Abstract
The effect of high-dose gamma-irradiation up to 50 MRad on the hysteresis width and critical current density J(c) of two fluorinated Tl-1223 samples is reported. gamma-irradiation was found to affect the critical current density of the sample Tl-1223/F-x with x = 1.0 both at low and high doses, but it has no effect on J(c) of the sample with x = 2.2. This means that addition of fluorine in a controlled manner to the Tl-1223 enhances J(c) and makes this material very sensitive to gamma-irradiation. These results are in agreement with our previous findings for the low-dose gamma-irradiation. (C) 2000 Elsevier Science B.V. All rights reserved.