Project/Area Number |
23540344
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Particle/Nuclear/Cosmic ray/Astro physics
|
Research Institution | Nagoya University |
Principal Investigator |
KOJIMA YASUAKI 名古屋大学, アイソトープ総合センター, 講師 (80314730)
|
Project Period (FY) |
2011 – 2013
|
Project Status |
Completed (Fiscal Year 2013)
|
Budget Amount *help |
¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2013: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2012: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2011: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
|
Keywords | 中性子過剰核 / 核構造 / 励起準位寿命 / 崩壊図式 / 半減期 / 励起準位 / 核分光 / 寿命測定 |
Research Abstract |
We have studied neutron-rich rare-earth nuclei around a mass number of 150 by means of beta-gamma decay spectroscopy methods. For 150Ce, a detailed decay scheme was constructed on the basis of gamma-gamma coincidence relations. It includes 18 excited levels and 54 gamma-rays, and gives more information on the level structure than that in the published data. For 149-150Pr and 149Nd, half-lives of excited levels were determined using the delayed coincidence technique. Among them, half-lives of 87- and 126-keV levels in 149Pr were first found to be 4.2(5) and 1.0(2)ns, respectively; The 110-keV level in 150Pr shows a half-life longer than 10ns, while detailed data analysis is now in progress. This level depopulates via E1 gamma-ray emission, which usually shows short half-lives; Long half-life values are not observed in the neighboring nuclei, so that the results are attractive from a view point of nuclear structure.
|