IPAC2013 - List of Keywords (factory)

Paper	Title	Other Keywords	Page
MOPEA070	Operating the Diamond Light Source in Low Alpha Mode for Users	injection, lattice, optics, electron	246
	I.P.S. Martin, R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas Diamond, Oxfordshire, United Kingdom R. Bartolini JAI, Oxford, United Kingdom
	Since its first introduction in April 2009, the low alpha operational mode has been continually refined in order to best meet the needs of the user community. Initially the optics were used only to generate short x-ray pulses, for which a stable, low emittance, single bunch was requested, with the emphasis placed on increased bunch charge over shortest absolute pulse duration. More recently, the optics have been adapted to enhance the CSR gain in the THz region of the electromagnetic spectrum. In this paper we summarise the work carried out in order to meet these two demands.

MOPFI005	XPS and UHV-AFM Analysis of the K2CsSb Photocathodes Growth	cathode, vacuum, electron, background	291
	S.G. Schubert HZB, Berlin, Germany I. Ben-Zvi, M. Ruiz-Osés Stony Brook University, Stony Brook, USA X. Liang SBU, Stony Brook, New York, USA H.A. Padmore, T. Vecchione LBNL, Berkeley, California, USA T. Rao, J. Smedley BNL, Upton, Long Island, New York, USA
	Funding: This work is funded by the Department of Energy, under Contract No. KC0407-ALSJNT-I0013, DE-SC0005713, the Bundesministerium für Bildung und Forschung (BMBF) and the state of Berlin, Germany. Next generation light sources, based on Energy Recovery Linac and Free Electron Laser technology will rely on photoinjector based electron sources. Successful operation of such sources requires reliable photocathodes with long operational life, uniform and high quantum efficiency, low thermal emittance and low dark current. The goal of this project is to construct a cathode which meets these requirements. Advances in photocathode research must take a combined effort. The materials have to be analyzed by means of chemical composition, surface structure and these findings have to be correlated to the quantum efficiency and performance in the injector. The presented work focuses on the chemical composition and surface structure of K2CsSb photocathodes. The XPS and AFM measurements were performed at the Center of Functional Nanomaterials at BNL. K2CsSb photocathodes were grown under UHV conditions. The components were adsorbed one at a time and after each growth step the corresponding XPS spectra was taken. During growth the quantum efficiency was recorded. As last step the sample was moved into the AFM without exposure to air to determine the surface roughness.

MOPFI076	Electron Emission Studies in the New High-charge Cs2Te Photoinjector at Argonne National Laboratory	gun, cathode, laser, wakefield	455
	E.E. Wisniewski, M.E. Conde, W. Gai, C.-J. Jing, W. Liu, J.G. Power ANL, Argonne, USA L.K. Spentzouris, Z.M. Yusof Illinois Institute of Technology, Chicago, Illinois, USA
	Funding: This work was funded by the U.S. Dept. of Energy Office of Science under contract number DE-AC02-06CH11357. A new L-band 1.3 GHz 1.5 cell gun for the new 75 MeV drive beam is being commissioned and will soon be operating at the Argonne Wakefield Accelerator (AWA) facility as part of the facility upgrade (see M. E. Conde, this proceedings.) The photoinjector is high-field (peak accelerating field > 80MV/m) and has a large \mathrm{Cs}₂\mathrm{Te} photocathode (diameter > 30 mm) fabricated in-house. The photoinjector generates high-charge, short pulse, single bunches (Q > 100 nC) or bunch-trains (Q ≈ 1000 nC) for wakefield experiments. Field emission from the \mathrm{Cs}₂\mathrm{Te} cathode is to be measured during RF conditioning and benchmarked against measurements from a copper cathode. Quantum efficiency (QE) will be measured in single and multi-bunch modes. Preliminary results are presented.

MOPME039	A New Method of Acquiring Fast Beam Transversal Profile in the Storage Ring	synchrotron, electron, synchrotron-radiation, simulation	556
	C. Cheng, P. Lu, B.G. Sun, K. Tang, F.F. Wu, Y.Y. Xiao, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	A new method of acquiring fast beam transverse profile has been developed and will be used in HLS II. This method is based on four signals from MAPMT (multi-anode photo-multiplier tube) and logarithm processing technique. First, the calculation formula of beam transversal size and position are deduced using above method. Then, the main performances (e.g. sensitivity and linearity range) are analyzed. According to stimulation result, regardless of cross-talk and inconsistency between channels, the size signal has a linear relation with size s when s=0.8-2mm and position d=±2mm, the position signal has a linear relation with position d and the linear range exceeds ±2mm when s=0.8-2mm. With channel cross-talk and channel inconsistency being considered, the stimulation results also are given. Finally, a fast beam transverse profile monitor is designed and provides turn-by-turn measurement of the beam transverse profile.

MOPWO008	Eigenmode Computation for Elliptical Cavities Subject to Geometric Variation using Perturbative Methods	cavity, simulation, higher-order-mode, SRF	900
	K. Brackebusch, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
	Funding: Work supported by Federal Ministry for Research and Education BMBF under contracts 05H09HR5 and 05K10H. Parametric studies of geometric variations are an essential part of the performance optimization and error estimation in the design of accelerator cavities. Using common eigenmode solvers the analysis of intentional and undesired geometric perturbations tend to be very extensive since any geometric variation involves an entire eigenmode recomputation. Perturbative methods constitute an efficient alternative for the computation of a multitude of moderately varying geometries. They require a common eigenmode computation of solely one (so called unperturbed) geometry and allow for deriving the eigenmodes of similar but modified (so called perturbed) geometries from these unperturbed eigenmodes. In [],[] the practicability of perturbative methods was already proven by means of simple cavity geometries. In this paper we investigate the applicability and efficiency for practically relevant cavities. For this, basic geometric parameters of elliptical cavities are varied and the respective eigenmodes are computed by using perturbative as well as common methods. The accuracy of the results and the computational effort of the different methods are compared. K. Brackebusch, H.-W. Glock, U. van Rienen, WEPPC096, IPAC 2011 **K. Brackebusch, U. van Rienen, MOPPC062, IPAC 2012

MOPWO054	The LHeC as a Higgs Boson Factory	linac, luminosity, lepton, electron	1017
	F. Zimmermann, O.S. Brüning CERN, Geneva, Switzerland M. Klein The University of Liverpool, Liverpool, United Kingdom
	The LHeC is designed to collide a new 60 GeV energy electron beam, from a 3-pass ERL, with the 7 TeV energy LHC proton beam. At the present target ep luminosity of 10³³cm^-2s^-1, the LHeC would produce a few 1000 Higgs bosons per year, allowing for precision coupling measurements, especially of the H –> b bbar decay in charged current deep inelastic scattering (ep –> nu H X). With a significant increase of the luminosity, rarer channels become accessible, as the charm decay. Here such an increase, to the level of 10³⁴cm^-2s^-1 or even beyond, is considered from a combination of improvements, namely with a smaller proton beam emittance, with a further reduction of the proton IP beta function, an increase of the proton bunch intensity and with doubling the lepton beam current, compared to the canonical values assumed in the CDR.

TUPEA073	Performances of VORPAL-GPU Slab-symmetric DLW	simulation, wakefield, electron, dumping	1298
	F. Lemery, K. Duffin, N. Karonis, D. Mihalcea, P. Piot, J. Winans Northern Illinois University, DeKalb, Illinois, USA P.J. Mullowney, P. Stoltz Tech-X, Boulder, Colorado, USA P. Piot Fermilab, Batavia, USA
	Funding: HDTRA1-10-1-0051, DOE(Grant No will be specified later) GPU-based computing has gained popularity in recent years due to its growing software support and greater processing capabilities than its CPU counterpart. GPU computing was recently added in the finite-difference time-domain program VORPAL. In this paper we carry electromagnetic simulations and optimization of a flat beam passing through a slab-symmetric dielectric-lined waveguide (DLW). We use this simulation model to explore the scaling of the GPU version of VORPAL on a new TOP1000-grade hybrid GPU/CPU computer cluster available at Northern Illinois University.

TUPFI018	A Simplified Magnetic Field Tapering and Target Optimisation for the Neutrino Factory Capture System	target, solenoid, proton, interaction-region	1370
	I. Efthymiopoulos, S.S. Gilardoni, O.M. Hansen, G. Prior CERN, Geneva, Switzerland O.M. Hansen University of Oslo, Oslo, Norway G. Prior University of Canterbury, Christchurch, New Zealand
	In the Neutrino Factory, a 4 MW proton beam with a kinetic energy between 5 and 15 GeV interacts with a liquid mercury jet target in order to produce pions that will decay to muons, which in turn decay to neutrinos. The baseline-capturing layout consists of a series of solenoids producing a tapered magnetic field from 20 T, near the target, down to 1.5 T at the entrance of the drift section where the captured pions decay into muons to produce a useful beam for the machine. In our alternative layout the magnetic field is rapidly squeezed from 20 T to 1.5T using only three solenoids. This layout showed to produce similar performance, having the advantage being simpler and could potentially be made more robust to radiation. Here we report on further optimization studies taking into account the complete path and shape fluctuations of the Hg-jet.

TUPFI019	Magnet Misalignment Studies for the Front-end of the Neutrino Factory	target, lattice, simulation, proton	1373
	G. Prior, I. Efthymiopoulos CERN, Geneva, Switzerland D.V. Neuffer, P. Snopok Fermilab, Batavia, USA C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom D. Stratakis BNL, Upton, Long Island, New York, USA
	In the Neutrino Factory Front-End the muon beam coming from the interaction of a high-power (4 MW) proton beam on a mercury jet target, is transformed through a buncher, a phase rotator and an ionization cooling channel before entering the downstream acceleration system. The muon Front-End channel is densely packed with solenoid magnets, normal conducting radio-frequency cavities and absorber windows (for the cooling section). The tolerance to the misalignment of the different components has to be determined in order on one hand to set the limits beyond which the performance of the Front-End channel would be degraded; on the other hand to optimize the design and assembly of the Front-End cells such that the component alignment can be checked and corrected for where crucial for the performance of the channel. In this paper we will show the results of the simulations of the Front-End channel performance where different components such as magnets, cavities have been randomly shifted or rotated. Detailed simulations have been done in G4BeamLine. T. J. Roberts et al. G4BeamLine 2.06 (2010) http://g4beamline.muonsinc.com/

TUPFI054	MICE Spectrometer Solenoid Magnetic Field Measurements	solenoid, emittance, simulation, shielding	1466
	M.A. Leonova Fermilab, Batavia, USA
	The Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with a 1% accuracy, corresponding to an absolute measurement accuracy of 0.1%. To measure the emittance, MICE uses two solenoidal spectrometers. The Spectrometer Solenoids are designed to have 4 T solenoidal fields, uniform at 3 per mil level in the tracking volumes. Analysis of magnetic field measurements of the Spectrometer Solenoids will be discussed, and results of extracting precise coil positions, angles, and coil radius measurements for input into magnet models will be presented.

