once aligned under the strong magnetic field (see Ref. [7]
for review). It is also a merit of the ADR that the
temperature can be controlled quite precisely by controlling
the current of superconducting magnet surrounding
the salt. On the other hand, when the magnetic spins are
completely randomized, i.e., no more heat can be absorbed,
a ‘‘recharge’’ of the refrigerator is necessary. The period to
the next recharge, i.e., temperature controlled time,
depends on the heat input to the salt, the temperature to
maintain, and the size of the salt