THERMAL FLUCTUATIONS OF THE MAGNETIC-FIELD OVER A THIN CONDUCTING PLATE

The thermal fluctuations of the magnetic field over a thin conducting plate are calculated. The plate is represented as a superposition of c ircuits, where each circuit consists of an array of current loops char acterized by a particular spatial frequency. The thermally induced cur rent in each loop is determined from the magnetic energy associated wi th the circuit and the equipartition theorem. This method gives result s that are nearly identical to a previously published analysis of this problem by Varpula and Poutanen [J. Appl. Phys. 55, 4015 (1984)], in the limit when the plate is thin. (C) 1998 American Institute of Physi cs. [S0021-8979(98)06702-4].