• A. Plotnikov, E. Floch, E. Mustafin, E. Schubert, T. Seidl, I. Strašík
  GSI, Darmstadt
• A. Smolyakov
  ITEP, Moscow

In the frame of the FAIR pro­ject in spring 2008 an ir­ra­di­a­tion test of su­per­con­duct­ing mag­net com­po­nents was done at GSI Darm­stadt. Cave HHD with the beam dump of SIS18 syn­chrotron was taken as the test area. The beam dump was reequipped to meet the ir­ra­di­a­tion test re­quire­ments. There­by the first stage of prepa­ra­tion for the ir­ra­di­a­tion test was to in­ves­ti­gate the ra­di­a­tion field around the re­con­struct­ed beam dump from the point of view of ra­di­a­tion safe­ty. FLUKA sim­u­la­tions were per­formed to es­ti­mate the dose rate in­side and im­me­di­ate out­side of the cave dur­ing the ir­ra­di­a­tion. The sim­u­la­tions showed safe level of the ra­di­a­tion field, and it was later con­firmed by the mea­sure­ments pro­vid­ed by the ra­di­a­tion safe­ty group of GSI.

• E. Mustafin, E. Floch, A. Plotnikov, E. Schubert, T. Seidl, I. Strašík
  GSI, Darmstadt
• L.N. Latysheva
  RAS/INR, Moscow
• A. Smolyakov
  ITEP, Moscow

In spring 2008 an ir­ra­di­a­tion test of su­per­con­duct­ing mag­net com­po­nents was done at GSI Darm­stadt in the frame of the FAIR pro­ject. Cave HHD with the beam dump of SIS syn­chrotron was used for ir­ra­di­a­tion. The ir­ra­di­a­tion set-up mod­eled a sce­nario of beam loss in a FAIR ac­cel­er­a­tor: U beam with en­er­gy of 1 GeV/u was used to ir­ra­di­ate a thin stain­less steel bar at very small angle, so that the test sam­ples sit­u­at­ed be­hind the stain­less steel bar were ex­posed to the beam of sec­ondary par­ti­cles cre­at­ed in the bar. The total num­ber of U ions dumped on the tar­get as­sem­bly was about 2·10¹⁴. Present­ly, in spring 2009 some sam­ples are still ra­dioac­tive. In the paper we pre­sent the es­ti­mates of the en­er­gy de­po­si­tion and sec­ondary par­ti­cle flu­ences in the test sam­ples and also dis­cuss some re­sults of the ir­ra­di­a­tion cam­paign.

• I. Strašík, E. Floch, E. Mustafin, A. Plotnikov, E. Schubert, T. Seidl, A. Smolyakov
  GSI, Darmstadt

Funding: Work is partially supported by project VEGA 1/0129/09.

In the frame of the FAIR pro­ject ir­ra­di­a­tion test of su­per­con­duct­ing mag­net com­po­nents was per­formed at GSI Darm­stadt in May 2008. As a part of the ex­per­i­ment stain­less steel sam­ples were ir­ra­di­at­ed by 1 GeV/u ²³⁸U ions. In con­trast to the pre­vi­ous ex­per­i­men­tal stud­ies per­formed with thick cylin­dri­cal sam­ples, the tar­get was a thin plate ir­ra­di­at­ed at small angle. The tar­get was con­sti­tut­ed as a set of in­di­vid­u­al foils. This stacked-foil tar­get con­fig­u­ra­tion was fore­seen for depth-pro­fil­ing of resid­u­al ac­tiv­i­ty. Gam­ma-ray spec­troscopy was used as the main an­a­lyt­i­cal tech­nique. The iso­topes with dom­i­nat­ing con­tri­bu­tion to the resid­u­al ac­tiv­i­ty in­duced in the sam­ples were iden­ti­fied and their con­tri­bu­tions were quan­ti­fied. Depth-pro­fil­ing of the resid­u­al ac­tiv­i­ty of all iden­ti­fied iso­topes was per­formed by mea­sure­ments of the in­di­vid­u­al tar­get foils. The char­ac­ter­is­tic shape of the depth-pro­files for the prod­ucts of tar­get ac­ti­va­tion and pro­jec­tile frag­ments was found and de­scribed. Monte Carlo code FLUKA was used for sim­u­la­tions of the resid­u­al ac­tiv­i­ty and for es­ti­ma­tion of the num­ber of ions de­liv­ered to the tar­get and their dis­tri­bu­tion. The mea­sured data are rel­e­vant for as­sess­ment of ra­di­a­tion sit­u­a­tion at high-en­er­gy ac­cel­er­a­tors dur­ing the “hands-on” main­te­nance as well for as­sess­ment of the tol­er­a­ble beam-loss­es.