A comparison of NMR concepts for polarization experiments

For a proposed high-accuracy measurement of the spin-dependent neutron scattering length of the deuteron, a precise relative knowledge of the polarization of the proton and deuteron spin systems in the target material is needed. A simulation of the Q-meter system has been performed to get a quantitative estimate of the influence of various causes on the determination of the signal integral. Experimental and theoretical line shapes have been used as input to the model circuit. The response, i.e. the signal output, has been treated in a realistic way (e.g. integral determination, residual baseline fitting) and the effect of circuit parameter drifts has been analyzed. Several Q-meter system setups and measurement modes have been investigated with respect to inherent limitations and sensitivity to parameter drifts.