TUPFI056	A Muon Collider as a Higgs Factory	collider, luminosity, emittance, target	1472
	D.V. Neuffer, Y.I. Alexahin, M.A. Palmer Fermilab, Batavia, USA C.M. Ankenbrandt Muons. Inc., USA J.-P. Delahaye SLAC, Menlo Park, California, USA
	Because muons connect directly to a standard-model Higgs particle in s-channel production, a muon collider would be an ideal device for precision measurement of the mass and width of a Higgs-like particle, and for further exploration of its production and decay properties. The LHC has seen evidence for a 126 GeV Higgs particle, and a muon collider at that energy could be constructed. Parameters of a high-precision muon collider are presented and the necessary components and performance are described. An important advantage of the muon collider approach is that the spin precession of the muons will enable energy measurements at extremely high accuracy (E/E to 10^-6 or better). Extension to a higher-energy higher-luminosity device is also discussed.

TUPFI057	Muon Accelerators for the Next Generation of High Energy Physics Experiments	collider, proton, target, background	1475
	M.A. Palmer, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, R.J. Lipton, D.V. Neuffer Fermilab, Batavia, USA C.M. Ankenbrandt Muons. Inc., USA S.A. Bogacz JLAB, Newport News, Virginia, USA J.-P. Delahaye SLAC, Menlo Park, California, USA P. Huber Virginia Polytechnic Institute and State University, Blacksburg, USA D.M. Kaplan, P. Snopok Illinois Institute of Technology, Chicago, Illinois, USA H.G. Kirk, R.B. Palmer BNL, Upton, Long Island, New York, USA R.D. Ryne LBNL, Berkeley, California, USA
	Funding: Work supported by the U.S. Department of Energy and the U.S. National Science Foundation Muon accelerator technology offers a unique and very promising avenue to a facility capable of producing high intensity muon beams for neutrino factory and multi-TeV lepton collider applications. The goal of the US Muon Accelerator Program is to provide an assessment, within the next 6 years, of the physics potential and technical feasibility of such a facility. This talk will describe the physics opportunities that are envisioned, along with the R&D efforts that are being undertaken to address key accelerator physics and technology questions.

TUPFI060	Complete Muon Cooling Channel Design and Simulations	emittance, beam-cooling, dipole, simulation	1484
	C. Y. Yoshikawa, C.M. Ankenbrandt, R.P. Johnson Muons. Inc., USA Y.S. Derbenev, V.S. Morozov JLAB, Newport News, Virginia, USA D.V. Neuffer, K. Yonehara Fermilab, Batavia, USA
	Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittance required for an Energy-Frontier Muon Collider, but lacks an end-to-end design. Meanwhile, the recent discovery of a Higgs-like boson has created interest in the High Energy physics community for a Higgs Factory to investigate its properties and verify whether it is Standard Model or beyond. We present principles and tools to match emittances between and within muon beam cooling subsystems that may have different characteristics. The Helical Cooling Channel (HCC), which combines helical dipoles and a solenoid field, allows a general analytic approach to guide designs of transitions from one set of cooling channel parameters to another. These principles and tools will be applied to design a complete cooling channel that would be applicable to a Higgs Factory and an Energy Frontier Muon Collider.

TUPFI061	Preliminary Design of a Higgs Factory μ+μ- Storage Ring	quadrupole, dipole, collider, storage-ring	1487
	A.V. Zlobin, Y.I. Alexahin, V.V. Kapin, V.V. Kashikhin, N.V. Mokhov, I.S. Tropin Fermilab, Batavia, USA
	Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, and by the US Department of Energy through the Muon Accelerator Program (MAP). A Muon Collider offers unique possibilities for studying the recently found Higgs boson. Higgs bosons can be produced in reasonable amounts in the s-channel, so that the colliding muon beam energy of just 62.5GeV is required. Precision direct measurements of the Higgs boson mass and width is possible due to absence of brems- and beam-strahlung. At the same time, there are difficulties specific to muon colliders: relatively large beam emittance which necessitates quite small beta-function values (~ a few cm) at the interaction point in order to obtain sufficiently high luminosity, as well as superconducting magnet and detector protection from showers generated by muon decay products. Due to these factors, the required aperture of the final focus quadrupoles is very large (up to 0.5 m) posing challenging engineering constraints as well as beam dynamics issues with fringe fields. The first results of a complex approach to these problems in the Higgs Factory collider design are presented which promise luminosities in excess of 1031 cm^-2s⁻¹ with a 4 MW proton driver.

TUPFI067	Energy Deposition and Shielding Study of the Front End for the Neutrino Factory	shielding, proton, target, solenoid	1505
	P. Snopok IIT, Chicago, Illinois, USA D.V. Neuffer Fermilab, Batavia, USA C.T. Rogers STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
	In the Neutrino Factory and Muon Collider muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. This method of pion production results in significant background from protons and electrons, which may result in heat deposition on superconducting materials and activation of the machine preventing manual handling. In this paper we discuss the design of a secondary particle handling system. The system comprises a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles, resulting in the rejection of low energy protons that pass through the solenoid chicane. We detail the design and optimization of the system, its integration with the rest of the muon front end, and energy deposition and shielding analysis in MARS15.

TUPFI069	Influence of Proton Beam Emittances on Particle Production off a Muon Collider Target	target, proton, emittance, collider	1511
	X.P. Ding, D.B. Cline UCLA, Los Angeles, California, USA J.S. Berg, H.G. Kirk, H. K. Sayed BNL, Upton, Long Island, New York, USA V.B. Graves ORNL, Oak Ridge, Tennessee, USA K.T. McDonald PU, Princeton, New Jersey, USA N. Souchlas, R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	Funding: Work supported in part by US DOE Contract NO. DE-AC02-98CHI10886. A free-mercury-jet or a free-gallium-jet is considered for the pion-production target at a Muon Collider or Neutrino Factory. Based on a simple Gaussian incident proton beams with an infinitely large Courant-Snyder β parameters, we have previously optimized the geometric parameters of the target to maximize particle production initiated by incoming protons with kinetic energies (KE) between 2 and 16 GeV by using the MARS15 code. In this paper, we extend our optimization to focused proton beams with various transverse emittances. For the special cases of proton beams with emittances of 2.5, 5 or 10 μm-rad and a kinetic energy of 8 GeV, we optimized the geometric parameters of the target: the radius of the proton beam, the radius of the liquid jet, the crossing angle between the jet and the proton beam, and the incoming proton beam angle. We also study the influence of a shift of the beam focal point relative to the intersection point of the beam and the jet.

TUPFI073	Design of Magnets for the Target and Decay Region of a Muon Collider/Neutrino Factory Target	target, collider, solenoid, proton	1514
	R.J. Weggel, N. Souchlas Particle Beam Lasers, Inc., Northridge, California, USA X.P. Ding UCLA, Los Angeles, California, USA V.B. Graves ORNL, Oak Ridge, Tennessee, USA H.G. Kirk, H. K. Sayed BNL, Upton, Long Island, New York, USA K.T. McDonald PU, Princeton, New Jersey, USA
	The target and decay region of a Muon Collider/Neutrino Factory transports pions and muons in a superconducting solenoid channel that must be protected from radiation damage secondary particles produced by the 4-MW proton beam. For this, He-gas-cooled tungsten beads will be arrayed inside the magnet coils, which leads to large coil radii and high stored magnetic energy (~3 GJ). The design of the superconducting coils, and the tungsten shielding for the ~ 50-m-long target and decay region is reviewed.

TUPFI074	Design of the Final Focus of the Proton Beam for a Neutrino Factory	target, proton, quadrupole, collider	1517
	J. Pasternak, M. Aslaninejad Imperial College of Science and Technology, Department of Physics, London, United Kingdom K. E. Gollwitzer Fermilab, Batavia, USA H.G. Kirk BNL, Upton, Long Island, New York, USA K.T. McDonald PU, Princeton, New Jersey, USA
	The ~ 8-GeV, 4-MW proton beam that drives a Neutrino Factory has a nominal 50-Hz macropulse structure with 2-3 micropulses ~ 100 ns apart. The nominal geometric beam emittance is 5 micron, and the desired rms beam radius at the liquid-metal-jet target is 1.2 mm. A quadrupole-triplet focusing system to deliver this beam spot is described.

TUPFI075	Optimizing Muon Capture and Transport for a Neutrino Factory/Muon Collider Front End	target, solenoid, proton, collider	1520
	H. K. Sayed, J.S. Berg, H.G. Kirk BNL, Upton, Long Island, New York, USA X.P. Ding UCLA, Los Angeles, California, USA K.T. McDonald PU, Princeton, New Jersey, USA
	In the baseline scheme of the Neutrino Factory/Muon Collider a muon beam from pion decay is produced by bombarding a liquid-mercury-jet target with a 4-MW pulsed proton beam. The target is embedded in a high-field solenoid magnet that is followed by a lower field Decay Channel. The adiabatic variation in solenoid field strength along the beam near the target performs an emittance exchange that affects the performance of the downstream Buncher, Phase Rotator, and Cooling Channel. An optimization was performed using MARS1510 and ICOOL codes in which the initial and final solenoid fields strengths, as well as the rate of change of the field along the beam, were varied to maximize the number of muons delivered to the Cooling Channel that fall within the acceptance cuts of the subsequent muon-acceleration systems.

TUPME007	Beam Lifetime in Low Emittance Rings	scattering, simulation, lattice, background	1574
	M. Boscolo INFN/LNF, Frascati (Roma), Italy
	In this paper I will review the main effects in low emittance rings that determine the beam lifetime by causing beam losses along the ring. As an example, the case for a B-factory based on the crab-waist collision scheme has been studied. During the machine design all the effects that determine the beam lifetime and induce backgrounds in the detector have been analyzed in details. The crab-waist scheme provides an higher luminosity, but at the same time it induces higher beam losses at the final focus. For this reason single beam effects such as Touschek and beam-gas scattering have been studied in details, by means of a macroparticle tracking code developed for this purpose. Also Radiative Bhabha scattering, that is the dominant effect to lifetime and backgrounds has been studied with the same technique to check possible multiturn losses at IR. An efficient collimation system has been designed to intercept scattered particles that would be lost in the IR in both the horizontal and the vertical plane. Recently, the Touschek tracking simulation code has been implemented to study the lifetime behavior for extremely low-emittance rings. M. Boscolo and P. Raimondi, “Monte Carlo simulation for the Touschek effect with the crab-waist scheme”, Phys. Rev. ST-AB 15 104201 (2012)

TUPME009	Measurement and Vibration Studies on the Final Focus Doublet at DAΦNE and new collider Implications	damping, collider, luminosity, resonance	1580
	S. Tomassini INFN/LNF, Frascati (Roma), Italy
	Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579. A Super Flavour Factory, to be built in the Tor Vergata University campus near Frascati, Italy, will have nano-beams in order to reach the design luminosity. The knowledge and compensation of the vibrations induced on the beams by the anthropic noise is then fundamental. The DAΦNE Phi-factory at LNF, Frascati, was upgraded in the second half of 2007 in order to implement the large Piwinski angle and crab waist collision scheme and in 2010 the KLOE experiment was rolled in for a new data taking and physic program. A measurement campaign has been performed on DAΦNE to find out the actual vibration sensitivity of the final focus doublets. Vibration measurements were performed on the Final Focus doublet because of luminosity losses and photon beam lines instability evidences. Results and stabilization technique to mitigate the effects of the ground motion induced by the “cultural noise” are presented. Implications on the design and stabilization of a Flavour Factory Final Focus doublets will be discussed.

