Precise energy measurements of the first-excited state in ¹⁹⁷Au

Institute for Nuclear Research, National Academy of Sciences - Prospect Nauki 47, 03680 Kiev, Ukraine

^a kirisch@mpca.kiev.ua

Received: 21 November 2011
Accepted: 13 December 2011

Abstract

The energy of the first-excited state in ¹⁹⁷Au has been measured with high precision using conventional γ-ray spectroscopy with HPGe detectors. A γ77 keV line of ¹⁹⁷Au and K_β lines of Au are overlapped almost completely and such measurements present a very serious challenge. The coincidence measurements have been applied, first, with the γ77 keV line for the precise energy calibration using K_α and K_β lines of Au, secondly, with K_α lines of Au for the precise energy measurement of the first-excited state in ¹⁹⁷Au. Our current result is 77.339± 0.003 keV, confirming the observations of the recent ¹⁹⁷Au NEET experiment performed at SPring-8, while, according to available nuclear data, the energy of the first-excited state in ¹⁹⁷Au is 77.351±0.002 keV.