stable RF Distribution System for the S-band Linac

controls, linac, klystron, feedback

2924

T. Naito, K. Ebihara, S. Nozawa, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan
M. Amemiya
AIST, Tsukuba, Japan

The phase stabilization of the RF phase is key issue for the stable linac operation. An RF distribution system with femto-second stability has been developed for S-band linac using optic fiber links. The system uses a phase stabilized optical fiber (PSOF) and an active fiber length stabilization.* The phase stability is 0.1 degree (100f s) for 24 hours observation. In this paper, we present the test results of the system stability and evaluation of the existing RF reference line by using this system.
* Naito et. al. IPAC10 MOPC146

WEPPR007

Simulation Calculation of Longitudinal Beam Distribution in J-PARC MR

injection, beam-loading, acceleration, simulation

2949

K. Hara, T. Koseki, C. Ohmori
KEK, Tokai, Ibaraki, Japan
Y. Sato
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC accelerator complex consists of 3 accelerators, a linear accelerator, a rapid cycle synchrotron (RCS) and a Main Ring (MR) synchrotron. Simulation calculation of longitudinal beam distribution in J-PARC Main Ring has been performed. The effect that RF voltage pattern, space charge, and beam loading gave was examined.

WEPPR008

Simulation of Controlled Longitudinal Emittance Blow-up in J-PARC RCS

emittance, simulation, resonance, cavity

2952

M. Yamamoto, M. Nomura, A. Schnase, T. Shimada, F. Tamura
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
E. Ezura, K. Hara, K. Hasegawa, C. Ohmori, A. Takagi, K. Takata, M. Toda, M. Yoshii
KEK, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

In the J-PARC RCS, a high intensity beam is prepared for the MR. The longitudinal beam emittance at the RCS extraction should be optimized to avoid beam loss during and after MR injection. In order to match the longitudinal emittance shape between the RCS and the MR, it is desirable to enlarge the longitudinal emittance during the RCS acceleration. We have performed the particle tracking simulation for the controlled longitudinal emittance blow up in the RCS.

WEPPR010

Comparison between Electron Cloud Build-Up Measurements and Simulations at the CERN PS

electron, simulation, pick-up, vacuum

2955

G. Iadarola
Naples University Federico II, Science and Technology Pole, Napoli, Italy
F. Caspers, S.S. Gilardoni, G. Iadarola, E. Mahner, G. Rumolo, C. Yin Vallgren
CERN, Geneva, Switzerland

The build up of an Electron Cloud (EC) has been observed at the CERN Proton Synchrotron (PS) during the last stages of the LHC high intensity beam preparation, especially after the bunch shortening before extraction. A dedicated EC experiment, equipped with two button pick-ups, a pressure gauge, a clearing electrode, and a small dipole magnet, is available in one of the straight sections of the machine. A measurement campaign has been carried out in order to scan the EC build-up of LHC-type beams with different bunch spacing, bunch intensity, and bunch length. Such information, combined with the results from build up simulations, is of relevance for the characterization in terms of Secondary Emission Yield (SEY) of the chamber inner surface. The interest is twofold: this will enable us to predict the EC build up distribution in the PS for higher intensity beams in the frame of the upgrade program, and it will provide validation of the EC simulation models and codes.

WEPPR013

Design of an Electrostatic Extraction Section for the University of Maryland Electron Ring

simulation, emittance, electron, lattice

2964

K.J. Ruisard
Rutgers University, The State University of New Jersey, Piscataway, New Jersey, USA
B.L. Beaudoin, I. Haber, R.A. Kishek, T.W. Koeth
UMD, College Park, Maryland, USA

Funding: This work is supported by the US Dept. of Energy Office of High Energy Physics.
The University of Maryland Electron Ring (UMER) is a 11.5 meter circumference, 10 keV, electron storage ring dedicated to the study of the physics space-charge-dominated beams transported over long path lengths. The intensity of the space charge in UMER can be varied by aperturing the injected beam current from 0.6 mA to 100 mA. Recently, the electron beam has been transported over one thousand turns. To fully characterize the transverse and longitudinal evolution of the beam on a turn-by-turn basis, extraction and transport to a diagnostic station is required. We present the design of a pulsed electric extraction system that satisfies the challenging constraint of fitting the hardware within the dense magnet lattice. The extraction system must universally accommodate the range beam intensities and minimize any disruption to the circulating beam

