Sign of the 41K electric quadrupole moment determined by ENDOR of F centres in KCl

Abstract

ENDOR measurements of F centres in KCl with a highly sensitive spectrometer allowed the measurement of the quadrupole line positions of the nearest 41K and 39K neighbours to ± 0.5 kHz. The sign of the quadrupole interaction constant was determined for 41K and 39K. It turned out to be positive for both nuclei. Hence the sign of the 41K quadrupole moment is positive in agreement with the only other determination so far by Bonczyk and Hughes with the molecular beam electric resonance method.