TUPME021	Optimization Parameter Design of a Circular e⁺e⁻ Higgs Factory	luminosity, emittance, synchrotron, collider	1616
	D. Wang, Y.W. An, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, S. Wang, M. Xiao, G. Xu, S.Y. Xu IHEP, Beijing, People's Republic of China
	Funding: NSFC:11175192 In this paper we will show a genral method of how to make an optimized parameter design of a circular e⁺e⁻ Higgs Factory by using analytical expression of maximum beam-beam parameter and beamstrahlung beam lifetime started from given design goal and technical limitations. A parameter space has been explored.

TUPWA043	Impedance Studies for VMTSA Module of LHC Equipped with RF Fingers	impedance, simulation, resonance	1805
	O. Kononenko, F. Caspers, A. Grudiev, E. Métral, B. Salvant CERN, Geneva, Switzerland
	During 2011 run of LHC it was found that beam-induced heating causes many issues for accelerator components. Particularly some of the double-bellow modules, called VMTSA modules, were found to have deformed RF fingers and a broken spring which ensured good contact between them and a central insert. Impedance studies have been performed for different types of nonconformities and benchmarked against measurements. It was found that even a small gap between the fingers and a central insert could be fatal for the VMTSA operation. Results of this study were an input for the further thermal analysis.

WEOAB103	Experimental Observations of a Multi-stream Instability in a Long Intense Beam	simulation, electron, space-charge, background	2044
	B.L. Beaudoin, S. Bernal, I. Haber, R.A. Kishek, T.W. Koeth UMD, College Park, Maryland, USA
	Funding: Supported by the US Dept. of Energy, Office of High Energy Physics, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office. We have observed evidence of a multi-stream instability in a long non-relativistic space-charge dominated beam evolving with an initial non-linear distribution and zero external longitudinal containment. This type of instability can be detrimental to intense accelerators that propagate rectangular distributions, such as in a ring with single or multi-bunch injection. The longitudinal forces in these intense bunches causes the beam to expand axially; in the case of the University of Maryland Electron Ring (UMER), the initial long bunch is injected to fill a fraction of the ring, coasting beyond the point where the head and tail overlap. Adjacent filaments at that point are separated in velocity space by 2cs and approach a separation of cs. The onset of the instability has been observed to depend on the injected beam current, bunch length, and other experimental factors. Comparisons with simple analytical calculations and PIC simulations have shown good agreement in the time to onset.
	Slides WEOAB103 [1.681 MB]

WEPWA028	Measurement and Research on Cryogenic Remanence of Chunks Permanent Magnet for Cryogenic Undulator	cryogenics, permanent-magnet, controls, undulator	2190
	Y.Z. He SINAP, Shanghai, People's Republic of China
	The higher-precision cryogenic remanence measurment technology and error for chunks permanent magnet were researched in china firstly (10-300K). Magnetic measurement tooling and magnetic field calculation and measurement method of cryogenic remanence measurement system of chunks permanent magnet for cryogenic undulator were optimized. Cryogenic calibration Hall probe were pasted on surface of domestic chunks permanent magnet(Nd2Fe14B: N52, N50M, etc.) and table magnetic field B of permanent magnet were measured, and after being converted, then cryogenic remanence of domestic chunks permanent magnet were obtained and cryogenic remanence variation of domestic chunks permanent magnet were researched. Cryogenic remanence measurement data were checked by pulse B-H tester and PPMS respectively, the results show that cryogenic remanence data has higher reliability. By this experiment, initial foundation were established for development of SSRF cryogenic undulator and for cryogenic remanence measurement and study of domestic other chunks permanent magnets.

WEPWA052	A Gun to Linac Operation Analysis of the Taiwan Light Source Injector	electron, linac, gun, synchrotron	2235
	H.C. Chen, H.H. Chen, S. Fann, S.J. Huang, J.A. Li, C.C. Liang, Y.K. Lin, Y.-C. Liu NSRRC, Hsinchu, Taiwan
	A response surface methodology (RSM) was used to study the gun to linac optimization process of the Taiwan Light Source (TLS) injector at the National Synchrotron Radiation Research Center (NSRRC). A study model, based on artificial neural network (ANN) theory, which uses electron beam tuning knobs as variables, was constructed. An optimization procedure was developed by designating electron beam efficiency as the objective function and the selected beam tuning knobs as the variables. The theoretical model and optimization procedure were both implemented to evaluate the model. By properly applying the constructed optimization procedure, the beam efficiency was improved. This report outlines the details of the gun to linac optimization process experiment.

WEPWO010	BERLinPro Seven-cell SRF Cavity Optimization and HOMs External Quality Factors Estimation	cavity, HOM, SRF, simulation	2331
	T. Galek, K. Brackebusch, T. Flisgen, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany J. Knobloch, A. Neumann HZB, Berlin, Germany B. Riemann, T. Weis DELTA, Dortmund, Germany
	Funding: Work funded by EU FP7 Research Infrastructure Grant No. 227579 and by German Federal Ministry of Research and Education, Project: 05K10HRC. The main scope of this work is the optimization of the superconducting radio frequency (SRF) accelerating cavity design for the Berlin Energy Recovery Linac Project (BERLinPro). BERLinPro shall serve as a demonstrator for 100-mA-class ERLs with CW LINAC technology. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. Consequently it is important, at the SRF cavity design optimization stage, to calculate the external quality factors of HOMs to avoid beam break up (BBU) instabilities. The optimization of the SRF cavity design consists of two steps. In the first step the cavities' end half-cells are tuned with respect to field flatness, effective shunt impedance and geometrical factor of the fundamental accelerating mode using robust eigenmode simulations. The second step involves frequency domain simulations and the extraction of external quality factors of HOMs from transmission S-parameter spectra using vector fitting procedure and an automated scheme to remove non-static poles . The eigenmode,as well as the frequency domain simulations are performed using CST Microwave Studio *. A. Neumann et al., Proc. of ICAP2012, pp. 278–280. T. Galek et al., Proc. of ICAP2012, pp. 152–154. * CST AG, http://www.cst.com

WEPWO071	Quench and High Field Q-SLOP Studies using a Single Cell Cavity with Artificial Pits	cavity, SRF, niobium, feedback	2465
	Y. Xie, G.H. Hoffstaetter, M. Liepe CLASSE, Ithaca, New York, USA
	Surface defects such as pits have been identified as some of the main sources of limitations of srf cavity performance. A single cell cavity was made with 30 artificial pits in the high magnetic field region to gain new insight in how pits limit the cavity performance. The test of the pit cavity showed clear evidence that the edges of two of the largest radius pits transitioned into the normal conducting state at field just below the quench field of the cavity, and that the quench was indeed induced by these two pits. Insights about quench and non-linear rf resistances will be presented.

WEPFI021	Influence of Core Winding Tension and Ribbon Quality on the MA Core RF Characteristics	impedance, synchrotron, vacuum, cavity	2747
	M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii KEK, Tokai, Ibaraki, Japan
	J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) and Main Ring (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. To achieve the high field gradient, the core shunt impedance is a key parameter. We found during the development of MA cores for RCS RF cavities that the core shunt impedance was increased by lowering a core winding tension. We lowered the core winding tension in order to improve the electrical insulation between MA ribbon layers. The lower winding tension reduced the core filling factor that is defined as the volume ratio of MA ribbons and geometrical dimensions. The core shunt impedance might be reduced according to the core filling factor reduction. We discuss the reason why the lower winding tension increased the core shunt impedance. We also report the influence of the ribbon quality variation on the MA core RF characteristics.

WEPFI054	Enlargement of Tuning Range in a Ferrite-tuned Cavity through Superposed Orthogonal and Parallel Magnetic Bias	cavity, resonance, radiation	2812
	C. Vollinger, F. Caspers CERN, Geneva, Switzerland
	Conventional ferrite-tuned cavities operate either with bias fields that are orthogonal or parallel to the magnetic RF-field. For a cavity that tunes rapidly over an overall frequency range around 100-400 MHz with high Q, we use ferrite garnets exposed to an innovative new biasing method consisting of a superposition of perpendicular and parallel magnetic fields. This method leads to a significant enlargement of the high-Q cavity tuning range by defining an operation point close to the magnetic saturation and thus improving ferrite material behaviour. A further advantage of this technique is the fast tuning speed resulting from the fact that tuning is carried out either with pure parallel biasing, or together with a very small change of operating point from perpendicular bias. In this paper, several scaled test models of ferrite-filled resonators are shown; measurements on the set-ups are compared and discussed.

WEPFI058	Breakdown Localization Studies on the SwissFEL C-band Test Structures	background, linac, coupling, impedance	2824
	J. Klavins, S. Dementjevs, F. Le Pimpec, L. Stingelin, M. Wohlmuther, R. Zennaro PSI, Villigen PSI, Switzerland N.C. Shipman CERN, Geneva, Switzerland
	The SwissFEL main linac will consist of 10⁴ C-band structures with a nominal accelerating gradient of 28MV/m. First power tests were performed on short constant impedance test-structures composed of eleven double-rounded cups. In order to localize breakdowns, two or three acoustic emission sensors were installed on the test-structures. In order to localize breakdowns we have analyzed, in addition to acoustic measurements, the delay and phase of the rf power signals. Parasitic, acoustic noise emitted from the loads of the structure complicated the data interpretation and necessitated appropriate processing of the acoustic signals. The Goals of the experiments were to identify design and manufacturing errors of the structures. The results indicate that breakdowns occur mostly at the input power coupler, as also confirmed by vacuum-events at the same location. The experiments show that the linac test-structures fulfill the requirements in breakdown probability. Moreover developing a detection system based on acoustic emission sensors for breakdown localization for our C-band structure seems reasonable given the results obtained.

WEPFI076	Experience with a 5 kW, 1.3 GHz Solid State Amplifier	linac, status, SRF, cryomodule	2869
	K.M.V. Ho, R. Eichhorn, D.L. Hartill, M. Liepe CLASSE, Ithaca, New York, USA
	This study describes the experience with and performance of a commercially available 1.3 GHz 5kW Solid State Amplifier in various experiments at Cornell University. This paper focuses on several key factors in testing the performance of the amplifier. Among those are phase and amplitude stability, gain linearity, and phase shift vs. power. High power amplifiers are usually built with multiple RF power modules and the individual output signals are then combined in a power combiner. Therefore, the phases of the individual RF output power signals have to be adjusted within tight tolerances. The relative phases can be affected by different lengths cables and also affect the overall gain performance of the amplifier.