WEPPR028

An Estimate of Out of Time Beam Upon Extraction for Mu2e

septum, scattering, proton, background

2994

N.J. Evans, S.E. Kopp
The University of Texas at Austin, Austin, Texas, USA
E. Prebys
Fermilab, Batavia, USA

Funding: U.S. Dept. of Energy.
A bunched beam with specific structure is crucial to attaining the experimental sensitivity desired by the Mu2e collaboration. The final goal is a ratio of in-time to out-of-time beam, known as beam extinction, of 10^-10. An AC dipole system is in development to attain the final goal by sweeping out-of-time beam onto a collimation system, but it is still necessary to achieve something on the order of 10^-5 when beam is extracted from the Fermilab Debuncher ring to the experiment hall. Several sources of out-of-time beam in the Debuncher ring are analyzed, including: intrabeam scattering, RF noise, beam-gas interaction and scattering off of the extraction septum. Estimates are given for each source as well as a final estimate of total out-of-time beam expected upon extraction.

WEPPR038

Independent Component Analysis (ICA) Applied to Long Bunch Beams in the Los Alamos Proton Storage Ring

betatron, linac, injection, coupling

3018

J.S. Kolski, R.J. Macek, R.C. McCrady, X. Pang
LANL, Los Alamos, New Mexico, USA

Independent component analysis (ICA) is a powerful blind source separation (BSS) method. Compared to the typical BSS method, principal component analysis (PCA), which is the BSS foundation of the well known model independent analysis (MIA), ICA is more robust to noise, coupling, and nonlinearity. ICA of turn-by-turn beam position data has been used to measure the transverse betatron phase and amplitude functions, dispersion function, linear coupling, sextupole strength, and nonlinear beam dynamics. We apply ICA in a new way to slices along the bunch and discuss the source signals identified as betatron motion and longitudinal beam structure.

WEPPR072

Increasing Instability Thresholds in the SPS by Lowering Transition Energy

optics, emittance, injection, coupling

3096

H. Bartosik, G. Arduini, T. Argyropoulos, T. Bohl, S. Cettour-Cave, K. Cornelis, J. Esteban Muller, W. Höfle, Y. Papaphilippou, G. Rumolo, B. Salvant, E.N. Shaposhnikova
CERN, Geneva, Switzerland

A new optics for the SPS with lower transition energy was tested experimentally during 2010-2011, showing a significant increase of the single bunch instability thresholds at injection, due to the 3-fold increase of the slip factor. This paper summarizes the series of performed machine studies for different LHC bunch structures and intensities. In particular, the search of the TMCI threshold in the new optics is presented. Observations on the longitudinal multi-bunch stability are compared between the nominal and the low-transition optics. Finally, optics variants with higher vertical tunes are discussed, which can allow to further increase the TMCI and vertical instability thresholds by reducing the vertical beta function.

THXA01

Producing Medical Isotopes using X-rays

linac, target, electron, neutron

3177

M.S. de Jong
CLS, Saskatoon, Saskatchewan, Canada

Funding: Natural Resources Canada Non-reactor-based Isotope Supply Program Contribution Agreement Saskatchewan Crown Investment Corporation Contribution Agreement
In recent years, there has been frequent shortages of Mo-99 and its daughter isotope, Tc-99m, which are the most heavily used medical diagnostic radio-isotopes. The Canadian Light Source is leading a project to demonstrate large-scale photo-neutron production of Mo-99 using a high-power 35 MeV electron linac as an alternative to production of Mo-99 from fission of highly enriched U-235 in research reactors. This talk will present the results that have been obtained to date and discuss the commercial potential for this alternative production scheme.

