A Prototype Neutron Spectrometer based on a
Single Crystal CVD Diamond
Greg Schmid
Tuesday, January 27, 2004
11:00 AM
Building 151, Room 1209 (Stevenson Conference Room)

Abstract:
We have fabricated and tested a prototype neutron spectrometer based on a 5 x 5 x 0.5 mm wafer of single crystal Chemical Vapor Deposition (CVD) diamond [1]. Results for 2.5 and 14 MeV incident neutrons are presented. The energy resolution at 14 MeV is shown to be at least 2.9%, as limited by the energy spread of the incident neutron beam, and perhaps as good as 0.3%, as extrapolated from high resolution alpha particle data. These results suggest that single crystal CVD diamond should make an excellent neutron spectrometer for the International Thermonuclear Experimental Reactor (ITER), and should exceed the performance of the natural diamond gemstones that have already been proposed [2]. Another possible application of single crystal CVD diamond would be fission neutron detection (e.g. the search for weapons grade Pu). Although much larger wafer sizes would be needed for a practical device, work in diamond growth is progressing, and there is reason for some optimism [3].

[1] J. Isberg et al, Science 297 (2002)1670
[2] L.C. Johnson et al., Rev. Sci. Inst 68 (1997)569
[3] S.T. Lee et al., Nature 424 (2003)500