Screening effects of the excimer laser produced plasma of YBa2CU3O7

The radiation screening properties of the excimer laser produced plasma of the YBCO high T-c superconductor were investigated. The plasma was created as a result of the ablation of bulk YBCO in air, following the absorption o f 30 ns duration excimer laser pulses and probed by laser pulses of the sam e characteristics. Plasma shielding was observed above approximately 1.4 J/ cm(2) of laser energy flux. The electron density of the plasma as a functio n of the laser energy flux, at the beginning of the plasma expansion, was e stimated. (C) 2001 Elsevier Science B,V. All rights reserved.