• P.J. Spiller, H. Eickhoff, H. Kollmus, P. Puppel, H. Reich-Sprenger
  GSI, Darmstadt
• L.H.J. Bozyk
  FIAS, Frankfurt am Main

After par­tial­ly com­plet­ing the up­grade pro­gram of SIS18, the num­ber of in­ter­me­di­ate charge state heavy ions ac­cel­er­at­ed to the FAIR boost­er en­er­gy of 200 MeV/u, could be in­creased by a fac­tor of 50. Mean­while, more than 10¹⁰ Ura­ni­um ions with charge state 27+ have been ac­cel­er­at­ed with mod­er­ate beam loss by ion­iza­tion and rea­son­ably sta­ble resid­u­al gas pres­sure con­di­tions. The spe­cif­ic chal­lenge for the SIS18 boost­er op­er­a­tion is the high cross sec­tion for ion­iza­tion due to the low charge state in com­bi­na­tion with gas des­orp­tion pro­cess­es and the dy­nam­ic vac­u­um pres­sure. Es­pe­cial­ly for this op­er­a­tion mode which is re­quied to match the in­ten­si­ty re­quire­ments for FAIR, an ex­tend­ed up­grade pro­gram of SIS18 is present­ly on­go­ing and par­tial­ly com­plet­ed. The achieved progress in min­i­miz­ing the ion­iza­tion beam loss un­der­lines that the cho­sen tech­ni­cal strate­gies de­scribed in this re­port are ap­pro­pri­ate.

• L.H.J. Bozyk
  TU Darmstadt, Darmstadt
• D.H.H. Hoffmann, H. Kollmus, P.J. Spiller
  GSI, Darmstadt

The cen­tral ac­cel­er­a­tor SIS100 of the FAIR-fa­cil­i­ty will pro­vide high in­ten­si­ty, in­ter­me­di­ate charge state heavy ion beams. In order to as­sure a re­li­able op­er­a­tion with the in­ter­me­di­ate charge states, a spe­cial syn­chrotron de­sign, in­clud­ing ion catch­er sys­tem had to be de­vel­oped. In­ter­me­di­ate charge state heavy ions suf­fer from high cross sec­tions for ion­iza­tion. Due to the ded­i­cat­ed syn­chrotron lay­out, ions which have been fur­ther stripped by col­li­sions with resid­u­al gas atoms are not lost un­con­trolled onto the beam pipe but are caught by the ion catch­er sys­tem in the cryo­genic arcs. The con­struc­tion and test of a cryo-catch­er pro­to­type at GSI is a work­pack­age of the EU-FP7 pro­ject COL­MAT. A pro­to­type catch­er in­clud­ing cryo­stat will be set-up at GSI to per­form mea­sure­ments with heavy ion beams of the heavy ion syn­chrotron SIS18.

• J. Stadlmann, H. Kollmus, E. Mustafin, I.J. Petzenhauser, P.J. Spiller, I. Strašík, N.A. Tahir, C. Trautmann
  GSI, Darmstadt
• L.H.J. Bozyk, M. Krause
  TU Darmstadt, Darmstadt
• M. Tomut
  INFIM, Bucharest

With­in the frame of the Eu­CARD pro­gram, the GSI Darm­stadt is per­form­ing ac­cel­er­a­tor R&D in work­pack­age 8: Col­Mat. The ef­fort is fo­cused on ma­te­ri­als im­por­tant for build­ing the FAIR ac­cel­er­a­tor fa­cil­i­ty at GSI and the LHC up­grade at CERN. Ac­cel­er­a­tor com­po­nents and es­pe­cial­ly pro­tec­tion de­vices have to be op­er­at­ed in high dose en­vi­ron­ments. The ra­di­a­tion haz­ard oc­curs ei­ther by the pri­ma­ry pro­ton and ion beams or the sec­ondary ra­di­a­tion. De­tailed nu­mer­i­cal sim­u­la­tions have been car­ried out to study the dam­age caused to solid tar­gets by the full im­pact of the LHC beam as well as the SPS beam. Tung­sten, cop­per and graphite tar­gets have been stud­ied. Ex­per­i­men­tal an the­o­ret­i­cal stud­ies on ra­di­a­tion dam­age on ma­te­ri­als used for the LHC up­grade and the FAIR ac­cel­er­a­tors are per­formed at the pre­sent GSI ex­per­i­men­tal fa­cil­i­ties. Tech­ni­cal de­ci­sions based on these re­sults will have an im­pact on the FAIR com­po­nent spec­i­fi­ca­tions. A cryo­genic ion-catch­er pro­to­type will be con­struct­ed and test­ed. The ion-catch­er is es­sen­tial for reach­ing high­est heavy ion beam in­ten­si­ties in SIS100. The pro­to­type will be set-up at GSI to per­form mea­sure­ments with heavy ion beams of syn­chrotron SIS18.