An intense 146 MeV/c pion beam was stopped inside a scintillating fiber
detector made out of 12 planes with 16 pixels each, where every pixel consists
out of 8 times 8 scintillating fibers of 500 mkm diameter dense packed. The
detector was irradiated for 52 hours to more than 1 Mrad at its center. Before
and directly after the irradiation the detector has been exposed to a particle
beam to compare the corresponding light output. This study was continued during
the following three months using cosmic rays. No damage was found taking into
account the measurement errors of 5-10 %. In contrast a 9 cm deep lucite
degrader became irreversibly non-transparent in the irradiation region.Comment: 16 pages, 11 figure