Slides THXA01 [6.482 MB]

THXA02

Operation and Patient Treatments at CNAO Facility

proton, ion, synchrotron, acceleration

3180

E. Bressi
CNAO Foundation, Milan, Italy

The CNAO (National Centre for Oncological Hadrontherapy) has been realized in Pavia. It is a clinical facility created and financed by the Italian Ministry of Health and conceived to supply hadrontherapy treatments to patients recruited all over the Country. A qualified network of clinical and research Institutes, the CNAO Collaboration, has been created to build and to run the centre. Three treatment rooms (three horizontal and one vertical) are installed. Beams of protons with kinetic energies up to 250 MeV and beams of carbon ions with maximum kinetic energy of 400 MeV/u are transported and delivered by active scanning systems. CNAO commissioning concerning the high technology started in 2009. First patient was treated with Proton beam in September 2011, the 22nd. This presentation presents the features of the system, together with the results of the first treatments.

Slides THXA02 [14.843 MB]

THEPPB006

Improving the Synchrotron Performance of the Heidelberg Ionbeam Therapy Center

ion, synchrotron, controls, dipole

3243

Th. Haberer
HIT, Heidelberg, Germany

The HIT linac-synchrotron-system routinely delivers pencil beams to the dose delivering rasterscanning devices at 3 treatment rooms, including the worldwide first scanning ion gantry, and 1 experimental cave. At HIT the quality-assured library of pencil beam parameters covers roughly 100.000 combinations of the ion, energy, intensity and beam size. Each patient-specific treatment plan defines a subset of these pencil beams being subsequently requested during the dose delivery. Aiming at shortened irradiation times an upgrade program making heavy use of feed-back mechanisms is under way. Driven by patient-specific data out of the scanning beam dose delivery process central synchrotron components are coupled to the therapy control system in order to tailor the beam characteristics in real-time to the clinical requirements. The paper will discuss the functional upgrades and report about the impact on the medical application at HIT.

THPPC012

Impedance Computation of Main Components in CSNS/RCS

impedance, cavity, simulation, vacuum

3299

Y. Li, L. Huang, Z.P. Li, Y.D. Liu, N. Wang, S. Wang
IHEP, Beijing, People's Republic of China

The rapid cycling synchrotron (RCS) of the China spallation neutron source (CSNS) is a high intensity proton accelerator. The study on the coupling impedance in the ring plays an important role in the stability of the beam. The impedance of the main vacuum components in the RCS ring, such as RF cavities, bellows, ports of vacuum pumps, collimator etc, was calculated by using numerical methods. Meantime, RF shielding of bellows, collimators and ports of vacuum pumps are considered. The impact of the busbar configuration on RF cavities and beams was estimated by impedance calculation.

THPPC030

Multi-physics Analysis of the Fermilab Booster RF Cavity

cavity, booster, proton, injection

3347

M.H. Awida, M.S. Champion, T.N. Khabiboulline, V.A. Lebedev, J. Reid, V.P. Yakovlev
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC, under Contract DE-AC02-07CH11359 with the U.S. DOE
After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

THPPC066

Adjustable High Power Coax RF Coupler without Moving Parts

coupling, cavity, solenoid

3443

M.L. Neubauer, A. Dudas, R. Sah
Muons, Inc, Batavia, USA
A. Nassiri
ANL, Argonne, USA

A high power fundamental RF power coupler (FPC) with an adjustable in situ coupling factor would be highly desirable for a number of applications; for example, the 352 MHz light source at APS and Project X. A Phase I project has been completed with a prototype constructed and modeled. The prototype includes a coaxial TEE with two windows a quarter wavelength apart, and a ferrite tuner. Two materials were tested and their characteristics measured in terms of loss and magnetic field requirements to produce the desired change in coupling. A VSWR of better than 1.05:1 and a bandwidth of at least 8% at 1.15:1 was measured. The tradeoffs of a final design are proposed based upon these results.

THPPC074

High Frequency High Power RF Generation using a Relativistic Electron Beam

wakefield, electron, damping, impedance

3458

C.-J. Jing, S.P. Antipov, A. Kanareykin, P. Schoessow
Euclid TechLabs, LLC, Solon, Ohio, USA
H. Chen, Y. Yang
TUB, Beijing, People's Republic of China
M.E. Conde, W. Gai, J.G. Power
ANL, Argonne, USA

High frequency, high power rf sources are required for many applications. Benefiting from the ~10 GW beam power provided by the high current linac at the Argonne Wakefield Accelerator facility, we propose to develop a series of high power rf sources based on the extraction of coherent Cherenkov radiation from the relativistic electron beam. The frequencies cover from C-band up to W-band with different structures. Simulations show that ~1 GW 20 ns rf pulse can be generated for an 11.7 GHz structure, ~400 MW for a 26 GHz structure, and ~14 MW for a 91 GHz structure.

