RF magnetic shielding effect of a sealed bottom HTS cylinder

The high-critical temperature superconductor (HTS) is an ideal material for use as a RF magnetic shielding vessel, which employs perfect diamagnetism. In general, however, the detailed characteristics of the radio frequency (RF) for a HTS vessel are unknown. In the present research, measurements are made of the RF shielding effect SD, that is, the ratio of the output powers of the receiving antenna with and without the shielding vessel, of a sealed bottom YBCO bulk cylinder. It was found that the values of the magnetic shielding effect SD/sub u/ for the sealed bottom YBCO cylinder exhibit constant values in frequency from range from 1 MHz to 10 MHz, and decrease with an increase in frequency from 30 MHz to 3000 MHz of the applied electromagnetic wave. It was also found that the shielding displayed no evidence of dependence on the RF magnetic power P/sub H/. For the RF electric shielding effect SD/sub E/, the cylinder exhibited no remarkable characteristics. Furthermore, it was found that the characteristics of SD/sub E/ for the cylinder displayed no evidence of dependence on the values of the RF input power P/sub E/. In addition, the shielding effects were shown to be improved by the superposition of a sealed bottom copper cylinder over the sealed bottom YBCO cylinder.