Title :
Shielding effect of superconducting magnetically shielded room
Author :
Yamazaki, Keita ; Unno, Ken-ichi ; Matsuba, Hironori ; Watanabe, Tomonori ; Irisawa, Daiichi ; Fujiwara, Koji
Author_Institution :
Takenaka Corp., Inzai, Japan
fDate :
9/1/1997 12:00:00 AM
Abstract :
A Superconducting Magnetically Shielded Room (SMSR) has been developed. Superconducting panels are soldered to form a shielding wall of which the soldered connections have normal conduction. Therefore, the Shielding Factor (SF) of the SMSR degrades especially at low frequency, which is different from a superconducting shielded room without a normal conductive connection. A permalloy box is combined inside the SMSR to improve the SF. The combination (CMSR) shows a SF of 2,000 at 0.3 Hz and 100,000 at 10 Hz. The SF of the CMSR exceeds the product of the SF of the SMSR with the SF of the permalloy box. This peculiar tendency of the CMSR is validated by a 3-D magnetic field analysis. The maximum SF is obtained with zero distance between the walls
Keywords :
Permalloy; magnetic fields; magnetic noise; magnetic shielding; superconducting devices; 0.3 Hz; 10 Hz; 3-D magnetic field analysis; magnetic noise; normal conduction soldered connections; permalloy box; shielding factor degradation; shielding wall; superconducting magnetically shielded room; superconducting panel soldering; Costs; Degradation; Frequency; Insulation; Magnetic analysis; Magnetic fields; Magnetic shielding; Nitrogen; Reservoirs; Soldering; Superconducting films; Superconducting magnets;
Journal_Title :
Magnetics, IEEE Transactions on
