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

为了观测用于开场等离子体装置等离子体约束研究的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，以抑制金属收集器二次电子发射的影响。为了采用这种特定的方法，值得注意的是，除了环境开放磁场之外，探测器结构不需要另外的附加磁系统。这一特性提供了整个检测系统的紧凑性和在不干扰等离子体约束磁场的情况下用于等离子体约束设备的可用性。该探测器包括一组相对于等离子体设备的环境磁力线的平行金属板，用于分析入射离子电流，以及用于保护收集器免受由于金属板偏置引起的杂散的栅格。表征实验是通过使用测试离子束线和额外使用亥姆霍兹线圈系统来形成类似于GAMMA10端区的开放磁场来进行的。探测器的可用性在GAMMA10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.