Author: Kinsho, M.
Paper Title Page
MOPME020 Development of the New Measurement Method for the Incoherent Tune Spread and the Tune Shift Caused by the Space Charge Effect 512
 
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
  • H. Harada, H. Hotchi, M. Kinsho, K. Okabe
    JAEA/J-PARC, Tokai-mura, Japan
  
  For the high in­ten­sity ac­cel­er­a­tor, the in­co­her­ent tune which is the fre­quency of the in­di­vid­ual par­ti­cles is shifted and de­creases due to the space charge ef­fect. In ad­di­tion, the in­co­her­ent tune is formed into spread shape com­monly. When the in­co­her­ent tune sat­is­fies a res­o­nance con­di­tion, it might be oc­curred the beam emit­tance growth and the beam loss. So it is nec­es­sary to re­duce the in­co­her­ent tune spread and the tune shift as much as pos­si­ble. To achieve this con­di­tion, it is de­sired to mea­sure the in­co­her­ent tune spread and the tune shift di­rectly. There­fore we are de­vel­op­ing the new mea­sure­ment method of the in­co­her­ent tune spread and the shift due to the space charge ef­fect. From the sim­u­la­tion re­sults, it was cleared that the beam dis­tri­b­u­tion can be mod­i­fied in the case of using the mono fre­quency di­pole ex­citer be­cause a par­ti­cle which has the tune cor­re­spond­ing to the ex­citer can be res­onated tem­po­rary. In ad­di­tion, it was cleared that it is pos­si­ble to eval­u­ate the in­co­her­ent tune spread and the tune shift by the mea­sure­ment of the dis­tri­b­u­tion tran­si­tion. We pre­sent the out­line of this method and the de­vel­op­ing plane at the J-PARC RCS.  
 
MOPME022 Beam Commissioning of Two Horizontal Pulse Steering Magnets for Changing Injection Painting Area from MLF to MR in the 3-GeV RCS of J-PARC 518
 
  • P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, T. Takayanagi, N. Tani
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
  
  We have been suc­cess­fully com­mis­sioned two pulse steer­ing mag­nets in­stalled in the Linac to 3-GeV RCS (Rapid Cy­cling Syn­chro­tron) in­jec­tion beam trans­port (BT) line of J-PARC. RCS has to de­liver a si­mul­ta­ne­ous as well as spe­cific beam as de­mand by the down­stream fa­cil­i­ties of MLF (Ma­te­r­ial and Life Sci­ence Fa­cil­ity) and the MR (Main Ring). In order to ob­tain rel­a­tively a smaller trans­verse emit­tance at ex­trac­tion, those mag­nets were de­signed to per­form a smaller in­jec­tion paint­ing for the MR beam as com­pared to the MLF one. As strip­per foil po­si­tion is fixed for the charge ex­change H− in­jec­tion, in­cli­na­tion of the in­jected beam cen­troid on foil for the MR beam is only moved to a smaller value by the pulse steer­ing mag­nets, while DC sep­tum mag­nets are fixed as de­ter­mined first for the MLF beam. Their pa­ra­me­ters were found to be very con­sis­tent with ex­pec­ta­tion and thus al­ready in op­er­a­tion for switch­ing to a paint­ing area of 100 pi mm mrad for the MR beam as com­pared to that of 150 pi mm mrad for the MLF beam.  
 
MOPME025 Production of Extraction Kicker Magnet of the J-PARC 3-GeV RCS 526
 
  • M. Kinsho, N. Ogiwara, K. Suganuma
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  The J-PARC 3-GeV rapid cy­cling syn­chro­tron (RCS) has been pro­vided pro­ton beam to the Ma­te­r­ial and Life Sci­ence Fa­cil­ity (MLF)as well as to the 50 GeV Main Ring (MR). Pro­ton beam is ac­cel­er­ated from 181 MeV to 3GeV in the RCS and im­me­di­ately ex­tracted it to the beam trans­port line to the MLF and the MR. Ex­trac­tion kicker mag­nets are used for this fast ex­trac­tion. To im­prove re­li­a­bil­ity of the RCS for user op­er­a­tion, pro­duc­tion of a re­serve kicker mag­net has been per­formed. The kicker mag­net mainly con­sists of Ni-Zn fer­rite cores and Alu­minum alloy plates, and these parts are in­stalled in vac­uum cham­ber to pre­vent dis­charge be­cause a high volt­age is ap­plied to the mag­net for a short pe­riod. Since it is im­por­tant to re­duce the out­gassing of water vapor form these parts to pre­vent dis­charge, we has been pro­duced the re­serve mag­net with low out­gassing at high volt­age dis­charge. Since as­sem­ble of the kicker mag­net al­ready fin­ished and vac­uum test has been per­formed, the re­sult of vac­uum test is re­ported.  
 
