• M. Kawase, M. Kinsho, O. Takeda, Y. Yamazaki, M. Yoshimoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken

The charge ex­change de­vice for 3GeV RCS in J-PARC, which re­quire that a bro­ken foil is ex­changed for a new foil by re­mote con­trol and au­to­mat­i­cal­ly in vac­u­um. The con­trol sys­tem's im­por­tant task will be to con­trol under the uni­fied man­age­ment of the vac­u­um sys­tem and foil driv­ing sys­tem and to sup­port EPICS. This de­vice con­sists of the vac­u­um sys­tem using PLC (Pro­grammable Logic Con­troller) and the foil driv­ing sys­tem using MCU (Multi Con­trol Unit). A work­sta­tion (WS) was re­quired, and we de­vel­oped con­trol sys­tem which con­trol under the uni­fied man­age­ment of 2 dif­fer­ent type of sys­tem. The uni­form man­age­ment con­trol sys­tem be­came com­plex sys­tem. In fact, there­fore con­trol sys­tem was un­fin­ished sys­tem, it did not pro­tect trou­ble such as the vac­u­um gate valve closed while trans­fer rod in­sert in the ring. Each al­go­rithm of PLC, MCU and WS was re­viewed, and the con­trol sys­tem that was able to do the uni­fied man­age­ment was re­struc­tured. Each al­go­rithm of PLC, MCU and WS was de­bugged so that this con­trol sys­tem is made re­mote con­trol using EPICS. We in­tro­duce the re­con­struc­tion of the con­trol sys­tem for the charge ex­change sys­tem at the RCS in J-PARC.

• T. Takayanagi, M. Kinsho, P.K. Saha, T. Togashi, T. Ueno, M. Watanabe, Y. Yamazaki, M. Yoshimoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• H. Fujimori
  J-PARC, KEK & JAEA, Ibaraki-ken
• Y. Irie
  KEK, Ibaraki

At the J-PARC 3-GeV in­jec­tion, the in­jec­tion paint­ing area is de­signed to be dif­fer­ent for sup­ply­ing the MLF (Ma­te­ri­al Life Sci­ence Fa­cil­i­ty) and MR (50GeV Main Ring) beams. Along with the in­jec­tion sys­tem in the ring, pulsed switch­ing mag­nets which are in­stalled in the in­jec­tion beam-line should also have a func­tion to con­trol the beam orbit at 25Hz. The de­flec­tion angle ranges from 3 to 38 mrad to meet the user op­er­a­tion as well as the beam physics run.

• P.K. Saha, H. Harada, H. Hotchi, K. Yamamoto, Y. Yamazaki, M. Yoshimoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• I. Sugai
  KEK, Ibaraki

The beam loss caused by the nu­cle­ar scat­ter­ing to­geth­er with the mul­ti­ple Coulomb scat­ter­ing at the strip­ping foil is one of the key issue in RCS (Rapid Cy­cling Syn­chrotron) of the J-PARC (Japan Pro­ton Ac­cel­er­a­tor Re­search Ac­cel­er­a­tor). In order to have a very re­al­is­tic un­der­stand­ing, a sys­tem­at­ic study with both ex­per­i­ment and sim­u­la­tion has been car­ried out re­cent­ly. A total of seven tar­gets with dif­fer­ent thick­ness were used and the mea­sured beam loss­es were found to be good in agree­ment with that in the sim­u­la­tion. A de­tail and re­al­is­tic un­der­stand­ing from such a study will be very use­ful not only to op­ti­mize the foil sys­tem in­clud­ing the thick­ness and size at pre­sent with the in­jec­tion beam en­er­gy of 181 MeV but also for the near fu­ture up­grade with 400 MeV and in ad­di­tion can be a good ex­am­ple for sim­i­lar ex­ist­ing and propos­ing pro­jects.

• Y. Yamazaki, M. Kinsho, O. Takeda, M. Yoshimoto
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• I. Sugai
  KEK, Ibaraki

J-PARC re­quires thick car­bon strip­per foils to strip elec­trons from the H^- beam sup­plied by the linac be­fore in­jec­tion into the Rapid Cy­cling Syn­chrotron (RCS). Foil thick­ness is about 200 μg/cm² cor­re­spond­ing to con­ver­sion ef­fi­cien­cy of 99.7% from the pri­ma­ry H^- beams of 181MeV en­er­gy to H⁺. For this pur­pose, we have suc­cess­ful­ly de­vel­oped hy­brid type thick boron-doped car­bon (HBC) strip­per foils, which showed a dras­tic im­prove­ment not only with re­spect to the life­time, but also with re­spect to thick­ness re­duc­tion and shrink­age at high tem­per­a­ture dur­ing long beam ir­ra­di­a­tion. We start­ed to study car­bon strip­per foils mi­cro­scop­i­cal­ly why car­bon foils have con­sid­er­able en­durance for the beam im­pact by boron-doped. At first, we made a com­par­i­son be­tween nom­i­nal car­bon and HBC by the elec­tric mi­cro­scope and ion-in­duced anal­y­sis. In this paper, we will in­tro­duce some re­sults for char­ac­ter­is­tics of HBC foils.

