Fabrication and characterization of polycrystalline diamond detectors for fast neutron monitoring

Diamond detectors have been fabricated using commercially available detector grade polycrystalline CVD substrates for fast neutron measurement in the Indian TBM Experiment at the upcoming ITER facility. Subsequent to fabrication, the detectors were characterized for leakage current and for response to alpha particles from Pu238+239 source. The detectors were observed to have low leakage currents at a field of 1 V mu m(-1). The stability of the alpha response and improvement in the count rate were achieved by beta-irradiation using Sr-90 beta source. The fast neutron response of the detectors was studied using a D-T fast neutron source in India. The detectors showed linear response in the measured neutron flux of 2.86 x 10(5)-8.76 x 10(6) n cm(-2) S-(1). The neutron response of detectors of 100 mu m and 300 mu m thicknesses was compared experimentally to study the neutron response dependence on detector thickness. Experimental results show that the detector of 100 mu m thickness has better performance compared to the detector of thickness of 300 mu m. The results presented in this paper confirm the suitability of commercially available films from Diamond Materials, GmbH, Germany for detector fabrication for fast neutron monitoring. The details of detector fabrication and results of characterization are presented in this paper. (C) 2015 Elsevier B.V. All rights reserved.