MOPME028 A Preliminary Study of the Vibration Wire Monitor for Beam Halo Diagnostic in J-PARC L3BT 535
 
  • K. Okabe, M. Kinsho, K. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  In the J-PARC 3-GeV Rapid Cycle Syn­chro­tron (RCS), trans­verse beam halo di­ag­nos­tic and scrap­ing are re­quired to in­crease the out­put beam power. Wire scan­ners and halo scrap­ers were used for mea­sure­ment of pro­jected beam dis­tri­b­u­tions to de­ter­mine the ex­tent of beam halo for­ma­tion at Linac-3GeV Beam Trans­port line (L3BT). In order to de­ter­mine more de­tail of halo for­ma­tion, Vi­bra­tion Wire Mon­i­tor (VWM) was in­stalled in L3BT for the beam halo mea­sure­ment and the of­fline study at the test stand with low en­ergy elec­tron gun are started. The high sen­si­tiv­ity of the VWM makes it a prospec­tive one for in­ves­ti­ga­tion of beam halo and weak beam scan­ning. In this paper, we will re­port a pre­lim­i­nary re­sults of of­fline stud­ies and beam halo mea­sure­ment by VWM at L3BT.  
 
MOPWA007 Operating Experience of Kicker Magnet System in the J-PARC 3GeV RCS 678
 
  • K. Suganuma, M. Kinsho, T. Togashi, M. Watanabe
    JAEA/J-PARC, Tokai-mura, Japan
  
  The J-PARC 3-GeV rapid cy­cling syn­chro­tron (RCS) has been pro­vided pro­ton beam to the Ma­te­r­ial and Life Sci­ence Fa­cil­ity (MLF)as well as to the 50 GeV Main Ring (MR). Pro­ton beam is ac­cel­er­ated from 181 MeV to 3GeV in the RCS and im­me­di­ately ex­tracted it to the beam trans­port line to the MLF and the MR. Ex­trac­tion kicker sys­tem is used for this fast ex­trac­tion. The RCS has been op­er­ated for the neu­tron and MLF users pro­gram from De­cem­ber 23rd, 2008. At the be­gin­ning of user op­er­a­tion there were many trou­bles for the ex­trac­tion kicker sys­tem, es­pe­cially, thyra­tron which are used for switch of power sup­ply often caused fail­ure. The beam stop rate due to RCS ex­trac­tion kicker sys­tem was more than 13% in the total beam stop of the J-PARC, es­tab­lish­ment and op­er­a­tion ex­pe­ri­ence of the tun­ing for power sup­ply of the ex­trac­tion kicker make the beam stop rate less than 0.5% in No­vem­ber 2012. In this paper, we are going to re­port about daily op­er­a­tion whose main is about op­er­a­tion of thyra­tron and the main­te­nance held in sum­mer 2012. And　 We also going to re­port about the ap­ti­tude test of thyra­tron as a plan of the fu­ture.  
 
MOPWA008 Power Supply of the Pulse Steering Magnet for Changing the Painting Area between the MLF and the MR at J-PARC 3 GeV RCS 681
 