• M. Yoshimoto, M. Kawase, M. Kinsho, O. Takeda, Y. Yamazaki
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• Z. Kabeya
  MHI, Nagoya
• Y. Saito
  KEK, Ibaraki

At the 3GeV RCS (Rapid Cy­cling Syn­chrotron) in J-PARC (Japan Pro­ton Ac­cel­er­a­tor Re­search Com­plex), the scheme of H^- charge ex­change in­jec­tion using strip­ping foils is adopt­ed. The charge ex­change sys­tem is com­posed of three strip­ping foil de­vices. The first strip­ping foil de­vice, which con­verts the H^- beam from the 181MeV LINAC into the H⁺ beam, can re­place the bro­ken foil with new one in vac­u­um re­mote­ly and au­to­mat­i­cal­ly. In Septem­ber 2007, me­chan­i­cal trou­ble with the first strip­ping foil de­vice had oc­curred just be­fore the RCS beam com­mis­sion­ing was start­ed. The mag­net­ic cou­pling of the trans­fer rod had been de­cou­pled and the trans­fer rod had been bro­ken which was caught in the vac­u­um gate valve. We stud­ied the trou­ble cause, re-ex­am­ined the struc­tural de­sign and the se­lec­tion for the ma­te­ri­al, and then ver­i­fied the spec­i­fi­ca­tion from en­durance tests with sam­ple pieces. Then the im­proved de­vice was in­stalled in the ring in Septem­ber 2008. In this pre­sen­ta­tion, we re­port the me­chan­i­cal trou­ble and that coun­ter­mea­sure, in­clud­ing the im­prove­ments of the charge ex­change sys­tem.

• M. Yoshimoto, H. Harada, N. Hayashi, H. Hotchi, Y. Irie, M. Kawase, M. Kinsho, R. Saeki, P.K. Saha, K. Yamamoto, Y. Yamazaki
  JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken
• T. Ishiyama
  KEK/JAEA, Ibaraki-Ken
• I. Sugai
  KEK, Ibaraki

The hy­brid type thick boron-doped car­bon (HBC) strip­ping foils are in­stalled and used for the beam in­jec­tion at the 3GeV RCS (Rapid Cy­cling Syn­chrotron) in J-PARC (Japan Pro­ton Ac­cel­er­a­tor Re­search Com­plex). The HBC foils are de­vel­oped by Sugai group in KEK, which im­proved the life­time dras­ti­cal­ly. Up to now, the per­for­mance de­te­ri­o­ra­tion of the strip­ping foils can not be seen after the long beam ir­ra­di­a­tion for the 120kW user op­er­a­tion and 300kW high power beam demon­stra­tion at the RCS. In order to ex­am­ine the char­ac­ter­is­tic of the HBC foils, var­i­ous beam stud­ies were car­ried out. The beam-ir­ra­di­at­ed spot at the foil was mea­sured by scan­ning the foil set­ting po­si­tion, the charge ex­change ef­fi­cien­cy was eval­u­at­ed with var­i­ous thick­ness foils, and the ef­fect of the SiC fibers sup­port­ing the foil mount­ing was checked with dif­fer­ent mount­ing foils. Beam study re­sults ob­tained with using the HBC foils will be pre­sent­ed. In ad­di­tion, the trends of out­gas from the strip­ping foils and the de­for­ma­tions of the foils dur­ing the beam ir­ra­di­a­tion will be re­port­ed.

• H. Ao, K. Hirano, T. Morishita
  JAEA/LINAC, Ibaraki-ken
• H. Asano, N. Ouchi, N. Tsubota
  JAEA/J-PARC, Tokai-mura
• K. Hasegawa
  JAEA, Ibaraki-ken
• F. Naito, K. Takata
  KEK, Ibaraki
• V.V. Paramonov
  RAS/INR, Moscow
• Y. Yamazaki
  J-PARC, KEK & JAEA, Ibaraki-ken

The mass pro­duc­tion of the ACS (An­nu­lar Cou­pled Struc­ture) cav­i­ty start­ed from March 2009 for the J-PARC Linac en­er­gy up­grade from 181 MeV to 400 MeV. This up­grade pro­ject re­quires 18 ACS ac­cel­er­at­ing mod­ules and two de­bunch­ers ad­di­tion­al­ly with­in three years. The con­struc­tion sched­ule is so tight that we have to op­ti­mize the fab­ri­ca­tion pro­cess. For ex­am­ple the ge­o­met­ri­cal beta is var­ied for each ac­cel­er­at­ing mod­ule, thus the sev­er­al test cells were fab­ri­cat­ed and for the all beta be­fore the mass pro­duc­tion to con­firm the ini­tial de­sign and the fre­quen­cy tun­ing pro­ce­dure. This paper de­scribes our ap­proach for the mass pro­duc­tion and the cur­rent sta­tus and re­sults.

