INVESTIGATION OF MULTIPLE SPIN FLIP PROCESSES TO PRODUCE TRANSITIONS AND INVERSIONS AT ARBITRARY FREQUENCIES

The rate equations governing the operation of a six-level maser utilizing cross relaxations between the three pairs of spin levels in phosphorous-boron doped silicon are derived. Excess populations are obtained under the assumption that the longitudinal relaxation time for electrons in boron states is much shorter than that for electrons in phosphorous states, in terms of a cross relaxation time tau sub x and the longitudinal times tau sub 1. Dependence of tau sub x on concentrations, and minimal conditions for inversion, are established. The criteria for the design and operation of a dual-mode spectrometer to be used (1) to measure tau sub x and (2) as a maser, are established in terms of microwave parameters and spin system-crystal parameters. Estimates of the operating values are made by taking reasonable values for the parameters. The final design and operation of the spectrometer is described. The effects of cavity loading are estimated in terms of the cavity mode and crystal lossiness, and are compared to the experimental practice. Sensitivity of the spectrometer and experimental results are given. (Author)