Calibration of the radiation monitors from DESY and SPring-8 at the quasi-mono-energetic neutron beams using 100 and 300 MeV 7Li(p,n) reaction at RCNP in Osaka Japan in November 2014

Abstract

At the ring cyclotron facility of the Research Center for Nuclear Physics (RCNP) Osaka University, Osaka, Japan a series of measurement campaigns had been continued with quasi mono-energetic neutron beams in November 2014. A 7Li target was bombarded with 100 and 300 MeV protons and the generated neutron beams were directed into a long time-of-flight tunnel at 0 and 25 degrees deflection angle with respect to the proton beam. At a distance of 41 m the cross section of the neutron beam was large enough for the illumination of square meter sized objects like extended range rem-counters. The research institutes SPring-8/RIKEN, Japan, and DESY, Germany, participated in this campaign for the calibration of 4 different types of active ambient dose rate monitors: LB 6411, LB 6411-Pb, LB 6419 and LB 6420. The measurements of their responses are reported and compared with the calculated values.