THE USE OF BALL MODERATORS FOR NEUTRON SPECTROMETRY

A spectrometer with ball moderators of polyethylene was designed at FSUE "VNIIFTRI". As a detector of slow neutrons there were used a LiI scintillator with natural lithium and a spherical proportional counter with a diameter of 5 cm filled with 10BF3 gas. Using two different detectors can reduce systematic measurement error. Response from the detectors which are placed in the ball moderators, is performed by using a specially designed device. Measurement and processing of measurements are carried out automatically using a developed program named ?boll?. Restoration of the neutron spectrum is carried out using a developed program named ?spectr?. Energy dependence of the sensitivity of the detectors placed in the moderators, which is needed for neutron spectrum restoration, is calculated using the Monte Carlo method.