THPOR —  Poster Session   (12-May-16   16:00—18:00)

Paper	Title	Page
THPOR001	Tolerance Studies and Dispersion Free Steering for Extreme Low Emittance in the FCC-ee Project	3759
	S. Aumon, A. Doblhammer, B. Haererpresenter, B.J. Holzer CERN, Geneva, Switzerland B. Haererpresenter KIT, Karlsruhe, Germany K. Oide KEK, Ibaraki, Japan
	The FCC-ee study is investigating the design of a 100 km e+/e− circular collider for precision measurements and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1035 cm-2s-1. In order to reach such performances, an extreme focusing of the beam is required in the interaction regions with a low vertical beta function of 2 mm at the IP. Moreover, the FCC-ee physics program requires very low emittances never achieved in a collider with 2 nm for εx and 2 pm for εy, reducing the coupling ratio to 1/1000. With such requirements, any field errors and sources of coupling will introduce spurious vertical dispersion which degrades emittances, limiting the luminosity of the machine. This paper describes the tolerance study and the impact of errors will affect the vertical emittance. In order to preserve the FCC-ee performances, in particular εy, a challenging correction scheme is proposed to keep the coupling and the vertical emittance as low as possible.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR001
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR002	Chromaticity Compensation Schemes for the Arc Lattice of the FCC-ee Collider	3763
SUPSS048	use link to see paper's listing under its alternate paper code
	B. Härer KIT, Karlsruhe, Germany A. Doblhammer, B.J. Holzer CERN, Geneva, Switzerland
	FCC-ee is an 100 km e+/e− collider that is being designed within the Future Circular Collider Study organised by CERN. It's layout is optimised for precision studies and rare decay observations in the range of 90 to 350 GeV center of mass energy with luminosities in the order of 1035 cm-2s-1. Extremely small vertical beta functions of 1 - 2 mm are required at the two interaction points to reach this goal. The strong focusing required in the final doublet quadrupoles drives the chromaticity to more than -2000 units, far beyond the values that had been achieved in previous storage rings. As a consequence a pure linear chromaticity compensation scheme will not be sufficient to obtain the required ± 2 % energy acceptance. A state of the art multi-family sextupole scheme will have to be combined with a local chromaticity correction. This paper presents the design of the arc lattice, optimised for highest momentum acceptance and the results of systematic studies of the sextupole scheme in the arcs in order to gain highest chromaticity performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR002
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR003	Tapering Options and Emittance Fine Tuning for the FCC-ee Collider	3767
	B. Härer, A. Doblhammer, B.J. Holzer CERN, Geneva, Switzerland
	The lepton collider version of the FCC study describes a future electron-positron collider with a circumference in the order of 100 km, optimised for operation with collision energies in the range of 90 GeV to 350 GeV (FCC- ee). This paper presents the layout of the machine and the constraints on the design of the arc lattice in the context of the four different beam energies that are foreseen for beam operation. Special emphasis is put on the compensation of the effect of the strong synchrotron radiation losses. The beam orbit as well as the optics have to be re-optimised for a given operation energy in order to achieve the foreseen emittance of ε = 1 nm in the horizontal and 1 pm in the vertical plane. Counter measures of the so-called saw-tooth effect of the design orbit are needed as well as a compensation of the energy loss on the beam optics. The paper summarizes different scenarios of how to achieve this goal as well as the need for additional emittance fine tuning using wiggler magnets.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR003
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR004	Magnetic Measurement for Superconducting-Quadrupole-Magnets of Final-Focus System for SuperKEKB	3771
	Y. Arimoto, M. Iwasaki, N. Ohuchi, K. Tsuchiya, X. Wang, H. Yamaoka, Z.G. Zong KEK, Ibaraki, Japan
	SuperKEKB is an upgrade project of KEKB to increase its luminosity to 8 x 1035 cm-2 s-1 based on the nano-beam scheme. In SuperKEKB, one of a key element is a final-focus system; it reduces e−/e+ beam size to 50 nm in vertical and 10 μm in horizontal direction at an interaction point (IP). The system consists of eight superconducting quadrupole magnets and four quadrupoles are aligned on the each beam line. The quadrupole, QC1P(QC1E), which is located at the closest position to the IP on the e+(e−) beam line, generates a field gradient of about 70 T/m. An inner diameter of coil and a magnetic length for QC1P(QC1E) are 25(33) mm and 334(373) mm, respectively. The production of all quadrupole magnets are completed. To confirm their field qualities, we performed magnetic measurement for each magnet in advance to be integrated into cryostats on the beam lines. In the measurement, the quadrupoles were cooled down to 4.2 K in a test vertical cryostat and field harmonic components were measured with harmonic coils. The magnitude of error multipole components for all magnets met requirements from beam optics design. In this paper we describe the measurement results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR004
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR005	Tunnel Level Variation in the SuperKEKB Interaction Region	3774
	M. Masuzawa, T. Adachi, T. Kawamoto KEK, Ibaraki, Japan
	SuperKEKB is an electron-positron collider, which aims to achieve a peak luminosity 40 times higher than that of KEKB. The vertical beam sizes of both rings are squeezed down to 50 - 60 nm at the interaction point (IP), which accounts for a factor of 20 in the luminosity increase, and the beam currents are doubled from those of KEKB. Tunnel motion can be critical for realizing the collisions of such small beams. A Hydrostatic Leveling System (HLS), which consists of 18 sensors, was installed on both sides of the IP to monitor tunnel level variations continuously. Effects of heavy rain and installation of the radiation shield blocks on the tunnel floor level are clearly seen. The HLS data during construction and SuperKEKB commissioning are reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR005
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR006	SuperKEKB Main Ring Magnet System	3778
	M. Masuzawa, K. Egawa, H. Iinuma, T. Kawamoto, S. Nakamura, Y. Ohsawa, T. Oki, R. Sugahara, N. Tokuda KEK, Ibaraki, Japan