WEPFI083	High Power Tests of the 2-Pin Waveguide Structures	linear-collider, collider, site, electron	2890
	F.Y. Wang, Z. Li SLAC, Menlo Park, California, USA
	An X-band Two-Pin Waveguide Structure has been designed to study the influence of power flow on rf breakdown. Three different sets of pins will be tested at SLAC. These sets were designed to achieve a similar peak surface electric field on one of the pins for input rf power levels that vary by about an order of magnitude (the other pin is used for matching). Two sets of pins have been tested so far, and the breakdown rate was found to be strongly dependent on the power flow. In this paper, we review the experimental setup, the complete set of results and their implications.

WEPME048	Adjusting and Calibration Method for TPS Laser PSD System	laser, alignment, storage-ring, synchrotron	3037
	M.L. Chen, J.-R. Chen, P.S.D. Chuang, H.C. Ho, K.H. Hsu, D.-G. Huang, W.Y. Lai, C.-S. Lin, C.J. Lin, H.C. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, T.C. Tseng, H.S. Wang, M.H. Wu NSRRC, Hsinchu, Taiwan J.-R. Chen National Tsing Hua University, Hsinchu, Taiwan
	Laser PSD positioning system is a part of the TPS girder auto-alignment system and is designed for aligning and positioning the straight-section girders of TPS storage ring. Although the components of Laser PSD system are fabricated, assembling and adjusting precisely in advance, the accuracy of Laser PSD system is still influenced by girder fabricating quality, assembling errors and moving errors by transportation. For system correction, Laser beam positions on four sets of PSDs are formulized as an equation and calibrated with Laser tracker ultimately. According to the PSD calibration formula, the two girders of 18m long straight-section can be aligned and positioned within 20um by comparing with Laser tracker. This paper describes the assembly, installation and calibration process of Laser PSD system.

THPEA048	The FPGA-based Power Monitoring System for TPS Facility	monitoring, controls, LabView, resonance	3252
	C.S. Chen, Z.-D. Tsai NSRRC, Hsinchu, Taiwan
	There are more and more non-linear electronic equipments such as inverters using in facility nowadays. These non-linear electronic equipments let us achieve energy saving, but induce other electrical pollution to the whole power grid in contrast. How to monitor the electrical noises from these non-linear equipments becomes an important issue. In this article, a set of power quality monitoring system based on FPGA and PAC has been built because of the programmability and fast processing speed. By using this monitoring system, any abnormality in power system and its spectrum will be recorded thoroughly. On the other hand, the maintainer could follow the trace of noise and then propose a suitable solution to eliminate the electrical interference too.

THPFI008	Experience and Benefits from PLM-based Parts Management at European XFEL	cavity, controls, linac, undulator	3306
	L. Hagge, J.A. Dammann, S. Eucker, A. Frank, J. Kreutzkamp, D. Käfer, D. Szepielak, N. Welle DESY, Hamburg, Germany
	DESY has developed a parts management solution, which is used in the series fabrication of accelerator components for the European XFEL. The parts management solution stores assembly instructions and drawings for each component, and it tracks the assembly progress of each individual component. It offers procedures for quality inspections, for handling non-conformities and for managing changes, and it tracks the current whereabouts and the entire history of each part. The solution is based on DESY's Product Lifecycle Management (PLM) System and integrates several laboratories and suppliers. The poster shows how parts management is used at the European XFEL in the production of the super-conducting rf cavities, in the assembly of the cryomodules and in the assembly of the undulators, and discusses experience and benefits.

THPFI013	Development of Cylindrical-type 1.2 MW High Power Water-load for Super KEKB	klystron, positron, collider, cavity	3318
	K. Watanabe, K. Ebihara, A. Kabe, K. Marutsuka, M. Nishiwaki KEK, Ibaraki, Japan Y. Kawane, A. Miura Nihon Koshuha Co. Ltd, Yokohama, Japan
	We have developed and manufactured CW 1.2 MW high power water-load for the use of the Super KEKB, an electron – positron double-ring collider at KEK. The tank and rf window of the water-load is the circular and cylindrical-type. The material to absorb the rf power is a tap water. This load is equipped on the 3rd port of the circulators to safe the 1.2 MW CW klystrons to drive the ARES cavities in main ring. The operational frequency is 508.9 MHz. A proto-type model of this water-load was fabricated at Sep 2012, and tested using by high power klystron (1 MW) at Oct 2012 at KEK D2-ET station. The result of high power test will be reported in this paper.

THPFI053	A Feasibility Experiment of a W-powder Target in the HiRadMat Facility of CERN	target, proton, laser, instrumentation	3409
	N. Charitonidis, I. Efthymiopoulos, A. Fabich CERN, Geneva, Switzerland O. Caretta, T.R. Davenne, C.J. Densham, M.D. Fitton, P. Loveridge STFC/RAL, Chilton, Didcot, Oxon, United Kingdom L. Rivkin EPFL, Lausanne, Switzerland
	Granular solid targets made of fluidized tungsten powder or static pebble bed of tungsten spheres, have been long proposed and are being studied as an alternative configurations towards high-power (>1MW of beam power) target systems, suitable for a future Super Beam or Neutrino Factory. Serving the lack of experimental data on this field, a feasibility experiment was performed in HiRadMat facility of CERN/SPS that tried in a pulse-by-pulse basis to address the effect of the impact of the SPS beam (440GeV/c) on a static tungsten powder target. Online instrumentation such as high-speed photography and Laser - Doppler Vibrometry was employed. Preliminary results show a powder disruption speed of less than 0.5 m/s while the disruption height appears to be scaling proportionally with the beam intensity. Other analysis results will be discussed.

THPFI065	Thermo-mechanical Investigations of the SINQ "Cannelloni" Target	target, simulation, neutron, scattering	3445
	R. Sobbia, S. Dementjevs, S. Joray, M. Wohlmuther PSI, Villigen PSI, Switzerland
	Numerical results of three-dimensional ANSYS thermo-mechanical simulations of single components of the SINQ target system are presented. Thermal stresses are generated by energy deposition in so-called ‘‘cannelloni'' consisting of a Zircaloy-2 rod filled with Lead to 90% of its inner volume. The molten region of the inner Lead filling is calculated by thermal analysis using the energy deposition profile imported from MCNPX calculations. Induced mechanical stresses are studied for a set of predefined parameters, the heat transfer coefficient and the bulk temperature of the heavy water cooling system. Critical stress regions are investigated to provide possible failure scenarios and overall system performance.

THPFI092	Design of the Mercury Handling System for a Muon Collider/Neutrino Factory Target	target, shielding, collider, proton	3505
	K.T. McDonald PU, Princeton, New Jersey, USA J.S. Berg, H.G. Kirk, H. K. Sayed BNL, Upton, Long Island, New York, USA X.P. Ding UCLA, Los Angeles, California, USA V.B. Graves ORNL, Oak Ridge, Tennessee, USA N. Souchlas, R.J. Weggel Particle Beam Lasers, Inc., Northridge, California, USA
	The baseline target concept for a Muon Collider or Neutrino Factory is a free mercury jet within a 20-T magnetic field being impacted by an 8-GeV proton beam. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. Modifications to this baseline are discussed in which the field at the target is reduced from 20 to 15 T, and in which the magnetic field drops from its peak value down to 1.5 T over 7 rather than 15 m.

THPME008	Experimental Study of Magnetic Properties for Magnet Material in CYCIAE-100	focusing, cyclotron, vacuum, resonance	3525
	J.Q. Zhong, T. Cui, M. Li, C. Wang, Z.H. Wang, J.J. Yang, T.J. Zhang CIAE, Beijing, People's Republic of China
	The magnetic property of magnet material is one of the key factors that influence the distribution of magnetic field in large scale cyclotrons, especially embody on the vertical focusing of field and the first harmonic field error in cyclotron. According to the requirements of the physical design of CYCIAE-100, we have studied the pivotal factors, which impact on the maximum permeability, coercivity and B-H curve of material of CYCIAE-100 magnet, including the cooling rate during magnetic annealing and residual stress. The study results will be shown in this paper.

THPWA019	THEORY RESEARCH ON APPLICATION OF CT TECHNOLOGY TO SHIELDED NUCLEAR MATERIAL DISCRIMINATION	electron, neutron, radiation, resonance	3669
	Y. Zhang, H.B. Chen, Q. Gao, J. Shi TUB, Beijing, People's Republic of China
	Smuggling of nuclear material is a serious threat to security of international society. Formal research on nuclear material discrimination can fulfil customs inspection requirement. This paper designs a situation that nuclear material which is packaged and shielded by heavy metal need to be discriminated accurately on the condition that the object being detected cannot be dismantled. Calculation results prove nuclear material could be discriminated accurately while the ideal condition is fulfilled. If multi-energy X-ray source is used the discrimination accuracy is declined. However the accuracy could be improved while energy spectrum shaping technique is used.

THPWA028	Analysis of Uncertainty of Dose Rate Measurement on the Accelerator “QiangGuang-I”	radiation, photon, electron, target	3684
	R.B. Li, X.Y. Bai, X.M. Jin, Q. Ma, C. Qi, G.Z. Wang NINT, Xi'an, People's Republic of China
	“QiangGuang-I”, working on short pulse state, can be used to research the transient radiation effects on electronic devices. The measurement of dose rate is significant for assessing devices’ radiation-resistant ability. This paper comprehensively analyzes the originations of uncertainty on dose rate’s measurement, such as thermoluminescent dosemeter’s linearity degree and response to X-rays energy spectrum, testing instruments’ resolution, waveforms’ transmission distortion , and positional error; figures out the extended uncertainty. The result shows that the expanded uncertainty of dose rate’s measurement is less than 20%, which is satisfactory for researching on devices’ transient radiation effects, and proves that the method used to measure dose rate is reasonable.

THPWA032	Fields of Charged Particle Bunches in Chiral Isotropic Medium	radiation, electromagnetic-fields, polarization, vacuum	3696
	S.N. Galyamin, A.A. Peshkov, A.V. Tyukhtin Saint-Petersburg State University, Russia
	Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation. We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.

FRYCA01	Neutrino Physics and Requirements to Accelerators	proton, target, site, background	4010
	Y.F. Wang IHEP, Bejing, People's Republic of China
	This presentation reviews recent progress of neutrino experiments, both reactor- and accelerator-based, and discusses requirements for accelerators.
	Slides FRYCA01 [4.070 MB]

Paper

Title

Other Keywords

Page

MOPEA070

Operating the Diamond Light Source in Low Alpha Mode for Users

injection, lattice, optics, electron

246

I.P.S. Martin, R. Bartolini, G. Cinque, G. Rehm, C.A. Thomas
Diamond, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Since its first introduction in April 2009, the low alpha operational mode has been continually refined in order to best meet the needs of the user community. Initially the optics were used only to generate short x-ray pulses, for which a stable, low emittance, single bunch was requested, with the emphasis placed on increased bunch charge over shortest absolute pulse duration. More recently, the optics have been adapted to enhance the CSR gain in the THz region of the electromagnetic spectrum. In this paper we summarise the work carried out in order to meet these two demands.

