IPAC2018 - List of Keywords (factory)

Paper	Title	Other Keywords	Page
MOPMF065	LHC- and FCC-Based Muon Colliders	positron, collider, emittance, target	273
	F. Zimmermann CERN, Geneva, Switzerland
	Funding: Work supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871. In recent years, three schemes for producing low-emittance muon beams have been proposed: (1) e⁺e⁻ annihilation above threshold using a positron storage ring with a thin target [M. Boscolo, P. Raimondi et al.], (2) laser/FEL-Compton back-scattering off high-energy proton beams circulating in the LHC or FCC-hh [L. Serafini et al.], (3) the Gamma factory concept, where partially stripped heavy ions collide with a laser pulse to directly generating muons [W. Krasny]. The Gamma factory would also generate copious amounts of positrons which could in turn be used as source for option (1). On the other hand the top-up booster of the FCC-ee design would be an outstanding e⁺ storage ring, at the right beam energy, around 45 GeV. After rapid acceleration the muons, produced in one of the three ways, could be collided in machines like the SPS, LHC or FCC-hh. Possible collider layouts are suggested.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF065
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MOPML013	Progress on Preliminary Conceptual Study of HIEPA, a Super Tau-Charm Factory in China	collider, positron, luminosity, electron	422
	Q. Luo, D.R. Xu USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Work supported by National Natural Science Foundation of China 11375178 and the Fundamental Research Funds for the Central Universities, Grant No WK2310000046. As the most successful tau-charm factory of the world, BEPC II will celebrate its 10th birthday this year and will finish its historical mission in the next decade. Because of its very important role in high energy phys-ics study, BEPC II will certainly need a successor, a new tau-charm collider. This paper discusses the feasi-bility of a greenfield next generation tau-charm collid-er named HIEPA. The luminosity of this successor is about 5×1034 cm−2s−1 pilot and 1×1035cm^-2s⁻¹ nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam parameters are shown. Several key technologies such as beam polarization and beam emittance diag-nostics are also discussed.
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TUPAF088	Final factory-side Measurements of the Next SC CH-Cavities for the HELIAC-Project	cavity, linac, resonance, heavy-ion	943
	M. Basten, M. Busch, H. Podlech, M. Schwarz IAP, Frankfurt am Main, Germany K. Aulenbacher, W.A. Barth, V. Gettmann, T. Kürzeder, M. Miski-Oglu HIM, Mainz, Germany W.A. Barth, F.D. Dziuba, M. Heilmann, S. Yaramyshev GSI, Darmstadt, Germany
	Funding: Work supported by the EU Framework Programme H2020 662186 (MYRTE); Work supported by BMBF Contr. No. 05P15RFBA; The upcoming FAIR project (Facility for Antiproton and Ion Research) at GSI will use the existing UNILAC (UNIversal Linear Accelerator) as an injector to provide high intensity heavy ion beams at low repetition rates. As a consequence a new superconducting (sc) continous wave (cw) high intensity heavy ion Linac is required to provide ion beams above the coulomb barrier to keep the Super Heavy Element (SHE) physics program at GSI competitive on an international level. The fundamental Linac design comprises a high performance ion source, the High Charge State Injector (HLI) upgraded for cw-operation and a matching line (1.4 MeV/u) followed by a sc Drift Tube Linac (DTL). Four cryo modules each equipped with three Crossbar-H-mode (CH) structures provide for acceleration up to 7.3 MeV/u. The first section of this ambitious accelerator project has been successfully commissioned and tested with heavy ion beam from the HLI in 2017. It comprises two sc 9.3 T solenoids and a sc 217 MHz CH-cavity with 15 equidistant gaps as a demonstrator. The construction of the next two sc 217 MHz 8 gap CH-cavities is nearly finished and final factory-side measurements will be presented.
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TUPMF011	Calculation of Expected Orbit Motion Due to Girder Resonant Vibration at the APS Upgrade	ground-motion, resonance, lattice, quadrupole	1269
	V. Sajaev, Z. Liu, J. Nudell, C.A. Preissner ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size. To keep the beam orbit stable on a sub-micron level, one needs to carefully design magnet supports/girders so that the ground motion does not lead to excessive orbit motion due to resonant modes of magnet supports. In this paper, we will describe the process of calculating the expected orbit motion due to girder resonant vibration. First, we will present the simulation results for the girder resonant modes, then we will calculate the orbit amplification factors for the girder deformation modes, then calculate the expected orbit motion using measured ground motion spectrum. This process can be used to evaluate the design of the magnet supports.
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TUPMF012	Determination of the Ground Motion Orbit Amplification Factors Dependence on the Frequency for the APS Upgrade Storage Ring	ground-motion, lattice, storage-ring, simulation	1272
	V. Sajaev, C.A. Preissner ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size, which translates to sub-micron orbit stability requirement. Ground motion provides significant contribution to the overall expected beam motion, especially at lower frequencies where the ground motion has larger amplitudes. At the same time, the lattice amplification factors reduce when the ground motion becomes coherent at low frequencies. In this paper, we will present simulation of the lattice amplification factor dependence on the ground motion coherence length and show results of the ground motion coherence measurements at APS. After that, we will determine the lattice amplification factors dependence on the ground motion frequency, that can be used to calculate the expected effect of the ground motion on the orbit stability.
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TUPML065	Phase Space Density Evolution in MICE	emittance, simulation, experiment, collider	1692
	D. Rajaram Illinois Institute of Technology, Chicago, Illinois, USA V. Blackmore Imperial College of Science and Technology, Department of Physics, London, United Kingdom
