INFLUENCE OF WEAK VISIBLE-LIGHT ON FLUX-CREEP IN HTSC AT LOW-TEMPERATURES

We present an experimental study of flux creep in YBCO film at low tem peratures (1.3 K < T < 25 K). A ring shaped film was used to obtain di rectly voltage-current characteristics of the film. it has been found that even very weak illumination greatly accelerates the flux creep at liquid helium temperatures, The influence of illumination is complete ly different from that caused by the temperature rise. We propose a si mple qualitative model to explain the high sensitivity of the flux cre ep to weak illumination. (C) 1997 Academic Press Limited.