Screening effects of the excimer laser produced plasma of YBa2Cu3O7

The radiation screening properties of the excimer laser produced plasma of the YBCO high Tc superconductor were investigated. The plasma was created as a result of the ablation of bulk YBCO in air, following the absorption of 30 ns duration excimer laser pulses and probed by laser pulses of the same characteristics. Plasma shielding was observed above approximately 1.4 J/cm2 of laser energy flux. The electron density of the plasma as a function of the laser energy flux, at the beginning of the plasma expansion, was estimated.