Efficient and Versatile scheme for nuclear-spin polarization by a train of short laser pulses

2015 Fiscal Year Final Research Report

• Project/Area Number: 23244053
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: Kyoto University
• Principal Investigator: Nakajima Takashi 京都大学, エネルギー理工学研究所, 准教授 (50281639)
• Co-Investigator(Kenkyū-buntansha): KOBAYASHI Tohru 理化学研究所, 主任研究員研究室等, 専任研究員 (70202067)
• Project Period (FY): 2011-04-01 – 2016-03-31
• Keywords: 核スピン / 偏極 / レーザー / コヒーレンス

Outline of Final Research Achievements

If the target atom to be polarized is in a beam, it is fairly easy to obtain high polarization efficiency by sending the laser pulse from the direction perpendicular to the atomic beam, because Doppler broadening can be neglected. However, for the case of atomic gas as a target, Doppler broadening is the main cause of low polarization and ionization efficiency. To overcome this problem, a straightforward solution is to use either broadband and hence incoherent nanosecond pulses or transform-limited picosecond pulses. Which is better is not a priori obvious. In this work we have carried out the study mainly to clarify this issue, and found that the use of transform-limited picosecond pulses is usually better than that of broadband incoherent nanosecond pulses.

Free Research Field

量子エレクトロニクス