Development of a Novel Ion-Current Semiconductor Detector Array Using a Self-Collection Method for Secondary-Electron Suppression

为了观测开放场等离子体装置中等离子体约束研究中离子和电子端损电流绝对值的空间分布，提出了一种基于自收集原理的小型静电端损电流探测器阵列，用于抑制金属收集极二次电子发射的影响。为了采用这种特定方法，值得注意的是，除了周围开放式磁场之外，检测器结构不需要另外的附加磁系统。这种特性提供了整个检测系统的紧凑性以及其在等离子体约束装置中使用的可用性，而不会干扰等离子体约束磁场。该检测器由一组相对于等离子体装置的环境磁力线平行的金属板组成，用于分析入射离子电流，沿着有网格，用于屏蔽收集器免受由于金属板偏置引起的杂散。通过使用测试离子束线沿着与一个额外的使用亥姆霍兹线圈系统的开放磁场的形成类似于那些在伽马10端部区域的特性实验进行。探测器的可用性在伽马10等离子体实验中得到了清楚的证明。

For the purpose of observations of the space profile on absolute values of ion-and electron-end-loss currents for plasma confinement studies in open-field plasma devices, a compact-sized electrostatic end-loss-current detector array is proposed on the basis of a self-collection principle for suppressing the effects of secondary-electron emission from a metal collector. For employing this specific method, it is worth noting that no further additional magnetic systems except the ambient open-ended magnetic fields are required for the detector structure. This characteristic property provides a compactness of the total detection system and availability for its use in plasma confinement devices without disturbing plasma-confining magnetic fields. The detector consists of a set of parallel metal plates with respect to lines of ambient magnetic forces of a plasma device for analyzing incident ion currents along with a grid for shielding the collector against strays due to the metal-plate biasing. The characterization experiments are carried out by the use of a test-ion-beam line along with an additional use of a Helmholtz coil system for the formation of open magnetic fields similar to those in the GAMMA10 end region. Availability of the detector is clearly demonstrated in the GAMMA10 plasma experiments.