• H. Higaki, H. Okamoto
  HU/AdSM, Higashi-Hiroshima
• Y. Enomoto, C.H. Kim, N. Kuroda, Y. Matsuda, H.A. Torii, Y. Yamazaki
  The University of Tokyo, Institute of Physics, Tokyo
• H. Hori
  MPQ, Garching, Munich
• H. Imao, Y. Kanai, A. Mohri, Y. Nagata
  RIKEN, Wako, Saitama
• K. Kira
  Hiroshima University, Graduate School of Advanced Sciences of Matter, Higashi-Hiroshima
• K. Michishio
  Tokyo University of Science, Tokyo

In An­tipro­ton De­cel­er­a­tor (AD) at CERN, unique low en­er­gy an­tipro­ton beams of 5.6 MeV have been de­liv­ered for physics ex­per­i­ments. Fur­ther­more, the RFQ de­cel­er­a­tor (RFQD) ded­i­cat­ed for Atom­ic Spec­troscopy And Col­li­sions Using Slow An­tipro­tons (ASACUSA) col­lab­o­ra­tion en­ables the use of 100 keV pulsed an­tipro­ton beams for ex­per­i­ments. What is more, Mono-en­er­get­ic Ultra Slow An­tipro­ton Source for High-pre­ci­sion In­ves­ti­ga­tions (MUSASHI) in ASACUSA can pro­duce an­tipro­ton beams with the en­er­gy of 100 ~ 1000 eV. Since the suc­cess­ful ex­trac­tion of 250 eV an­tipro­ton beams re­port­ed in 2005, con­tin­u­ous im­prove­ments on beam qual­i­ty and equip­ments have been con­duct­ed. Here, the basic prop­er­ties of a tank cir­cuit at­tached to MUSASHI trap are re­port­ed. Sig­nals from a tank cir­cuit pro­vide in­for­ma­tion on the trapped an­tipro­tons, as Shot­tky sig­nals do for high en­er­gy beams in ac­cel­er­a­tors. In fact, it is known that this kind of trap-based beams are phys­i­cal­ly equiv­a­lent with those in a FODO lat­tice. Mon­i­tor­ing the tank cir­cuit sig­nals will be use­ful for on-line han­dling of the low en­er­gy an­tipro­ton beams from MUSASHI.

• N. Kuroda, Y. Enomoto, H. Imao, C.H. Kim, Y. Matsuda, H.A. Torii, Y. Yamazaki
  The University of Tokyo, Institute of Physics, Tokyo
• H. Higaki
  HU/AdSM, Higashi-Hiroshima
• H. Hori
  MPQ, Garching, Munich
• Y. Kanai, A. Mohri, Y. Nagata
  RIKEN, Wako, Saitama
• K. Kira
  Hiroshima University, Graduate School of Advanced Sciences of Matter, Higashi-Hiroshima
• K. Michishio
  Tokyo University of Science, Tokyo
• H. Saitoh
  University of Tokyo, Chiba
• M. Shibata
  KEK, Tsukuba

The ASACUSA col­lab­o­ra­tion at CERN has been de­vel­oped a unique Mono-en­er­get­ic Ul­ta-Slow An­tipro­ton beam Source for High-pre­ci­sion In­ves­ti­ga­tion (MUSASHI) for col­li­sion stud­ies be­tween an­tipro­ton and atoms at very low en­er­gy re­gion, which also used as an in­tense ul­tra-low en­er­gy an­tipro­ton source for the syn­the­sis of an­ti­hy­dro­gen atoms in order to test CPT sym­me­try. MUSASHI con­sists of a mul­ti-ring elec­trode trap housed in a bore sur­round­ed by a su­per­con­duct­ing solenoid, which works with a se­quen­tial com­bi­na­tion of the CERN An­tipro­ton De­cel­er­a­tor and the Ra­dio-Fre­quen­cy Quadrupole De­cel­er­a­tor. GM-type re­frig­er­a­tors were used to cool the solenoid and also the bore at 4K to avoid loss­es of an­tipro­tons with resid­u­al gasses. Up to 1.8 mil­lions of an­tipro­tons per one AD cycle were suc­cess­ful­ly trapped and cooled. MUSASHI achieved to ac­cu­mu­late more than 12 mil­lions of cold an­tipro­tons by stack­ing sev­er­al AD shots. Such cooled an­tipro­tons were ex­tract­ed as 150 or 250eV beams with var­i­ous bunch lengths from 2 mi­corosec­onds to 30 sec­onds long, whose en­er­gy width was the order of sub-eV. The beam in­ten­si­ty was en­hanced by a ra­di­al com­pres­sion tech­nique for the trapped an­tipro­ton cloud.