• J.K. Sekutowicz, M. Dohlus, A. Goessel, N. Mildner
  DESY, Hamburg

High fre­quen­cy High­er Order Modes (HOM) prop­a­gat­ing in the beam line of a su­per­con­duct­ing linac can carry a sub­stan­tial frac­tion of the en­er­gy de­posit­ed in ac­cel­er­at­ing struc­tures by the beam. In this con­tri­bu­tion, we re­port test re­sults of the beam line ab­sorber (BLA), which was de­signed and fab­ri­cat­ed at DESY, and in­stalled in the FLASH ac­cel­er­a­tor to ab­sorb the HOM en­er­gy gen­er­at­ed by high cur­rent beams. Two tests were car­ried out, in Septem­ber 2008 and Septem­ber 2009, dur­ing so called high cur­rent runs. The ex­per­i­ments con­firmed the con­cept of the BLA de­sign and showed re­mark­able agree­ment with com­put­er mod­el­ing of the HOM en­er­gy ab­sorp­tion.