Half-life of ¹⁸⁴Re populated by photodisintegration reaction with Laser Compton scattering γ-rays at NewSUBARU

Abstract

Abstract. We report a half-life of the ground state of 184 Re populated by the 185 Re(γ,n) 184 Re reaction with the Laser Compton scattering γ-rays generated through relativistic engineering. The γ rays are provided at the electron storage ring NewSUBARU. The half-life of the 3 − ground state of 184 Re, 38.0±0.5 d, has been taken as a recommended value, which was measured using deuteron-induced reactions. However, this half-life may include a possible contribution from the 8 + isomer (T 1/2 = 169±8 d) of 184 Re since the presence of the isomer was not known at that time. In contrast, the (γ,n) reaction has the advantage to selectively populate the ground state because this reaction does not bring large angular momentum. The measured half-life of 35.4 ± 0.7 d is shorter than the previous half-life by about 7%. This difference is crucial for applications using the activation method.

Proposal for selective isotope transmutation of long-lived fission products using quasi-monochromatic γ-ray beams

“…refs. [25,26]). The nuclear structure of 123 Sn is similar to that of 121 Sn; there are an isomer with a halflife of 40 m (J π = 3/2 + ) and the ground state with a halflife of 129 d (J π = 11/2 − ).…”

Proposal of Nondestructive Radionuclide Assay Using a High-Flux Gamma-Ray Source and Nuclear Resonance Fluorescence

“…Laser Compton gamma-ray facilities have been constructed as parasitic beam lines of electron storage rings, where gamma-ray flux F $ 10 1 À 10 4 /s/keV is available. [7][8][9] Such facilities have been used for studying nuclear physics 10,11) and astrophysics. 12,13) In order to increase the flux of laser Compton gammaray sources, the density of laser photons and electrons at the collision point must be increased.…”