	Funding: STFC, DOE, NSF, INFN, and CHIPP The Muon Ionization Cooling Experiment (MICE) collaboration will demonstrate the feasibility of ionization cooling, the technique proposed to cool the muon beam at a future neutrino factory or muon collider. The muon beam parameters are measured before and after the cooling cell using high precision scintillating-fibre trackers in a solenoidal magnetic field. Position and momentum reconstruction of each muon in MICE allows the development of several alternative figures of merit in addition to emittance. Contraction of the phase-space volume of the sample, or equivalently the increase in phases-pace density at its core, is an unequivocal cooling signature. Single-particle amplitude, defined as a weighted distance to the sample centroid, can be used to probe the change in density in the core of the beam. Alternatively, non-parametric statistics provide reliable methods to estimate the entire phase-space density distribution and reconstruct probability contours. The aforementioned techniques, robust to transmission losses and sample non linearities, are ideal candidates for a cooling measurement in MICE. Preliminary results are presented here. Submitted by the MICE Speakers bureau, to be prepared and presented by a MICE member to be selected in due course
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WEXGBD1	Development of Very Short Period Undulators	undulator, electron, radiation, vacuum	1735
	S. Yamamoto KEK, Ibaraki, Japan
	Scientists and engineers at KEK have developed undulator magnets having very short period lengths. Magnet plates 100mm and 152mm long with 4-mm period length have been successfully fabricated. They produce an undulator field of approximately 4kG at a gap of 1.6mm. The magnetic field characterization shows that the undulator field is satisfactory in quality for a very short period undulator. KEK has recently installed a short-period undulator at a 50-MeV linac and observed a first light, and will soon start an experiment using a short-period undulator with laser-accelerated electrons for future table-top XFELs. This invited talk summarizes the current status, and experimental activities and results related to short-period undulators and table-top FELs.
	Slides WEXGBD1 [3.515 MB]
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WEYGBD3	The CERN Gamma Factory Initiative: An Ultra-High Intensity Gamma Source	photon, electron, neutron, positron	1780
	M.W. Krasny LPNHE, Paris, France R. Alemany-Fernández, H. Bartosik, N. Biancacci, P. Czodrowski, B. Goddard, S. Hirlaender, J.M. Jowett, R. Kersevan, M. Kowalska, M.W. Krasny, M. Lamont, D. Manglunki, A.V. Petrenko, M. Schaumann, C. Yin Vallgren, F. Zimmermann CERN, Geneva, Switzerland P.S. Antsifarov Institute of Spectroscopy, Russian Academy of Science, Troitsk, Moscow, Russia A. Apyan ANSL, Yerevan, Armenia E.G. Bessonov LPI, Moscow, Russia J. Bieron, K. Dzierzega, W. Placzek, S. Pustelny Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland D. Budker Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany K. Cassou, I. Chaikovska, R. Chehab, K. Dupraz, A. Martens, Z.F. Zomer LAL, Orsay, France F. Castelli Università degli Studi di Milano, Milano, Italy C. Curatolo, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy K. Kroeger FSU Jena, Jena, Germany V. Petrillo Universita' degli Studi di Milano & INFN, Milano, Italy V.P. Shevelko LPI RAS, Moscow, Russia T. Stöhlker HIJ, Jena, Germany G. Weber IOQ, Jena, Germany Y.K. Wu FEL/Duke University, Durham, North Carolina, USA M.S. Zolotorev LBNL, Berkeley, California, USA
	This contribution discusses the possibility of broadening the present CERN research programme making use of a novel concept of light source. The proposed, Partially Stripped Ion beam driven, light source is the backbone of the Gamma Factory (GF) initiative. It could be realized at CERN by using the infrastructure of the already existing accelerators. It could push the intensity limits of the presently operating light-sources by up to 7 orders of magnitude, reaching fluxes of 10¹⁷ photons/s in the interesting gamma-ray energy domain between 1 MeV and 400 MeV. The GF light-source cannot be replaced, in this energy domain, by a FEL source as long as the multi TeV electron beams are not available. Its intensity is beyond the reach of the Inverse Compton Scattering sources. The unprecedented-intensity, energy-tuned gamma beams, together with the gamma-beams-driven secondary beams of polarized leptons, neutrinos, neutrons and radioactive ions are the basic research tools of the proposed Gamma Factory. A broad spectrum of new opportunities, in a vast domain of uncharted fundamental and applied physics territories, could be opened by the Gamma Factory research programme.
	Slides WEYGBD3 [7.531 MB]
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WEYGBF3	Nb3Sn Multicell Cavity Coating at JLab	cavity, niobium, SRF, superconductivity	1798
	U. Pudasaini, M.J. Kelley The College of William and Mary, Williamsburg, Virginia, USA G. Ciovati, G.V. Eremeev, M.J. Kelley, C.E. Reece JLab, Newport News, Virginia, USA M.J. Kelley Virginia Polytechnic Institute and State University, Blacksburg, USA I.P. Parajuli, MNS. Sayeed ODU, Norfolk, Virginia, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics. Following encouraging results with Nb3Sn-coated R&D cavities, the existing coating system was upgraded to allow for Nb3Sn coating of CEBAF accelerator cavities. The upgrade was designed to allow Nb3Sn coating of original CEBAF 5-cell cavities with the vapor diffusion technique. Several CEBAF cavities were coated in the upgraded system to investigate vapor diffusion coatings on extended structures. Witness samples coated along with the cavities were characterized with material science techniques, while coated cavities were measured at 4 and 2 K. The progress, lessons learned, and the pathforward are discussed.
	Slides WEYGBF3 [2.381 MB]
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WEPAF075	Availability Allocation to Particle Accelerators Subsystems by Complexity Criteria	operation, collider, linear-collider, target	2009
	O. Rey Orozko, A. Apollonio, M. Jonker, J.A. Uythoven CERN, Geneva, Switzerland
