Nuclear resonant excitation and detection of its decay signal for the 26.27-keV level of 201Hg is demonstrated with high-brilliance synchrotron radiation (SR) and a fast x-ray detector system. This SR-based photonuclear excitation scheme, known as nuclear resonant scattering (NRS) in the field of materials science, is also useful for investigating nuclear properties, such as the half-lives and radiative widths of excited nuclear levels. To date, because of the limited time response of the x-ray detector, the nuclear levels to which this method could be applied have been limited to the one whose half-lives are longer than ∼1 ns. The faster time response of the NRS measurement makes possible NRS experiments on nuclear levels with much shorter half-lives. We have fabricated an x-ray detector system that has a time resolution of 56 ps and a shorter tail function than that reported previously. With the implemented detector system, the NRS signal of the 26.27-keV state of 201 Hg could be clearly discriminated from the electronic scattering signal at an elapsed time of 1 ns after the SR pulse. The half-life of the state was determined as 629 ± 18 ps, which has better precision by a factor of three compared with that reported to date obtained from nuclear decay spectroscopy.
https://www.nuclock.eu/wp-content/uploads/2015/07/nuclock-color-300x77.png 0 0 Thorsten Schumm https://www.nuclock.eu/wp-content/uploads/2015/07/nuclock-color-300x77.png Thorsten Schumm2019-01-14 14:29:452019-01-14 14:31:12Nuclear resonant scattering experiment with fast time response: Photonuclear excitation of 201Hg