THPPD002

The First Magnetic Field Control (B-Train) to Optimize the Duty Cycle of a Synchrotron in Clinical Operation

controls, synchrotron, feedback, pick-up

3503

E. Feldmeier, R. Cee, M. Galonska, Th. Haberer, A. Peters, S. Scheloske
HIT, Heidelberg, Germany

In December 2011 the Heidelberg Ion Therapy Center started to use the magnetic field feedback control for its clinical operation. Therewith the magnetic field deviation of the ramped magnets in the synchrotron depending on eddy currents and hysteresis are no longer in effect. Waiting times on the flattop and the "chimney" in the recovery phase of the synchrotron cycle are no longer necessary. The efficiency of the accelerator is increased by more than 20\% and the treatment time shortens accordingly. The core of the magnetic feedback system is a real time measuring system of the magnetic field with extremely high precision.

THPPD049

Conceptual Design of a Superconducting Septum for FFAGs

septum, ion, proton, simulation

3620

H. Witte
BNL, Upton, Long Island, New York, USA
M. Aslaninejad, J. Pasternak
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
K.J. Peach, T. Yokoi
JAI, Oxford, United Kingdom

Funding: This work was supported by STFC grant ST/G008531/1 and EPSRC Grant EP/E032869/1.
The fixed magnetic field in FFAG (Fixed Field Alternating Gradient) accelerators means that particles can be accelerated very rapidly. This makes them attractive candidates for many applications, for example for accelerating muons for a neutrino factory or for charged particle therapy (CPT). To benefit fully from this the particles have to be extracted at the same rate. In combination with the high magnetic rigidity of the particles this represents a significant challenge, especially where variable energy extraction is required, which implies extraction at variable radius. This paper presents a conceptual design of a 4T superconducting septum for the PAMELA accelerator, which is an FFAG for a combined proton/carbon ion therapy facility. The field in the septum is varied as a function of the horizontal position, which allows variable energy extraction without the need for sweeping of the magnetic field.

THPPD052

Operation and Current Status of Injection, Extraction, Kicker Magnet and the Power Supply for J-PARC 3 GeV RCS

kicker, impedance, power-supply, injection

3629

M. Watanabe, N. Hayashi, Y. Shobuda, K. Suganuma, T. Takayanagi, T. Togashi
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

3-GeV RCS (Rapid Cycling Synchrotron) at High Intensity Proton Accelerator Facility (J-PARC) have started for 24-hour operation with repetition rate of 25 pps in February, 2009. Kicker power supply system which uses thyratrons switches is used for extraction of the proton beam. There were many troubles for unstable operation of the thyratrons just after beam commissioning started. Recently, however, the operations were improved and the failure rate was reduced to approximately 0.1 % in October 2010. After the earthquake on March 11, 2011, the injection and extraction magnets, power supplies, the cables and the bus-duct have been checked. Insulation resistance test, impedance test were performed. Reflected wave measurements by the low-level and high-power pulse of the kicker magnets were performed. Visual checks by a fiber endoscope were also performed in the kicker magnets. The results of the measurements and the checks were all not in the problem.

THPPD069

Adjustable Pulse Duration Fast Kicker for the CRYRING Storage Ring

kicker, injection, high-voltage, controls

3671

J.-P. Lavieville, P. Lebasque
SOLEIL, Gif-sur-Yvette, France
W. Beeckman, O. Cosson
Sigmaphi, Vannes, France

