Keyword: positron
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MOPAB061 DAΦNE BTF Improvements of the Transverse Beam Diagnostics software, detector, linac, timing 250
 
  • P. Valente
    INFN-Roma, Roma, Italy
  • B. Buonomo, D.G.C. Di Giulio, L.G. Foggetta
    INFN/LNF, Frascati (Roma), Italy
  
  The DAΦNE BTF (beam-test fa­cil­ity) can pro­vide elec­trons and positrons, tun­ing at run­time dif­fer­ent beam pa­ra­me­ters: en­ergy (from about 50 MeV up to 750 MeV for e- and 540 MeV for e+), in­ten­sity (from sin­gle par­ti­cle up to 1010/bunch) and pulse length (in the range 1.5-40 ns) up to 49 Hz, de­pend­ing on the op­er­a­tions of the DAΦNE col­lider. The beam spot and di­ver­gence can be ad­justed, down to sub-mm sizes and 2 mrad (down­stream of the vac­uum beam-pipe exit win­dow), match­ing the user needs. We de­scribe of the BTF beam trans­verse mon­i­tor sys­tems based on Fit­PIX de­tec­tors, op­er­at­ing in bus syn­chro­niza­tion mode ex­ter­nally timed to the BTF beam. We also de­scribe our cus­tom soft­ware al­low­ing the ac­qui­si­tion and syn­chro­niza­tion of the beam di­ag­nos­tics with the users data, using TCP/IP calls to MEM­CACHED. The per­for­mance of the sys­tem in a va­ri­ety of beam in­ten­sity, en­ergy and fo­cus­ing con­di­tions is re­ported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB061  
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MOPIK080 Research of the Electro-Gravitational Induction by Using COD Signals in Charged Particle Storage Rings storage-ring, induction, electron, feedback 719
 
  • D. Dong
    IHEP, Beijing, People's Republic of China
  • J.Y. Dong
    Binghamton University, State University of New York, Binghamton, New York, USA
  
  Funding: The project was supported by the National Natural Science Foundation of China under Grant No. 11575215, partly.
Form the beam in­sta­bil­ity in the charged par­ti­cle stor­age ring; re­searchers have known that one kinds of long term beam in­sta­bil­ity, the pe­riod of 12 hours, comes from the grav­ity changes, the change of ac­cel­er­a­tion of grav­ity g, delta g caused by the moon and sun mov­ing rel­a­tive to the earth, so called the ter­res­trial tidal forces. Phe­nom­e­nol­ogy, we would say that the grav­ity changes caused by the moon and sun mov­ing at the stor­age ring have caused the beam en­ergy changes in the stor­age ring. If it is true, then it may be the elec­tro-grav­i­ta­tional in­duc­tion (EGI). In this paper, we will dis­cuss the pos­si­bil­ity of EGI, and es­ti­mate the max­i­mum value of the grav­ity co­ef­fi­cient of the in­duced elec­tro­mo­tive force by using the ex­ist­ing beam data from the stor­age rings. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPIK080  
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MOPVA078 The Window Replacement and Q Recovery of BEPCII Storage Ring SCC cavity, vacuum, operation, radiation 1046
 
  • T.M. Huang, J.P. Dai, R. Ge, S.P. Li, Z.Q. Li, H.Y. Lin, Q. Ma, W.M. Pan, Y. Sun, G.W. Wang
    IHEP, Beijing, People's Republic of China
  • P. Sha
    Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
  
  The stor­age ring RF sys­tem for the up­grade of the Bei­jing Elec­tron Positron Col­lider (BEPCII) adopted two 500 MHz su­per­con­duct­ing cav­i­ties: west for the positron ring (BPR); east for the elec­tron ring (BER). The ex­ces­sive heat­ing of the west win­dow was ob­served in Nov.2013, and not cured thor­oughly*. After two years op­er­a­tion, the win­dow cracked sud­denly on Nov.18th, 2015. The re­place­ment of the win­dow was sub­se­quently im­ple­mented in tun­nel. How­ever, the qual­ity fac­tor (Q) of the cav­ity de­cayed a lot after the win­dow re­place­ment. 90 de­grees Cel­sius N2 gas bak­ing of the outer sur­face of the cav­ity was car­ried out in situ and the Q re­cov­ered in a short time. This paper will pre­sent the process of the win­dow re­place­ment and the cav­ity Q re­cov­ery in de­tail.
* Tong-ming Huang et al., Chinese Physics C Vol. 40, No. 6 (2016) 067001 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPVA078  
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TUZB2 Commissioning Status of High Luminosity Collider Rings for SuperKEKB electron, solenoid, emittance, quadrupole 1275
 
  • H. Koiso
    KEK, Ibaraki, Japan
  
  Su­perKEKB pro­ject aims to ob­tain the world's high­est lu­mi­nos­ity of 8x1035/cm/s, in order to dis­cover new par­ti­cle physics be­yond the Stan­dard Model. Key tech­nolo­gies for the high lu­mi­nos­ity are nano-beam scheme at the col­li­sion point and high positron and elec­tron stored cur­rent with low emit­tance, which re­quire the sig­nif­i­cant up­grade of both the in­jec­tor and the col­lider rings. Re­cently com­mis­sion­ing of the re­newal col­lider rings has been per­formed with­out final focus mag­nets and the Belle II de­tec­tor (Phase 1). This talk gives re­sults of the Phase 1 com­mis­sion­ing and con­struc­tion sta­tus to­ward the first beam col­li­sions (Phase 2).  
slides icon Slides TUZB2 [64.509 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUZB2  
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TUPAB002 Material Tests for the ILC Positron Source target, electron, photon, operation 1293
 
