Measurement of the Dαspectrum produced by fast ions in DIII-D
- Author(s): Luo, Y
- Heidbrink, WW
- Burrell, KH
- Kaplan, DH
- Gohil, P
- et al.
Published Web Locationhttps://doi.org/10.1063/1.2712806
Fast ions are produced by neutral beam injection and ion cyclotron heating in toroidal magnetic fusion devices. As deuterium fast ions orbit around the device and pass through a neutral beam, some deuterons neutralize and emit Dαlight. For a favorable viewing geometry, the emission is Doppler shifted away from other bright interfering signals. In the 2005 campaign, we built a two channel charge-coupled device based diagnostic to measure the fast-ion velocity distribution and spatial profile under a wide variety of operating conditions. Fast-ion data are acquired with a time resolution of ∼1 ms, spatial resolution of ∼5 cm, and energy resolution of ∼10 keV. Background subtraction and fitting techniques eliminate various contaminants in the spectrum. Neutral particle and neutron diagnostics corroborate the Dαmeasurement. Examples of fast-ion slowing down and pitch angle scattering in quiescent plasma and fast-ion acceleration by high harmonic ion cyclotron heating are presented. © 2007 American Institute of Physics.
Many UC-authored scholarly publications are freely available on this site because of the UC Academic Senate's Open Access Policy. Let us know how this access is important for you.