Indus accelerator complex using bismuth fission detectors

This paper reports the measurement of high energy neutron component (E > 50 MeV) carried out at the Indus-1 (450 MeV) and Indus-2 (2.5 GeV) electron accelerators (RRCAT, Indore, India). The study is based on the registration of neutron induced fission fragments from bismuth radiators in the adjoint solid polymeric track detectors. These bismuth fission detector (BFD) stacks are exposed at the injection septums of booster synchrotron, Indus-1 and Indus-2 storage rings, where the possibility of dose due to beam loss is expected to be maximum. The detection efficiency of BFD is enhanced by enlarging the detector surface area and accordingly a large area spark counter is fabricated for automatic and rapid counting of the track densities. The dose equivalent rates are found to be about 0.11 mSv/h at the booster synchrotron and the Indus-1 storage ring, and about 0.62-0.65 mSv/h at the Indus-2 storage ring.