  • A. Ushakov, G.A. Moortgat-Pick
    University of Hamburg, Hamburg, Germany
  • K. Aulenbacher, Th. Beiser, P. Heil, V. Tioukine
    IKP, Mainz, Germany
  • A. Ignatenko, S. Riemann
    DESY Zeuthen, Zeuthen, Germany
  • A.L. Prudnikava, Y. Tamashevich
    University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
  
  The positron source is a vital sys­tem of the ILC. The con­ver­sion tar­get that yields 1014 positrons per sec­ond will un­dergo high peak and cyclic load dur­ing ILC op­er­a­tion. In order to en­sure sta­ble long term op­er­a­tion of the positron source the can­di­date ma­te­r­ial for the con­ver­sion tar­get has to be tested. The in­tense elec­tron beam at the Mainz Mi­cro­tron (MAMI) pro­vides a good op­por­tu­nity for such tests. The first re­sults for Ti6Al4V are pre­sented which is the can­di­date ma­te­r­ial for the positron con­ver­sion tar­get as well as for the exit win­dow to the pho­ton beam ab­sorber.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB002  
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TUPAB003 High Energy Density Irradiation With MAMI LINAC target, electron, radiation, photon 1296
 
  • P. Heil, K. Aulenbacher, Th. Beiser
    IKP, Mainz, Germany
  • A. Ignatenko, G.A. Moortgat-Pick, A. Ushakov
    DESY, Hamburg, Germany
  • S. Riemann
    DESY Zeuthen, Zeuthen, Germany
  
  In order to build a positron source for the ILC, a high en­ergy den­sity ir­ra­di­a­tion is needed to test the used ma­te­ri­als. At the MAMI lin­ear ac­cel­er­a­tor such a ra­di­a­tion can be pro­vided at dif­fer­ent elec­tron en­er­gies. With a macro pulsed source it is pos­si­ble to im­i­tate a year­long ra­di­a­tion at the ILC within sev­eral hours. Small trans­ver­sal beam sizes need to be pro­vided with the fo­cus­ing sys­tem and be mea­sured at high beam cur­rents using tran­si­tion ra­di­a­tion and cur­rent mea­sure­ments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB003  
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TUPAB004 Progress of 7-GeV SuperKEKB Injector Linac Upgrade and Commissioning gun, injection, linac, electron 1300
 
  • K. Furukawa, M. Akemoto, D.A. Arakawa, Y. Arakida, H. Ego, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funahashi, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, M. Kawamura, M. Kurashina, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Miura, F. Miyahara, H. Nakajima, K. Nakao, T. Natsui, M. Nishida, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, M. Satoh, Y. Seimiya, A. Shirakawa, H. Sugimoto, H. Sugimura, T. Suwada, T. Takatomi, T. Takenaka, M. Tanaka, N. Toge, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou
    KEK, Ibaraki, Japan
  
  KEK in­jec­tor linac has de­liv­ered elec­trons and positrons for par­ti­cle physics and pho­ton sci­ence ex­per­i­ments for more than 30 years. It is being up­graded for the Su­perKEKB pro­ject, which aims at a 40-fold in­crease in lu­mi­nos­ity over the pre­vi­ous pro­ject KEKB, in order to in­crease our un­der­stand­ing of new physics be­yond the stan­dard model of el­e­men­tary par­ti­cle physics. Su­perKEKB asym­met­ric elec­tron and positron col­lider with its ex­tremely high lu­mi­nos­ity re­quires a high cur­rent, low emit­tance and low en­ergy spread in­jec­tion beam from the in­jec­tor. Elec­tron beams will be gen­er­ated by a new type of RF gun, that will pro­vide a much higher beam cur­rent to cor­re­spond to a large stored beam cur­rent and a short life­time in the ring. The positron source is an­other major chal­lenge that en­hances the positron bunch in­ten­sity from 1 to 4 nC by in­creas­ing the positron cap­ture ef­fi­ciency, and the positron beam emit­tance is re­duced from 2000 mi­cron to 20 mi­cron in the ver­ti­cal plane by in­tro­duc­ing a damp­ing ring, fol­lowed by the bunch com­pres­sor and en­ergy com­pres­sor. The re­cent sta­tus of the up­grade and beam com­mis­sion­ing is re­ported.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB004  
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TUPAB008 CEPC Linac Design and Beam Dynamics linac, electron, target, quadrupole 1315
 
  • C. Meng, Y.L. Chi, X.P. Li, G. Pei, S. Pei, D. Wang, J.R. Zhang
    IHEP, Beijing, People's Republic of China
  
  Cir­cu­lar Elec­tron-Positron Col­lider (CEPC) is a 100 km ring e+ e− col­lider for a Higgs fac­tory, which is or­ga­nized and led by the In­sti­tute of High En­ergy Physics (IHEP) of the Chi­nese Acad­emy of Sci­ences (CAS) in col­lab­o­ra­tion with a num­ber of in­sti­tu­tions from var­i­ous coun­tries. The linac of CEPC is a nor­mal con-duct­ing S-band linac with fre­quency in 2856.75 MHz and pro­vide elec­tron and positron beam at an en­ergy up to 10 GeV with bunch charge in 1.0 nC and rep­e­ti­tion fre­quency in 100 Hz. The linac scheme will be de­tailed dis­cussed in this paper, in­clud­ing elec­tron bunch­ing sys­tem, positron source de­sign, and main linac. Positrons are gen­er­ated using a 4 GeV elec­tron beam with bunch charge 10 nC hit tung­sten tar­get and the positron source de­sign are pre­sented. The beam dy­namic re­sults with lon­gi­tu­di­nal short Wake­field, trans­verse Wake­field and er­rors are pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB008  
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TUPAB009 Design Study on CEPC Positron Damping Ring and Bunch Compressor damping, linac, emittance, injection 1318
 
