Nonequilibrium in Josephson junctions: A possibility for low-energy radiation/particle detection

The nonequilibrium behavior of the Josephson critical current produced by the absorption of an incident energy quantum in a superconducting tunnel junction detector has been studied in the framework of nonequilibrium theory. The dependence of the Josephson current on the released energy (x-ray and ultraviolet photons) has been obtained in the limit k(B)T much less than Delta. Possible designs for high-energy resolution radiation/particle detectors are presented and discussed in terms of detection properties. [S0163-1829(99)03841-2].