	In the early design stages of an accelerator, an effective allocation method is needed to translate an overall accelerator availability goal into availability requirements for its subsystems. During the allocation process, many factors are considered to obtain so-called ‘complexity weights', which are at the basis of the system availability allocation. Some of these factors can be measured quantitatively while other have to be assessed qualitatively. Based on our analysis of factors affecting availability, we list six criteria for complexity resulting in an availability allocation of accelerator subsystems. System experts determine the scales of factors and relationships between subsystems. In this paper, we consider four availability apportionment techniques to allocate complexity weights to subsystems. Finally, we apply this method to the Compact Linear Collider (CLIC) and we propose another application of the complexity weights to the Large Hadron Collider (LHC).
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WEPAK010	Simulations and Measurements of the BPM Non Linearity and Kicker Timing Influence on the Tune Shift With Amplitude (TSWA) Measurement at BESSY II	kicker, simulation, optics, diagnostics	2107
	F. Kramer, P. Goslawski, J.G. Hwang, A. Jankowiak, P. Kuske, M. Ruprecht, A. Schälicke HZB, Berlin, Germany
	The Tune Shift With Amplitude (TSWA) does not only determine the position of the stable fix points for the Transverse Resonant Island Buckets (TRIBs) but also represents a global observable for the nonlinear optics in general. For theoretical investigations of the TRIBs a reliable nonlinear optics of the machine is required and thus all measurable global observables for the nonlinear optics are of great interest. The measurement of the TSWA for the BESSY II standard optics was performed using an injection kicker to excite high amplitude betatron oscillations and then extract the amplitude dependant frequency from the synchrotron radiation damped oscillation with a Hilbert transformation. With TRIBs optics the injection kicker was not able to sufficienty excite the beam. The impact and correctability of the BPM nonlinearity at the reached amplitudes and the reason for the failure of the excitation method for our TRIBs optics shall be looked onto in this paper.
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WEPMF064	Daresbury Laboratory Short Pulse Klystron Modulators	klystron, high-voltage, operation, power-supply	2515
	C. Chipman, M.P.J. Gaudreau, L. Jashari, M.K. Kempkes, J. Kinross-Wright, R.E. Simpson Diversified Technologies, Inc., Bedford, Massachusetts, USA S.A. Griffiths, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom H.J. Zhang Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People's Republic of China
	Diversified Technologies, Inc. (DTI) has developed a unique short pulse klystron modulator system for the Compact Linear Advanced Research Accelerator (CLARA) Project at Daresbury Laboratory. One unit has been delivered and three more are on contract. This system is based on the combination of a high voltage solid-state switch, with a conventional 1:7 pulse transformer, and a passive pulse corrector with automated adjustment. This unique passive circuitry delivers the extremely flat output pulse required for advanced accelerator applications. The CLARA modulators share design elements with previous DTI modulators which provides both a lower cost and easier to maintain system. The modulators are designed to pulse 80 MW-class klystrons at an avg power of 250 kW and provides adjustable high efficiency operation in the 45 kV to 450 kV range for currents up to 545 A and pulse lengths of 1.5 to 4.0 μs. One key objective of modulator development is optimization of voltage flatness (± 0.02 %), stability (± 0.05 %), and reproducibility (± 0.05 %).
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WEPMK016	New Insight on Nitrogen Infusion Revealed by Successive Nanometric Material Removal	cavity, SRF, accelerating-gradient, niobium	2665
	M. Checchin, A. Grassellino, M. Martinello, O.S. Melnychuk, S. Posen, A.S. Romanenko, D.A. Sergatskov Fermilab, Batavia, Illinois, USA
	In this study we present new insight on low temperature nitrogen infusion on bulk niobium superconducting radio-frequency (SRF) cavities. Nitrogen infusion is a thermal treatment recently discovered at Fermilab that allows to reach high accelerating gradients, of the order of 45MV/m, with high Q-factors, of the order of 2 · 10¹⁰. Detailed depth dependent RF studies (by means of subsequent HF rinses) and comparisonwith SIMS results pinpointed interstitial nitrogen as the responsible for the improved performance and uncovered the extension of its profile inside the material.
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WEPML016	Development of Nb3Sn Coatings for Superconducting RF Cavities at Fermilab	cavity, SRF, superconductivity, network	2718
	S. Posen, S.K. Chandrasekaran, O.S. Melnychuk, D.A. Sergatskov, B. Tennis, Y. Trenikhina Fermilab, Batavia, Illinois, USA J. Lee NU, Evanston, Illinois, USA
	Nb3Sn films are a promising alternative material for su-perconducting RF cavities, with proven high quality factors at medium fields and predictions for increased superheating field as well. In this contribution, we de-scribe the latest results from the Fermilab Nb3Sn SRF program. Early experiments have been focused on single cell 1.3 GHz cavities. We briefly review efforts to bring the parameters used in the coating process into a range where they produce uniform surfaces without regions showing signs of excess tin or thin/uncoated areas. We then present the latest cavity results, after modifications to the coating recipe based on feedback from film appear-ance and RF performance. These results show high Q0 at medium fields and a maximum field of ~18 MV/m.
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THPAF036	Longitudinal and Quadrupolar Coupling Impedance of an Elliptical Vacuum Chamber With Finite Conductivity in Terms of Mathieu Functions	impedance, vacuum, coupling, electromagnetic-fields	3040
	M. Migliorati, L. Palumbo Sapienza University of Rome, Rome, Italy N. Biancacci CERN, Geneva, Switzerland M. Migliorati, L. Palumbo INFN-Roma1, Rome, Italy V.G. Vaccaro Naples University Federico II and INFN, Napoli, Italy