  • D. Wang, Y.L. Chi, J. Gao, X.P. Li, C. Meng, J.R. Zhang
    IHEP, Beijing, People's Republic of China
  • G. Pei
    Institute of High Energy Physics (IHEP), Chinese Academy of Sciences, Beijing, People's Republic of China
  
  The pri­mary pur­pose of CEPC damp­ing ring is to re­duce the trans­verse phase spaces of positron beam to suit­ably small value at the be­gin­ning of Linac and also ad­just the time struc­ture of positron beam for rein­jec­tion into the Linac. Lon­gi­tu­di­nal bunch length con­trol was pro­vided to min­i­mize wake field ef­fects in the Linac by a bunch com­pres­sor sys­tem after the damp­ing ring. Both de­signs for damp­ing ring and bunch com­pres­sor were dis­cussed in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB009  
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TUPAB014 Preliminary Design of FCC-ee Pre-Injector Complex linac, emittance, damping, booster 1337
 
  • S. Ogur, Y. Papaphilippou, F. Zimmermann
    CERN, Geneva, Switzerland
  • A.M. Barnyakov, A.E. Levichev, D.A. Nikiforov
    BINP SB RAS, Novosibirsk, Russia
  • K. Furukawa, N. Iida, F. Miyahara, K. Oide
    KEK, Ibaraki, Japan
  
  The de­sign of a 100 km cir­cu­lar e+e− col­lider with ex­tremely high lu­mi­nos­ity is an im­por­tant com­po­nent of the global Fu­ture Cir­cu­lar Col­lider (FCC) study hosted by CERN. FCC-ee is being de­signed to serve as Z, W, H and top fac­tory, cov­er­ing beam en­er­gies from 45.6 to 175 GeV. For the in­jec­tors, the Z-op­er­a­tion is the most chal­leng­ing mode, due to the high total charge and low equi­lib­rium emit­tance in the col­lider at this en­ergy. Thus, ful­fill­ing the Z-mode will also meet the de­mands for all other modes of FCC-ee. This goal can be achieved by using a 6 GeV NC linac with an S-band RF fre­quency of 2.856 GHz and a rep­e­ti­tion rate of 100 Hz. This linac will ac­cel­er­ate two bunches per RF pulse, each with a charge of 6.5 nC. Positrons will be gen­er­ated by send­ing 4.46 GeV e- onto a hy­brid tar­get so that the e+ cre­ated can still be ac­cel­er­ated to 1.54 GeV in the re­main­ing part of the same linac. The emit­tance of the e+ beam will then shrink to the nm level in a 1.54 GeV damp­ing ring. After damp­ing, the e+ will be rein­jected into the linac and ac­cel­er­ated to 6 GeV. The e- and e+ will then be ac­cel­er­ated al­ter­nately to 45.6 GeV in the booster, be­fore they are in­jected into the col­lider.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB014  
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TUPAB018 Initial Data From an Electron Cloud Detector in a Quadrupole Magnet at CesrTA electron, quadrupole, detector, storage-ring 1352
 
  • J.P. Sikora, S.T. Barrett, M.G. Billing, J.A. Crittenden, K.A. Jones, Y. Li, T.I. O'Connell
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  Funding: This work is supported by the US National Science Foundation PHY-0734867, PHY-1002467 and the US Department of Energy DE-FC02-08ER41538, DE-SC0006505
In Sep­tem­ber 2016, we in­stalled a de­tec­tor in a quadru­pole mag­net that mea­sures the elec­tron cloud den­sity using two in­de­pen­dent tech­niques. Stripline elec­trodes col­lect cloud elec­trons which pass through holes in the beam-pipe wall. The array of small holes shields the striplines from the beam-in­duced elec­tro­mag­netic pulse. The beam-pipe cham­ber has also been de­signed so that mi­crowave mea­sure­ments of the elec­tron cloud den­sity can be per­formed. The res­o­nant mi­crowaves are con­fined to be within the 56 cm length of the quadru­pole. The de­tec­tor is placed in a newly in­stalled quadru­pole that is ad­ja­cent to an ex­ist­ing lat­tice quadru­pole of the same po­lar­ity. Since they are pow­ered in­de­pen­dently, their rel­a­tive strengths can be var­ied with stored beam – al­low­ing elec­tron cloud mea­sure­ments to be made as a func­tion of gra­di­ent. This paper pre­sents the first data ob­tained with this de­tec­tor with trains of positron bunches at 5.3 GeV. The de­tec­tor is in­stalled in the Cor­nell Elec­tron Stor­age Ring and is part of the test ac­cel­er­a­tor pro­gram for the study of elec­tron cloud build-up using elec­tron and positron beams from 2 to 5 GeV. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB018  
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TUPIK026 Simulations of Positron Capture and Acceleration in the Linear Wakefield of Plasma wakefield, plasma, laser, emittance 1737
 
  • M.M. Peng, W. Gai
    TUB, Beijing, People's Republic of China
  
  We pre­sent the study of positrons cap­tur­ing dy­nam­ics in the wake­field of plasma gen­er­ated ei­ther by a laser or elec­tron beam. Only sim­pli­fied lin­ear wake­field mod­els were used as first order ap­prox­i­ma­tion. By analysing the phase space and beam dy­nam­ics, we show that phase space for cap­tur­ing is rather small, only high bright­ness beam with very short pulse length can be cap­tured with rea­son­able rate for wake­fields of 1 - 10 GeV/m and wave-length of 100 mi­cron.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPIK026  
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WEOBA3 Studies of a Scheme for Low Emittance Muon Beam Production From Positrons on Target target, emittance, scattering, simulation 2486
 
