Status and plans of neutral particle analyzers as fast ion diagnostics for HL-2A/M

A multi-spatial channel compact pinhole NPA (CP-NPA) has been developed for HL-2A tokamak. CP-NPA has 11 spatial channels, with 2.2° view angle for each channel. CP-NPA will be maintained and calibrated using an energetic neutral source. This neutral source is based on a small ion accelerator system. The source has the following features: Source Particle: H or/and D; Energy range: 0.5keV-70keV; Beam current: ~ 20μA; Small energy dispersion; Beam spot: < 5mm². To calibrate different channels of CP-NPA, we will side lay the CP-NPA and rotate it on a platform. Axis of rotation is at the center line of the slit. In this way, with a single neutral beam, all the detectors could be calibrated.

Diamond detectors have been used for NPA on some devices such as LHD, and will be built for HL-2A/M. Diamond detector has many important advantages to be used as a CX neutral particle spectrometer, for example, very compact size, high energy resolution, and high radiation hardness etc. A new NPA capable of mass resolution and broader energy resolution is planned to be built. The analyzer will be the combination of a permanent magnet and a condenser, to resolve both momentum and energy.