Nuclear Laser Spectroscopy of Be Isotopes with Ion-trap

使用离子阱进行 Be 同位素核激光光谱分析

• 批准号: 09440099
• 负责人: WADA Michiharu
• 金额: $ 9.34万
• 依托单位: High Energy Accelerator Research Organization
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09440099/
• 关键词: Hyerfine anomaly; Be; Laser-microwave spectroscopy; RF-ionguide; RFイオンガイド; ベリリウム-7; 超微細構造定数; 超微細構造異常; 価中性子

This research project aimed at developing an experimental method to perform nuclear laser spectroscopy of unstable Be isotopes. The hyperfine coupling constant A in the atomic hyperfine interaction shows a weak but finite isotope dependence called hyperfine anomaly, the main part of which stems from the finite size of the magnetization distribution in the nucleus (Bohr-Weisskopf effect). This effect affords a unique and interesting probe for valence neutron distribution in a nucleus, particularly in a so-called neutron halo nucleus such as Be-ll.Various developments for the experimental technique have been carried out using the stable isotope of Be-9 trapped in a linear RE trap placed at a weak magnetic field. High sensitive detection of microwave-resonance was demonstrated using continuous irradiation method where laser and microwave radiations were continuously applied. A high S/N resonance signal was observed with in a few seconds of measurement. A high precision measurement was also tested using a pulsed method. By repeating the short cycle (a few ins) of alternative irradiation of laser and microwave radiation, reasonably high accuracy of 2*1O-7 was obtained.Trial experiments for investigating the first unstable isotope of Be-7 have been carried out, however, no fluorescence signal was observed so far. The difficulty is considered to be due to the luck of knowledge in the resonant wave-length and to the fact that the number of Be-7 ions in the trap are critical. Various kind of improvements in the theoretical calculation of the specific isotope shift as well as in the experimental technique to increase the density of Be-7 ions in the trap are under progress.For shorter lifetime isotopes, such as Be-ll, an on-line trapping method for energetic beams from a fragment isotope separator is also under development using a newly proposed RE-ionguide technique.

该研究项目旨在开发一种实验方法，以执行不稳定同位素的核激光光谱。原子超精美相互作用中的超精细耦合常数A显示出弱但有限的同位素依赖性称为超精细异常，主要部分源于细胞核中磁化分布的有限大小（Bohr-Weisskopf效应）。这种作用为核中的价中子分布提供了独特而有趣的探针，尤其是在所谓的中子晕核核（例如Be-ll）中。已使用将BE-9的稳定同位素捕获在弱磁场上的线性重置中的BE-9的稳定同位素进行了实验技术。使用连续辐照方法证明了微波谐振的高敏感检测，在这种方法中，激光和微波辐射连续使用。在几秒钟的测量中观察到了高S/N共振信号。还使用脉冲方法测试了高精度测量。通过重复对激光和微波辐射的替代辐射的短周期（几个INS），可以获得相当高的2*1O-7精度。难度被认为是由于谐振波长度中的知识运气以及陷阱中的BE-7离子数量至关重要的事实。特定同位素转移的理论计算以及陷阱中BE-7离子的密度的各种改进正在进行中。对于较短的终生同位素，例如Be-ll，一种在线陷阱的陷阱，用于使用碎片分离器的在线陷阱，用于使用碎片分离器的能量束，也是在使用新的Ineposed Re-Indosed Re-Inguide Inquique中。

项目成果

K.Okada et.al.: "Laser-microwave double resonance spectroscopy of laser-cooled 9Be+ ions in a weak magnetic field for studying unstable Be isotopes" Journal of Physical Society of Japan. 67. 3073- (1998)

K.Okada 等人：“弱磁场中激光冷却 9Be 离子的激光-微波双共振光谱用于研究不稳定 Be 同位素”日本物理学会杂志。

K..Okada,I.Katayama M.Wada et al: "Status of the laser-microwave spectroscopy Experiment for the hyportsis Structure of ^7Be" Hypertive Interactions.

K..Okada,I.Katayama M.Wada 等人：“^7Be 假设结构的激光微波光谱实验的状态”过度相互作用。

I.Katayama, M.Wada, H.Kawakami, J.Tanaka and K.Noda: ""Cyclotron ion guide for energetic radioactive nuclear ions"" Hyper.Inter.115. 165 (1998)

I.Katayama、M.Wada、H.Kawakami、J.Tanaka 和 K.Noda：“高能放射性核离子的回旋离子引导”Hyper.Inter.115。

K.Okada, I.Katayama, M.Wada, T.Nakamura, S.Ohtani, G.Marx, S.Fujitaka, J.Tanaka and H.Kawakami: ""Status of the laser-microwave spectroscopy experiment for the hyperfine structure of 7Be"" Hyper.Inter.115. 209 (1998)

K.Okada、I.Katayama、M.Wada、T.Nakamura、S.Ohtani、G.Marx、S.Fujitaka、J.Tanaka 和 H.Kawakami：“超精细结构激光微波光谱实验的现状”

K.Okada et.al.: "Status of the laser-microwave spectroscopy experiment for the hyperfine structure of 7Be" Hyper fine Interactions. 115. 209- (1998)

K.Okada 等人：“7Be 超精细结构激光微波光谱实验的现状”超精细相互作用。