About nuclear spin kinetics in solid 3He at magnetic field

Abstract

It is shown that the nuclear spin system of solid 3He in paramagnetic phase cannot be divided into two almost independent subsystems (the Zeeman reservoir and the exchange reservoir) in case when the Zeeman energy exceeds the heat energy. The introduced representation about spin excitons in nuclear system of solid 3He at a rather high magnetic fields allows to eliminate the reasons for the appearance of strong thermodynamic coupling between subsystems. The preliminary calculations give the evidence that an effective cooling of solid 3He nuclear spin system can be achieved at NMR saturation and show that important information about the validity of taking into account the spin-spin interactions of different nature can be obtained from nuclear spin lattice relaxation measurements at these conditions. © 2003 Elsevier Science B.V. All rights reserved.