MOPFI005

XPS and UHV-AFM Analysis of the K2CsSb Photocathodes Growth

cathode, vacuum, electron, background

291

S.G. Schubert
HZB, Berlin, Germany
I. Ben-Zvi, M. Ruiz-Osés
Stony Brook University, Stony Brook, USA
X. Liang
SBU, Stony Brook, New York, USA
H.A. Padmore, T. Vecchione
LBNL, Berkeley, California, USA
T. Rao, J. Smedley
BNL, Upton, Long Island, New York, USA

Funding: This work is funded by the Department of Energy, under Contract No. KC0407-ALSJNT-I0013, DE-SC0005713, the Bundesministerium für Bildung und Forschung (BMBF) and the state of Berlin, Germany.
Next generation light sources, based on Energy Recovery Linac and Free Electron Laser technology will rely on photoinjector based electron sources. Successful operation of such sources requires reliable photocathodes with long operational life, uniform and high quantum efficiency, low thermal emittance and low dark current. The goal of this project is to construct a cathode which meets these requirements. Advances in photocathode research must take a combined effort. The materials have to be analyzed by means of chemical composition, surface structure and these findings have to be correlated to the quantum efficiency and performance in the injector. The presented work focuses on the chemical composition and surface structure of K2CsSb photocathodes. The XPS and AFM measurements were performed at the Center of Functional Nanomaterials at BNL. K2CsSb photocathodes were grown under UHV conditions. The components were adsorbed one at a time and after each growth step the corresponding XPS spectra was taken. During growth the quantum efficiency was recorded. As last step the sample was moved into the AFM without exposure to air to determine the surface roughness.

MOPFI076

Electron Emission Studies in the New High-charge Cs2Te Photoinjector at Argonne National Laboratory

gun, cathode, laser, wakefield

455

E.E. Wisniewski, M.E. Conde, W. Gai, C.-J. Jing, W. Liu, J.G. Power
ANL, Argonne, USA
L.K. Spentzouris, Z.M. Yusof
Illinois Institute of Technology, Chicago, Illinois, USA

Funding: This work was funded by the U.S. Dept. of Energy Office of Science under contract number DE-AC02-06CH11357.
A new L-band 1.3 GHz 1.5 cell gun for the new 75 MeV drive beam is being commissioned and will soon be operating at the Argonne Wakefield Accelerator (AWA) facility as part of the facility upgrade (see M. E. Conde, this proceedings.) The photoinjector is high-field (peak accelerating field > 80MV/m) and has a large \mathrm{Cs}₂\mathrm{Te} photocathode (diameter > 30 mm) fabricated in-house. The photoinjector generates high-charge, short pulse, single bunches (Q > 100 nC) or bunch-trains (Q ≈ 1000 nC) for wakefield experiments. Field emission from the \mathrm{Cs}₂\mathrm{Te} cathode is to be measured during RF conditioning and benchmarked against measurements from a copper cathode. Quantum efficiency (QE) will be measured in single and multi-bunch modes. Preliminary results are presented.

MOPME039

A New Method of Acquiring Fast Beam Transversal Profile in the Storage Ring

synchrotron, electron, synchrotron-radiation, simulation

556

C. Cheng, P. Lu, B.G. Sun, K. Tang, F.F. Wu, Y.Y. Xiao, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

A new method of acquiring fast beam transverse profile has been developed and will be used in HLS II. This method is based on four signals from MAPMT (multi-anode photo-multiplier tube) and logarithm processing technique. First, the calculation formula of beam transversal size and position are deduced using above method. Then, the main performances (e.g. sensitivity and linearity range) are analyzed. According to stimulation result, regardless of cross-talk and inconsistency between channels, the size signal has a linear relation with size s when s=0.8-2mm and position d=±2mm, the position signal has a linear relation with position d and the linear range exceeds ±2mm when s=0.8-2mm. With channel cross-talk and channel inconsistency being considered, the stimulation results also are given. Finally, a fast beam transverse profile monitor is designed and provides turn-by-turn measurement of the beam transverse profile.

MOPWO008

Eigenmode Computation for Elliptical Cavities Subject to Geometric Variation using Perturbative Methods

cavity, simulation, higher-order-mode, SRF

900

K. Brackebusch, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany

Funding: Work supported by Federal Ministry for Research and Education BMBF under contracts 05H09HR5 and 05K10H.
Parametric studies of geometric variations are an essential part of the performance optimization and error estimation in the design of accelerator cavities. Using common eigenmode solvers the analysis of intentional and undesired geometric perturbations tend to be very extensive since any geometric variation involves an entire eigenmode recomputation. Perturbative methods constitute an efficient alternative for the computation of a multitude of moderately varying geometries. They require a common eigenmode computation of solely one (so called unperturbed) geometry and allow for deriving the eigenmodes of similar but modified (so called perturbed) geometries from these unperturbed eigenmodes. In [*],[**] the practicability of perturbative methods was already proven by means of simple cavity geometries. In this paper we investigate the applicability and efficiency for practically relevant cavities. For this, basic geometric parameters of elliptical cavities are varied and the respective eigenmodes are computed by using perturbative as well as common methods. The accuracy of the results and the computational effort of the different methods are compared.
*K. Brackebusch, H.-W. Glock, U. van Rienen, WEPPC096, IPAC 2011
**K. Brackebusch, U. van Rienen, MOPPC062, IPAC 2012

MOPWO054

The LHeC as a Higgs Boson Factory

linac, luminosity, lepton, electron

1017

F. Zimmermann, O.S. Brüning
CERN, Geneva, Switzerland
M. Klein
The University of Liverpool, Liverpool, United Kingdom

The LHeC is designed to collide a new 60 GeV energy electron beam, from a 3-pass ERL, with the 7 TeV energy LHC proton beam. At the present target ep luminosity of 10³³cm^-2s^-1, the LHeC would produce a few 1000 Higgs bosons per year, allowing for precision coupling measurements, especially of the H –> b bbar decay in charged current deep inelastic scattering (ep –> nu H X). With a significant increase of the luminosity, rarer channels become accessible, as the charm decay. Here such an increase, to the level of 10³⁴cm^-2s^-1 or even beyond, is considered from a combination of improvements, namely with a smaller proton beam emittance, with a further reduction of the proton IP beta function, an increase of the proton bunch intensity and with doubling the lepton beam current, compared to the canonical values assumed in the CDR.

TUPEA073

Performances of VORPAL-GPU Slab-symmetric DLW

simulation, wakefield, electron, dumping

1298

F. Lemery, K. Duffin, N. Karonis, D. Mihalcea, P. Piot, J. Winans
Northern Illinois University, DeKalb, Illinois, USA
P.J. Mullowney, P. Stoltz
Tech-X, Boulder, Colorado, USA
P. Piot
Fermilab, Batavia, USA

Funding: HDTRA1-10-1-0051, DOE(Grant No will be specified later)
GPU-based computing has gained popularity in recent years due to its growing software support and greater processing capabilities than its CPU counterpart. GPU computing was recently added in the finite-difference time-domain program VORPAL. In this paper we carry electromagnetic simulations and optimization of a flat beam passing through a slab-symmetric dielectric-lined waveguide (DLW). We use this simulation model to explore the scaling of the GPU version of VORPAL on a new TOP1000-grade hybrid GPU/CPU computer cluster available at Northern Illinois University.

TUPFI018

A Simplified Magnetic Field Tapering and Target Optimisation for the Neutrino Factory Capture System

target, solenoid, proton, interaction-region

1370

I. Efthymiopoulos, S.S. Gilardoni, O.M. Hansen, G. Prior
CERN, Geneva, Switzerland
O.M. Hansen
University of Oslo, Oslo, Norway
G. Prior
University of Canterbury, Christchurch, New Zealand

In the Neutrino Factory, a 4 MW proton beam with a kinetic energy between 5 and 15 GeV interacts with a liquid mercury jet target in order to produce pions that will decay to muons, which in turn decay to neutrinos. The baseline-capturing layout consists of a series of solenoids producing a tapered magnetic field from 20 T, near the target, down to 1.5 T at the entrance of the drift section where the captured pions decay into muons to produce a useful beam for the machine. In our alternative layout the magnetic field is rapidly squeezed from 20 T to 1.5T using only three solenoids. This layout showed to produce similar performance, having the advantage being simpler and could potentially be made more robust to radiation. Here we report on further optimization studies taking into account the complete path and shape fluctuations of the Hg-jet.

TUPFI019

Magnet Misalignment Studies for the Front-end of the Neutrino Factory

target, lattice, simulation, proton

1373

G. Prior, I. Efthymiopoulos
CERN, Geneva, Switzerland
D.V. Neuffer, P. Snopok
Fermilab, Batavia, USA
C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
D. Stratakis
BNL, Upton, Long Island, New York, USA

In the Neutrino Factory Front-End the muon beam coming from the interaction of a high-power (4 MW) proton beam on a mercury jet target, is transformed through a buncher, a phase rotator and an ionization cooling channel before entering the downstream acceleration system. The muon Front-End channel is densely packed with solenoid magnets, normal conducting radio-frequency cavities and absorber windows (for the cooling section). The tolerance to the misalignment of the different components has to be determined in order on one hand to set the limits beyond which the performance of the Front-End channel would be degraded; on the other hand to optimize the design and assembly of the Front-End cells such that the component alignment can be checked and corrected for where crucial for the performance of the channel. In this paper we will show the results of the simulations of the Front-End channel performance where different components such as magnets, cavities have been randomly shifted or rotated. Detailed simulations have been done in G4BeamLine*. * T. J. Roberts et al. G4BeamLine 2.06 (2010) http://g4beamline.muonsinc.com/

TUPFI054

MICE Spectrometer Solenoid Magnetic Field Measurements

solenoid, emittance, simulation, shielding

1466

M.A. Leonova
Fermilab, Batavia, USA

The Muon Ionisation Cooling Experiment (MICE) is designed to demonstrate ionization cooling in a muon beam. Its goal is to measure a 10% change in transverse emittance of a muon beam going through a prototype Neutrino Factory cooling channel section with a 1% accuracy, corresponding to an absolute measurement accuracy of 0.1%. To measure the emittance, MICE uses two solenoidal spectrometers. The Spectrometer Solenoids are designed to have 4 T solenoidal fields, uniform at 3 per mil level in the tracking volumes. Analysis of magnetic field measurements of the Spectrometer Solenoids will be discussed, and results of extracting precise coil positions, angles, and coil radius measurements for input into magnet models will be presented.

TUPFI056

A Muon Collider as a Higgs Factory

collider, luminosity, emittance, target

1472

D.V. Neuffer, Y.I. Alexahin, M.A. Palmer
Fermilab, Batavia, USA
C.M. Ankenbrandt
Muons. Inc., USA
J.-P. Delahaye
SLAC, Menlo Park, California, USA

Because muons connect directly to a standard-model Higgs particle in s-channel production, a muon collider would be an ideal device for precision measurement of the mass and width of a Higgs-like particle, and for further exploration of its production and decay properties. The LHC has seen evidence for a 126 GeV Higgs particle, and a muon collider at that energy could be constructed. Parameters of a high-precision muon collider are presented and the necessary components and performance are described. An important advantage of the muon collider approach is that the spin precession of the muons will enable energy measurements at extremely high accuracy (E/E to 10^-6 or better). Extension to a higher-energy higher-luminosity device is also discussed.