  • T. Takayanagi, N. Hayashi, K. Horino, M. Kinsho, T. Togashi, T. Ueno, Y. Watanabe
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  
  The power sup­ply of the pulse steer­ing mag­net (PSTR) has been pro­duced. The PSTR of the 3-GeV RCS (Rapid Cy­cling Syn­chro­tron) in the J-PARC (Japan Pro­ton Ac­cel­er­a­tor Re­search Com­plex) aims at chang­ing the paint­ing area in a pulse-to-pulse mode at 25Hz be­tween the MLF (Ma­te­r­ial and Life sci­ence Ex­per­i­men­tal Fa­cil­ity) and the MR (50-GeV Main Ring syn­chro­tron) at J-PARC. The power sup­ply has the equip­ment used to ex­cite the pulse cur­rent and the di­rect cur­rent (DC) to cor­re­spond to two modes that the paint in­jec­tion for beam users and the cen­tral in­jec­tion for beam com­mis­sion­ing. In case of the paint in­jec­tion, the power sup­ply ex­cites the cur­rent from 40 A to 450 A in pulse mode, which has the ca­pa­bil­ity to switch from pos­i­tive to neg­a­tive po­lar­ity. The pulse cur­rent has been per­formed with good ac­cu­racy whose de­vi­a­tion to a set­ting cur­rent be­comes to be less than ± 0.2 %. In case of the cen­tral in­jec­tion, the power sup­ply ex­cites the cur­rent from 1000 A to 3000A in DC mode, which has been re­al­ized out­put cur­rent de­vi­a­tion below ± 0.01 %. This paper sum­ma­rizes the de­sign pa­ra­me­ters and the ex­per­i­men­tal re­sults of the power sup­ply.  
 
WEPME020 Alignment Plan and Survey Results of the Equipment for J-PARC 3 GeV RCS 2971
 
  • N. Tani, H. Hotchi, J. Kamiya, M. Kinsho, O. Takeda, M. Yamamoto
    JAEA/J-PARC, Tokai-mura, Japan
  
  Mis­align­ment of sev­eral mil­lime­ters of the mag­nets of J-PARC 3GeV RCS in both hor­i­zon­tal and ver­ti­cal di­rec­tions was caused by the To­hoku Re­gion Pa­cific Coast Earth­quake on March 11, 2011. As the re­sult of orbit cal­cu­la­tion showed that the beam loss was ac­cept­able for beam op­er­a­tion at 300kW, beam op­er­a­tion with the cur­rent place­ment has been im­ple­mented. Re­align­ment of the equip­ment will be car­ried out from Au­gust to De­cem­ber in 2013. Sur­vey car­ried out in the sum­mer of 2013 found out mis­align­ment of ce­ramic vac­uum ducts there­fore their po­si­tion­ing is nec­es­sary. In this paper, these mea­sure­ment re­sult and lat­est align­ment plan for J-PARC 3GeV RCS are re­ported.  
 
THPFI014 Bellows with a New RF Shield Made of Metal Braid for High Intensity Proton Accelerators 3321
 
  • N. Ogiwara, J. Kamiya, M. Kinsho, Y. Shobuda
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • O. Koizumi
    Sun-Tech limited, Kobe, Japan
  
  In the 3 GeV-RCS (Rapid cy­cling Syn­chro­tron) in J-PARC (Japan Ac­cel­er­a­tor Re­search Com­plex) pro­ject, large-scale hy­dro-formed bel­lows were de­vel­oped to ad­just the gap be­tween the ce­ramic ducts and/or be­tween the ce­ramic ducts and the trans­port ducts. They have been equipped with a newly de­vel­oped RF shield, be­cause the usual beryl­lium-cop­per spring fin­ger con­tacts were found to be very hard (roughly 1000 N/mm) owing to the large size. This con­tact is made of Ti braid, which con­sists of wires with a di­am­e­ter of 0.3 mm. This RF con­tact is a kind of bas­ket (with two ports) made with the braids. Be­cause of the spring ef­fect, the con­tact can change shape eas­ily. In ad­di­tion, the con­tact can eas­ily con­nect the dif­fer­ent cross sec­tions in a smooth fash­ion. Fur­ther­more, this struc­ture is al­most free from the dust gen­er­a­tion, which is one of the most trou­ble­some prob­lems for the usual spring fin­ger con­tacts. This time, we have con­structed re­serve bel­lows with the RF shield made of SUS 316L wires to im­prove the re­li­a­bil­ity of user op­er­a­tion. The out­line of the bel­lows will be pre­sented, es­pe­cially lay­ing em­pha­sis on the me­chan­i­cal func­tion of the RF shield.  
 