The CRYRING storage ring of the Manne Siegbahn Laboratory (MSL, Stockholm) shall be moved to become part of FLAIR accelerators complex in Darmstadt to be used for deceleration of antiprotons and charged ions. That needs an upgrade to adapt it to the full energy range (30MeV – 0.13 MeV) of its future exploitation. SIGMAPHI, in close collaboration with SOLEIL light Source, is in charge of new fast injection and extraction magnets kickers and their pulsed power supplies. The injection will be done at maximum energy (30 MeV) while the extraction need to cover the full energy range (30 MeV – 0.13 MeV) that requires a continuous adjustment capability on the pulse duration and on the deviation amplitude. The development made specifically for the CRYRING kickers is based on a new design involving two different pulsed power supplies, each one managing either the fast rise time or the current flat top. Using solid state switches allows adapting simultaneously the pulse duration and its amplitude. This contribution presents the specific scheme and the development of a kicker system working up to 20 kV with pulse duration from 1.62 μs to 16.3 μs with transient times less than 300 ns.

THPPD078

Cold Cathode Thyratron Based High-voltage Kicker Generators at the Duke Accelerators: Six Year Experience

kicker, power-supply, cathode, high-voltage

3698

V. Popov, S.F. Mikhailov, P.W. Wallace, Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA

Funding: This work is supported in part by the US DOE grant #DE-FG02-97ER41033.
The performance of the Duke storage ring based light sources, the Duke storage ring FEL and High Intensity Gamma-ray Source (HIGS), has been greatly improved since 2007 as the result of operating a new full-energy, top-off booster injector (0.18 - 1.2 GeV), allowing fixed energy operation of the storage ring (0.25 - 1.2 GeV). The injection/extraction kicker system is one of the key components of the accelerator facility which determines efficiency and reliability of the light source operation. Pseudo-Spark Switches(PSS), also known as cold cathode thyratrons, are the critical components of the high voltage pulse generators for kickers. More than six years of operation has allowed us to study the lifetime issue for the 10 kA class devices. Recently, we have tested the next generation cold cathode thyratron, with one installed in one of our storage ring kicker high voltage generators. In the present paper we will also present preliminary test results of this new thyratron and the required modifications of its triggering driver to improve its performance.

THPPP008

The ELENA Project: Progress in the Design

electron, vacuum, antiproton, emittance

3740

T. Eriksson, W. Bartmann, P. Belochitskii, H. Breuker, F. Butin, C. Carli, R. Kersevan, M. Martini, S. Maury, S. Pasinelli, G. Tranquille
CERN, Geneva, Switzerland
W. Oelert
Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich, Germany

The Extra Low ENergy Antiproton ring (ELENA) project started in June 2011 and is aimed at substantially increasing the number of antiprotons delivered to the Antiproton Decelerator (AD) physics community. ELENA will be a small machine that receives antiprotons from AD at 5.3 MeV kinetic energy and decelerates them further down to 100 keV. It will be equipped with an electron cooler to avoid beam losses during deceleration and to reduce beam phase space at extraction. Design work is progressing with emphasis on machine parameters and design as well as infrastructure, ring, transfer lines and vital subsystem design.

THPPP016

Upgrade Strategies for the Proton Synchrotron Booster Dump at CERN

proton, booster, cavity, synchrotron

3761

A. Sarrió Martínez, F. Loprete, C. Maglioni
CERN, Geneva, Switzerland

CERN’s LHC Injection chain Upgrade (LIU) involves a revision of the Proton Synchrotron Booster dump, which was designed in the 1960’s to cope with beam energies reaching 800 MeV and intensities of 10⁺¹³ particles per pulse. Thermo-mechanical studies highlighted the need for an upgrade of the dump, so that it is capable of withstanding energies in the order of 2 GeV and intensities up to 10⁺¹⁴ particles per pulse. This paper proposes a new design of the dump in the light of various constraints and choices such as the geometry, materials and the integration of the required cooling system. Further topics discussed include the strategy for dismantling the old device, which has been continuously irradiated for almost 40 years and presents a difficult access. Therefore, a detailed ALARA procedure is being prepared in order to carry out the upgrade works in the area.