TUPFI057

Muon Accelerators for the Next Generation of High Energy Physics Experiments

collider, proton, target, background

1475

M.A. Palmer, S. Brice, A.D. Bross, D.S. Denisov, E. Eichten, R.J. Lipton, D.V. Neuffer
Fermilab, Batavia, USA
C.M. Ankenbrandt
Muons. Inc., USA
S.A. Bogacz
JLAB, Newport News, Virginia, USA
J.-P. Delahaye
SLAC, Menlo Park, California, USA
P. Huber
Virginia Polytechnic Institute and State University, Blacksburg, USA
D.M. Kaplan, P. Snopok
Illinois Institute of Technology, Chicago, Illinois, USA
H.G. Kirk, R.B. Palmer
BNL, Upton, Long Island, New York, USA
R.D. Ryne
LBNL, Berkeley, California, USA

Funding: Work supported by the U.S. Department of Energy and the U.S. National Science Foundation
Muon accelerator technology offers a unique and very promising avenue to a facility capable of producing high intensity muon beams for neutrino factory and multi-TeV lepton collider applications. The goal of the US Muon Accelerator Program is to provide an assessment, within the next 6 years, of the physics potential and technical feasibility of such a facility. This talk will describe the physics opportunities that are envisioned, along with the R&D efforts that are being undertaken to address key accelerator physics and technology questions.

TUPFI060

Complete Muon Cooling Channel Design and Simulations

emittance, beam-cooling, dipole, simulation

1484

C. Y. Yoshikawa, C.M. Ankenbrandt, R.P. Johnson
Muons. Inc., USA
Y.S. Derbenev, V.S. Morozov
JLAB, Newport News, Virginia, USA
D.V. Neuffer, K. Yonehara
Fermilab, Batavia, USA

Considerable progress has been made in developing promising subsystems for muon beam cooling channels to provide the extraordinary reduction of emittance required for an Energy-Frontier Muon Collider, but lacks an end-to-end design. Meanwhile, the recent discovery of a Higgs-like boson has created interest in the High Energy physics community for a Higgs Factory to investigate its properties and verify whether it is Standard Model or beyond. We present principles and tools to match emittances between and within muon beam cooling subsystems that may have different characteristics. The Helical Cooling Channel (HCC), which combines helical dipoles and a solenoid field, allows a general analytic approach to guide designs of transitions from one set of cooling channel parameters to another. These principles and tools will be applied to design a complete cooling channel that would be applicable to a Higgs Factory and an Energy Frontier Muon Collider.

TUPFI061

Preliminary Design of a Higgs Factory μ+μ- Storage Ring

quadrupole, dipole, collider, storage-ring

1487

A.V. Zlobin, Y.I. Alexahin, V.V. Kapin, V.V. Kashikhin, N.V. Mokhov, I.S. Tropin
Fermilab, Batavia, USA

Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy, and by the US Department of Energy through the Muon Accelerator Program (MAP).
A Muon Collider offers unique possibilities for studying the recently found Higgs boson. Higgs bosons can be produced in reasonable amounts in the s-channel, so that the colliding muon beam energy of just 62.5GeV is required. Precision direct measurements of the Higgs boson mass and width is possible due to absence of brems- and beam-strahlung. At the same time, there are difficulties specific to muon colliders: relatively large beam emittance which necessitates quite small beta-function values (~ a few cm) at the interaction point in order to obtain sufficiently high luminosity, as well as superconducting magnet and detector protection from showers generated by muon decay products. Due to these factors, the required aperture of the final focus quadrupoles is very large (up to 0.5 m) posing challenging engineering constraints as well as beam dynamics issues with fringe fields. The first results of a complex approach to these problems in the Higgs Factory collider design are presented which promise luminosities in excess of 1031 cm^-2s⁻¹ with a 4 MW proton driver.

TUPFI067

Energy Deposition and Shielding Study of the Front End for the Neutrino Factory

shielding, proton, target, solenoid

1505

P. Snopok
IIT, Chicago, Illinois, USA
D.V. Neuffer
Fermilab, Batavia, USA
C.T. Rogers
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom

In the Neutrino Factory and Muon Collider muons are produced by firing high energy protons onto a target to produce pions. The pions decay to muons which are then accelerated. This method of pion production results in significant background from protons and electrons, which may result in heat deposition on superconducting materials and activation of the machine preventing manual handling. In this paper we discuss the design of a secondary particle handling system. The system comprises a solenoidal chicane that filters high momentum particles, followed by a proton absorber that reduces the energy of all particles, resulting in the rejection of low energy protons that pass through the solenoid chicane. We detail the design and optimization of the system, its integration with the rest of the muon front end, and energy deposition and shielding analysis in MARS15.

TUPFI069

Influence of Proton Beam Emittances on Particle Production off a Muon Collider Target

target, proton, emittance, collider

1511

X.P. Ding, D.B. Cline
UCLA, Los Angeles, California, USA
J.S. Berg, H.G. Kirk, H. K. Sayed
BNL, Upton, Long Island, New York, USA
V.B. Graves
ORNL, Oak Ridge, Tennessee, USA
K.T. McDonald
PU, Princeton, New Jersey, USA
N. Souchlas, R.J. Weggel
Particle Beam Lasers, Inc., Northridge, California, USA

Funding: Work supported in part by US DOE Contract NO. DE-AC02-98CHI10886.
A free-mercury-jet or a free-gallium-jet is considered for the pion-production target at a Muon Collider or Neutrino Factory. Based on a simple Gaussian incident proton beams with an infinitely large Courant-Snyder β parameters, we have previously optimized the geometric parameters of the target to maximize particle production initiated by incoming protons with kinetic energies (KE) between 2 and 16 GeV by using the MARS15 code. In this paper, we extend our optimization to focused proton beams with various transverse emittances. For the special cases of proton beams with emittances of 2.5, 5 or 10 μm-rad and a kinetic energy of 8 GeV, we optimized the geometric parameters of the target: the radius of the proton beam, the radius of the liquid jet, the crossing angle between the jet and the proton beam, and the incoming proton beam angle. We also study the influence of a shift of the beam focal point relative to the intersection point of the beam and the jet.

TUPFI073

Design of Magnets for the Target and Decay Region of a Muon Collider/Neutrino Factory Target

target, collider, solenoid, proton

1514

R.J. Weggel, N. Souchlas
Particle Beam Lasers, Inc., Northridge, California, USA
X.P. Ding
UCLA, Los Angeles, California, USA
V.B. Graves
ORNL, Oak Ridge, Tennessee, USA
H.G. Kirk, H. K. Sayed
BNL, Upton, Long Island, New York, USA
K.T. McDonald
PU, Princeton, New Jersey, USA

The target and decay region of a Muon Collider/Neutrino Factory transports pions and muons in a superconducting solenoid channel that must be protected from radiation damage secondary particles produced by the 4-MW proton beam. For this, He-gas-cooled tungsten beads will be arrayed inside the magnet coils, which leads to large coil radii and high stored magnetic energy (~3 GJ). The design of the superconducting coils, and the tungsten shielding for the ~ 50-m-long target and decay region is reviewed.

TUPFI074

Design of the Final Focus of the Proton Beam for a Neutrino Factory

target, proton, quadrupole, collider

1517

J. Pasternak, M. Aslaninejad
Imperial College of Science and Technology, Department of Physics, London, United Kingdom
K. E. Gollwitzer
Fermilab, Batavia, USA
H.G. Kirk
BNL, Upton, Long Island, New York, USA
K.T. McDonald
PU, Princeton, New Jersey, USA

The ~ 8-GeV, 4-MW proton beam that drives a Neutrino Factory has a nominal 50-Hz macropulse structure with 2-3 micropulses ~ 100 ns apart. The nominal geometric beam emittance is 5 micron, and the desired rms beam radius at the liquid-metal-jet target is 1.2 mm. A quadrupole-triplet focusing system to deliver this beam spot is described.

TUPFI075

Optimizing Muon Capture and Transport for a Neutrino Factory/Muon Collider Front End

target, solenoid, proton, collider

1520

H. K. Sayed, J.S. Berg, H.G. Kirk
BNL, Upton, Long Island, New York, USA
X.P. Ding
UCLA, Los Angeles, California, USA
K.T. McDonald
PU, Princeton, New Jersey, USA

In the baseline scheme of the Neutrino Factory/Muon Collider a muon beam from pion decay is produced by bombarding a liquid-mercury-jet target with a 4-MW pulsed proton beam. The target is embedded in a high-field solenoid magnet that is followed by a lower field Decay Channel. The adiabatic variation in solenoid field strength along the beam near the target performs an emittance exchange that affects the performance of the downstream Buncher, Phase Rotator, and Cooling Channel. An optimization was performed using MARS1510 and ICOOL codes in which the initial and final solenoid fields strengths, as well as the rate of change of the field along the beam, were varied to maximize the number of muons delivered to the Cooling Channel that fall within the acceptance cuts of the subsequent muon-acceleration systems.

TUPME007

Beam Lifetime in Low Emittance Rings

scattering, simulation, lattice, background

1574

M. Boscolo
INFN/LNF, Frascati (Roma), Italy

In this paper I will review the main effects in low emittance rings that determine the beam lifetime by causing beam losses along the ring. As an example, the case for a B-factory based on the crab-waist collision scheme has been studied. During the machine design all the effects that determine the beam lifetime and induce backgrounds in the detector have been analyzed in details. The crab-waist scheme provides an higher luminosity, but at the same time it induces higher beam losses at the final focus. For this reason single beam effects such as Touschek and beam-gas scattering have been studied in details, by means of a macroparticle tracking code developed for this purpose*. Also Radiative Bhabha scattering, that is the dominant effect to lifetime and backgrounds has been studied with the same technique to check possible multiturn losses at IR. An efficient collimation system has been designed to intercept scattered particles that would be lost in the IR in both the horizontal and the vertical plane. Recently, the Touschek tracking simulation code has been implemented to study the lifetime behavior for extremely low-emittance rings.
* M. Boscolo and P. Raimondi, “Monte Carlo simulation for the Touschek effect with the crab-waist scheme”, Phys. Rev. ST-AB 15 104201 (2012)

TUPME009

Measurement and Vibration Studies on the Final Focus Doublet at DAΦNE and new collider Implications

damping, collider, luminosity, resonance

1580

S. Tomassini
INFN/LNF, Frascati (Roma), Italy

Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu-CARD, grant agreement no. 227579.
A Super Flavour Factory, to be built in the Tor Vergata University campus near Frascati, Italy, will have nano-beams in order to reach the design luminosity. The knowledge and compensation of the vibrations induced on the beams by the anthropic noise is then fundamental. The DAΦNE Phi-factory at LNF, Frascati, was upgraded in the second half of 2007 in order to implement the large Piwinski angle and crab waist collision scheme and in 2010 the KLOE experiment was rolled in for a new data taking and physic program. A measurement campaign has been performed on DAΦNE to find out the actual vibration sensitivity of the final focus doublets. Vibration measurements were performed on the Final Focus doublet because of luminosity losses and photon beam lines instability evidences. Results and stabilization technique to mitigate the effects of the ground motion induced by the “cultural noise” are presented. Implications on the design and stabilization of a Flavour Factory Final Focus doublets will be discussed.