	SuperKEKB is an electron-positroncollider, which aims to achieve a peak luminosity 40 times higher than that of KEKB by using the so-called 'nano-beam' scheme. A major upgrade to the Main Ring (MR) magnet system was needed to realize this scheme. The upgrade includes 1) new beam lines in the entire interaction region;2) replacement of the main dipole magnets in the positron ring; 3) a new layout of the wiggler sections in the positron ring, and newly added wiggler section in the electron ring, and; 4) sextupole magnets with tunable tilting tables to control the ratio of skew/normal sextupole components in the positron ring. More than 400 magnets were designed, fabricated, field-measured, installed in the tunnel and aligned in time for Phase 1 commissioning. Alignment of the MR magnets was challenging, since the survey network was destroyed by the Great East Japan Earthquake. Tunnel position changes during the magnet alignment work caused by construction of a new facilities building made the alignment work even more challenging. Construction of the MR magnet system and its first commissioning are reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR006
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR007	Optics Measurements and Corrections at the Early Commissioning of SuperKEKB	3782
	Y. Ohnishi, Y. Funakoshi, H. Koiso, A. Morita, K. Ohmipresenter, K. Oide, H. Sugimoto, D. Zhou KEK, Ibaraki, Japan M.E. Biagini, M. Boscolo, S. Guiducci INFN/LNF, Frascati (Roma), Italy N. Carmignani, S.M. Liuzzo ESRF, Grenoble, France
	We present experimental results of measurements and corrections of the optics at the early Phase-1 commissioning of SuperKEKB which is a positron-electron collider built to achieve the target luminosity of 8x1035 cm-2s-1. We have three stages; the Phase-1 is the commissioning of the machine without the final focus magnets and detector solenoid(no collision); the collision with the final focus system and the Belle II detector will be performed at the Phase-2 and Phase-3. The strategy for the luminosity upgrade is a novel "nano-beam'' scheme found elsewhere*. In order to achieve the target luminosity, the vertical emittance has to be reduced by corrections of machine error measured by orbit responses. The vertical emittance should be achieved to be less than 6 pm(0.2 % coupling) during the Phase-1 by fully utilizing correction tools of skew quadrupole-like coils wound on sextupole magnets and power supplies for each correction coil in quadrupole magnets. In addition to the linear optics, the optics for off-momentum particles is also studied to understand a dynamic aperture affects the Touschek lifetime. * "SuperB Conceptual Design Report", INFN/AE-07/2, SLAV-R-856, LAL 07-15, (2007).
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR007
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR009	Cepc Partial Double Ring Lattice Design	3785
	F. Su Institute of High Energy Physics (IHEP), People's Republic of China S. Bai, T.J. Bian, Z. Duan, J. Gao, H. Geng, D. Wang, Y. Wangpresenter, M. Xiao, G. Xu, Y. Zhang IHEP, Beijing, People's Republic of China
	In this paper, we introduced the layout and lattice design of Circular-Electron-Positron-Collider (CEPC) partial double ring (PDR) scheme. The baseline design of CEPC is a single beam-pipe electron positron collider, which has to adopt pretzel orbit scheme. And it is not suitable to serve as a high luminosity Z factory. If we choose partial double ring scheme, we can get a higher luminosity with lower power and be suitable to serve as a high luminosity Z factory. In this paper, we discussed the details of CEPC partial double ring lattice design and showed the dynamic aperture study and optimization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR009
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR010	CEPC Parameter Choice and Partial Double Ring Design	3788
	D. Wang, S. Bai, T.J. Bian, X. Cui, Z. Duan, J. Gao, H. Geng, Y.Y. Guo, Q. Qin, N. Wang, Y. Wangpresenter, M. Xiao, J.Y. Zhai, C. Zhang, Y. Zhang IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218) In order to avoid the pretzel orbit, CEPC is proposed to use partial double ring scheme in CDR. Based on crab waist scheme, we hope to either increase the luminosity with same beam power as Pre-CDR, or reduce the beam power while keeping the same luminosity in Pre-CDR. FFS with crab sextupoles has been developed and the arc lattice was redesigned to acheive the lower emittance for crab waist scheme.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR010
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR011	Design study of CEPC Alternating Magnetic Field Booster	3791
	T.J. Bian, S. Bai, X. Cui, J. Gao, D. Wang, Y. Wangpresenter, M. Xiao, C. Zhang IHEP, Beijing, People's Republic of China Y. Cai SLAC, Menlo Park, California, USA M. Koratzinos DPNC, Genève, Switzerland F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	CEPC is next generation circular collider proposed by China. The design of the full energy booster ring of the CEPC is especially challenging. The ejected beam energy is 120GeV but the injected beam only 6GeV. In a conventional approach, the low magnetic field of the main dipole magnets creates problems. We propose to operate the booster ring as a large wiggler at low beam energies and as a normal ring at high energies to avoid the problem of very low dipole magnet fields.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR011
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR012	Dynamic Aperture Study of the CEPC Main Ring with Interaction Region	3795
	Y. Wang, S. Bai, T.J. Bian, J. Gao, H. Geng, D. Wang, Y. Zhang IHEP, Beijing, People's Republic of China F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	CEPC is a Circular Electron and Positron Collider proposed by China to mainly study the Higgs boson. In order to achieve factory luminosity, a strong focusing system and low-emittance are required. A momentum acceptance as large as 2\% is also required to get a reasonable beam lifetime. This is one of the key issues of the CEPC accelerator physics. In this paper, the optics design of the interaction region and the optimization of dynamic aperture for the whole ring (single ring scheme) will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR012
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR013	Magnet Error Effect on Dynamic Aperture in CEPC	3798
	S. Bai, J. Gao, Y. Wangpresenter, D.J. Xiao IHEP, Beijing, People's Republic of China
	With the discovery of the higgs boson at around 125GeV, a circular higgs factory design with high luminosity (L ~ 1034 cm-2s−1) is becoming more popular in the accelerator world. The CEPC project in China is one of them. The performance of the machine can be influenced by the existence of every kind of inaccuracies of the magnets, such as misalignment errors and field errors, multipole errors etc on. In this paper, we reported the errors that used in the CEPC beam dynamic study, and the influence on dynamic aperture of the CEPC main ring when introducing these kinds of errors.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR013
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR014	MDI Design in CEPC Partial Double Ring	3802
