Innovative Development for High Intensity Proton Synchrotron with High Permeability Magnetic Alloy

高磁导率磁性合金高强度质子同步加速器的创新开发

• 批准号: 09309002
• 负责人: MORI Yoshiharu
• 金额: $ 19.26万
• 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 (A)
• 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-09309002/
• 关键词: high permeability magnetic alloy; high accelerationg field gradient; accelerating cavity; impedance tuner; space charge eanceleration

We have measured various characteristics of the different types of high permeability magnetic alloy (MA) core and found that a large accelerating field gradient of more than 100kV/m is possible with the MA cores. This is because the maximum allowable if magnetic flux of the MA core is more than 2kG which is ten times larger than that of the ferrite core. Based on these measurements, the prototype of the single-gap high gradient cavity whose total length is only 40cm has been developed. This cavity consits of 8 MA cores. With this cavity, a maximum voltage of 20kV, which is limited by the rf amplifier whose maximum power is 300kW, has been obtained at the resonant frequency of about 2.-3MIHz so far. This corresponds that the effective accelerating field gradient is 50kV/m, which is almost 5 times larger than that of the ordinary ferrite loaded if accelerating cavity. The Q value of this cavity is relatively low (Q-0.6), thus, its band width is very broad, which would be beneficial for acceleration of heavy ion. This cavity was installed at HIMAC and successfully accelerated heavy ions such as He, C, Ne ions up to several 100MeV/u.We designed the "Impedance tuner" consisting of the inductive material, high permeability magnetic alloy (MA) cores, to cancel the space charge impedance in the longitudinal direction. It was installed in the KEK PS main ring. We observed the frequency shift of the coherent quadrupole oscillations and inferred the shift of the incoherent synchrotron oscillation. Total reactive impedance can be estimated as the coefficient between the shift and beam intensity. The measured impedance is reduced from-j2475OMEGA to-j1182OMEGA by the impedance tuner. We demonstrated the space charge impedance is compensated by the impedance tuner.

我们测量了不同类型高磁导率磁性合金 (MA) 磁芯的各种特性，发现 MA 磁芯可以实现超过 100kV/m 的大加速场梯度。这是因为MA磁芯的最大允许磁通量超过2kG，是铁氧体磁芯的十倍。基于这些测量，开发出了总长度仅为40cm的单间隙高梯度腔原型。该腔体由 8 个 MA 磁芯组成。利用该腔体，迄今为止在约2.-3MIHz的谐振频率下获得了20kV的最大电压，该电压受到最大功率为300kW的射频放大器的限制。这对应的有效加速场梯度为50kV/m，几乎比普通铁氧体加载加速腔的加速场梯度大5倍。该腔的Q值较低（Q-0.6），因此其带宽很宽，有利于重离子的加速。该腔体安装在HIMAC，成功地将He、C、Ne等重离子加速到数100MeV/u。我们设计了由感应材料、高磁导率磁性合金（MA）磁芯组成的“阻抗调谐器”，以消除纵向上的空间电荷阻抗。它安装在 KEK PS 主环中。我们观察了相干四极振荡的频移并推断了非相干同步加速器振荡的频移。总无功阻抗可以估计为位移和光束强度之间的系数。阻抗调谐器将测得的阻抗从-j2475OMEGA 减小到-j1182OMEGA。我们证明了空间电荷阻抗是由阻抗调谐器补偿的。

项目成果

M.Fujieda et al.: "MA-load cavity for barrier bucket experiment." Proc.of the Sixth European Particle Accelerator Conf., Stockholm, 22-26 June 1998.1796-1798 (1998)

M.Fujieda 等人：“用于屏障桶实验的 MA 负载腔。”

M.Fujieda et.al.: "MA-loaded cavity for barrier bucket experiment." Proc.of the Sixth European Particle Accelerator Conf., Stockholm, 22-26 June 1998. 1796-1798 (1998)

M.Fujieda 等人：“用于屏障桶实验的 MA 加载腔。”

Yoshiharu Mori: "The design and R&D works for the 50-GeV synchrotron of Japan hadron facility" Proc of the Asian Particle Accelerator Conf. (APAC'98), Tsukuba, Japan, March 1998.375-377 (1999)

森喜晴：“设计和 R

Y.Mori: "A new type of RF cavity for high intensity proton synchrotron using high permeability magnetic alloy." Proc.of the Sixth European Particle Accelerator Conf., Stockholm, 22-26 June 1988. 299-301 (1998)

Y.Mori：“一种使用高磁导率磁性合金的新型高强度质子同步加速器射频腔。”

Yoshiharu Mori: "A new type of RF cavity for high intensity proton synchrotron using high permeability magnetic alloy." Proc.of the Sixth European Particle Accelerator Conf., Stockholm, 22-26 June 1998.299-301 (1998)

Yoshiharu Mori：“一种使用高磁导率磁性合金的新型高强度质子同步加速器射频腔。”