THPPP017

ELENA: From the First Ideas to the Project

antiproton, electron, rfq, vacuum

3764

G. Tranquille, P. Belochitskii, T. Eriksson, S. Maury
CERN, Geneva, Switzerland
W. Oelert
Forschungszentrum Jülich GmbH, Institut fur Nuklearchemie (INC), Jülich, Germany

Successful commissioning of the CERN Antiproton Decelerator (AD) in 2000 was followed by significant progress in the creation of antihydrogen atoms. The extraction energy of the decelerated antiprotons is nevertheless very high compared to that required by experiments and results in a trapping efficiency of only 0.1% to 3%. To improve this value by an order of magnitude the study of an Extra Low ENergy Antiproton ring (ELENA) started in 2003 and was approved as a CERN construction project in 2011. During these years the choice of the main machine parameters such as the beam extraction energy, emittance and bunch length were defined, taking into account requests from the physics community. The main challenges were also identified, such as dealing with the large space charge tune, the ultra high vacuum required and the tight requirements for the electron cooler. Housing the ELENA ring within the AD hall significantly reduced the project cost as well as simplifying the beam transfer from AD to ELENA and from ELENA to the existing experimental areas. This contribution will follow ELENA from its beginnings to the final, approved project proposal.

THPPP020

Project X with Superconducting Rapid Cycling Synchrotron

synchrotron, proton, beam-losses, FEL

3773

H. Piekarz
Fermilab, Batavia, USA

A synchrotron-based upgrade of Fermilab accelerator complex for high intensity physics with Project X is described. It consists of: 1 GeV pulse linac, 1-8 GeV superconducting rapid cycling synchrotron (SRCS), dual 8 GeV storage ring (SR1,2), and 60 GeV Main Injector(MI). Pulse linac and SRCS operate at 10 Hz while SR1, SR2, and MI operate at 1.33 Hz. SR1 stores 3 and SR2 4 SRCS pulses making physics cycle 0.7 s. SR1 batch is extracted in 0.5 s at 3 locations of its ring providing beams to kaon and 2 muon experiments. SR2 batch is transferred to MI, accelerated to 60 GeV, and extracted to 3 neutrino production targets for Minos, Nova, and LBNE experiments. Main synchrotron parameters are listed and magnet systems described. Projected beam power is compared to expectations with linac-only based upgrade as well as with current and planned similar accelerator facilities elsewhere.

THPPP023

Momentum Cogging at the Fermilab Booster

booster, dipole, injection, controls

3782

K. Seiya, C.C. Drennan, W. Pellico, A.K. Triplett, A.M. Waller
Fermilab, Batavia, USA

The Fermilab booster has an intensity upgrade plan called the Proton Improvement plan (PIP). The flux throughput goal is 2·10¹⁷ protons/hour which is almost double the current operation at 1.10¹⁷ protons/hour. The beam loss in the machine is going to be an issue. The booster accelerates beam from 400 MeV to 8GeV and extracts to The Main Injector (MI). Cogging is the process that synchronizes the extraction kicker gap to the MI by changing radial position of the beam during the cycle. The gap creation occurs at about 700MeV which is 6msec into the cycle. The variation of the revolution frequency from cycle to cycle is larger at lower energy and it is hard to control by changing the radial position because of aperture limitations. Momentum cogging is able to move the gap creation earlier by using dipole correctors and radial position feedback, and controlling the revolution frequency and radial position at the same time. The new cogging is going to save energy loss and aperture. The progress of the momentum cogging system development is going to be discussed in this paper.

THPPP065

The FNAL Injector Upgrade Status

rfq, emittance, beam-transport, vacuum

3886

C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.

THPPP079

Status of J-PARC Main Ring After Recovery from the Great East Japan Earthquake Damage

kicker, injection, proton, status

3915

T. Koseki
KEK, Ibaraki, Japan

The J-PARC facility was heavily damaged by the Great East Japan Earthquake on March 11, 2011. For the Main Ring synchrotron (MR), a few tens of cracks were found in the tunnel and many of them leaked groundwater. Displacements of magnet positions after the earthquake were larger than ±15 mm in horizontal and ±5 mm in vertical. Re-alignment of all the magnets and monitors in the MR were carried out in the autumn 2011. Accelerator study and users operation are plan to resume in December 2011 and January 2012, respectively. During the long shutdown period from March to December of 2011, we made work not only for the recovery from the earthquake damages but also for improvements to increase beam power as follows; replacement of injection kickers, upgrade of the ring collimator section, installation of a new collimator system in the slow extraction sections, two rf-systems, four skew-quadrupoles and three octupoles. In this paper, the recovery work and the improvements made in the shutdown periods are reported. Status of high power beam operation after the long shutdown is also presented in details.