  • M. Boscolo, M. Antonelli, M.E. Biagini, O.R. Blanco-García, A. Variola
    INFN/LNF, Frascati (Roma), Italy
  • A. Bacci
    Istituto Nazionale di Fisica Nucleare, Milano, Italy
  • I. Chaikovska, R. Chehab
    LAL, Orsay, France
  • F. Collamati
    INFN-Roma1, Rome, Italy
  • M. Iafrati
    ENEA, Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile, Frascati, Italy
  • L. Keller
    SLAC, Menlo Park, California, USA
  • S.M. Liuzzo, P. Raimondi
    ESRF, Grenoble, France
  • P. Sievers
    CERN, Geneva, Switzerland
  
  We are study­ing a new scheme to pro­duce very low emit­tance muon beams using a positron beam of about 45 GeV in­ter­act­ing on elec­trons on tar­get. This is a chal­leng­ing and in­no­v­a­tive scheme that needs a full de­sign study. One of the in­no­v­a­tive top­ics to be in­ves­ti­gated is the be­hav­iour of the positron beam stored in a low emit­tance ring with a thin tar­get, that is di­rectly in­serted in the ring cham­ber to pro­duce muons. Muons will be im­me­di­ately col­lected at the exit of the tar­get and trans­ported to two mu+ and mu- ac­cu­mu­la­tor rings. We focus in this paper on the sim­u­la­tion of the e+ beam in­ter­act­ing with the tar­get, its degra­da­tion in the 6-D phase space and the op­ti­miza­tion of the e+ ring de­sign mainly to max­i­mize the en­ergy ac­cep­tance. We will in­ves­ti­gate the per­for­mances of this scheme, ring op­tics plus tar­get sys­tem, com­par­ing dif­fer­ent multi-turn sim­u­la­tions.  
slides icon Slides WEOBA3 [3.737 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEOBA3  
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WEPIK001 Advanced Beam Dump for FCC-ee collider, simulation, electron, distributed 2906
 
  • A. Apyan
    ANSL, Yerevan, Armenia
  • B. Goddard, F. Zimmermann
    CERN, Geneva, Switzerland
  • K. Oide
    KEK, Ibaraki, Japan
  
  A mod­i­fied beam dump for the fu­ture elec­tron positron cir­cu­lar col­lider FCC-ee is dis­cussed. The ex­trac­tion line with a di­lu­tion kicker sys­tem dis­trib­utes bunches at dif­fer­ent trans­verse lo­ca­tions on the face of the beam dump. For a stan­dard ab­sorber the max­i­mum en­ergy de­po­si­tion of all bunches oc­curs at the same lon­gi­tu­di­nal po­si­tion in­side the beam dump. This re­gion ex­pe­ri­ences an enor­mous tem­per­a­ture rise com­pared with the sur­round­ing parts of the beam dump. We pro­pose a novel type of beam dump which spreads out the de­posited en­ergy over its whole vol­ume quasi-uni­formly, thereby re­duc­ing the max­i­mum tem­per­a­ture rise. Re­sults of Monte-Carlo sim­u­la­tions for a multi-ma­te­r­ial mo­saic beam dump and for ab­sorbers with dis­torted shapes are shown.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK001  
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WEPIK002 Experimental Activities on High Intensity Positron Sources Using Channeling target, electron, photon, experiment 2910
 
  • I. Chaikovska, R. Chehab, H. Guler, V. Kubytskyi
    LAL, Orsay, France
  • X. Artru
    IN2P3 IPNL, Villeurbanne, France
  • K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada
    KEK, Ibaraki, Japan
  • V. Rodin
    National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
  • P. Sievers
    CERN, Geneva, Switzerland
  
  The positron source under in­ves­ti­ga­tion is using chan­nel­ing ra­di­a­tion of multi-GeV elec­trons in a tung­sten crys­tal. The ra­di­ated pho­tons are im­ping­ing on the amor­phous tar­gets cre­at­ing e+e− pairs. A di­pole mag­net be­tween the crys­tal-ra­di­a­tor and the amor­phous-con­verter al­lows the charged par­ti­cles to be swept off and only emit­ted pho­tons to gen­er­ate e+e− pairs in the con­verter. Gran­u­lar tar­gets of dif­fer­ent thick­nesses, made of small tung­sten spheres, have been re­cently in­ves­ti­gated as a tar­get-con­verter. This paper is de­scrib­ing the ex­per­i­men­tal stud­ies con­ducted at the KEKB linac with such de­vice. After the de­scrip­tion of the ex­per­i­men­tal set-up and beam pa­ra­me­ters, the mea­sure­ment meth­ods and pre­lim­i­nary re­sults are pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK002  
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WEPIK008 Problems in SuperKEKB Vacuum System During the Phase-1 Commissioning and Their Mitigation Measures wiggler, vacuum, electron, photon 2925
 
  • Y. Suetsugu, H. Hisamatsu, T. Ishibashi, K. Kanazawa, K. Shibata, M. Shirai, S. Terui
    KEK, Ibaraki, Japan
  
