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.推导了储存环中形成滑行晶体束的单个粒子运动的轨道方程。2.获得了抑制束流冷却过程中严重集体不稳定性发生的必要条件。3.发现了束状晶体束特有的新型色散效应。4.为了系统地研究超冷离子束的基本性质，我们开发了一种超冷离子束流场。 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，还可以考虑激光光子和快速存储离子之间的耗散相互作用。5.采用新的MD模拟代码，我们证实了共振耦合方法的有效性。此外，已经证明，通过结合现有的加速器技术，可以在适当设计的存储环中形成一维或二维晶体束。 实验结果：1.我们设计并构建了一个专用于束流物理目的，特别是空间电荷效应研究的线性保罗陷阱。为了在粒子加速器中重现晶格相关现象，开发了一种可以产生任意脉冲波形的射频电源系统。2.进行了初步实验来检查我们系统的性能。用MCP探测器获得的测量数据表明，可以在足够长的时间内将大量离子限制在我们的陷阱中。3.已经建造了几个紧凑的原子炉来产生Ca等离子体。通过向四极电极施加适当的偏压，我们成功地限制了几乎纯的^<40>Ca^+等离子体。4.我们为我们的陷阱系统配备了激光冷却器，用于控制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