	Funding: Work supported by the CERN PS-LIU project The resistive wall impedance of an elliptical vacuum chamber in the classical regime with infinite thickness is known analytically for ultra-relativistic beams by means of the Yokoya form factors. Starting from the longitudinal electric field of a point charge moving at arbitrary speed in an elliptical vacuum chamber, which we express in terms of Mathieu functions, in this paper we take into account the finite conductivity of the beam pipe walls and evaluate the longitudinal and quadrupolar impedance for any beam velocity. We also obtain that the quadrupolar impedance of a circular pipe is different from zero, approaching zero only for ultra-relativistic particles. Even if some of the results, in particular in the ultra-relativistic limit, are already known and expressed in terms of form factors, this approach is the first step towards the calculation of the general problem of a multi-layer vacuum chamber with different conductivities and of elliptic cross section.
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THPAK001	Impedance Evaluation of In-Vacuum Undulator at KEK Photon Factory	impedance, simulation, undulator, vacuum	3200
	O. Tanaka, M. Adachi, R. Kato, N. Nakamura, T. Obina, S. Sakanaka, R. Takai, K. Tsuchiya, N. Yamamoto KEK, Ibaraki, Japan
	The estimate of impedance and kick factors of the recently installed at KEK Photon Factory (PF) four In-Vacuum Undulators (IVU) is currently a very important issue, because they could be considerable contributors to the total impedance of PF. Moreover, the coupling impedance of the IVUs could lead to the beam energy loss, changes in the bunch shape, betatron tune shifts and, finally, to the various beam instabilities. Using the simulation tool (CST Particle Studio), longitudinal and transverse impedances of the IVUs were evaluated and compared to analytical formulas and measurement results. The study provides guidelines for mitigation of unwanted impedance, for the accurate estimate of its effects on the beam quality and beam instabilities and also for the impedance budget of a newly designed next-generation machine which has many IVUs and small-aperture beam pipes.
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THPAK079	New Algorithms in Zgoubi	dipole, proton, polarization, simulation	3418
	D.T. Abell RadiaSoft LLC, Boulder, Colorado, USA F. Méot BNL, Upton, Long Island, New York, USA
	Funding: This work was supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics under Award No. DE-SC0017181. The particle tracking code Zgoubi,* is used for a broad array of accelerator design studies, including FFAGs* and EICs,**. In this paper, we describe recent work aimed at improving Zgoubi's speed and flexibility. In particular, we describe a new implementation of the Zgoubi tracking algorithm that requires significantly less memory and arithmetic. And we describe a new algorithm that performs symplectic tracking through field maps. In addition, we describe the current efforts to parallelize Zgoubi. https://sourceforge.net/projects/zgoubi/ F. Méot, FERMILAB-TM-2010, 1997 F. Lemuet et al., NIM-A, 547:638, 2005 *F. Méot et al., eRHIC/45, 2015 ***F. Lin et al., IPAC17, WEPIK114, 2017
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THPAL032	1.3GHz Nb Single-Cell Cavity Vertical Electropolishing with Ninja Cathode and Results of Vertical Test	cavity, cathode, accelerating-gradient, experiment	3702
	K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi MGH, Hyogo-ken, Japan H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe KEK, Ibaraki, Japan H. Ito Sokendai, Ibaraki, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	Marui Galvanizing Co., Ltd. has been developing Nb cavity vertical electropolishing (VEP) technologies in collaboration with KEK. Until now, we reported that inner surface state and removal thickness distribution were improved in VEP with Ninja cathode and coupon cavity. This time, a 1.3GHz Nb single-cell cavity VEP with Ninja cathode was performed in Marui and vertical test was performed in KEK. The inner surface state and removal thickness distribution were satisfactory. And as a result of vertical test, the accelerating gradient of 32MV/m (Q0=8.0E9) was achieved.
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THPMF015	Lifetime and Beam Losses Studies of Partially Strip Ions in the SPS (129Xe³⁹⁺)	vacuum, injection, beam-losses, electron	4070
	S. Hirlaender, R. Alemany-Fernández, H. Bartosik, N. Biancacci, T. Bohl, S. Cettour Cave, K. Cornelis, B. Goddard, V. Kain, M.W. Krasny, M. Lamont, D. Manglunki, G. Papotti, M. Schaumann, F. Zimmermann CERN, Geneva, Switzerland K. Kroeger FSU Jena, Jena, Germany V.P. Shevelko LPI RAS, Moscow, Russia T. Stöhlker, G. Weber IOQ, Jena, Germany
	The CERN multipurpose Gamma Factory proposal relies on using Partially Stripped Ion (PSI) beams, instead of electron beams, as the drivers of its light source. If such beams could be successfully stored in the LHC ring, fluxes of the order of 10¹⁷ photons/s, in the gamma-ray energy domain between 1 MeV and 400 MeV could be achieved. This energy domain is out of reach for the FEL-based light sources as long as the multi TeV electron beams are not available. The CERN Gamma Factory proposal has the potential of increasing by 7 orders of magnitude the intensity limits of the present Inverse Compton Scattering sources. In 2017 the CERN accelerator complex demonstrated its flexibility by producing a new, xenon, ion beam. The Gamma Factory study group, based on this achievement, requested special studies. Its aim was to inject and to accelerate, in the SPS, partially stripped xenon ions Xe³⁹⁺ measure their life time, and determine the relative strength of the processes responsible for the PSI beam losses. This study, the results of which are presented in this contribution, was an initial step in view of the the future studies programmed for 2018 with lead PSI beams.
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THPMF076	New Simulation Programs for Partially Stripped Ions - Laser Light Collisions	photon, laser, electron, FEL	4249
	C. Curatolo, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy M.W. Krasny LPNHE, Paris, France W. Placzek Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland
	We present for the first time two new indipendent Monte Carlo codes for simulating the collisions of Partially Stripped Ions with Laser light. Such collisions if realised at LHC could drive a high intensity gamma source and are the back-bone of the recent Gamma Factory proposal. The implementation aspects will be discussed and the simulation results will be compared.
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Paper