TUPME021

Optimization Parameter Design of a Circular e⁺e⁻ Higgs Factory

luminosity, emittance, synchrotron, collider

1616

D. Wang, Y.W. An, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, S. Wang, M. Xiao, G. Xu, S.Y. Xu
IHEP, Beijing, People's Republic of China

Funding: NSFC:11175192
In this paper we will show a genral method of how to make an optimized parameter design of a circular e⁺e⁻ Higgs Factory by using analytical expression of maximum beam-beam parameter and beamstrahlung beam lifetime started from given design goal and technical limitations. A parameter space has been explored.

TUPWA043

Impedance Studies for VMTSA Module of LHC Equipped with RF Fingers

impedance, simulation, resonance

1805

O. Kononenko, F. Caspers, A. Grudiev, E. Métral, B. Salvant
CERN, Geneva, Switzerland

During 2011 run of LHC it was found that beam-induced heating causes many issues for accelerator components. Particularly some of the double-bellow modules, called VMTSA modules, were found to have deformed RF fingers and a broken spring which ensured good contact between them and a central insert. Impedance studies have been performed for different types of nonconformities and benchmarked against measurements. It was found that even a small gap between the fingers and a central insert could be fatal for the VMTSA operation. Results of this study were an input for the further thermal analysis.

WEOAB103

Experimental Observations of a Multi-stream Instability in a Long Intense Beam

simulation, electron, space-charge, background

2044

B.L. Beaudoin, S. Bernal, I. Haber, R.A. Kishek, T.W. Koeth
UMD, College Park, Maryland, USA

Funding: Supported by the US Dept. of Energy, Office of High Energy Physics, and by the US Dept. of Defense, Office of Naval Research and the Joint Technology Office.
We have observed evidence of a multi-stream instability in a long non-relativistic space-charge dominated beam evolving with an initial non-linear distribution and zero external longitudinal containment. This type of instability can be detrimental to intense accelerators that propagate rectangular distributions, such as in a ring with single or multi-bunch injection. The longitudinal forces in these intense bunches causes the beam to expand axially; in the case of the University of Maryland Electron Ring (UMER), the initial long bunch is injected to fill a fraction of the ring, coasting beyond the point where the head and tail overlap. Adjacent filaments at that point are separated in velocity space by 2cs and approach a separation of cs. The onset of the instability has been observed to depend on the injected beam current, bunch length, and other experimental factors. Comparisons with simple analytical calculations and PIC simulations have shown good agreement in the time to onset.

Slides WEOAB103 [1.681 MB]

WEPWA028

Measurement and Research on Cryogenic Remanence of Chunks Permanent Magnet for Cryogenic Undulator

cryogenics, permanent-magnet, controls, undulator

2190

Y.Z. He
SINAP, Shanghai, People's Republic of China

The higher-precision cryogenic remanence measurment technology and error for chunks permanent magnet were researched in china firstly (10-300K). Magnetic measurement tooling and magnetic field calculation and measurement method of cryogenic remanence measurement system of chunks permanent magnet for cryogenic undulator were optimized. Cryogenic calibration Hall probe were pasted on surface of domestic chunks permanent magnet(Nd2Fe14B: N52, N50M, etc.) and table magnetic field B of permanent magnet were measured, and after being converted, then cryogenic remanence of domestic chunks permanent magnet were obtained and cryogenic remanence variation of domestic chunks permanent magnet were researched. Cryogenic remanence measurement data were checked by pulse B-H tester and PPMS respectively, the results show that cryogenic remanence data has higher reliability. By this experiment, initial foundation were established for development of SSRF cryogenic undulator and for cryogenic remanence measurement and study of domestic other chunks permanent magnets.

WEPWA052

A Gun to Linac Operation Analysis of the Taiwan Light Source Injector

electron, linac, gun, synchrotron

2235

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

A response surface methodology (RSM) was used to study the gun to linac optimization process of the Taiwan Light Source (TLS) injector at the National Synchrotron Radiation Research Center (NSRRC). A study model, based on artificial neural network (ANN) theory, which uses electron beam tuning knobs as variables, was constructed. An optimization procedure was developed by designating electron beam efficiency as the objective function and the selected beam tuning knobs as the variables. The theoretical model and optimization procedure were both implemented to evaluate the model. By properly applying the constructed optimization procedure, the beam efficiency was improved. This report outlines the details of the gun to linac optimization process experiment.

WEPWO010

BERLinPro Seven-cell SRF Cavity Optimization and HOMs External Quality Factors Estimation

cavity, HOM, SRF, simulation

2331

T. Galek, K. Brackebusch, T. Flisgen, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
J. Knobloch, A. Neumann
HZB, Berlin, Germany
B. Riemann, T. Weis
DELTA, Dortmund, Germany

Funding: Work funded by EU FP7 Research Infrastructure Grant No. 227579 and by German Federal Ministry of Research and Education, Project: 05K10HRC.
The main scope of this work is the optimization of the superconducting radio frequency (SRF) accelerating cavity design for the Berlin Energy Recovery Linac Project (BERLinPro)*. BERLinPro shall serve as a demonstrator for 100-mA-class ERLs with CW LINAC technology. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. Consequently it is important, at the SRF cavity design optimization stage, to calculate the external quality factors of HOMs to avoid beam break up (BBU) instabilities. The optimization of the SRF cavity design consists of two steps. In the first step the cavities' end half-cells are tuned with respect to field flatness, effective shunt impedance and geometrical factor of the fundamental accelerating mode using robust eigenmode simulations. The second step involves frequency domain simulations and the extraction of external quality factors of HOMs from transmission S-parameter spectra using vector fitting procedure and an automated scheme to remove non-static poles **. The eigenmode,as well as the frequency domain simulations are performed using CST Microwave Studio ***.
* A. Neumann et al., Proc. of ICAP2012, pp. 278–280.
** T. Galek et al., Proc. of ICAP2012, pp. 152–154.
*** CST AG, http://www.cst.com

WEPWO071

Quench and High Field Q-SLOP Studies using a Single Cell Cavity with Artificial Pits

cavity, SRF, niobium, feedback

2465

Y. Xie, G.H. Hoffstaetter, M. Liepe
CLASSE, Ithaca, New York, USA

Surface defects such as pits have been identified as some of the main sources of limitations of srf cavity performance. A single cell cavity was made with 30 artificial pits in the high magnetic field region to gain new insight in how pits limit the cavity performance. The test of the pit cavity showed clear evidence that the edges of two of the largest radius pits transitioned into the normal conducting state at field just below the quench field of the cavity, and that the quench was indeed induced by these two pits. Insights about quench and non-linear rf resistances will be presented.

WEPFI021

Influence of Core Winding Tension and Ribbon Quality on the MA Core RF Characteristics

impedance, synchrotron, vacuum, cavity

2747

M. Nomura, A. Schnase, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan
K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii
KEK, Tokai, Ibaraki, Japan

J-PARC 3 GeV Rapid Cycling Synchrotron (RCS) and Main Ring (MR) employ RF cavities loaded with Magnetic Alloy (MA) cores to generate a high field gradient. To achieve the high field gradient, the core shunt impedance is a key parameter. We found during the development of MA cores for RCS RF cavities that the core shunt impedance was increased by lowering a core winding tension. We lowered the core winding tension in order to improve the electrical insulation between MA ribbon layers. The lower winding tension reduced the core filling factor that is defined as the volume ratio of MA ribbons and geometrical dimensions. The core shunt impedance might be reduced according to the core filling factor reduction. We discuss the reason why the lower winding tension increased the core shunt impedance. We also report the influence of the ribbon quality variation on the MA core RF characteristics.

WEPFI054

Enlargement of Tuning Range in a Ferrite-tuned Cavity through Superposed Orthogonal and Parallel Magnetic Bias

cavity, resonance, radiation

2812

C. Vollinger, F. Caspers
CERN, Geneva, Switzerland

Conventional ferrite-tuned cavities operate either with bias fields that are orthogonal or parallel to the magnetic RF-field. For a cavity that tunes rapidly over an overall frequency range around 100-400 MHz with high Q, we use ferrite garnets exposed to an innovative new biasing method consisting of a superposition of perpendicular and parallel magnetic fields. This method leads to a significant enlargement of the high-Q cavity tuning range by defining an operation point close to the magnetic saturation and thus improving ferrite material behaviour. A further advantage of this technique is the fast tuning speed resulting from the fact that tuning is carried out either with pure parallel biasing, or together with a very small change of operating point from perpendicular bias. In this paper, several scaled test models of ferrite-filled resonators are shown; measurements on the set-ups are compared and discussed.

WEPFI058

Breakdown Localization Studies on the SwissFEL C-band Test Structures

background, linac, coupling, impedance

2824

J. Klavins, S. Dementjevs, F. Le Pimpec, L. Stingelin, M. Wohlmuther, R. Zennaro
PSI, Villigen PSI, Switzerland
N.C. Shipman
CERN, Geneva, Switzerland

The SwissFEL main linac will consist of 10⁴ C-band structures with a nominal accelerating gradient of 28MV/m. First power tests were performed on short constant impedance test-structures composed of eleven double-rounded cups. In order to localize breakdowns, two or three acoustic emission sensors were installed on the test-structures. In order to localize breakdowns we have analyzed, in addition to acoustic measurements, the delay and phase of the rf power signals. Parasitic, acoustic noise emitted from the loads of the structure complicated the data interpretation and necessitated appropriate processing of the acoustic signals. The Goals of the experiments were to identify design and manufacturing errors of the structures. The results indicate that breakdowns occur mostly at the input power coupler, as also confirmed by vacuum-events at the same location. The experiments show that the linac test-structures fulfill the requirements in breakdown probability. Moreover developing a detection system based on acoustic emission sensors for breakdown localization for our C-band structure seems reasonable given the results obtained.

WEPFI076

Experience with a 5 kW, 1.3 GHz Solid State Amplifier

linac, status, SRF, cryomodule

2869

K.M.V. Ho, R. Eichhorn, D.L. Hartill, M. Liepe
CLASSE, Ithaca, New York, USA

This study describes the experience with and performance of a commercially available 1.3 GHz 5kW Solid State Amplifier in various experiments at Cornell University. This paper focuses on several key factors in testing the performance of the amplifier. Among those are phase and amplitude stability, gain linearity, and phase shift vs. power. High power amplifiers are usually built with multiple RF power modules and the individual output signals are then combined in a power combiner. Therefore, the phases of the individual RF output power signals have to be adjusted within tight tolerances. The relative phases can be affected by different lengths cables and also affect the overall gain performance of the amplifier.

