Fisher R K, Pace D C, García-Muñoz M, Heidbrink W W, Muscatello C M, Van Zeeland M A, Zhu Y B
General Atomics, P.O. Box 85608, San Diego, California 92186-5608, USA.
Rev Sci Instrum. 2010 Oct;81(10):10D307. doi: 10.1063/1.3490020.
A new scintillator-based fast ion loss detector has been installed on DIII-D with the time response (>100 kHz) needed to study energetic ion losses induced by Alfvén eigenmodes and other MHD instabilities. Based on the design used on ASDEX Upgrade, the diagnostic measures the pitch angle and gyroradius of ion losses based on the position of the ions striking the two-dimensional scintillator. For fast time response measurements, a beam splitter and fiberoptics couple a portion of the scintillator light to a photomultiplier. Reverse orbit following techniques trace the lost ions to their possible origin within the plasma. Initial DIII-D results showing prompt losses and energetic ion loss due to MHD instabilities are discussed.
一个基于闪烁体的新型快速离子损失探测器已安装在DIII-D装置上，其时间响应（>100 kHz）满足研究阿尔文本征模和其他磁流体动力学不稳定性所引起的高能离子损失的需求。基于ASDEX升级装置所采用的设计，该诊断设备根据撞击二维闪烁体的离子位置来测量离子损失的俯仰角和回旋半径。对于快速时间响应测量，一个分束器和光纤将一部分闪烁体发出的光耦合到一个光电倍增管。反向轨道跟踪技术可将损失的离子追溯到它们在等离子体中可能的起源位置。文中讨论了DIII-D装置的初步结果，这些结果展示了由磁流体动力学不稳定性导致的即时损失和高能离子损失。