  The first (Phase-1) com­mis­sion­ing of the Su­perKEKB, an en­ergy-asym­met­ric elec­tron-positron col­lider in KEK, Japan, started in Feb­ru­ary and ended in June, 2016. The vac­uum sys­tem of the main ring worked well through the com­mis­sion­ing pe­riod as a whole, but ex­pe­ri­enced sev­eral prob­lems, such as the elec­tron cloud ef­fect (ECE) in the positron ring, the pres­sure bursts ac­com­pa­ny­ing beam losses due to dust par­ti­cles in the beam pipe, an air leak at a con­nec­tion flange due to the di­rect hit­ting of syn­chro­tron ra­di­a­tion (SR), and so on. To­wards the next (Phase-2) com­mis­sion­ing, coun­ter­mea­sures to these prob­lems are taken dur­ing the shut­down pe­riod. For ex­am­ple, per­ma­nent mag­nets gen­er­at­ing axial mag­netic fields are at­tached to beam pipes at drift spaces for the sup­pres­sion of the ECE. Knock­ers, which can ar­ti­fi­cially drop dust par­ti­cles at­tached to the top sur­face in beam pipes by con­tin­u­ous im­pacts, are pre­pared to the beam pipes at which the pres­sure bursts had been fre­quently ob­served. Bel­lows cham­bers with masks are in­stalled to pro­tect the leaked flange from SR. The prob­lems and their mit­i­ga­tion mea­sures will be sum­ma­rized in the pre­sen­ta­tion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK008  
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WEPIK009 Collimators for SuperKEKB Main Ring impedance, background, factory, HOM 2929
 
  • T. Ishibashi, Y. Suetsugu, S. Terui
    KEK, Ibaraki, Japan
  
  Su­perKEKB, which is an up­grade pro­ject of KEKB, is an elec­tron-positron col­lider with ex­tremely high lu­mi­nos­ity. Col­li­ma­tors (mov­able masks) for Su­perKEKB have been de­signed to fit an an­techam­ber scheme of the vac­uum sys­tem and will be op­er­ated to im­prove back­grounds in the par­ti­cle de­tec­tor named Belle II. We are de­vel­op­ing two types of col­li­ma­tors; a hor­i­zon­tal and ver­ti­cal col­li­ma­tor. The col­li­ma­tor has a pair of hor­i­zon­tally or ver­ti­cally op­posed mov­able jaws with RF fin­gers. Each jaw trav­els in­de­pen­dently through 5-25 mm hor­i­zon­tally or 2-12 mm ver­ti­cally in a dis­tance be­tween the beam axis and the tip of the jaw. Su­perKEKB will op­er­ate with high cur­rents of short bunch lengths, there­fore it is im­por­tant to es­ti­mate and de­crease the im­ped­ance of the col­li­ma­tors. Two hor­i­zon­tal col­li­ma­tors were al­ready in­stalled in the positron ring and op­er­ated dur­ing Phase-1 com­mis­sion­ing for ap­prox­i­mately 5 months, from Feb­ru­ary to June 2016. In this pre­sen­ta­tion, the lat­est de­sign, and the re­sults in the Phase-1 com­mis­sion­ing are pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK009  
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WEPIK016 CEPC-SppC Towards CDR collider, luminosity, booster, detector 2954
 
  • J. Gao
    IHEP, Beijing, People's Republic of China
  
  Funding: supported by National Key Programme for S&T Research and Development (2016YFA0400400), National Natural Science Foundation of China (11575218, 11605211, 11605210, 11505198), Key Research Program of Frontier Sciences, CAS, (QYZDJ-SSW-SLH004) and CAS Center for Excellence in Particle Physics (CCEPP)
In this paper we will give an in­tro­duc­tion to Cir­cu­lar Elec­tron Positron Col­lider (CEPC). The sci­en­tific back­ground, physics goal, the col­lider de­sign re­quire­ments and the con­cep­tual de­sign prin­ci­ple of CEPC are de­scribed. On CEPC ac­cel­er­a­tor, the op­ti­miza­tion of pa­ra­me­ter de­signs for CEPC with dif­fer­ent en­er­gies, ma­chine lengthes, sin­gle ring and crab-waist col­li­sion par­tial dou­ble ring, ad­vanced par­tial dou­ble par­tial ring and fully par­tial dou­ble ring op­tions, etc. have been dis­cussed sys­tem­at­i­cally, and com­pared. CEPC ac­cel­er­a­tor base­line and al­ter­na­tive de­signs have been pro­posed based on the lu­mi­nos­ity po­ten­tial in re­la­tion with the de­sign goals. The sub-sys­tems of CEPC, such as col­lider main ring, booster, elec­tron positron in­jec­tor, etc. ave also been in­tro­duced. The de­tec­tor and MDI de­sign have been briefly men­tioned. Fi­nally, the op­ti­miza­tion de­sign of Super Pro­ton-Pro­ton Col­lider (SppC), its en­ergy and lu­mi­nos­ity po­ten­tials, in the same tun­nel of CEPC are also dis­cussed. The CEPC-SppC Progress Re­port (2015-2016) has been pub­lished. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK016  
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WEPIK026 VEPP-5 Injection Complex: Two Colliders Operation Experience injection, collider, operation, extraction 2982
 
