Theory of line narrowing by doublehyphen;frequency irradiation in NQR

摘要

It is shown that the standard timehyphen;dependent perturbation theory is inadequate to treat the problem of line narrowing by doublehyphen;frequency irradiation in NQR. We show here that a semiclassical treatment which avoids the secular terms provides results in agreement with the radiation field quantization method, which is here extended for the first time to NQR problems. As an application, we consider a hypothetical14N NQR double irradiation experiment and we determine the conditions which lead to line narrowing.