	S. Bai, J. Gao, Y. Wangpresenter, Q.L. Xiu, W.C. Yao, Y. Yue IHEP, Beijing, People's Republic of China
	With the discovery of the higgs boson at around 125GeV, a circular higgs factory design with high luminosity (L ~ 1034 cm-2 s-1) is becoming more popular in the accelerator world. The CEPC project in China is one of them. Machine Detector Interface (MDI) is the key research area in electron-positron colliders, especially in CEPC, it is one of the criteria to measure the accelerator and detector design performance. Detector background, collimator and solenoid compensation are the most critical physics problem. Beamstrahlung is the problem which is never gotten into before in the existed electron positron collider of world history. Every kinds of background are bad for detector, and solenoid can make damage to accelerator beam. We will use a Monte Carlo simulation method to calculate and analysis the CEPC detector background and the harm it makes to detector. Anti-solenoid are designed to compensate the strong detector solenoid field of several tesla.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR014
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR015	CEPC Bunch Lengthening and Cavity HOM Analysis	3805
	H.J. Zheng, J. Gao, Y. Wangpresenter IHEP, Beijing, People's Republic of China
	In this paper we will show the higher order mode (HOM) analysis of the cavity for the Circular Electron-Positron Collider (CEPC) partial double ring (PDR) scheme. In order to study the single bunch longitudinal instability in CEPC, bunch lengthening and energy spread are estimated based on Gao's theory. Different models are used to study the bunch lengthening and energy spread of the ring.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR015
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR017	Dynamic Aperture Optimization at CEPC with Pretzel Orbit	3808
	H. Geng, S. Bai, X. Cui, Z. Duan, J. Gao, Y.Y. Guo, Y.M. Peng, Q. Qin, D. Wang, N. Wang, Y. Wang, G. Xu, Y. Yue, Y. Zhangpresenter IHEP, Beijing, People's Republic of China W. Chou Fermilab, Batavia, Illinois, USA F. Su Institute of High Energy Physics (IHEP), People's Republic of China
	A preliminary design of the CEPC ring with pretzel orbit will be presented. The ring and pretzel orbit will be designed for 50 bunches, as required in the CEPC Pre-CDR. The linear optics, as well as the non-linear chromaticity compensation with the presence of pretzel orbit will be described. Different phase advance difference between the long and short straight sections, have been tried to optimize the dynamic aperture, the results will be shown in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR017
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR018	Comissioning of Upgraded VEPP-2000 Injection Chain	3811
	D.E. Berkaev, A.V. Andrianov, K.V. Astrelina, V.V. Balakin, A.M. Barnyakov, O.V. Belikov, M.F. Blinov, D.V. Bochek, D. Bolkhovityanov, F.A. Emanov, A.R. Frolov, K. Gorchakov, Ye.A. Gusev, A.S. Kasaev, E. Kenzhbulatov, I. Koop, I.E. Korenev, G.Y. Kurkin, N.N. Lebedev, A.E. Levichev, P.V. Logatchov, A.P. Lysenko, D.A. Nikiforov, V.P. Prosvetov, Yu. A. Rogovsky, S.L. Samoylov, A.I. Senchenko, P.Yu. Shatunov, Y.M. Shatunov, D.B. Shwartz, A.A. Starostenko, I.M. Zemlyansky, Yu.M. Zharinov BINP SB RAS, Novosibirsk, Russia F.A. Emanov, Yu. A. Rogovsky, A.I. Senchenko, A.A. Starostenko NSU, Novosibirsk, Russia
	The upgrade of VEPP-2000 e+e− collider injection chain includes the connection to BINP Injection Complex (IC) via newly constructed transfer line K-500 as well as upgrade of the booster synchrotron BEP to the energy of 1 GeV. Modernization has started in the middle of 2013 and now the electron and positron beams with highly increased production rate together with top-up injection from BEP are ready to feed VEPP-2000 ring and provide design luminosity at the whole energy range limited only by beam-beam effects. The design and operation experience of IC damping ring, 250 m transfer channel and booster BEP dealing with 2.6 T magnets at top energy will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR018
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR019	Momentum Acceptance Optimization in FCC-ee Lattice (CERN)	3814
	A.V. Bogomyagkov, E.B. Levichevpresenter BINP SB RAS, Novosibirsk, Russia
	Funding: Work is supported by the Ministry of Education and Science of the Russian Federation. The part of the ongoing study of the future circular collider (FCC) is an electron positron machine with center of mass energy from 90 to 350 GeV. Crab waist collision scheme and small (1 mm) vertical beta function at the interaction point (IP) provide superior luminosity. At the top energy, radiation in the field of the opposite bunch (beamstrahlung) limits the beam lifetime and therefore achievable luminosity. Beamstrahlung influence depends on momentum acceptance of the lattice, the value of 2% provides acceptable lifetime. The small value of vertical beta function enhances effects of nonlinear chromaticity. The present work describes principles used in design and optimization of FCC-ee momentum acceptance optimization and are based on chromatic variations of beta function.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR020	Status of VEPP-4M Collider	3818
	E.B. Levichev, O.I. Meshkov, P.A. Piminov, A.N. Zhuravlev BINP SB RAS, Novosibirsk, Russia
	At present the VEPP-4 storage ring facility provides varied experimental programs including HEP, nuclear physics, synchrotron radiation, polarized electron/positron beam research, etc. Until now, the studies were mainly performed at the beam energy below 2 GeV but a strong interest of experimentalists encourages us to increase the beam energy up to 5 GeV. Reliable and high-performance operation at high energy is a challenge for the machine. Here we discuss the recent experimental results at the low energy, and prospects and constraints of the energy ramp.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR020
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR022	Design of Beam Optics for the FCC-ee Collider Ring	3821
	K. Oide, K. Ohmi, D. Zhou KEK, Ibaraki, Japan M. Aiba PSI, Villigen PSI, Switzerland S. Aumon, M. Benedikt, H. Burkhardt, A. Doblhammer, B. Härer, B.J. Holzer, J.M. Jowett, M. Koratzinos, L.E. Medina Medrano, Y. Papaphilippou, J. Wenninger, F. Zimmermannpresenter CERN, Geneva, Switzerland A.P. Blondel DPNC, Genève, Switzerland A.V. Bogomyagkov, I. Koop, E.B. Levichev, P.A. Piminov, D.N. Shatilov, D.B. Shwartz, S.V. Sinyatkin BINP SB RAS, Novosibirsk, Russia M. Boscolo INFN/LNF, Frascati (Roma), Italy Y. Cai, M.K. Sullivan, U. Wienands SLAC, Menlo Park, California, USA