Title

Other Keywords

Page

MOPMF065

LHC- and FCC-Based Muon Colliders

positron, collider, emittance, target

273

F. Zimmermann
CERN, Geneva, Switzerland

Funding: Work supported by the European Commission under the HORIZON 2020 project ARIES, grant agreement no. 730871.
In recent years, three schemes for producing low-emittance muon beams have been proposed: (1) e⁺e⁻ annihilation above threshold using a positron storage ring with a thin target [M. Boscolo, P. Raimondi et al.], (2) laser/FEL-Compton back-scattering off high-energy proton beams circulating in the LHC or FCC-hh [L. Serafini et al.], (3) the Gamma factory concept, where partially stripped heavy ions collide with a laser pulse to directly generating muons [W. Krasny]. The Gamma factory would also generate copious amounts of positrons which could in turn be used as source for option (1). On the other hand the top-up booster of the FCC-ee design would be an outstanding e⁺ storage ring, at the right beam energy, around 45 GeV. After rapid acceleration the muons, produced in one of the three ways, could be collided in machines like the SPS, LHC or FCC-hh. Possible collider layouts are suggested.

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MOPML013

Progress on Preliminary Conceptual Study of HIEPA, a Super Tau-Charm Factory in China

collider, positron, luminosity, electron

422

Q. Luo, D.R. Xu
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Work supported by National Natural Science Foundation of China 11375178 and the Fundamental Research Funds for the Central Universities, Grant No WK2310000046.
As the most successful tau-charm factory of the world, BEPC II will celebrate its 10th birthday this year and will finish its historical mission in the next decade. Because of its very important role in high energy phys-ics study, BEPC II will certainly need a successor, a new tau-charm collider. This paper discusses the feasi-bility of a greenfield next generation tau-charm collid-er named HIEPA. The luminosity of this successor is about 5×1034 cm−2s−1 pilot and 1×1035cm^-2s⁻¹ nominal, with the electron beam longitudinally polarized at the IP. The general scheme of the accelerators and the beam parameters are shown. Several key technologies such as beam polarization and beam emittance diag-nostics are also discussed.

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TUPAF088

Final factory-side Measurements of the Next SC CH-Cavities for the HELIAC-Project

cavity, linac, resonance, heavy-ion

943

M. Basten, M. Busch, H. Podlech, M. Schwarz
IAP, Frankfurt am Main, Germany
K. Aulenbacher, W.A. Barth, V. Gettmann, T. Kürzeder, M. Miski-Oglu
HIM, Mainz, Germany
W.A. Barth, F.D. Dziuba, M. Heilmann, S. Yaramyshev
GSI, Darmstadt, Germany

Funding: Work supported by the EU Framework Programme H2020 662186 (MYRTE); Work supported by BMBF Contr. No. 05P15RFBA;
The upcoming FAIR project (Facility for Antiproton and Ion Research) at GSI will use the existing UNILAC (UNIversal Linear Accelerator) as an injector to provide high intensity heavy ion beams at low repetition rates. As a consequence a new superconducting (sc) continous wave (cw) high intensity heavy ion Linac is required to provide ion beams above the coulomb barrier to keep the Super Heavy Element (SHE) physics program at GSI competitive on an international level. The fundamental Linac design comprises a high performance ion source, the High Charge State Injector (HLI) upgraded for cw-operation and a matching line (1.4 MeV/u) followed by a sc Drift Tube Linac (DTL). Four cryo modules each equipped with three Crossbar-H-mode (CH) structures provide for acceleration up to 7.3 MeV/u. The first section of this ambitious accelerator project has been successfully commissioned and tested with heavy ion beam from the HLI in 2017. It comprises two sc 9.3 T solenoids and a sc 217 MHz CH-cavity with 15 equidistant gaps as a demonstrator. The construction of the next two sc 217 MHz 8 gap CH-cavities is nearly finished and final factory-side measurements will be presented.

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TUPMF011

Calculation of Expected Orbit Motion Due to Girder Resonant Vibration at the APS Upgrade

ground-motion, resonance, lattice, quadrupole

1269

V. Sajaev, Z. Liu, J. Nudell, C.A. Preissner
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size. To keep the beam orbit stable on a sub-micron level, one needs to carefully design magnet supports/girders so that the ground motion does not lead to excessive orbit motion due to resonant modes of magnet supports. In this paper, we will describe the process of calculating the expected orbit motion due to girder resonant vibration. First, we will present the simulation results for the girder resonant modes, then we will calculate the orbit amplification factors for the girder deformation modes, then calculate the expected orbit motion using measured ground motion spectrum. This process can be used to evaluate the design of the magnet supports.

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TUPMF012

Determination of the Ground Motion Orbit Amplification Factors Dependence on the Frequency for the APS Upgrade Storage Ring

ground-motion, lattice, storage-ring, simulation

1272

V. Sajaev, C.A. Preissner
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The Advanced Photon Source (APS) is pursuing an upgrade to the storage ring that will provide electron beam with extremely low emittance. To allow users to take advantage of this small beam size, the beam orbit motion has to be kept stable to within a fraction of the beam size, which translates to sub-micron orbit stability requirement. Ground motion provides significant contribution to the overall expected beam motion, especially at lower frequencies where the ground motion has larger amplitudes. At the same time, the lattice amplification factors reduce when the ground motion becomes coherent at low frequencies. In this paper, we will present simulation of the lattice amplification factor dependence on the ground motion coherence length and show results of the ground motion coherence measurements at APS. After that, we will determine the lattice amplification factors dependence on the ground motion frequency, that can be used to calculate the expected effect of the ground motion on the orbit stability.

