FURTHER DEVELOPMENTS OF SERIES-CONNECTED SUPERCONDUCTING TUNNEL JUNCTION TO RADIATION DETECTION

One of the promising radiation detection devices for various practical applications is the series-connected superconducting tunnel junction (STJ) detector. In this article, interesting topics of the detectors a re described since our previous work: e.g., more than two order higher detection efficiency compared with single STJ detectors, high count r ate detection, and position resolution. Detectors were cooled to 0.35- 0.4 K by means of a convenient He-3 cryostat. The 5.9 and 6.5 keV x ra ys from Fe-55 are separated by a detector specially designed for x-ray detection. The possible count rate of the series-junction detector es timated from the shaping-time constant applied in the measurements is high, e.g., over 10(4) counts per second. A series-junction detector e quipped with a position sensing mechanism has shown a position resolut ion of about 35 mu m in a sensing area with a radius of 1.1 mm. The po sition resolution of series junctions improves the energy resolution. A new type series-connected STJ detector is also proposed, i.e., the d ispersed multitrap series-junction detector, for further improvement o f detection efficiency and energy resolution. (C) 1997 American Instit ute of Physics.