THPPP080

Beam Halo Reduction in the J-PARC 3-GeV RCS

emittance, injection, bunching, linac

3918

H. Hotchi, H. Harada, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
Y. Irie, T. Koseki, Y. Sato, M.J. Shirakata
KEK, Ibaraki, Japan
K. Satou
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The J-PARC RCS (3-GeV rapid cycling synchrotron) has two functions as a proton driver to the MLF (Materials and life science facility) and an injector to the MR (50-GeV main ring synchrotron). One of important issues in the current RCS bam tuning is to suppress the beam halo formation, which is essential especially to reduce the beam loss at the MR. In this paper, we present beam study results on the formation mechanism and reduction of the beam halo in the RCS.

THPPP083

Status of J-PARC 3 GeV RCS

injection, beam-losses, beam-transport, vacuum

3927

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

J-PARC RCS have delivered beam progressively since 2008. The RCS ramped up the beam power, and delivered beam of 300kW equivalent and 220kW to MR and MLF, respectively, before the earthquake disaster. The RCS was heavily affected by the last Great East Japan Earthquake. At the RCS, the circulating road went wavy and the yard area for electricity and cooling water devices was heavily distorted. We have investigated damages of each device and also have tried to restore beam operation. From middle of December last year we could start beam test and also would start to deliver beam to MR and MLF for user operation from this January. We have been performed not only recovery works but also improvement of the RCS for realizing high power stable operation with low beam losses. I report status of beam operation and near future plan for the RCS.

THPPR009

Optimization of the Electron Beam Extraction Efficiency in a Booster for TLS

electron, booster, factory, kicker

3981

H.C. Chen, H.-P. Chang, H.H. Chen, S. Fann, S.J. Huang, J.A. Li, C.C. Liang, Y.K. Lin, Y.-C. Liu
NSRRC, Hsinchu, Taiwan

The Response Surface Methodology (RSM), is used to study the optimization process of the electron beam extraction efficiency for Taiwan Light Source (TLS) in NSRRC. A study model was constructed based on the Artificial Neural Network (ANN) theory by using selected beam extraction tuning knobs as the variables. An optimization procedure is developed by taking extraction efficiency as the objective function and the selected beam tuning knobs as the variables. Furthermore, this theoretical model and optimization procedure have been put into practice in verifying how effectively the model can accomplish. By properly applying the constructed optimization procedure for electron beam extraction study, the efficiency has been improved effectively. The details of the study will be reported in this paper.

THPPR030

High Power Test of RF Separator For 12 GeV Upgrade of CEBAF at Jefferson Lab

cavity, vacuum, ion, coupling

4032

S. Ahmed, C. Hovater, G.A. Krafft, J.D. Mammosser, M. Spata, M.J. Wissmann
JLAB, Newport News, Virginia, USA
J.R. Delayen
ODU, Norfolk, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
CEBAF at JLab is in the process of an energy upgrade from 6 GeV to 12 GeV. The existing setup of the RF separator cavities in the 5th pass will not be adequate enough to extract the highest energy (11 GeV) beam to any two existing halls (A, B or C) while simultaneously delivering to the new hall D in the case of the proposed 12 GeV upgrade of the machine. To restore this capability, several options including the extension of existing normal conducting (NC) and a potential 499 MHz TEM-type superconducting (SC) cavity design have been investigated using computer simulations. Detailed numerical studies suggest that six 2-cell normal conducting structures meet the requirements; each 2-cell structure will require up to 4 kW RF input power in contrast with the current nominal operating power of 1.0 to 2.0 kW. A high power test to 4 kW is required to confirm the cavity’s operate-ability at these elevated gradient and power levels. We have assembled a 2-cell cavity, pumped down to 2.0·10^-9 torr using ion pump and confirmed the low level RF performance. A high power test is in progress and will be completed soon. The detailed numerical and experimental results will be discussed in the paper.