	A design of beam optics will be presented for the FCC-ee double-ring collider. The main characteristics are 45 to 175 GeV beam energy, 100 km circumference with two IPs/ring, 30 mrad crossing angle at the IP, crab-waist scheme with local chromaticity correction system, and "tapering" of the magnets along with the local beam energy. An asymmetric layout near the interaction region suppresses the critical energy of synchrotron radiation toward the detector at the IP less than 100 keV, while keeping the geometry as close as to the FCC-hh beam line. A sufficient transverse/longitudinal dynamic aperture is obtained to assure the lifetime with beamstrahlung and top-up injection. The synchrotron radiation in all magnets, the IP solenoid and its compensation, nonlinearity of the final quadrupoles are taken into account.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR022
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR023	The FCC-ee Interaction Region Magnet Design	3824
	M. Koratzinos, A.P. Blondel DPNC, Genève, Switzerland M. Benedikt, B.J. Holzer, F. Zimmermannpresenter, J. van Nugteren CERN, Geneva, Switzerland A.V. Bogomyagkov, S.V. Sinyatkin BINP SB RAS, Novosibirsk, Russia K. Oide KEK, Ibaraki, Japan
	The design of the region close to the interaction point of the FCC-ee experiments is especially challenging. The beams collide at an angle (±15 mrad) in the high-field region of the detector solenoid. Moreover, the very low vertical β* of the machine necessitates that the final focusing quadrupoles have a distance from the IP (L*) of around 2 m and therefore are inside the main detector solenoid. The beams should be screened from the effect of the detector magnetic field, and the emittance blow-up due to vertical dispersion in the interaction region should be minimized, while leaving enough space for detector components. Crosstalk between the two final focus quadrupoles, only about 6 cm apart at the tip, should also be minimized.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR023
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR024	Electrical Power Budget for FCC-ee	3828
	F. Zimmermann, S. Aull, M. Benedikt, D. Bozzini, O. Brunner, J.-P. Burnet, A.C. Butterworth, R. Calaga, E. Jensen, V. Mertens, A. Milanese, M. Nonis, N. Schwerg, L.J. Tavian, J. Wenninger CERN, Geneva, Switzerland A.P. Blondel, M. Koratzinos DPNC, Genève, Switzerland Sh. Gorgi Zadeh Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany K. Oide KEK, Ibaraki, Japan L. Rinolfi JUAS, Archamps, France
	Funding: Supported by the European Commission under the Capacities 7th Framework Programme project EuCARD-2, grant agreement 312453. We present a first rough estimate for the electrical power consumption of the FCC-ee lepton collider. This electrical power is dominated by the RF system, which provides the motivation for the ongoing R&D on highly efficient RF power sources. Other contributions come from the warm arc magnets, the cryogenics systems, cooling, ventilation, general services, the particle-physics detectors, and the injector complex.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR024
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR025	Wedge Absorbers for Final Cooling for a High-Energy High-Luminosity Lepton Collider	3832
	D.V. Neuffer Fermilab, Batavia, Illinois, USA T.A. Mohayai IIT, Chicago, Illinois, USA P. Snopok Illinois Institute of Technology, Chicago, Illinois, USA D.J. Summers UMiss, University, Mississippi, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the U. S. Department of Energy. A high-energy high-luminosity muon collider scenario requires a "final cooling" system that reduces transverse emittance to ~25 microns (normalized) while allowing longitudinal emittance increase. Ionization cooling using high-field solenoids (or Li Lens) can reduce transverse emittances to ~100 microns in readily achievable configurations, confirmed by simulation. Passing these muon beams at ~100 MeV/c through cm-sized diamond wedges can reduce transverse emittances to ~25 microns, while increasing longitudinal emittance by a factor of ~5. Implementation will require optical matching of the exiting beam into downstream acceleration systems.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR025
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR026	Change Management at the International Linear Collider ILC	3835
	B. List, L. Haggepresenter, N. Walker DESY, Hamburg, Germany
	The Linear Collider Collaboration has introduced a change management process to ensure that changes to the ILC baseline design are properly reviewed and implemented in an orderly fashion. A change management board oversees the process, establishes the review procedure based on the overall impact of the proposed change, decides, and monitors the implementation. This change management process has become an important factor that gives structure and direction to the ongoing design activities around the world. For example, one CR called for a harmonisation of the final focus quadrupole position between the two detector concepts; extensive studies from both experiments were carried out as part of the review process and took almost a year. Another CR by the experiments asked for a vertical shaft access to the interaction hall that required a relocation of the whole accelerator. The change process made sure that the stakeholders were part of the review and decision process from the beginning and contributed to a design change acceptable to all parties involved. The poster will present the change management process and give examples of change requests that have already been processed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR026
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR028	Numerical Analysis of Stresses for the Target of the ILC 300 Hz Conventional Positron Source	3838
	S. Jin, J. Gao IHEP, Beijing, People's Republic of China T. Omori KEK, Ibaraki, Japan P. Sievers CERN, Geneva, Switzerland
	A 300Hz conventional, e- driven positron source for the ILC is proposed by an international team. In this paper, we focus on numerical analysis of dynamic stresses in the Tungsten target. These are driven by the pulsed e-beam, which causes rapid heating and subsequent, dynamic loads in the target which can lead to fracture and failure of it. A program of ANSYS workbench is used in the study. The dynamic stresses from both of extremely short (10 ns) and nominal (1μs) thermal pulses are systematically studied in various target related parts such as small spheres, cylinders. Particular attention has also been paid to the buckling of foils. (*) The first proposal was published in NIMA 672 (2012) 52-56 by T. Omori, et. al.. The authors come from seven institutes including KEK, Hiroshima U., DESY, ANL, IHEP, SOKENDAI, U. of Hamburg
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR028
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR029	First Start-to-End BBA Results in the CLIC RTML	3841
	Y. Han, L. Ma SDU, Shandong, People's Republic of China A. Latina, D. Schulte CERN, Geneva, Switzerland
