Thermal magnetic noise in a strip wound crystalline ferromagnetic core at 4.2 Kстатья
Информация о цитировании статьи получена из
Scopus,
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
Авторы:Snigirev O.V.,
Maslennikov Y.V.,
Vitale S.,
Cerdonio M.,
Prodi G.A.
Аннотация:A de SQUID magnetometer-based system has been developed and used to measure, in the frequency range 50-2300 Hz, the complex magnetic permeability mu(r)(v) and the magnetization noise at 4.2 K in a strip wound toroid. This toroidal core has been made of the 3-mu m-thick ribbon fabricated from a crystalline magnetically soft alloy, Ultraperm. Below 1 KHz a constant value of -arg[mu(r)(v)] approximate to 2x10(-3) and 1/v shaped noise spectral density have been measured. For frequencies higher than 1 KHz a linear growth of the imaginary part mu(r), and a white noise have been found. The noise due to the sample is found in quantitative agreement with the standard fluctuation-dissipation formula for the thermal noise, while a comparison of the permeability imaginary part magnitude with the theoretical value has indicated a partially shorted windings in the toroid, which have decreased the toroid roll-off frequency down to 1 MHz. (C) 1996 American Institute of Physics.