High-frequency paramagnetic susceptibility and cavity parameters

In a study on the relation between HF susceptibility and cavity parameters a discussion of higher-order effects is included and demagnetizing effects of the HF field are dealt with. Final formulas are given for an ellipsoidal sample in a collinear region of the HF field and for arbitrary orientation of the HF field with respect to the static field. The relation between the eigenfrequency and the admittance of the cavity is deduced by means of an unusual but more direct formalism which exploits the Poynting vector as basic quantity.