Si(Li) Coaxial Detectors

Lithium drifted silicon coaxial detectors have been fabricated from 19 mm diameter material with volumes up to 5 cm3. Essentially single line response, the double escape peak, is observed for gamma rays interacting by pair production. Resolutions (FWHM) of 5 keV and approximately 10 keV have been observed for incident gamma rays of 2.62 and 7.64 MeV. Slices, 2 to 3 mm thick, have been taken from such coaxial detectors and used as low capacity, high resolution X-ray detectors. A FWHM of 300 eV has been obtained at 6.4 keV using a detector with an active area slightly greater than 200 mm2.