  • D.E. Berkaev, A.V. Andrianov, K.V. Astrelina, V.V. Balakin, A.M. Batrakov, O.V. Belikov, M.F. Blinov, D. Bolkhovityanov, A. Butakov, E.V. Bykov, N.S. Dikansky, F.A. Emanov, A.R. Frolov, V.V. Gambaryan, K. Gorchakov, Ye.A. Gusev, S.E. Karnaev, G.V. Karpov, A.S. Kasaev, E. Kenzhebulatov, V.A. Kiselev, S. Kluschev, A.A. Kondakov, I. Koop, I.E. Korenev, N.Kh. Kot, V.R. Kozak, A.A. Krasnov, S.A. Krutikhin, I.V. Kuptsov, G.Y. Kurkin, N.N. Lebedev, A.E. Levichev, P.V. Logatchov, Yu. Maltseva, A.A. Murasev, V. Muslivets, D.A. Nikiforov, An.A. Novikov, A.V. Ottmar, A.V. Pavlenko, I.L. Pivovarov, V.V. Rashchenko, Yu. A. Rogovsky, S.L. Samoylov, N. Sazonov, A.V. Semenov, S.V. Shiyankov, D.B. Shwartz, A.N. Skrinsky, A.A. Starostenko, D.A. Starostenko, A.G. Tribendis, A.S. Tsyganov, S.S. Vasichev, S.V. Vasiliev, V.D. Yudin, I.M. Zemlyansky, A.N. Zhuravlev
    BINP SB RAS, Novosibirsk, Russia
  • A.V. Andrianov, V.V. Balakin, F.A. Emanov, I. Koop, A.A. Krasnov, A.E. Levichev, D.A. Nikiforov, A.V. Pavlenko, Yu. A. Rogovsky, D.B. Shwartz, A.A. Starostenko
    NSU, Novosibirsk, Russia
  • A.I. Mickailov
    Budker INP & NSU, Novosibirsk, Russia
  • A.G. Tribendis
    NSTU, Novosibirsk, Russia
  
  Two BINP col­lid­ers VEPP-4M and VEPP-2000 e+e− col­lid­ers are under op­er­a­tion with the beams feed­ing from VEPP-5 In­jec­tion Com­plex via newly con­structed K-500 beam trans­fer line. Up­graded in­jec­tion chain demon­strated abil­ity to pro­vide de­signed lu­mi­nos­ity both to VEPP-4M and VEPP-2000 and tech­niques of re­li­able op­er­a­tion are under de­vel­op­ment now. The de­sign and op­er­a­tion ex­pe­ri­ence of In­jec­tion Com­plex and trans­fer lines are pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK026  
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WEPIK028 Status of the Electron-Positron Collider VEPP-4 electron, collider, storage-ring, experiment 2985
 
  • P.A. Piminov
    BINP SB RAS, Novosibirsk, Russia
  
  The next phase of the e+e− col­lider VEPP-4 (Bud­ker INP, Novosi­birsk) is fo­cused on ex­per­i­ments in the en­ergy range from 4 to 10 GeV (c.m.). To re­cover the lack of positrons at high en­ergy a new positron source was con­nected to the col­lider. The paper dis­cusses the fa­cil­ity per­for­mance with new in­jec­tion and other as­pects of ex­per­i­men­tal study at high en­ergy in­clud­ing laser po­larime­ter for pre­cise en­ergy cal­i­bra­tion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK028  
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WEPIK029 High Luminosity at VEPP-2000 Collider With New Injector luminosity, collider, detector, injection 2989
 
  • P.Yu. Shatunov, O.V. Belikov, D.E. Berkaev, K. Gorchakov, A.S. Kasaev, A.N. Kirpotin, I. Koop, A.A. Krasnov, A.P. Lysenko, S.V. Motygin, E. Perevedentsev, V.P. Prosvetov, D.V. Rabusov, Yu. A. Rogovsky, A.M. Semenov, A.I. Senchenko, Y.M. Shatunov, D.B. Shwartz, M.V. Timoshenko, I.M. Zemlyansky, Yu.M. Zharinov
    BINP SB RAS, Novosibirsk, Russia
  • E. Perevedentsev, Yu. A. Rogovsky, A.I. Senchenko, D.B. Shwartz
    NSU, Novosibirsk, Russia
  
  VEPP-2000 e+e− col­lider at BINP was com­mis­sioned and started data tak­ing with two de­tec­tors in 2010 with old in­jec­tion chain. In the mid­dle en­ergy range, where the lu­mi­nos­ity was lim­ited by beam-beam ef­fects, the world record val­ues of beam-beam pa­ra­me­ter were achieved, ksi=0.12/IP. At the same time the de­sign lu­mi­nos­ity value of L = 1032 cm-2s−1 at top en­ergy (E = 1 GeV per beam) re­mained un­reach­able due to lim­ited e+ pro­duc­tion rate. The in­jec­tion chain was sig­nif­i­cantly up­graded in 2013-2016. The ex­pe­ri­ence of up­graded VEPP-2000 com­plex op­er­a­tion at top en­er­gies with Round Col­lid­ing Beams will be pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK029  
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WEPIK119 Lost Muon Study for the Muon g-2 Experiment at Fermilab storage-ring, background, quadrupole, experiment 3230
 
  • J.D. Crnkovic, W. Morse
    BNL, Upton, Long Island, New York, USA
  • S. Ganguly
    University of Illinois at Urbana-Champaign, Urbana, USA
  • D. Stratakis
    Fermilab, Batavia, Illinois, USA
  
  The Fer­mi­lab Muon g-2 Ex­per­i­ment has a goal of mea­sur­ing the muon anom­alous mag­netic mo­ment to a pre­ci­sion of 140 ppb - a four­fold im­prove­ment over the 540 ppb pre­ci­sion ob­tained by the BNL Muon g-2 Ex­per­i­ment. Some muons in the stor­age ring will in­ter­act with ma­te­r­ial and un­dergo bremsstrahlung, emit­ting ra­di­a­tion and loos­ing en­ergy. These so called lost muons will curl in to­wards the cen­ter of the ring and be lost, but some of them will be de­tected by the calorime­ters. A sys­tem­atic error will arise if the lost muons have a dif­fer­ent av­er­age spin phase than the stored muons. Al­go­rithms are being de­vel­oped to es­ti­mate the rel­a­tive num­ber of lost muons, so as to op­ti­mize the stored muon beam. This study pre­sents ini­tial test­ing of al­go­rithms that can be used to es­ti­mate the lost muons by using ei­ther dou­ble or triple de­tec­tion co­in­ci­dences in the calorime­ters.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPIK119  
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WEPVA071 Preliminary Conceptual Study of Next Generation Tau-Charm Factory at China luminosity, factory, collider, electron 3436
 