	CLIC is a design study for a 3 TeV linear collider designed for the high-energy frontier in the post-LHC era. The Ring To Main Linac (RTML) part of CLIC is a long section that must transport the electron and the positron bunches through more than 20 km of beamlines, with minimal emittance growth. A sequence of three beam-based alignment (BBA) techniques must be used to transport the beam: one-to-one correction (OTO), dispersion-free steering (DFS), and sextupole correction (SCS). The performance of the whole correction procedure is tested under several realistic imperfections: magnets position offsets, magnets rotation errors, magnets strength errors and emittance measurement errors. The results show that the emittance growth budgets can be met both in the horizontal and vertical planes.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR029
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR030	Commissioning and First Performance Studies of a Single Vertical Beam Halo Collimation System at ATF2	3844
	N. Fuster-Martínez, A. Faus-Golfe IFIC, Valencia, Spain P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang LAL, Orsay, France K. Kubo, T. Okugi, T. Tauchi, N. Terunuma KEK, Ibaraki, Japan I. Podadera, F. Toral CIEMAT, Madrid, Spain T. Tauchi, N. Terunuma Sokendai, Ibaraki, Japan
	A single vertical beam halo collimation system has been installed in the ATF2 beamline to reduce the background that could limit the precision of the diagnostics located in the post-IP beamline. On this paper the commissioning and first performance studies of a single vertical beam halo collimation system are reported. Furthermore realistic efficiency studies have been done using the simulation code BDSIM and compared with the first experimental tests.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR030
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR031	Beam-Loading Effect on Breakdown Rate in High-Gradient Accelerating Structures	3848
	F. Tecker, T. Argyropoulos, N. Catalán Lasheras, R. Corsini, A. Degiovanni, D. Gamba, J. Giner Navarro, A. Grudiev, G. McMonagle, J.L. Navarro Quirante, R. Rajamaki, E. Senes, I. Syratchev, B.J. Woolley, W. Wuensch CERN, Geneva, Switzerland T. Argyropoulos, J. Giner Navarro IFIC, Valencia, Spain A. Degiovanni, J.L. Navarro Quirante ADAM, Geneva, Switzerland D. Gamba JAI, Oxford, United Kingdom R. Rajamaki Aalto University, School of Science and Technology, Aalto, Finland E. Senes Torino University, Torino, Italy J. Tagg National Instruments Switzerland, Ennetbaden, Switzerland
	The Compact Linear Collider (CLIC) study for a future electron-positron collider with a center-of-mass energy up to 3 TeV aims for an accelerating gradient of 100 MV/m. The gradient is limited by RF breakdowns, and the luminosity requirements impose a limit on the admissible RF breakdown rate. RF testing of 12 GHz structure prototypes has shown that gradients in excess of 100 MV/m can be reached with the required breakdown rate. However at CLIC, the structures will be operated with significant beam-loading, modifying the field distribution inside. The effect of the beam-loading must be well understood but has not been previously measured. The commissioning and operation of an experiment to measure the effect of beam-loading on breakdown rate and the measurement results are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR031
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR032	Effect and Optimisation of Non-Linear Chromatic Aberrations of the CLIC Drive Beam Recombination at CTF3	3852
	D. Gamba, R. Corsini, P.K. Skowroński, F. Teckerpresenter CERN, Geneva, Switzerland P. Burrows JAI, Oxford, United Kingdom P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom
	The CLIC design relies on the two-beam acceleration principle, i.e. the energy transfer from the so called drive beam to the main colliding beams. At the CLIC Test Facility (CTF3) at CERN the feasibility of this principle is being tested in terms of performance and achievable specifications. The high-current drive beam is generated by recombining its parts in a delay loop and a combiner ring. Preserving the drive beam emittance during the recombination process is crucial to ensure beam-current and power production stability. Present theoretical and experimental studies show that non-linear energy dependence of the transverse optics heavily spoils the quality of the recombined beam. Conventionally these effects are cured by means of non-linear corrections using sextupoles. In this work we propose a mitigation of these effects by optimising the linear lattice, leading to a more robust and easy to operate drive beam recombination complex. The latest results are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR032
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR033	Integration and Testing of 3 Consecutive CLIC Two-Beam Modules	3856
	A.L. Vamvakas, M. Aicheler, S. Döbert, M. Duquenne, H.M. Durand, M. Sosin, J.I. Väinölä CERN, Geneva, Switzerland V. Rude ESGT-CNAM, Le Mans, France
	CLIC (Compact LInear Collider) is a study of a 50 km long linear electron-positron collider, consisting of ap-proximately 20,000 repetitive 2 m long modules. Micron level manufacturing and alignment tolerances are re-quired for the RF and magnet components due to the nanometre beam size and luminosity goal. The effect of thermal, vacuum and mechanical loads needs to be as-sessed, both in transient and in steady state conditions. The dynamic behaviour of mock-ups was investigated on the prototype two-beam module. Two additional two-beam modules are installed to further investigate the interconnections between them, in a machine-like envi-ronment. The array of three consecutive modules allows for alignment tests of the module sequence, while thermal and vacuum tests can be executed simultaneously. A transportation experiment is foreseen, investigating the feasibility of installing prealigned modules. Finally, new design of components is being tested, based on the expe-rience gathered from the first module and leading to a new generation module.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR033
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR034	Bunch-by-bunch Position and Angle Stabilisation at ATF based on Sub-micron Resolution Stripline Beam Position Monitors	3859
	N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland
	A low-latency, sub-micron resolution stripline beam position monitoring (BPM) system has been developed and tested with beam at the KEK Accelerator Test Facility (ATF2), where it has been used to drive a beam stabilisation system. The fast analogue front-end signal processor is based on a single-stage radio-frequency down-mixer, with a measured latency of 16 ns and a demonstrated single-pass beam position resolution of below 300 nm using a beam with a bunch charge of approximately 1 nC. The BPM position data are digitised on a digital feedback board which is used to drive a pair of kickers local to the BPMs and nominally orthogonal in phase in closed-loop feedback mode, thus achieving both beam position and angle stabilisation. We report the reduction in jitter as measured at a witness stripline BPM located 30 metres downstream of the feedback system and its propagation to the ATF interaction point.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR034
