Abstract:
GaAs Schottky barrier detectors for $\alpha$ particle spectrometry have been tested. Detectors had an input window area of 80 mm$^2$ and a working barrier layer thickness of 40–50 $\mu$m. The energy resolution (FWHM) measured on 5.499 MeV $\alpha$ line of $^{238}$Pu source amounted to 17.5 keV at a generator peak width of 7.8 keV. In the measurements on a $^{226}$Ra source, detectors showed linear response and nearly 100% charge collection efficiency at reverse bias above 65 V for all energies of $\alpha$ particles emitted from the source. Tests for thermal stability showed that the proposed detectors can be used in alpha-spectrometry of radionuclides at temperatures up to 120$^{\circ}$C.