Consorzio RFX, 35127 Padua, Italy.
Culham Centre for Fusion Energy, Culham Science Centre, United Kingdom Atomic Energy Authority, Abingdon, Oxfordshire OX14 3DB, UK.
Sensors (Basel). 2023 Jul 7;23(13):6211. doi: 10.3390/s23136211.
Stable and uniform beams with low divergence are required in particle accelerators; therefore, beyond the accelerated current, measuring the beam current spatial uniformity and stability over time is necessary to assess the beam performance, since these parameters affect the perveance and thus the beam optics. For high-power beams operating with long pulses, it is convenient to directly measure these current parameters with a non-intercepting system due to the heat management requirement. Such a system needs to be capable of operating in a vacuum in the presence of strong electromagnetic fields and overvoltages, due to electrical breakdowns in the accelerator. Finally, the measure of the beam current needs to be efficiently integrated into a pulse file with the other relevant plant parameters to allow the data analyses required for beam optimization. This paper describes the development, design and commissioning of such a non-intercepting system, the so-called beamlet current monitor (BCM), aimed to directly measure the electric current of a particle beam. In particular, the layout of the system was adapted to the SPIDER experiment, the ion source (IS) prototype of the heating neutral beam injectors (HNB) for the ITER fusion reactor. The diagnostic is suitable to provide the electric current of five beamlets from DC up to 10 MHz.
在粒子加速器中需要稳定且均匀的低发散度光束；因此，为了评估光束性能，除了加速电流之外，还需要测量光束电流的空间均匀性和随时间的稳定性，因为这些参数会影响束流导纳，从而影响光束光学。对于采用长脉冲运行的高功率束流，由于热管理的要求，方便的方法是使用非截获系统直接测量这些电流参数。由于加速器中可能发生电击穿，因此该系统需要能够在存在强电磁场和过电压的情况下在真空中运行。最后，为了进行束流优化所需的数据分析，必须将束流的测量有效地集成到脉冲文件中，并与其他相关的工厂参数集成。本文介绍了这种非截获系统的开发、设计和调试，即所谓的束流监视器（BCM），旨在直接测量粒子束的电流。特别是，该系统的布局适应了 SPIDER 实验，SPIDER 实验是 ITER 聚变反应堆加热中性束注入器（HNB）的离子源（IS）原型。该诊断设备适用于提供从直流到 10MHz 的五个束流的电流。