WEPFI083

High Power Tests of the 2-Pin Waveguide Structures

linear-collider, collider, site, electron

2890

F.Y. Wang, Z. Li
SLAC, Menlo Park, California, USA

An X-band Two-Pin Waveguide Structure has been designed to study the influence of power flow on rf breakdown. Three different sets of pins will be tested at SLAC. These sets were designed to achieve a similar peak surface electric field on one of the pins for input rf power levels that vary by about an order of magnitude (the other pin is used for matching). Two sets of pins have been tested so far, and the breakdown rate was found to be strongly dependent on the power flow. In this paper, we review the experimental setup, the complete set of results and their implications.

WEPME048

Adjusting and Calibration Method for TPS Laser PSD System

laser, alignment, storage-ring, synchrotron

3037

M.L. Chen, J.-R. Chen, P.S.D. Chuang, H.C. Ho, K.H. Hsu, D.-G. Huang, W.Y. Lai, C.-S. Lin, C.J. Lin, H.C. Lin, H.M. Luo, S.Y. Perng, P.L. Sung, T.C. Tseng, H.S. Wang, M.H. Wu
NSRRC, Hsinchu, Taiwan
J.-R. Chen
National Tsing Hua University, Hsinchu, Taiwan

Laser PSD positioning system is a part of the TPS girder auto-alignment system and is designed for aligning and positioning the straight-section girders of TPS storage ring. Although the components of Laser PSD system are fabricated, assembling and adjusting precisely in advance, the accuracy of Laser PSD system is still influenced by girder fabricating quality, assembling errors and moving errors by transportation. For system correction, Laser beam positions on four sets of PSDs are formulized as an equation and calibrated with Laser tracker ultimately. According to the PSD calibration formula, the two girders of 18m long straight-section can be aligned and positioned within 20um by comparing with Laser tracker. This paper describes the assembly, installation and calibration process of Laser PSD system.

THPEA048

The FPGA-based Power Monitoring System for TPS Facility

monitoring, controls, LabView, resonance

3252

C.S. Chen, Z.-D. Tsai
NSRRC, Hsinchu, Taiwan

There are more and more non-linear electronic equipments such as inverters using in facility nowadays. These non-linear electronic equipments let us achieve energy saving, but induce other electrical pollution to the whole power grid in contrast. How to monitor the electrical noises from these non-linear equipments becomes an important issue. In this article, a set of power quality monitoring system based on FPGA and PAC has been built because of the programmability and fast processing speed. By using this monitoring system, any abnormality in power system and its spectrum will be recorded thoroughly. On the other hand, the maintainer could follow the trace of noise and then propose a suitable solution to eliminate the electrical interference too.

THPFI008

Experience and Benefits from PLM-based Parts Management at European XFEL

cavity, controls, linac, undulator

3306

L. Hagge, J.A. Dammann, S. Eucker, A. Frank, J. Kreutzkamp, D. Käfer, D. Szepielak, N. Welle
DESY, Hamburg, Germany

DESY has developed a parts management solution, which is used in the series fabrication of accelerator components for the European XFEL. The parts management solution stores assembly instructions and drawings for each component, and it tracks the assembly progress of each individual component. It offers procedures for quality inspections, for handling non-conformities and for managing changes, and it tracks the current whereabouts and the entire history of each part. The solution is based on DESY's Product Lifecycle Management (PLM) System and integrates several laboratories and suppliers. The poster shows how parts management is used at the European XFEL in the production of the super-conducting rf cavities, in the assembly of the cryomodules and in the assembly of the undulators, and discusses experience and benefits.

THPFI013

Development of Cylindrical-type 1.2 MW High Power Water-load for Super KEKB

klystron, positron, collider, cavity

3318

K. Watanabe, K. Ebihara, A. Kabe, K. Marutsuka, M. Nishiwaki
KEK, Ibaraki, Japan
Y. Kawane, A. Miura
Nihon Koshuha Co. Ltd, Yokohama, Japan

We have developed and manufactured CW 1.2 MW high power water-load for the use of the Super KEKB, an electron – positron double-ring collider at KEK. The tank and rf window of the water-load is the circular and cylindrical-type. The material to absorb the rf power is a tap water. This load is equipped on the 3rd port of the circulators to safe the 1.2 MW CW klystrons to drive the ARES cavities in main ring. The operational frequency is 508.9 MHz. A proto-type model of this water-load was fabricated at Sep 2012, and tested using by high power klystron (1 MW) at Oct 2012 at KEK D2-ET station. The result of high power test will be reported in this paper.

THPFI053

A Feasibility Experiment of a W-powder Target in the HiRadMat Facility of CERN

target, proton, laser, instrumentation

3409

N. Charitonidis, I. Efthymiopoulos, A. Fabich
CERN, Geneva, Switzerland
O. Caretta, T.R. Davenne, C.J. Densham, M.D. Fitton, P. Loveridge
STFC/RAL, Chilton, Didcot, Oxon, United Kingdom
L. Rivkin
EPFL, Lausanne, Switzerland

Granular solid targets made of fluidized tungsten powder or static pebble bed of tungsten spheres, have been long proposed and are being studied as an alternative configurations towards high-power (>1MW of beam power) target systems, suitable for a future Super Beam or Neutrino Factory. Serving the lack of experimental data on this field, a feasibility experiment was performed in HiRadMat facility of CERN/SPS that tried in a pulse-by-pulse basis to address the effect of the impact of the SPS beam (440GeV/c) on a static tungsten powder target. Online instrumentation such as high-speed photography and Laser - Doppler Vibrometry was employed. Preliminary results show a powder disruption speed of less than 0.5 m/s while the disruption height appears to be scaling proportionally with the beam intensity. Other analysis results will be discussed.

THPFI065

Thermo-mechanical Investigations of the SINQ "Cannelloni" Target

target, simulation, neutron, scattering

3445

R. Sobbia, S. Dementjevs, S. Joray, M. Wohlmuther
PSI, Villigen PSI, Switzerland

Numerical results of three-dimensional ANSYS thermo-mechanical simulations of single components of the SINQ target system are presented. Thermal stresses are generated by energy deposition in so-called ‘‘cannelloni'' consisting of a Zircaloy-2 rod filled with Lead to 90% of its inner volume. The molten region of the inner Lead filling is calculated by thermal analysis using the energy deposition profile imported from MCNPX calculations. Induced mechanical stresses are studied for a set of predefined parameters, the heat transfer coefficient and the bulk temperature of the heavy water cooling system. Critical stress regions are investigated to provide possible failure scenarios and overall system performance.

THPFI092

Design of the Mercury Handling System for a Muon Collider/Neutrino Factory Target

target, shielding, collider, proton

3505

K.T. McDonald
PU, Princeton, New Jersey, USA
J.S. Berg, H.G. Kirk, H. K. Sayed
BNL, Upton, Long Island, New York, USA
X.P. Ding
UCLA, Los Angeles, California, USA
V.B. Graves
ORNL, Oak Ridge, Tennessee, USA
N. Souchlas, R.J. Weggel
Particle Beam Lasers, Inc., Northridge, California, USA

The baseline target concept for a Muon Collider or Neutrino Factory is a free mercury jet within a 20-T magnetic field being impacted by an 8-GeV proton beam. A pool of mercury serves as a receiving reservoir for the mercury and a dump for the unexpended proton beam. Modifications to this baseline are discussed in which the field at the target is reduced from 20 to 15 T, and in which the magnetic field drops from its peak value down to 1.5 T over 7 rather than 15 m.

THPME008

Experimental Study of Magnetic Properties for Magnet Material in CYCIAE-100

focusing, cyclotron, vacuum, resonance

3525

J.Q. Zhong, T. Cui, M. Li, C. Wang, Z.H. Wang, J.J. Yang, T.J. Zhang
CIAE, Beijing, People's Republic of China

The magnetic property of magnet material is one of the key factors that influence the distribution of magnetic field in large scale cyclotrons, especially embody on the vertical focusing of field and the first harmonic field error in cyclotron. According to the requirements of the physical design of CYCIAE-100, we have studied the pivotal factors, which impact on the maximum permeability, coercivity and B-H curve of material of CYCIAE-100 magnet, including the cooling rate during magnetic annealing and residual stress. The study results will be shown in this paper.

THPWA019

THEORY RESEARCH ON APPLICATION OF CT TECHNOLOGY TO SHIELDED NUCLEAR MATERIAL DISCRIMINATION

electron, neutron, radiation, resonance

3669

Y. Zhang, H.B. Chen, Q. Gao, J. Shi
TUB, Beijing, People's Republic of China

Smuggling of nuclear material is a serious threat to security of international society. Formal research on nuclear material discrimination can fulfil customs inspection requirement. This paper designs a situation that nuclear material which is packaged and shielded by heavy metal need to be discriminated accurately on the condition that the object being detected cannot be dismantled. Calculation results prove nuclear material could be discriminated accurately while the ideal condition is fulfilled. If multi-energy X-ray source is used the discrimination accuracy is declined. However the accuracy could be improved while energy spectrum shaping technique is used.

THPWA028

Analysis of Uncertainty of Dose Rate Measurement on the Accelerator “QiangGuang-I”

radiation, photon, electron, target

3684

R.B. Li, X.Y. Bai, X.M. Jin, Q. Ma, C. Qi, G.Z. Wang
NINT, Xi'an, People's Republic of China

“QiangGuang-I”, working on short pulse state, can be used to research the transient radiation effects on electronic devices. The measurement of dose rate is significant for assessing devices’ radiation-resistant ability. This paper comprehensively analyzes the originations of uncertainty on dose rate’s measurement, such as thermoluminescent dosemeter’s linearity degree and response to X-rays energy spectrum, testing instruments’ resolution, waveforms’ transmission distortion , and positional error; figures out the extended uncertainty. The result shows that the expanded uncertainty of dose rate’s measurement is less than 20%, which is satisfactory for researching on devices’ transient radiation effects, and proves that the method used to measure dose rate is reasonable.

THPWA032

Fields of Charged Particle Bunches in Chiral Isotropic Medium

radiation, electromagnetic-fields, polarization, vacuum

3696

S.N. Galyamin, A.A. Peshkov, A.V. Tyukhtin
Saint-Petersburg State University, Russia

Funding: Work is supported by Russian Foundation for Basic Research and the Dmitry Zimin "Dynasty" Foundation.
We study electromagnetic fields produced by charged particle bunches moving in a chiral isotropic medium. Such properties are typical for most of organic matters and some artificial materials (metamaterials). Therefore, this subject is of interest for chemical, biological, and medical applications as well as for study of metamaterials. First, we investigate in detail the field of a point charge. We obtain exact and approximate formulas and develop algorithm for calculation of the point charge field. Further, we use these expressions for calculation of fields produced by finite size bunches. We also present the typical energetic patterns of radiation and spectra of energy losses. Possibilities of using the obtained results for different applications are discussed.

FRYCA01

Neutrino Physics and Requirements to Accelerators

proton, target, site, background

4010

Y.F. Wang
IHEP, Bejing, People's Republic of China

This presentation reviews recent progress of neutrino experiments, both reactor- and accelerator-based, and discusses requirements for accelerators.

Slides FRYCA01 [4.070 MB]