Applying the Adiabatic Demagnetization Technique to Detect Explosive Substances by the Nuclear Quadrupole Resonance Method

摘要

An experiment in applying the adiabatic demagnetization technique to considerably increase the sensitivity of the nuclear quadrupole resonance (NQR) method for the multipulse detection of one of the most widely used explosives pentaerythritol tetranitrate (PETN)-is described. The results were obtained using a highly inhomogeneous magnetic field produced by permanent magnets. The dependences of the NQR signal enhancement on the carrier frequency offset and the time during which the sample was kept in the magnetic field were studied while using the adiabatic demagnetisation technique.