Systematic investigations and improvements of the efficiency, purity and emittance of charge bred ion beams from the TRIUMF charge state booster.

对 TRIUMF 电荷态增强器的电荷孕育离子束的效率、纯度和发射率进行系统研究和改进。

• 批准号: SAPPJ-2018-00023
• 负责人: Kester, Oliver
• 金额: $ 1.09万
• 依托单位: TRIUMF
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Project
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=655375
• 关键词: Systematic; investigations; improvements; efficiency; purity

The TRIUMF charge state booster (CSB) raises the charge state of ions from rare isotopes prior to injection into the ISAC-I linac. Therewith, it allows the post acceleration of isotopes from elements beyond mass 30 and avoids the stripping of ions at very low kinetic energies downstream the ISAC-I Radio Frequency Quadrupole (RFQ) into an A/q mass range below 7. An inherent issue of the CSB is the operation vacuum pressure. An ECRIS does not operate at Ultra High Vacuum (UHV), which is the cause of the high level of impurities in such devices, which is an issue when dealing with very low radioactive ion intensities. However, the 1+ ->n+ conversion rate depends on the flexibility of the injection optics, the plasma conditions, the plasma confinement and the beam formation upon ion extraction, which can be optimized. The ECRIS is definitely superior to an EBIS related to the production of intense beams of rare isotopes >10^9 per second. ***The main objective of this proposal is to improve the TRIUMF CSB performance in terms of beam quality, charge breeding efficiency and beam purity, by introducing techniques which are used or under investigation at other ECRIS systems. The goal is to bring TRIUMF into the international leadership in charge breeding with ECRIS devices and to deliver higher quality and new beams to the experiments. As the injection- and the ionisation efficiency as well as the beam purity essentially depend on the plasma conditions, the two-frequency heating and the tuning of the microwave frequency, will be introduced. These techniques rely on the generation of plasma modes that allow higher plasma densities and optimum coupling of the rf-power. The project described in this proposal intends to investigate systematically the charge breeding efficiency and the beam quality by ***- modifying the plasma conditions using two frequency heating and frequency tuning***- variation of the plasma chamber working gas pressure, use of UHV technology associated with the control of the plasma chamber material and the support gas composition***- beam emittance measurements using a slit-slit emittance scanner and corresponding beam extraction calculations.***In addition, the CSB will be modified by adding a high temperature oven, to exploit a new type of beam delivery via the production of highly charged ion beams from samples in the solid state. The oven need to be resistive against reactive metals, in particular for Ti-isotopes. The goal is to demonstrate a lifetime of the oven for at least several days Ti operation. This can be used to deliver long lived 44Ti (t1/2 =59Y) to users at TRIUMF.***The significant improvement of the CSB beam properties and additional beam production capabilities will benefit the experimental program at ISAC in particular for accelerated beam experiments. The second aspect is the training of highly qualified personnel in the field of plasma ion sources in general and on ECRIS sources in particular.

TriumF电荷升高（CSB）在注入ISAC-I Linac之前从稀有同位素的离子荷兰升高。因此，它允许从质量30以外的元素加速同位素的后加速度，并避免在下游的非常低的动力学能量下剥离离子iSAC-1射频四极管（RFQ）进入7。 CSB是操作真空压力。 ECRIS不在超高真空（UHV）上运行，这是这种设备中高水平杂质的原因，这是处理非常低的放射性离子强度时的问题。但是，1+ - > n+转换率取决于入口光学元件的柔韧性，血浆条件，血浆限制和离子提取后的束形成，可以优化。 ECRIS绝对优于与稀有同位素强束的产生> 10^9相关的EBIS。 ***该提案的主要目的是通过在其他ECRIS系统中引入或正在研究的技术来改善Triumf CSB的性能，从光束质量，电荷育种效率和光束纯度方面提高。目的是将Triumf带入以ECRIS设备为负责繁殖的国际领导人，并为实验提供更高质量和新的光束。由于注射效率和电离效率以及梁纯度在本质上取决于血浆条件，因此将引入两频加热和微波频率的调整。这些技术依赖于等离子体模式的产生，这些等离子体模式允许更高的血浆密度和最佳的RF耦合。该提案中描述的项目旨在通过***进行系统地调查电荷育种效率和光束质量 - 使用两个频率加热和频率调谐*** - 等离子体室内工作气压的变化，使用UHV与血浆室材料的控制和支持气体组成相关的技术*** - 梁发射率测量器使用缝隙缝隙散布扫描仪和相应的束提取计算。温度烤箱，通过从固态中的样品中产生高电荷离子束来利用新型的光束传递。烤箱需要抵抗反应金属，尤其是对于Ti同位素。目标是至少在Ti操作中展示烤箱的寿命。这可用于将长期寿命的44TI（T1/2 = 59Y）传递给Triumf的用户。 。第二个方面是在总体上，尤其是在ECRIS来源的血浆离子来源领域对高素质人员的培训。