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TUPML065

Phase Space Density Evolution in MICE

emittance, simulation, experiment, collider

1692

D. Rajaram
Illinois Institute of Technology, Chicago, Illinois, USA
V. Blackmore
Imperial College of Science and Technology, Department of Physics, London, United Kingdom

Funding: STFC, DOE, NSF, INFN, and CHIPP
The Muon Ionization Cooling Experiment (MICE) collaboration will demonstrate the feasibility of ionization cooling, the technique proposed to cool the muon beam at a future neutrino factory or muon collider. The muon beam parameters are measured before and after the cooling cell using high precision scintillating-fibre trackers in a solenoidal magnetic field. Position and momentum reconstruction of each muon in MICE allows the development of several alternative figures of merit in addition to emittance. Contraction of the phase-space volume of the sample, or equivalently the increase in phases-pace density at its core, is an unequivocal cooling signature. Single-particle amplitude, defined as a weighted distance to the sample centroid, can be used to probe the change in density in the core of the beam. Alternatively, non-parametric statistics provide reliable methods to estimate the entire phase-space density distribution and reconstruct probability contours. The aforementioned techniques, robust to transmission losses and sample non linearities, are ideal candidates for a cooling measurement in MICE. Preliminary results are presented here*.
*Submitted by the MICE Speakers bureau, to be prepared and presented by a MICE member to be selected in due course

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WEXGBD1

Development of Very Short Period Undulators

undulator, electron, radiation, vacuum

1735

S. Yamamoto
KEK, Ibaraki, Japan

Scientists and engineers at KEK have developed undulator magnets having very short period lengths. Magnet plates 100mm and 152mm long with 4-mm period length have been successfully fabricated. They produce an undulator field of approximately 4kG at a gap of 1.6mm. The magnetic field characterization shows that the undulator field is satisfactory in quality for a very short period undulator. KEK has recently installed a short-period undulator at a 50-MeV linac and observed a first light, and will soon start an experiment using a short-period undulator with laser-accelerated electrons for future table-top XFELs. This invited talk summarizes the current status, and experimental activities and results related to short-period undulators and table-top FELs.

Slides WEXGBD1 [3.515 MB]

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WEYGBD3

The CERN Gamma Factory Initiative: An Ultra-High Intensity Gamma Source

photon, electron, neutron, positron

1780

M.W. Krasny
LPNHE, Paris, France
R. Alemany-Fernández, H. Bartosik, N. Biancacci, P. Czodrowski, B. Goddard, S. Hirlaender, J.M. Jowett, R. Kersevan, M. Kowalska, M.W. Krasny, M. Lamont, D. Manglunki, A.V. Petrenko, M. Schaumann, C. Yin Vallgren, F. Zimmermann
CERN, Geneva, Switzerland
P.S. Antsifarov
Institute of Spectroscopy, Russian Academy of Science, Troitsk, Moscow, Russia
A. Apyan
ANSL, Yerevan, Armenia
E.G. Bessonov
LPI, Moscow, Russia
J. Bieron, K. Dzierzega, W. Placzek, S. Pustelny
Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland
D. Budker
Johannes Gutenberg University Mainz, Institut für Physik, Mainz, Germany
K. Cassou, I. Chaikovska, R. Chehab, K. Dupraz, A. Martens, Z.F. Zomer
LAL, Orsay, France
F. Castelli
Università degli Studi di Milano, Milano, Italy
C. Curatolo, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
K. Kroeger
FSU Jena, Jena, Germany
V. Petrillo
Universita' degli Studi di Milano & INFN, Milano, Italy
V.P. Shevelko
LPI RAS, Moscow, Russia
T. Stöhlker
HIJ, Jena, Germany
G. Weber
IOQ, Jena, Germany
Y.K. Wu
FEL/Duke University, Durham, North Carolina, USA
M.S. Zolotorev
LBNL, Berkeley, California, USA

This contribution discusses the possibility of broadening the present CERN research programme making use of a novel concept of light source. The proposed, Partially Stripped Ion beam driven, light source is the backbone of the Gamma Factory (GF) initiative. It could be realized at CERN by using the infrastructure of the already existing accelerators. It could push the intensity limits of the presently operating light-sources by up to 7 orders of magnitude, reaching fluxes of 10¹⁷ photons/s in the interesting gamma-ray energy domain between 1 MeV and 400 MeV. The GF light-source cannot be replaced, in this energy domain, by a FEL source as long as the multi TeV electron beams are not available. Its intensity is beyond the reach of the Inverse Compton Scattering sources. The unprecedented-intensity, energy-tuned gamma beams, together with the gamma-beams-driven secondary beams of polarized leptons, neutrinos, neutrons and radioactive ions are the basic research tools of the proposed Gamma Factory. A broad spectrum of new opportunities, in a vast domain of uncharted fundamental and applied physics territories, could be opened by the Gamma Factory research programme.

Slides WEYGBD3 [7.531 MB]

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WEYGBF3

Nb3Sn Multicell Cavity Coating at JLab

cavity, niobium, SRF, superconductivity

1798

U. Pudasaini, M.J. Kelley
The College of William and Mary, Williamsburg, Virginia, USA
G. Ciovati, G.V. Eremeev, M.J. Kelley, C.E. Reece
JLab, Newport News, Virginia, USA
M.J. Kelley
Virginia Polytechnic Institute and State University, Blacksburg, USA
I.P. Parajuli, MNS. Sayeed
ODU, Norfolk, Virginia, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics.
Following encouraging results with Nb3Sn-coated R&D cavities, the existing coating system was upgraded to allow for Nb3Sn coating of CEBAF accelerator cavities. The upgrade was designed to allow Nb3Sn coating of original CEBAF 5-cell cavities with the vapor diffusion technique. Several CEBAF cavities were coated in the upgraded system to investigate vapor diffusion coatings on extended structures. Witness samples coated along with the cavities were characterized with material science techniques, while coated cavities were measured at 4 and 2 K. The progress, lessons learned, and the pathforward are discussed.

Slides WEYGBF3 [2.381 MB]

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WEPAF075

Availability Allocation to Particle Accelerators Subsystems by Complexity Criteria

operation, collider, linear-collider, target

2009

O. Rey Orozko, A. Apollonio, M. Jonker, J.A. Uythoven
CERN, Geneva, Switzerland

In the early design stages of an accelerator, an effective allocation method is needed to translate an overall accelerator availability goal into availability requirements for its subsystems. During the allocation process, many factors are considered to obtain so-called ‘complexity weights', which are at the basis of the system availability allocation. Some of these factors can be measured quantitatively while other have to be assessed qualitatively. Based on our analysis of factors affecting availability, we list six criteria for complexity resulting in an availability allocation of accelerator subsystems. System experts determine the scales of factors and relationships between subsystems. In this paper, we consider four availability apportionment techniques to allocate complexity weights to subsystems. Finally, we apply this method to the Compact Linear Collider (CLIC) and we propose another application of the complexity weights to the Large Hadron Collider (LHC).