THPFI015 In-situ Degassing of the Ferrite Cores in the Extraction Kicker Magnets of the J-PARC 3-GeV RCS 3324
 
  • J. Kamiya, Y. Hikichi, M. Kinsho, M. Nishikawa, N. Ogiwara, K. Suganuma, T. Yanagibashi
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  
  Kicker mag­nets ex­tract the ac­cel­er­ated beam to the beam trans­port lines in the RCS of the J-PARC. The kicker mag­nets mainly con­sist of Ni-Zn fer­rite cores and Al alloy plates, and are in­stalled in a vac­uum to pre­vent dis­charge be­cause a high volt­age is ap­plied for a short pe­riod. It is im­por­tant to re­duce the out­gassing of water vapor from the fer­rite cores. Al­though the kicker mag­nets have been work­ing well, re­cently the vac­uum qual­ity be­came a lit­tle poor. Thus, we de­vel­oped the in-situ de­gassing method for the fer­rite cores. This is achieved by di­rect­ing the heat from the heat source to the kicker mag­net and not to the cham­ber wall. With the test stand we suc­ceeded to flow al­most all the heat to­ward the kicker mag­net and to bake out the fer­rite cores about 150°C, main­tain­ing the tem­per­a­ture of the cham­ber wall less than 50°C. As the pre­vi­ous work with TDS mea­sure­ments re­vealed that the ab­sorbed water mol­e­cules can be eas­ily re­moved by the bake-out at 100-150°C in a vac­uum, the out­gassing from the fer­rite cores was suc­cess­fully re­duced. The de­tails of the in-situ de­gassing method will be re­ported, in­clud­ing the prac­ti­cal method to re­duce the out­gassing of the work­ing kick­ers.  
 
THPFI016 DESIGN CONSIDERATION OF BEAM DUCTS FOR QUADRUPOLE CORRECTORS IN J-PARC RCS 3327
 
  • J. Kamiya, N. Hayashi, H. Hotchi, M. Kinsho, N. Ogiwara, N. Tani, Y. Watanabe
    JAEA/J-PARC, Tokai-mura, Japan
  
  which rapidly cor­rect the tunes, are planned to be in­stalled dur­ing the sum­mer shut­down in 2013. The char­ac­ter­is­tic of the ex­ci­ta­tion pat­tern of such quadrupoles (quadru­pole cor­rec­tor) is their fast change of mag­netic field, which are more than 200T/s at the fastest point. In this re­port, we de­scribe a de­lib­er­a­tion flow about the de­sign of a vac­uum cham­ber, which is in­stalled in the quadru­pole cor­rec­tor. The ef­fect of eddy cur­rent was cal­cu­lated in the case of the cur­rent ti­ta­nium vac­uum cham­ber. The re­sults showed that the tem­per­a­ture rise was too much (up to ~350oC) and the mag­netic field in the vac­uum cham­ber is largely dis­torted by the eddy cur­rent. There­fore we de­cided to em­ploy an alu­mina ce­ram­ics vac­uum cham­ber, for which we have a past achieve­ment in RCS*. We es­ti­mated the dis­place­ment and stress, which is caused by the at­mos­pheric pres­sure, for the alu­mina ce­ram­ics vac­uum cham­ber and vac­uum com­po­nent around it by mak­ing the cal­cu­la­tion model for the fi­nite el­e­ment method. It was found that there was no large dis­place­ment and stress by in­stalling the alu­mina ce­ram­ics vac­uum cham­ber.
*M. Kinsho, et al. Vacuum 81 (2007) 808. 		 
 
