Overview of the beam emission spectroscopy diagnostic system on the National Spherical Torus Experiment
1Department of Engineering Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. drsmith@engr.wisc.edu
Abstract:
A beam emission spectroscopy (BES) system has been installed on the National Spherical Torus Experiment (NSTX) to study ion gyroscale fluctuations. The BES system measures D(α) emission from a deuterium neutral heating beam. The system includes two optical views centered at r/a≈0.45 and 0.85 and aligned to magnetic field pitch angles at the neutral beam. f/1.5 collection optics produce 2-3 cm spot sizes at the neutral beam. The initial channel layout includes radial arrays, poloidal arrays, and two-dimensional grids. Radial arrays provide coverage from r/a≈0.1 to beyond the last-closed flux surface. Photodetectors and digital filters provide high-sensitivity, low-noise measurements at frequencies of up to 1 MHz. The BES system will be a valuable tool for investigating ion gyroscale turbulence and Alfvén/energetic particle modes on NSTX.
Related Concept Videos
Atomic Emission Spectroscopy: Instrumentation
Atomic Emission Spectroscopy: Overview
Atomic Emission Spectroscopy: Lab
Inductively Coupled Plasma Atomic Emission Spectroscopy: Instrumentation
There are three main types of inductively coupled plasma atomic emission spectroscopy (ICP-AES) instruments: sequential, simultaneous multichannel, and Fourier transform instruments, with the latter being less commonly used.
Tandem Mass Spectrometry
Atomic Absorption Spectroscopy: Instrumentation
The atomizer used in AAS can be either a flame atomizer or an...

