Irradiated silicon detectors operated at cryogenic temperatures: the Lazarus effect.

An increasing interest in the behaviour of silicon detectors at cryogenic temperatures has been awakened by the discovery of the so-called Lazarus effect, namely the recovery of charge collection efficiency (CCE) by means of cryogenic cooling. We measured the CCEs of three single diodes previously irradiated with different neutron fluences. The current-voltage characteristic were measured at 300 and 77 K, showing that the low-temperature operation considerably decreases the steady-state current. This is also the case when a forward voltage bias is applied, which then becomes a suitable option. At 77 K, in the case of samples irradiated with 5 x 10[sup 14] neutrons cm[sup -2], the CCE is completely recovered. A third sample irradiated with 2 x 10[sup 15] neutrons cm[sup -2] shows a 60% CCE at 250 V forward bias. [ABSTRACT FROM AUTHOR]