  • Q. Luo
    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 BEPC II would ac­com­plish its mis­sion in the next decade, re­search on high en­ergy sci­ence de­mands a suc­ces­sor. The lu­mi­nos­ity of this suc­ces­sor should be one or two or­ders higher than BEPC II, while the elec­tron beam should be lon­gi­tu­di­nal po­lar­ized at the IP. This paper dis­cusses the fea­si­bil­ity and key tech­nolo­gies of the next tau-charm col­lider: a green­field new fa­cil­ity or an up­grade of BEPC II. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA071  
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WEPVA148 Dynamics of Target Motion Under Exposure of Hard Gamma Undulator Radiation target, electron, undulator, photon 3618
 
  • A.A. Mikhailichenko
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  
  We de­scribe time de­pen­dent dy­nam­ics of the tar­get mo­tion under ex­po­sure by un­du­la­tor ra­di­a­tion in a sys­tem for positron pro­duc­tion. We took into ac­count in­er­tia of ma­te­r­ial of tar­get. Cal­cu­la­tions car­ried with help of Flex­PDE code.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-WEPVA148  
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THOBA3 A Compact 335 MeV Positron Damping Ring Design for FACET-II damping, emittance, linac, quadrupole 3652
 
  • G.R. White, Y. Cai, R.O. Hettel, M.A.G. Johansson, V. Yakimenko, G. Yocky
    SLAC, Menlo Park, California, USA
  
  Funding: This work was supported by the Department of Energy under Contract Number: DE-AC02-76SF00515.
FACET-II will be a new test fa­cil­ity, start­ing con­struc­tion in 2018 within the main SLAC Linac. Its pur­pose is to build on the decades-long ex­pe­ri­ence de­vel­oped con­duct­ing ac­cel­er­a­tor R&D at SLAC in the areas of ad­vanced ac­cel­er­a­tion and co­her­ent ra­di­a­tion tech­niques with high-en­ergy elec­tron and positron beams. The positron sys­tem de­sign uti­lizes an ex­ist­ing W-Re tar­get in Linac Sec­tor 19, dri­ven by 4 nC elec­trons bunches at 10 GeV. We pre­sent the de­sign of a 335 MeV, 21.4 m cir­cum­fer­ence damp­ing ring re­quired to damp emit­tance from a mod­i­fied positron re­turn beam­line by a fac­tor of 500. The trans­verse emit­tance is cal­cu­lated to be 6 um-rad, fully cou­pled, with a bunch length of 4 mm and en­ergy spread 0.06 %, at a bunch charge of 1 nC. The arc mag­nets need to be es­pe­cially com­pact due to tight space con­straints (in­stal­la­tion will be in the ex­ist­ing SLAC Linac tun­nel, Sec­tor 10, with 3 m width avail­able) and were a key de­sign chal­lenge. We pre­sent a so­lu­tion with com­bined func­tion bend/quadru­pole/sex­tu­pole mag­nets which have been mod­elled in 3D using Opera. 		 
slides icon Slides THOBA3 [8.372 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THOBA3  
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THPAB019 PSPA, a Web Platform for Simulation of Particle Accelerator simulation, lattice, linac, interface 3730
 
  • M.E. Biagini, A. Variola
    INFN/LNF, Frascati (Roma), Italy
  • L. Garnier, H. Guler, C. Helft, G. Le Meur, M. Nicolas, A. Pérus, F. Touze
    LAL, Orsay, France
  
  PSPA (Plat­form for Sim­u­la­tion of Par­ti­cle Ac­cel­er­a­tors) is an orig­i­nal web-based in­ter­ac­tive sim­u­la­tion plat­form for de­sign­ing and mod­el­ling par­ti­cle ac­cel­er­a­tors cre­ated at Lab­o­ra­toire de l'Accéléra­teur Linéaire, Orsay. It aims at even­tu­ally con­tain­ing all the tools to make a start-to-end sim­u­la­tion of an ac­cel­er­a­tor, and make it pos­si­ble to run in­ter­ac­tively sev­eral open source sim­u­la­tions codes avail­able world­wide. At the mo­ment, the focus is on elec­tron/positron ac­cel­er­a­tors. PSPA will op­ti­mize the work of ac­cel­er­a­tor de­sign­ers by fac­tor­ing once and for all the te­dious, time-con­sum­ing and error prone process of trans­lat­ing data for­mats be­tween the var­i­ous codes in­volved in the mod­el­ling of a ma­chine, con­trol­ling the re­peated ex­e­cu­tion of these mod­els by eas­ily vary­ing some pa­ra­me­ter and man­ag­ing the as­so­ci­ated data. More­over, as a truly in­no­v­a­tive fea­ture, it will pro­vide a con­ve­nient means for test­ing dif­fer­ent phys­i­cal mod­els of a given part of a ma­chine. The sta­tus of the pro­ject is de­scribed in this paper, and ex­am­ples of its ap­pli­ca­tion to the ThomX com­pact Comp­ton backscat­ter­ing source at LAL are pre­sented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB019  
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THPAB021 Wake Field and Head-Tail Instability in Beam-Beam Collision with a Large Crossing Angle wakefield, electron, simulation, dipole 3738
 
  • K. Ohmi, D. Zhou
    KEK, Ibaraki, Japan
  • N. Kuroo
    UTTAC, Tsukuba, Ibaraki, Japan
  • K. Oide, F. Zimmermann
    CERN, Geneva, Switzerland
  
