Title :
A micrometric thickness silicon diode proposed as a microdosimeter
Author :
Fazzi, Alberto ; Agosteo, Stefano ; Pola, Andrea ; Varoli, Vincenzo ; Zotto, Pierluigi
Author_Institution :
Nucl. Eng. Dept., Milano Univ.
Abstract :
A thin silicon diode formed by a deep p+ implantation under a shallow n+ one is proposed as a solid state microdosimeter. The thickness of the sensitive layer of the tested device is about two micrometers and the active area is about 10 mm2. Due to the very large electric capacitance of the diode (about 1 nF) a low noise read-out circuit based on a discrete JFET has been developed. The noise due to the parasitic resistance of the detector itself dominates and fixes the lower threshold of the energy spectrum. A prototype of the proposed microdosimeter covered with a polyethylene converter has been irradiated with fast monoenergetic neutrons at the INFN-Legnaro Labs (I). The first experimental spectra are in good agreement with the simulated ones. The effect of direct interactions of thermal neutrons in silicon has been measured
Keywords :
dosimeters; junction gate field effect transistors; silicon radiation detectors; JFET; deep p+ implantation; electric capacitance; low-noise read-out circuit based; monoenergetic neutrons; parasitic resistance; polyethylene converter; shallow n+ implantation; silicon diode; solid state microdosimeter; thermal neutron interactions; Circuit noise; Circuit testing; Detectors; Diodes; Electric resistance; JFET circuits; Neutrons; Parasitic capacitance; Silicon; Solid state circuits; Field funnelling; microdosimetry; sensitive volume; silicon diode; silicon microdosimetry;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2006.869832
