The Development of an MOS Dosimetry Unit for Use in Space

A space qualified integrating radiation dosimeter, using a special extra-sensitive metal-oxide-semiconductor (named the TOT 201 transistor) as the sensing device has been put into geostationary orbit aboard a European ccmTunication satellite (OTS). This paper describes the fabrication and calibration of a specially sensitive MOS transistor (sensitivity of 3.8 10-4 Volt rad-1) and the design and calibration of × the flight circuit. This is the first known use of a special MOS device to measure the internal environment of a space vehicle. Weight size and power demand are so low that the unit could be widely used as a ´housekeeping monitor´ in future orbital payloads.