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WEPAK010

Simulations and Measurements of the BPM Non Linearity and Kicker Timing Influence on the Tune Shift With Amplitude (TSWA) Measurement at BESSY II

kicker, simulation, optics, diagnostics

2107

F. Kramer, P. Goslawski, J.G. Hwang, A. Jankowiak, P. Kuske, M. Ruprecht, A. Schälicke
HZB, Berlin, Germany

The Tune Shift With Amplitude (TSWA) does not only determine the position of the stable fix points for the Transverse Resonant Island Buckets (TRIBs) but also represents a global observable for the nonlinear optics in general. For theoretical investigations of the TRIBs a reliable nonlinear optics of the machine is required and thus all measurable global observables for the nonlinear optics are of great interest. The measurement of the TSWA for the BESSY II standard optics was performed using an injection kicker to excite high amplitude betatron oscillations and then extract the amplitude dependant frequency from the synchrotron radiation damped oscillation with a Hilbert transformation. With TRIBs optics the injection kicker was not able to sufficienty excite the beam. The impact and correctability of the BPM nonlinearity at the reached amplitudes and the reason for the failure of the excitation method for our TRIBs optics shall be looked onto in this paper.

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WEPMF064

Daresbury Laboratory Short Pulse Klystron Modulators

klystron, high-voltage, operation, power-supply

2515

C. Chipman, M.P.J. Gaudreau, L. Jashari, M.K. Kempkes, J. Kinross-Wright, R.E. Simpson
Diversified Technologies, Inc., Bedford, Massachusetts, USA
S.A. Griffiths, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
H.J. Zhang
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People's Republic of China

Diversified Technologies, Inc. (DTI) has developed a unique short pulse klystron modulator system for the Compact Linear Advanced Research Accelerator (CLARA) Project at Daresbury Laboratory. One unit has been delivered and three more are on contract. This system is based on the combination of a high voltage solid-state switch, with a conventional 1:7 pulse transformer, and a passive pulse corrector with automated adjustment. This unique passive circuitry delivers the extremely flat output pulse required for advanced accelerator applications. The CLARA modulators share design elements with previous DTI modulators which provides both a lower cost and easier to maintain system. The modulators are designed to pulse 80 MW-class klystrons at an avg power of 250 kW and provides adjustable high efficiency operation in the 45 kV to 450 kV range for currents up to 545 A and pulse lengths of 1.5 to 4.0 μs. One key objective of modulator development is optimization of voltage flatness (± 0.02 %), stability (± 0.05 %), and reproducibility (± 0.05 %).

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WEPMK016

New Insight on Nitrogen Infusion Revealed by Successive Nanometric Material Removal

cavity, SRF, accelerating-gradient, niobium

2665

M. Checchin, A. Grassellino, M. Martinello, O.S. Melnychuk, S. Posen, A.S. Romanenko, D.A. Sergatskov
Fermilab, Batavia, Illinois, USA

In this study we present new insight on low temperature nitrogen infusion on bulk niobium superconducting radio-frequency (SRF) cavities. Nitrogen infusion is a thermal treatment recently discovered at Fermilab that allows to reach high accelerating gradients, of the order of 45MV/m, with high Q-factors, of the order of 2 · 10¹⁰. Detailed depth dependent RF studies (by means of subsequent HF rinses) and comparisonwith SIMS results pinpointed interstitial nitrogen as the responsible for the improved performance and uncovered the extension of its profile inside the material.

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WEPML016

Development of Nb3Sn Coatings for Superconducting RF Cavities at Fermilab

cavity, SRF, superconductivity, network

2718

S. Posen, S.K. Chandrasekaran, O.S. Melnychuk, D.A. Sergatskov, B. Tennis, Y. Trenikhina
Fermilab, Batavia, Illinois, USA
J. Lee
NU, Evanston, Illinois, USA

Nb3Sn films are a promising alternative material for su-perconducting RF cavities, with proven high quality factors at medium fields and predictions for increased superheating field as well. In this contribution, we de-scribe the latest results from the Fermilab Nb3Sn SRF program. Early experiments have been focused on single cell 1.3 GHz cavities. We briefly review efforts to bring the parameters used in the coating process into a range where they produce uniform surfaces without regions showing signs of excess tin or thin/uncoated areas. We then present the latest cavity results, after modifications to the coating recipe based on feedback from film appear-ance and RF performance. These results show high Q0 at medium fields and a maximum field of ~18 MV/m.

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THPAF036

Longitudinal and Quadrupolar Coupling Impedance of an Elliptical Vacuum Chamber With Finite Conductivity in Terms of Mathieu Functions

impedance, vacuum, coupling, electromagnetic-fields

3040

M. Migliorati, L. Palumbo
Sapienza University of Rome, Rome, Italy
N. Biancacci
CERN, Geneva, Switzerland
M. Migliorati, L. Palumbo
INFN-Roma1, Rome, Italy
V.G. Vaccaro
Naples University Federico II and INFN, Napoli, Italy

Funding: Work supported by the CERN PS-LIU project
The resistive wall impedance of an elliptical vacuum chamber in the classical regime with infinite thickness is known analytically for ultra-relativistic beams by means of the Yokoya form factors. Starting from the longitudinal electric field of a point charge moving at arbitrary speed in an elliptical vacuum chamber, which we express in terms of Mathieu functions, in this paper we take into account the finite conductivity of the beam pipe walls and evaluate the longitudinal and quadrupolar impedance for any beam velocity. We also obtain that the quadrupolar impedance of a circular pipe is different from zero, approaching zero only for ultra-relativistic particles. Even if some of the results, in particular in the ultra-relativistic limit, are already known and expressed in terms of form factors, this approach is the first step towards the calculation of the general problem of a multi-layer vacuum chamber with different conductivities and of elliptic cross section.

