Toward the realization of crystalline beams-----Overall investigation of the fundamental properties of ultracold ion beams-----

迈向晶体束的实现-----超冷离子束基本特性的全面研究-----

• 批准号: 14340078
• 负责人: OKAMOTO Hiromi
• 金额: $ 9.22万
• 依托单位: HIROSHIMA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14340078/
• 关键词: Crystalline beam; Linear Paul trap; Nonneutral plasma; Space charge effects; Laser cooling; Particle accelerator; Ion beam

Theoretical Results :1.We have derived the orbit equations that govern the motion of individual particles forming a coasting crystalline beam in a storage ring.2.The necessary condition has been obtained to suppress the occurrence of severe collective instability during a beam cooling process.3.A novel dispersive effect peculiar to bunched crystalline beams has been discovered.4.In order to study the fundamental properties of ultracold ion beams systematically, we have developed a molecular dynamics (MD) code in which not only the exact lattice structure of a storage ring but also the dissipative interactions between laser photons and fast stored ions can be considered.5.Employing the new MD simulation code, we have confirmed the effectiveness of the resonant coupling method. In addition, it has been demonstrated that one- or two-dimensional crystalline beams could be formed in a properly-designed storage ring by combining existing accelerator technologies.Experimental Results :1.We have designed and constructed a linear Paul trap dedicated to beam-physics purposes, in particular, the study of space-charge effects. In order to reproduce lattice-dependent phenomena in a particle accelerator, a radio-frequency power supply system that can generate an arbitrary pulse waveform has been developed.2.Preliminary experiments have been done to check the performance of our system. Measurement data obtained with a MCP detector indicate that it is possible to confine a large number of ions in our trap for a sufficiently long time.3.Several compact atomic ovens have been constructed to produce Ca plasmas. We have succeeded in confining an almost pure ^<40>Ca^+ plasma by applying proper bias voltages to the quadrupole electrodes.4.We have equipped our trap system with a laser cooler that controls the phase-space density of a Ca plasma.

理论结果：1；我们推导出了控制单个粒子在存储环中形成滑行结晶束的运动的轨道方程。得到了抑制束流冷却过程中严重集体失稳发生的必要条件。束状晶体光束所特有的一种新的色散效应已经被发现。为了系统地研究超冷离子束的基本性质，我们开发了一种分子动力学（MD）代码，其中不仅可以考虑存储环的精确晶格结构，而且可以考虑激光光子与快速存储离子之间的耗散相互作用。采用新的MD仿真程序，验证了共振耦合方法的有效性。此外，还证明了结合现有加速器技术，可以在设计合理的存储环中形成一维或二维结晶束。实验结果：1；我们设计并建造了一个线性保罗陷阱，专门用于光束物理目的，特别是空间电荷效应的研究。为了在粒子加速器中再现晶格依赖现象，研制了一种能产生任意脉冲波形的射频电源系统。初步的实验验证了系统的性能。用MCP检测器获得的测量数据表明，在我们的陷阱中有可能将大量离子限制足够长的时间。已经建造了几个紧凑的原子炉来产生钙等离子体。通过在四极电极上施加适当的偏置电压，我们成功地限制了几乎纯的^<40>Ca^+等离子体。我们已经为我们的陷阱系统配备了一个激光冷却器来控制Ca等离子体的相空间密度。

项目成果

Heavy ion storage ring without linear dispersion

无线性色散的重离子存储环

• 发表时间: 2004
• 期刊: Phys.Rev.ST Accel.Beams 7
• 作者: K.Hatanaka;A.Kaneko;M.Ikegami
• 通讯作者: M.Ikegami

Emittance limitation in cooled hadron beams

冷却强子束的发射限制

• 发表时间: 2003
• 期刊: Jpn.J.Appl.Phys. 42
• 作者: M.Takagi;S.Yoshida;N.Kamikubota;J.Odagiri;H.Nakagawa;N.Yamamoto;J.Chiba;T.Katoh;K.Okabe
• 通讯作者: K.Okabe

Generating ultralow-emittance ion beams in a storage ring.

• DOI: 10.1103/physrevlett.93.204801
• 发表时间: 2004-11
• 期刊: Physical review letters
• 影响因子: 8.6
• 作者: Y. Yuri;H. Okamoto

Parametric resonances in intense one-dimensional beams propagating through a periodic focusing channel

通过周期性聚焦通道传播的强一维光束中的参数共振

• 发表时间: 2002
• 期刊: Nucl.Instrum.Meth. A482
• 作者: H.Okamoto

Parametric collective resonances and space-charge limit in high-intensity rings

高强度环中的参数集体共振和空间电荷限制

• 发表时间: 2003
• 期刊: Phys.Rev.ST Accel.Beams 6
• 作者: T.Katoh;J.Chiba;K.Furukawa;N.Kamikubota;H.Nakagawa;K.Niki;J.Odagiri;Y.Takeuchi;N.Yamamoto;M.Furuse;Y.Kato;H.Sakaki;H.Takahashi;F Tamura;M.Tanaka;K.Watanabe;A.V.Fedotov
• 通讯作者: A.V.Fedotov