Response function measurement of layered type CVD single crystal diamond radiation detectors for 14  MeV neutrons

• Published in: Review of Scientific Instruments 2004-10, Vol.75 (10), p.3581-3584
• Main Authors: Kaneko, J. H., Teraji, T., Hirai, Y., Shiraishi, M., Kawamura, S., Yoshizaki, S., Ito, T., Ochiai, K., Nishitani, T., Sawamura, T.
• Format: Article
• Language: English
• Subjects: ALPHA PARTICLES; BERYLLIUM 9; CARBON 12; CHEMICAL VAPOR DEPOSITION; CRYSTAL GROWTH; DOPED MATERIALS; ENERGY RESOLUTION; MATERIALS SCIENCE; MEV RANGE 10-100; MONOCRYSTALS; NEUTRON DETECTION; NEUTRON FLUENCE; NEUTRON SPECTROMETERS; RADIATION DETECTORS; RESPONSE FUNCTIONS; THICKNESS
• ISSN: 0034-6748; 1089-7623
• DOI: 10.1063/1.1787918

Response function measurement of layered-type chemical vapor deposition single crystal diamond radiation detectors for 14  MeV neutrons was carried out. The detector had a layered structure that was composed of a boron-doped diamond layer of 0.5 μ m in thickness and a nondoped diamond layer of 20 μ m on an inexpensive high pressure and high temperature-type Ib diamond substrate. The detector had energy resolution of 2.6% for 5.5  MeV α particles. This experiment was mainly carried out in order to understand the present status of the detector as a 14  MeV neutron spectrometer and an extent of charge trapping. As result, a peak caused by the 12 C (n,α 0 ) 9 Be reactions was clearly observed; the best energy resolution of 6% as for a synthetic diamond radiation detector was achieved. Detection efficiency was 3.2×10 −7 counts/unit neutron fluence. However, taking the energy resolution for α particles, etc., into account, the energy resolution for 14  MeV neutrons was not so high. Further improvement based on better crystal growth is indispensable.