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THPAK001

Impedance Evaluation of In-Vacuum Undulator at KEK Photon Factory

impedance, simulation, undulator, vacuum

3200

O. Tanaka, M. Adachi, R. Kato, N. Nakamura, T. Obina, S. Sakanaka, R. Takai, K. Tsuchiya, N. Yamamoto
KEK, Ibaraki, Japan

The estimate of impedance and kick factors of the recently installed at KEK Photon Factory (PF) four In-Vacuum Undulators (IVU) is currently a very important issue, because they could be considerable contributors to the total impedance of PF. Moreover, the coupling impedance of the IVUs could lead to the beam energy loss, changes in the bunch shape, betatron tune shifts and, finally, to the various beam instabilities. Using the simulation tool (CST Particle Studio), longitudinal and transverse impedances of the IVUs were evaluated and compared to analytical formulas and measurement results. The study provides guidelines for mitigation of unwanted impedance, for the accurate estimate of its effects on the beam quality and beam instabilities and also for the impedance budget of a newly designed next-generation machine which has many IVUs and small-aperture beam pipes.

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THPAK079

New Algorithms in Zgoubi

dipole, proton, polarization, simulation

3418

D.T. Abell
RadiaSoft LLC, Boulder, Colorado, USA
F. Méot
BNL, Upton, Long Island, New York, USA

Funding: This work was supported in part by the US Department of Energy, Office of Science, Office of Nuclear Physics under Award No. DE-SC0017181.
The particle tracking code Zgoubi*,** is used for a broad array of accelerator design studies, including FFAGs*** and EICs****,*****. In this paper, we describe recent work aimed at improving Zgoubi's speed and flexibility. In particular, we describe a new implementation of the Zgoubi tracking algorithm that requires significantly less memory and arithmetic. And we describe a new algorithm that performs symplectic tracking through field maps. In addition, we describe the current efforts to parallelize Zgoubi.
*https://sourceforge.net/projects/zgoubi/
**F. Méot, FERMILAB-TM-2010, 1997
***F. Lemuet et al., NIM-A, 547:638, 2005
****F. Méot et al., eRHIC/45, 2015
*****F. Lin et al., IPAC17, WEPIK114, 2017

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THPAL032

1.3GHz Nb Single-Cell Cavity Vertical Electropolishing with Ninja Cathode and Results of Vertical Test

cavity, cathode, accelerating-gradient, experiment

3702

K.N. Nii, V. Chouhan, Y.I. Ida, T.Y. Yamaguchi
MGH, Hyogo-ken, Japan
H. Hayano, S. Kato, H. Monjushiro, T. Saeki, M. Sawabe
KEK, Ibaraki, Japan
H. Ito
Sokendai, Ibaraki, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

Marui Galvanizing Co., Ltd. has been developing Nb cavity vertical electropolishing (VEP) technologies in collaboration with KEK. Until now, we reported that inner surface state and removal thickness distribution were improved in VEP with Ninja cathode and coupon cavity. This time, a 1.3GHz Nb single-cell cavity VEP with Ninja cathode was performed in Marui and vertical test was performed in KEK. The inner surface state and removal thickness distribution were satisfactory. And as a result of vertical test, the accelerating gradient of 32MV/m (Q0=8.0E9) was achieved.

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THPMF015

Lifetime and Beam Losses Studies of Partially Strip Ions in the SPS (129Xe³⁹⁺)

vacuum, injection, beam-losses, electron

4070

S. Hirlaender, R. Alemany-Fernández, H. Bartosik, N. Biancacci, T. Bohl, S. Cettour Cave, K. Cornelis, B. Goddard, V. Kain, M.W. Krasny, M. Lamont, D. Manglunki, G. Papotti, M. Schaumann, F. Zimmermann
CERN, Geneva, Switzerland
K. Kroeger
FSU Jena, Jena, Germany
V.P. Shevelko
LPI RAS, Moscow, Russia
T. Stöhlker, G. Weber
IOQ, Jena, Germany

The CERN multipurpose Gamma Factory proposal relies on using Partially Stripped Ion (PSI) beams, instead of electron beams, as the drivers of its light source. If such beams could be successfully stored in the LHC ring, fluxes of the order of 10¹⁷ photons/s, in the gamma-ray energy domain between 1 MeV and 400 MeV could be achieved. This energy domain is out of reach for the FEL-based light sources as long as the multi TeV electron beams are not available. The CERN Gamma Factory proposal has the potential of increasing by 7 orders of magnitude the intensity limits of the present Inverse Compton Scattering sources. In 2017 the CERN accelerator complex demonstrated its flexibility by producing a new, xenon, ion beam. The Gamma Factory study group, based on this achievement, requested special studies. Its aim was to inject and to accelerate, in the SPS, partially stripped xenon ions Xe³⁹⁺ measure their life time, and determine the relative strength of the processes responsible for the PSI beam losses. This study, the results of which are presented in this contribution, was an initial step in view of the the future studies programmed for 2018 with lead PSI beams.

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THPMF076

New Simulation Programs for Partially Stripped Ions - Laser Light Collisions

photon, laser, electron, FEL

4249

C. Curatolo, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
M.W. Krasny
LPNHE, Paris, France
W. Placzek
Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków, Poland

We present for the first time two new indipendent Monte Carlo codes for simulating the collisions of Partially Stripped Ions with Laser light. Such collisions if realised at LHC could drive a high intensity gamma source and are the back-bone of the recent Gamma Factory proposal. The implementation aspects will be discussed and the simulation results will be compared.

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