  Head-tail type of co­her­ent beam-beam in­sta­bil­ity has been seen in a strong-strong beam-beam sim­u­la­tion for col­li­sion with a large Pi­win­ski angle σzθ/σx>>1, where θ is a half cross­ing angle. Beta x* is key pa­ra­me­ter for the in­sta­bil­ity. The in­sta­bil­ity is not se­ri­ous for Su­perKEKB, but can be seen in phase II com­mis­sion­ing stage. It has a large im­pact for de­sign of FCC-ee. We in­tro­duce wake field due to the beam-beam col­li­sion. The wake field gives turn-by-turn cor­re­la­tion of head-tail mode. Head-tail in­sta­bil­ity caused by the wake field ex­plains that seen in the strong-strong beam-beam sim­u­la­tion.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPAB021  
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THPVA034 Comparison of the Coupling of Dipole Motion From Bunch to Bunch in an Electron Beam Caused by Electron Clouds at CesrTA Due to Variations in Bunch Length and Chromaticity electron, damping, dipole, coupling 4509
 
  • M.G. Billing, L.Y. Bartnik, J.A. Crittenden, M.J. Forster, N.T. Rider, J.P. Shanks, M.B. Spiegel, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • R. Holtzapple
    CalPoly, San Luis Obispo, California, USA
  • E.C. Runburg
    University of Notre Dame, Indiana, USA
  
  Ear­lier ex­per­i­ments at the Cor­nell Elec­tron-Positron Stor­age Ring Test Ac­cel­er­a­tor (Ces­rTA) have probed the in­ter­ac­tion of the elec­tron cloud (EC) with a 2.1 GeV stored positron beam. Since a very low EC den­sity is ex­pected with the elec­tron bunches, these re­sults char­ac­ter­ize the de­pen­dence of beam-vac­uum cham­ber im­ped­ance in­ter­ac­tions, which are com­mon to both positron and elec­tron beams. The ex­per­i­ments were per­formed on a 30-bunch elec­tron train with a 14 ns spac­ing, at a fixed cur­rent of 0.75mA/bunch, at two dif­fer­ent ver­ti­cal chro­matic­ity set­tings and for four dif­fer­ent bunch lengths (or syn­chro­tron tunes.) The beam dy­nam­ics of the stored beam, in the pres­ence of the elec­tron cloud, was quan­ti­fied using: 20 turn-by-turn beam po­si­tion mon­i­tors in CESR to mea­sure the cor­re­lated bunch-by-bunch di­pole mo­tion and an x-ray beam size mon­i­tor to record the bunch-by-bunch, turn-by-turn ver­ti­cal size of each bunch within the trains. In this paper we re­port on the analy­sis of the ob­ser­va­tions from these ex­per­i­ments and com­pare them with ef­fects of the EC on the positron beam's di­pole mo­tion and cou­pling of the mo­tion from each bunch to its suc­ceed­ing bunches.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA034  
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THPVA035 Dependence of the Coupling of Dipole Motion From Bunch to Bunch Caused by Electron Clouds at CesrTA Due to Variations in Bunch Length and Chromaticity damping, electron, dipole, synchrotron 4512
 
  • M.G. Billing, L.Y. Bartnik, J.A. Crittenden, M.J. Forster, N.T. Rider, J.P. Shanks, M.B. Spiegel, S. Wang
    Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
  • R. Holtzapple
    CalPoly, San Luis Obispo, California, USA
  • E.C. Runburg
    University of Notre Dame, Indiana, USA
  
  The Cor­nell Elec­tron-Positron Stor­age Ring Test Ac­cel­er­a­tor (Ces­rTA) has con­ducted ex­per­i­ments to probe the in­ter­ac­tion of the elec­tron cloud (EC) with a 2.1 GeV stored positron beam. These ex­per­i­ments in­ves­ti­gate the de­pen­dence of beam'elec­tron cloud in­ter­ac­tions vs. bunch length (or syn­chro­tron tune) at two val­ues of the ver­ti­cal chro­matic­ity. The ex­per­i­ments uti­lized a 30-bunch positron train with a 14 ns spac­ing, at a fixed cur­rent of 0.75mA/bunch. The beam dy­nam­ics of the stored beam, in the pres­ence of the elec­tron cloud, was quan­ti­fied using: 20 turn-by-turn beam po­si­tion mon­i­tors in CESR to mea­sure the cor­re­lated bunch-by-bunch di­pole mo­tion and an x-ray beam size mon­i­tor to record the bunch-by-bunch, turn-by-turn ver­ti­cal size of each bunch within the trains. In this paper we re­port on the ob­ser­va­tions from these ex­per­i­ments and a more de­tailed analy­sis for the cou­pling of di­pole mo­tion via the EC from each bunch to suc­ceed­ing bunches in the train.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-THPVA035  
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FRYCA1 The Future of High-energy Accelerators collider, electron, proton, hadron 4856
 
  • J. Mnich
    DESY, Hamburg, Germany
  
  The physics re­sults from high en­ergy col­lid­ers, neu­trino ex­per­i­ments and from ex­per­i­ments in space are chang­ing the par­ti­cle physics land­scape. In the last decade sev­eral ac­cel­er­a­tor de­signs and stud­ies have taken shape and reached a high level of ma­tu­rity both at the high en­ergy and high in­ten­sity fron­tiers. The talk should re­view the physics ques­tions fac­ing the HEP com­mu­nity and the strat­egy to ad­dress them in view of the next up­date of the Eu­ro­pean Strat­egy for Par­ti­cle Physics.  
slides icon Slides FRYCA1 [9.087 MB]  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-FRYCA1  
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