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 ^238+239Pu source. The detectors were observed to have low leakage currents at a field of 1 V µm⁻¹. The stability of the alpha response and improvement in the count rate were achieved by β-irradiation using ⁹⁰Sr β 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 2.86×10⁵–8.76×10⁶ n cm⁻² s⁻¹. The neutron response of detectors of 100 µm and 300 µm thicknesses was compared experimentally to study the neutron response dependence on detector thickness. Experimental results show that the detector of 100 µm thickness has better performance compared to the detector of thickness of 300 µm. 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