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR035	Development of a Low-latency, Micrometre-level Precision, Intra-train Beam Feedback System based on Cavity Beam Position Monitors	3862
	N. Blaskovic Kraljevic, R.M. Bodenstein, T. Bromwich, P. Burrows, G.B. Christian, M.R. Davis, C. Perry, R.L. Ramjiawan JAI, Oxford, United Kingdom D.R. Bett CERN, Geneva, Switzerland
	A low-latency, intra-train, beam feedback system utilising a cavity beam position monitor (BPM) has been developed and tested at the final focus of the Accelerator Test Facility (ATF2) at KEK. A low-Q cavity BPM was utilised with custom signal processing electronics, designed for low latency and optimal position resolution, to provide an input beam position signal to the feedback system. A custom stripline kicker and power amplifier, and a digital feedback board, were used to provide beam correction and feedback control, respectively. The system was deployed in single-pass, multi-bunch mode with the aim of demonstrating intra-train beam stabilisation on electron bunches of charge ~1 nC separated in time by c. 220 ns. The system has been used to demonstrate beam stabilisation to below the 75 nm level. Results of the latest beam tests, aimed at even higher performance, will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR035
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR036	Updates on the Sliding Contact Cooling ILC Positron Source Target Development	3865
	W. Liu, D.S. Doran, R.A. Erck, G.R. Fenske, W. Gaipresenter, V.J. Guarino ANL, Argonne, Illinois, USA
	The R&D of the baseline positron source target for ILC is still ongoing after TDR due to the uncertainty of rotating vacuum seal and water cooling system of the fast spinning target wheel. Different institutes around the globe have proposed different approaches to tackle this issue. A spinning target wheel system with sliding contact cooling has been proposed by ANL. The proposed system eliminated the needs of rotating vacuum seal by using magnetic torque coupler to drive the solid spinning wheel target. The energy deposited from positron production process is taken away via cooling pads sliding against the spinning wheel. A full size test wheel has been built and some initial tests have been done with promising outcomes. Results of these tests are presented in this paper along with a plan for developing a prototype.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR036
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR037	TW-Structure Design and E-Field Study for CLIC Booster Linac	3868
	E. Darvish Roknabadi IPM, Tehran, Iran S. Döbert CERN, Geneva, Switzerland
	Using the SUPERFISH code we present a design for a traveling wave (TW) structure of the Booster Linac for CLIC. The structure, consisting of thirty asymmetric cells attached to the beam pipes at two ends, works in 2Pi/3 operating mode at working frequency 2 GHz. The RF field transmitted through the designed cavity is prepared in an RF field data file to be used in the PARMELA code. We will then compare the resultant output PARMELA field with that of the ideal RF field which obtained from the usual method for a traveling wave structure. * Based on CLIC Note 1051, 2015
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR037
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR040	Emittance Growth by Misalignments and Jitters in SuperKEKB Injector Linac	3871
	Y. Seimiya, Y. Enomoto, K. Furukawa, T. Higo, T. Kamitani, F. Miyahara, Y. Ohnishi, M. Satoh, T. Suwada, M. Tanaka KEK, Ibaraki, Japan
	Funding: This work was partly supported by JSPS KAKENHI Grant Number 16K17545. SuperKEKB injector linac have to transport high-charged beam with low emittance to SuperKEKB ring for high luminosity, 8¥times1035. For the low emittance, photocathode RF gun was adopted as electron source. One of the main reason of the beam emittance blow-up electron linac is generally induced by wakefield in acceleration cavities. A charged beam with a offset from a center of a cavity is affected by the wakefield depending on the offset size in the acceleration cavity and the beam emittance is increased. This emittance blow-up can be eliminated by appropriate steering magnet control so as to cancel the wake effect in the acceleration cavity. We perform particle tracking simulation with some misalignments and beam jitter. Emittance growth by the misalignments and the beam jitter is evaluated in this report.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR040
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR041	High Gradient Properties of a CLIC Prototype Accelerating Structure made by Tsinghua University	3874
	X.W. Wu, H.B. Chen, J. Shi TUB, Beijing, People's Republic of China T. Higo, S. Matsumoto KEK, Ibaraki, Japan W. Wuensch CERN, Geneva, Switzerland
	A CLIC prototype structure, T24_THU_#1, was recently high-gradient tested at KEK X-band test stand, Nextef. The copper parts of this 24-cell TW structure were delivered from CERN, were bonded and brazed, bench-tested and tuned in Tsinghua University. The aim of this test was not only to verify the cavity high-gradient properties under 100 MV/m but also to study the breakdown phenomenon in high gradient. High power test results were presented and breakdown rate under 100 MV/m was compared to previously-tested CLIC prototype structures. The assembly capability of Tsinghua University for X-band high gradient structures was validated by the good high gradient performance of T24_THU_#1.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR041
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR042	New Quantity Describing the Pulse Shape Dependence of the High Gradient Limit in Single Cell Standing-Wave Accelerating Structures	3878
	J. Shi, H.B. Chen, X.W. Wupresenter TUB, Beijing, People's Republic of China V.A. Dolgashev SLAC, Menlo Park, California, USA A. Grudiev, W. Wuensch CERN, Geneva, Switzerland Y. Higashi KEK, Ibaraki, Japan B. Spataro INFN/LNF, Frascati (Roma), Italy
	A new quantity has been developed to study the relationship among the breakdown rate, the pulse width and the gradient. Difference pulse shapes can be treated by introducing a Green's function. This paper describes the quantity and the results while it is applied to the data of many high-power test runs of different single-cell standing wave accelerating structures. A remarkably similar relationship between the new quantity and breakdown rate is observed from all of the test results.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR042
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR043	High Power Test of X-band Single Cell HOM-free Choke-mode Damped Accelerating Structure made by Tsinghua University	3881
