Evidence for nuclear excitation by electron transition on 193Ir and its probability

✍ Scribed by S. Kishimoto; Y. Yoda; Y. Kobayashi; S. Kitao; R. Haruki; M. Seto

• Publisher: Elsevier Science
• Year: 2005
• Tongue: English
• Weight: 130 KB
• Volume: 748
• Category: Article
• ISSN: 0375-9474
• DOI: 10.1016/j.nuclphysa.2004.10.016

✦ Synopsis

Nuclear excitation by electron transition (NEET) has been observed for 193 Ir in K-shell photoionization, following a previous measurement for 197 Au. We detected internal conversion electrons emitted by decaying excited nuclei of 193 Ir in time spectroscopy using a silicon avalanche photodiode. The incident synchrotron X-rays were monochromatized and scanned around the iridium K-edge ( E = 0 eV). At energies of between E = +105 and +344 eV, an increase of event rates due to nuclear excitation was observed at a level of 2.2-times higher than the standard deviation of the background measured at energies of between E = -3 and -324 eV. The NEET probability at E = +128 eV was obtained to be (2.8 ± 0.4) × 10 -9 , which is less than one tenth of the probability for NEET on 197 Au.