High resistivity(over 1O.Okohm.cm) extrinsec P-type Si was produced from high pure P-type Si(resistivity between 1.0 and 2.Skohm.cm,lifetime over 1 ms),using the neutron transmutation doping technique.Material obtained by this method,used for detectors,has better properties in dopant homogeneity and controllability than conventionally doped ones. Improved radiation detectors of surface barrier type were obtained by deposition of amorphous Ge and Al,Au, respectively, for contacts.Results obtained by testing two types of detection structures are presented.First type,for gamma radiation are of sensitive area of 100 sqxnm sensitive depth of 300 μm.They present a good response for Cs-137, higher than 400 p/s/cGy/h. The second type, for alfa-radiation (2...9 MeV) and beta-radiation (225keV...2.26MeV) are of sensitive area of 5sqcm and sensitive depth of 250 μm. Calibration was done obtaining: R_∞=min.1 p.sqcm/s.Bq for Am-241 (5.45 MeV) and R_β=min. 0.7 p. sqcm/ s .Bq for Sr-9 0+ Y-9 0 (2.26 MeV). Original results concerning functioning tests of these detectors in special conditions, such as temperature between -25°C and +45°C, humidity 90% at 30°C and mechanical shocks are presented.

Date Published: 22 December 1992
PDF: 8 pages
Proc. SPIE 1734, Gamma-Ray Detectors, (22 December 1992); doi: 10.1117/12.138593

Published in SPIE Proceedings Vol. 1734:
Gamma-Ray Detectors
Elena Aprile, Editor(s)