adiabatic demagnetization

Adiabatic demagnetization

The removal or diminution of a magnetic field applied to a magnetic substance when the latter has been thermally isolated from its surroundings. The process concerns paramagnetic substances almost exclusively, in which case a drop in temperature of the working substance is produced (magnetic cooling). See Paramagnetism

Nuclear magnetic moments are one or two thousand times smaller than their ionic (that is, electronic) counterparts, and the characteristic temperature of their mutual interaction lies in the microkelvin rather than millikelvin region. Successful experiments in nuclear adiabatic demagnetization date from the mid-1950s. See Absolute zero, Cryogenics, Low-temperature physics

adiabatic demagnetization

[¦ad·ē·ə¦bad·ik ‚de‚mag·nəd·ə′zā·shən]
(cryogenics)
A method of cooling paramagnetic salts to temperatures of 10-3K; the sample is cooled to the boiling point of helium in a strong magnetic field, thermally isolated, and then removed from the field to demagnetize it. Also known as Giaque-Debye method; magnetic cooling; paramagnetic cooling.
References in periodicals archive ?
Contract notice: Providing a refrigeration unit to adiabatic demagnetization ( adr) and execution of related services.
Low temperatures were achieved by adiabatic demagnetization of Cerous Magnesium Nitrate.
Early magnetic coolers were used to achieve extreme cryogenic temperatures and used an adiabatic demagnetization refrigeration (ADR) cycle.
Even lower temperatures can be obtained through the application of adiabatic demagnetization.
The NIST energy dispersive microcalorimeter spectrometer for x-ray microanalysis used cryogens and an adiabatic demagnetization refrigerator (ADR) to achieve the working temperatures (<100 inK) of the superconducting TES.
These early "one-shot" systems consisted of a solid piece of magnetocaloric material, and they used an adiabatic demagnetization to achieve very low temperatures.
The adiabatic demagnetization mentioned may have been the first effect of a possible cometary infall, although I'm not fully committed to this idea.

Full browser ?