THPPR038

Failure Studies at the Compact Linear Collider: Main Linac and Beam Delivery System

linac, quadrupole, betatron, wakefield

4056

C.O. Maidana, M. Jonker, A. Latina
CERN, Geneva, Switzerland

The proposed Compact Linear Collider (CLIC) is based on a two-beam acceleration scheme. The energy of two high-intensity, low-energy drive beams is extracted and transferred to two low-intensity, high-energy main beams. The machine protection and electrical integrity group has the mission to protect the various machine components from damage caused by ill controlled beams. Various failure scenarios were studied and the potential damage these failures could cause to the machine structures were estimated. In this paper, first results of the beam response to correctors and/or quadrupole kick failures in the main linac and in the beam delivery system (BDS) sections are presented as well as possible collimator damage scenarios. The use of the code PLACET for machine protection analysis is described as well.

THPPR053

A CW FFAG for Proton Computed Tomography

cyclotron, proton, lattice, acceleration

4094

C. Johnstone, D.V. Neuffer
Fermilab, Batavia, USA
H.L. Owen
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
P. Snopok
IIT, Chicago, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
An advantage of the cyclotron in proton therapy is the continuous (CW) beam output which reduces complexity and response time in the dosimetry requirements and beam controls. A CW accelerator requires isochronous particle orbits at all energies through the acceleration cycle and present compact isochronous cyclotrons for proton therapy reach only 250 MeV (kinetic energy) which is required for patient treatment, but low for full Proton Computed Tomography (PCT) capability. PCT specifications need 300-330 MeV in order for protons to transit the human body. Recent innovations in nonscaling FFAG design have achieved isochronous performance in a compact (~3 m radius) design at these higher energies. Preliminary isochronous designs are presented here. Lower energy beams can be efficiently extracted for patient treatment without changes to the acceleration cycle and magnet currents.

THPPR063

1 GeV CW Nonscaling FFAG for ADS, and Magnet Parameters

lattice, cyclotron, simulation, proton

4118

F. Méot, W.-T. Weng
BNL, Upton, Long Island, New York, USA
C. Johnstone
Fermilab, Batavia, USA
P. Snopok
Illinois Institute of Technology, Chicago, IL, USA

Multi-MW proton driver capability remains a challenging, critical technology for many core HEP programs, particularly the neutrino ones such as the Muon Collider and Neutrino factory, and for next generation energy applications such as Accelerator Driven Subcritical Reactors (ADS) and Accelerator Transmutation of Waste for nuclear power and waste management. Work is focused almost exclusively on an SRF linac, as, to date, no re-circulating accelerator can attain the 10^-20 MW capability necessary for the nuclear applications. Recently, the concept of isochronous orbits has been explored and developed for nonscaling FFAGs using powerful new methodologies in FFAG accelerator design. The FFAG can remain isochronous beyond the energy reach of cyclotrons and with fixed magnetic fields and strong focusing coupled to recent advances in tune stability, dynamic aperture, and footprint, serious study is underway on a potential application to the ADS problem. Work is progressing on a stable, high intensity, 0.25-1GeV isochronous FFAG. Development and studies of novel magnets with the nonlinear radial fields required to support isochronous operation are reported here.

THPPR064

MW-class 800 MeV/n H²⁺ SC-Cyclotron for ADC application, Design Study and Goals

cyclotron, injection, target, closed-orbit

4121

F. Méot, T. Roser, W.-T. Weng
BNL, Upton, Long Island, New York, USA
L. Calabretta
INFN/LNS, Catania, Italy
A. Calanna
CSFNSM, Catania, Italy

A megawatt class isochronous cyclotron is a potential candidate for accelerator driven systems, as in the subcritical-fission molten-salt reactor application. A scheme for a 800 MeV/nucleon cyclotron accelerating molecular H₂⁺ has been derived from on-going proton driver design studies for neutrino beam production. The present paper reports on beam dynamics studies regarding that cyclotron, exploiting its superconducting coil magnetic sector OPERA field map. These studies are aimed at assessing lattice properties as accelerated orbit, phase oscillations, tunes, beam envelopes and other resonance effects.