Study of photonuclear reactions in the DELTA-resonance region using a polarized ^3He target

使用偏振 ^3He 靶研究 DELTA 共振区域的光核反应

• 批准号: 06640370
• 负责人: TERASAWA Tatsuo
• 金额: $ 1.41万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640370/
• 关键词: polarized ^3He target; polarized rubidium; optical pumping; Farady rotation; DELTA-resonance; photonuclear reaction

This research project aims to investigate nucleon-nucleon correlations in ^3He by means of photonuclear reactions using a polarized ^3He target. The polarized target is obtained by a spin exchange reaction between a polarized alkaline atom and a target atom.As a first step to make the polarized ^3He target, we tried to produce polarized rubidium atoms using an optical pumping method with a circularly polarized laser light. We have used a 0.5W titanium-sapphire laser as the source, and, in order to prevent the depolarization due to the collision between produced polarized atoms and the pumping cell wall, we have coated the wall with dimethyldichlorosilane.A search for the most optimum condition for the production needs a quick and precise measurement of the polarization and the tthickness of the products. We have developed a high speed measuring system, which enable to measure the Faraday rotation abgle with the precision less than 0.01 deg.Finally we have succeeded to produce a polarized rubidium atoms having the polarization of 0.4 with the thickness of 10^<14> atoms/cm^2.

本研究项目旨在利用极化^3He靶，通过光核反应研究^3He中的核子-核子相关性。通过极化碱性原子与靶原子之间的自旋交换反应得到极化靶。作为制造偏振光^3He靶的第一步，我们尝试用圆偏振激光的光泵浦方法产生偏振光铷原子。我们使用了0.5W的钛蓝宝石激光器作为光源，为了防止产生的极化原子与泵浦细胞壁碰撞导致去极化，我们在细胞壁上涂上了二甲基二氯硅烷。为了寻找最佳的生产条件，需要对产品的极化和厚度进行快速而精确的测量。我们开发了一套高速测量系统，能够以小于0.01度的精度测量法拉第自转角，最终成功地制备出偏振度为0.4，厚度为10^<14>原子/cm^2的铷原子。