THPWO031 Status of J-PARC Accelerators 3830
 
  • K. Hasegawa, M. Kinsho, H. Oguri
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • T. Koseki
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  After nine-months of beam shut­down by the Great Earth­quake in March 2011, the J-PARC fa­cil­ity re­sumed beam op­er­a­tion. In De­cem­ber 2011, op­er­a­tions were car­ried out at low duty such as sin­gle-shots or 1 to 2.5 Hz for beam tun­ing. At the be­gin­ning of Jan­u­ary 2012, we started beam tun­ing at the full rep­e­ti­tion rate of 25 Hz at the linac and the 3 GeV Rapid Cy­cling Syn­chro­tron (RCS). After the tun­ing, user pro­grams of the Ma­te­ri­als and Life Sci­ence Ex­per­i­ment Fa­cil­ity (MLF), the Neu­trino fa­cil­ity and the Hadron fa­cil­ity started. The beam power was in­creased from 100 to 300 kW to the MLF users, from 3.3 kW to 6 kW to the Hadron users, and from 140 to 200 kW to the Neu­trino users. The beam avail­abil­ity went lower to 73 % in JFY 2011 due to the trou­ble of the linac kly­stron power sup­ply in March, but it has got back to 90-94 % as of No­vem­ber in JFY2012. We have also much up­grade work dur­ing the shut­down pe­riod or in par­al­lel to the op­er­a­tion. We’ve demon­strated new record power be­yond 500kW from the RCS. The sta­tus and progress of the J-PARC ac­cel­er­a­tors are pre­sented.  
 
THPWO032 Progress of Injection Energy Upgrade Project for J-PARC RCS 3833
 
  • N. Hayashi, H. Harada, K. Horino, H. Hotchi, J. Kamiya, M. Kinsho, P.K. Saha, Y. Shobuda, T. Takayanagi, N. Tani, T. Togashi, T. Ueno, M. Watanabe, Y. Watanabe, K. Yamamoto, M. Yamamoto, Y. Yamazaki, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • T. Toyama
    J-PARC, KEK & JAEA, Ibaraki-ken, Japan
  
  The in­jec­tion en­ergy of the J-PARC RCS will be up­graded in 2013. New power sup­plies for the shift bump mag­net sys­tem will be in­stalled. Some of other sys­tems, up­grade of the paint­ing bump power sup­plies and pulse steer­ing sys­tems, are al­ready in­stalled and tested or used for the nom­i­nal op­er­a­tion. The paper re­ports the progress of in­jec­tion en­ergy up­grade pro­ject.  
 
THPWO033 High Intensity Beam Trial of up to 540 kW in J-PARC RCS 3836
 
  • H. Hotchi, H. Harada, N. Hayashi, M. Kinsho, P.K. Saha, Y. Shobuda, F. Tamura, K. Yamamoto, M. Yamamoto, M. Yoshimoto
    JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
  • Y. Irie
    KEK, Ibaraki, Japan
  • S. Kato
    Tohoku University, Graduate School of Science, Sendai, Japan
  
  Re­cently we have per­formed a high in­ten­sity beam trial of up to 540 kW. In this paper, beam in­ten­sity de­pen­dece and in­jec­tion paint­ing pa­ra­me­ter de­pen­dence of beam loss, ob­served in this beam ex­per­i­ment, will be dis­cussed with the cor­re­spond­ing nu­mer­i­cal sim­u­la­tion re­sults.  
 
THPWO037 Status and Progress of the J-PARC 3 GeV RCS 3848
 
  • M. Kinsho
    JAEA/J-PARC, Tokai-mura, Japan
  
  The J-PARC rapid cy­cling syn­chro­tron (RCS) has been de­liv­ered 300kW beam to both the MLF and the MR with high re­li­a­bil­ity and small beam loss for user op­er­a­tion. To re­al­ize si­mul­ta­ne­ously two kinds of beam shape which are re­quired from the MLF and the MR, two pulse di­pole mag­nets for in­jec­tion paint­ing were in­stalled in the beam trans­port line from the Linac to the RCS. It was suc­cess­ful to make two kinds of beam shape with in­jec­tion paint­ing bump mag­nets and these added pulse di­pole mag­nets. This in­jec­tion paint­ing sys­tem is used for user op­er­a­tion and works well for re­duc­tion of beam losses. Not only user op­er­a­tion but also high power beam test was per­formed, and beam power of 524kW for 35 sec­ond was achieved with low beam loss in the RCS. Al­most all beam loss was lo­cal­ized at the ring col­li­ma­tor and the loss rate was about 2% and this was ac­cept­able be­cause de­sign value of the beam loss was 3%. This power cor­re­sponds to 1.8MW for 400MeV in­jec­tion in terms of the Lasslett tune shift. In this high-in­ten­sity trial, sig­nif­i­cant progress to­ward de­sign out­put beam power of 1 MW was demon­strated. The sta­tus and progress of the RCS in J-PARC are pre­sented.