	X.W. Wu, H.B. Chen, J. Shi TUB, Beijing, People's Republic of China T. Abe, T. Higo KEK, Ibaraki, Japan W. Wuensch, H. Zha CERN, Geneva, Switzerland
	As an alternative design for CLIC main accelerating structures, X-band choke-mode damped structures had been studied for several years. However, the performance of choke-mode cavity under high power is still in lack of research. Two standing wave single cell choke-mode damped accelerating structures with different choke dimensions which are working at 11.424 GHz were designed, manufactured and bench tested by accelerator group in Tsinghua University. High power test was carried out on it to study the breakdown phenomenon in high gradient. A single cell structure without choke which almost has the same inner dimension as choke-mode cavity will also be tested to make a comparison and study how the choke affects high-gradient properties.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR043
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR044	mm-Wave Standing-Wave Accelerating Structures for High-Gradient Tests	3884
	E.A. Nanni, M. Dal Fornopresenter, V.A. Dolgashev, J. Neilson, S.G. Tantawi SLAC, Menlo Park, California, USA S.C. Schaub MIT, Cambridge, Massachusetts, USA R.J. Temkin MIT/PSFC, Cambridge, Massachusetts, USA
	We present the design and parameters of single-cell accelerating structures for high-gradient testing at 110 GHz. The purpose of this work is to study the basic physics of ultrahigh vacuum RF breakdown in high-gradient RF accelerators. The accelerating structures consist of pi-mode standing-wave cavities fed with TM01 circular waveguide mode. The geometry and field shape of these accelerating structures is as close as practical to single-cell standing-wave X-band accelerating structures, more than 40 of which were tested at SLAC. This wealth of X-band data will serve as a baseline for these 110 GHz tests. The structures will be powered from a pulsed MW gyrotron oscillator. One MW of RF power from the gyrotron may allow us to reach a peak accelerating gradient of 400 MeV/m.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR044
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR045	Analytical Estimation of ATF Beam Halo Distribution	3888
	D. Wang, J. Gao IHEP, Beijing, People's Republic of China P. Bambadepresenter LAL, Orsay, France T. Naito KEK, Ibaraki, Japan
	Funding: Work supported by the National Foundation of Natural Sciences (11505198 and 11575218) Halo distribution is a key topic for background study. This paper has developed an analytical method to give an estimation of ATF beam halo distribution. The equilibrium particle distribution of the beam tail in the ATF damping ring is calculated analytically with different emittance and different vacuum degree. The analytical results agree the measurements very well. This is a general method which can be applied to any electron rings.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR045
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR046	CEPC 650 MHz Klystron Development	3891
	Z.S. Zhou, D. Dong, S. Fukuda, Z.J. Lu, G. Pei, S.C. Wang, O. Xiaopresenter, .. Zaib-un-Nisa IHEP, Beijing, People's Republic of China S. Fukuda KEK, Ibaraki, Japan
	The CEPC collider beam power is about 100 MW, so the efficiency of amplifier is very important for cost of project implementation. The high power klystron is the more attractive because of its potential for higher efficiency than solid state amplifier. For CEPC klystron output power is not so high, the operation voltage can be a safe value. Advantage for single beam: reliable, low phase noise, some perspective technology can be used to improve efficiency. The accelerating frequency is 650 MHz, output power is a maximum power of 800kW, and efficiency is about 70%. In this paper, the specifications and developments of 650 MHz CW klystron, including the klystron gun prototype and future high efficiency consideration are summarized.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR046
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR047	Preliminary Concept and Key Technologies of HIEPA Accelerator	3895
	Z.R. Zhou, Q. Luopresenter, L. Wang, W. Xu, B. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by National Natural Science Foundation of China (11375178 and 11575181) and the Fundamental Research Funds for the Central Universities, Grant No WK2310000046 High energy physicists proposed a new collider: super tau-charm factory. The name of the project is high intensity electron positron accelerator facility. As high intensity electron positron collider, it runs in an energy range of 2-7 GeV. As an advanced light source, it can also provide high quality synchrotron radiation from VUV to soft X-ray. The facility will be a symmetrical two-ring collider located at Hefei. This paper shows preliminary conception of the storage rings.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR047
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR048	Beam Losses at CERNs PS and SPS Measured with Diamond Particle Detectors	3898
	F. Burkart, W. Bartmann, B. Dehning, E. Effinger, M.A. Fraser, B. Goddard, V. Kain, O. Stein CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria O. Stein University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	Diamond particle detectors have been used in the LHC to measure fast particle losses with a nanosecond time resolution. In addition, these detectors were installed in the PS and the SPS. The detectors are mounted close to the extraction septum of the PS (transfer line to SPS) and the SPS (transfer lines TI2 and TI8 to LHC). Mainly, they monitor the losses occurring during the extraction process but the detectors are also able to measure turn-by-turn losses in the accelerators. In addition, detailed studies concerning losses due to ghost bunches were performed. This paper will describe the installed diamond detector setup, discuss the measurement results and possible loss mitigations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR048
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR049	Considerations for the Injection and Extraction Kicker Systems of a 100 TeV Centre-of-Mass FCC-hh Collider	3901
	T. Kramer, M.J. Barnes, W. Bartmann, F. Burkartpresenter, L. Ducimetière, B. Goddard, V. Senaj, T. Stadlbauer, D.G. Woog CERN, Geneva, Switzerland D. Barna Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary
