The characteristics of the newly designed microchannel plate detector in astrong magnetic field

A gold neutral beam probe system which uses a microchannel plate (MCP) as a beam detector is being constructed in order to measure the electrostatic p otential at the inner mirror throat (IMT) of the plug/barrier cell in the t andem mirror. The MCP detector was newly designed so as to be able to be us ed in the IMT strong magnetic field. The characteristics of the MCP gain we re measured on a test stand with the strong magnetic field. The characteris tic curves of the relative MCP gain were described as functions of the magn etic field strength, the MCP bias voltage, and the angle between the magnet ic field and the capillary axis of the MCP. It was found that the newly des igned MCP detector was useful for the potential measurement at the IMT regi on. (C) 1999 American Institute of Physics. [S0034-6748(99)04508-6].