Nuclear Polarization by Means of Laser Optical Pumping and its Application to the Research for Nuclear Structure.

Research Project

Project/Area Number	60460016
Research Category	Grant-in-Aid for General Scientific Research (B)
Allocation Type	Single-year Grants
Research Field	核・宇宙線・素粒子
Research Institution	Kyoto University
Principal Investigator	MATSUKI Seishi Institute for Chemical Research, Kyoto University Associate Professor, 化学研究所, 助教授 (50037941)
Co-Investigator(Kenkyū-buntansha)	大沢孝夫京都大学, 化学研究所, 助手 (20027072) OHSAWA Takao Institute for Chemical Research, Kyoto University Research Associate
Project Period (FY)	1985 – 1986
Project Status	Completed (Fiscal Year 1986)
Budget Amount *help	¥8,300,000 (Direct Cost: ¥8,300,000) Fiscal Year 1986: ¥500,000 (Direct Cost: ¥500,000) Fiscal Year 1985: ¥7,800,000 (Direct Cost: ¥7,800,000)
Keywords	Isotope shift of erbium I / Mean-square nuclear charge-radii / Production of the <^(211m)Po> isotopes with the ( <alpha> ,n) reaction / Nuclear polarization of <^(170)Tm> in <SrF_2> by means of laser optical pumping / Detection of nuclear polarization with associated radiations / レーザーによる原子核構造の研究
Research Abstract	Just after the laser system has been installed, the isotope shift of erbium I was investigated. The transition of 582.7 nm for the natural Er I was used for the measurement of the isotope shift and thus of the change of the mean-square nuclear charge-radii. Also the hyperfine structure of <^(197)Er> was investigated. Even-odd staggering in the mean square nuclear charge radii was also observed in the Er, similar to the neighboring isotopes. Production rate of the <^(211m)Po> isomer was measured with the ( <alpha> ,n) reaction. The transition strength for the 16831 <cm^(-1)> level in the Po was also investigated for the use in laser optical pumping. Feasibility study for the possible application of spin-exchange reaction to the achievement of nuclear polarization of Po is now in progress. Nuclear polarization of <^(170)Tm> (unstable) in <SrF_2> crystal was produced with the laser optical pumping via the excitation of broad absorption band in divalent Tm atom. Nuclear alignment and polarization were measured with the detection of beta and gamma rays emitted in the decay of unstable Tm isotope. Obtained nuclear polarization was about 8 <+!-> 4 %, indicating potential applicability of this method for the study of the nuclear structure.