	A 100 TeV center-of-mass energy frontier proton collider in a new tunnel of ~100 km circumference is a central part of CERN's Future Circular Colliders (FCC) design study. One of the major challenges for such a machine will be the beam injection and extraction. This paper outlines the recent developments on the injection and extraction kicker system concepts. For injection the system requirements and progress on a new inductive adder design will be presented together with first considerations on the injection kicker magnets. The extraction kicker system comprises the extraction kickers itself as well as the beam dilution kickers, both of which will be part of the FCC beam dump system and will have to reliably abort proton beams with stored energies in the range of 8 Gigajoule. First concepts for the beam dump kicker magnet and generator as well as for the dilution kicker system are described and its feasibility for an abort gap in the 1 μs range is discussed. The potential implications on the overall machine and other key subsystems are outlined, including requirements on (and from) dilution patterns, interlocking, beam intercepting devices and insertion design.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR049
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR050	New Working Point for CERN Proton Synchrotron	3905
	F. Sperati, A. Beaumont, S.S. Gilardoni, D. Schoerling, M. Serluca, G. Sterbini CERN, Geneva, Switzerland
	The LHC High-luminosity project requests high brightness and intensity beams from the CERN Proton Synchrotron (PS). The generation of such beams is limited due to resonance effects at injection. The impact of resonances can be minimized by performing appropriate correction with dedicated magnets and by optimizing the tune working point. Currently the tune working point at injection is naturally set by the quadrupolar component generated by the one hundred combined function normal conducting magnets installed in the PS, and slightly corrected by low energy quadrupole magnets. In this paper, a study is presented exploiting the use of the available five auxiliary individually powered circuits to adjust the quadrupolar and higher-order multipole components for changing the tune integer at injection. Due to the non-linear contribution of each circuit to the magnetic field distribution a finite-element magnetic model was prepared to predict the required currents in the auxiliary coils. The magnetic model was benchmarked with magnetic measurements and then tested in the PS machine during dedicated machine development times.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR050
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR051	Beam Based Measurements to Check Integrity of LHC Dump Protection Elements	3908
	C. Bracco, W. Bartmann, M.A. Fraser, B. Goddard, A. Lechner CERN, Geneva, Switzerland
	LHC operation is approaching its nominal operating goals and several upgrades are also being prepared to increase the beam intensity and brightness. In case of an asynchronous beam dump at 6.5 - 7 TeV a non-negligible fraction of the stored energy (360 MJ during nominal operation) will be deposited on the protection elements (TCDQ and TCDS) located downstream of the extraction kickers. These elements are designed to protect the machine aperture from the large amplitude particles resulting from the asynchronous dump. A number of checks and measurements with beam have been worked out to verify the integrity of these elements, after a potentially harmful event, without opening the machine vacuum. Details on measurements and simulations performed to evaluate the validity of the proposed method are presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR051
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR052	A Beam-based Measurement of the LHC Beam Dump Kicker Waveform	3911
	M.A. Fraser, W. Bartmann, C. Braccopresenter, E. Carlier, B. Goddard, V. Kain, N. Magnin, J.A. Uythoven, F.M. Velotti CERN, Geneva, Switzerland
	The increase of the LHC collision energy to 13 TeV after Long Shutdown 1 has doubled the operational energy range of the LHC beam dump system (LBDS) during Run 2. In preparation for the safe operation of the LHC, the waveform of the LBDS extraction kicker was measured using beam-based measurements for the first time during the machine's re-commissioning period. The measurements provide a reference for a more precise synchronisation of the dump system and abort-gap timing, and provide an independent check of the system's calibration. The precision of the beam-based technique allowed the necessary adjustments to the LBDS trigger delays to ensure the synchronous firing of the LBDS at all beam energies up to 6.5 TeV. In this paper the measurement and simulation campaign is described and the performance of the system reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR052
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR054	Analysis of the SPS Long Term Orbit Drifts	3914
	F.M. Velotti, C. Braccopresenter, K. Cornelis, L.N. Drøsdal, M.A. Fraser, B. Goddard, V. Kain, M. Meddahi CERN, Geneva, Switzerland E. Gianfelice-Wendt Fermilab, Batavia, Illinois, USA
	The Super Proton Synchrotron (SPS) is the last accelerator in the Large Hadron Collider (LHC) injector chain, and has to deliver the two high-intensity 450 GeV proton beams to the LHC. The transport from SPS to LHC is done through the two Transfer Lines (TL), TI2 and TI8, for Beam 1 (B1) and Beam 2 (B2) respectively. During the first LHC operation period Run 1, a long term drift of the SPS orbit was observed, causing changes in the LHC injection due to the resulting changes in the TL trajectories. This translated into longer LHC turnaround because of the necessity to periodically correct the TL trajectories in order to preserve the beam quality at injection into the LHC. Different sources for the SPS orbit drifts have been investigated: each of them can account only partially for the total orbit drift observed. In this paper, the possible sources of such drift are described, together with the simulated and measured effect they cause. Possible solutions and countermeasures are also discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR054
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)
THPOR055	Characterisation of the SPS Slow-extraction Parameters	3918
	F.M. Velotti, W. Bartmann, T. Bohl, C. Braccopresenter, K. Cornelis, M.A. Fraser, B. Goddard, V. Kain, L.S. Stoel CERN, Geneva, Switzerland
	The Super Proton Synchrotron (SPS) is the last accelerator in the Large Hadron Collider (LHC) injector chain but its main users are the fixed-target experiments located in the North Area (NA). The beams, which are among the most intense circulating in the SPS, are extracted to the NA over several thousands of turns by exploiting a third-integer resonant extraction. The unavoidable losses intrinsic to such an extraction makes its optimisation one of the main priorities for operation, to reduce beam induced activation of the machine. The settings of the extraction systems, together with the tune sweep speed and the beam characteristics (momentum spread, emittance, etc.) are the parameters that can be controlled for spill and loss optimisation. In this paper, the contribution of these parameters to the slow-extraction spill quality are investigated through tracking simulations. The simulation model is compared with beam measurements and optimisations suggested.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPOR055
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)