INFLUENCE OF THE DIAMETER AND WALL THICKNESS OF A QUARTZ PIPE INSERTED IN THE EPR CAVITY ON THE SIGNAL INTENSITY

Some dependences between the EPR signal intensity of point samples and the diameter and wall thickness of the quartz tubes with which a stan dard rectangular TE(102) EPR cavity is loaded are reported. It is foun d that the EPR signal intensity linearly depends on the wall thickness of the container and can be increased approximately twice when thick sample tubes are used. The microwave power in the location of the samp le increases similarly whereas the normalized bell-shape distribution of the signal intensity along the z-axis of the cavity remains unchang ed. The effective microwave power necessary to saturate the sample dec reases and the cavity filling factor increases.