ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A spectroscopic diagnostic for measurement of slowing-down alpha particles is under development and will be implemented for D–T operation of the Tokamak Fusion Test Reactor. The visible 468.6 nm He+ line (n=3–4) is excited by charge exchange recombination of alphas with a heating neutral beam (55 keV/amu), and the distortion of the line profile caused by alphas with energies up to 0.5–1.0 MeV is observed. Expected intensities are 0.1%–10% of the bremsstrahlung background for D–T discharges with Q=0.2–1.0. Because the signal is small, a high-throughput optical system is needed to achieve the desired signal-to-noise ratio of 10–100. Vertical and horizontal arrays of sightlines with five spatial channels will be used. Initially, two spatial channels will be coupled via fiber optics to an f/3.8 spectrometer equipped with a low-noise charge coupled device detector, with expansion to 5–10 spatial channels planned for D–T operation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1143474
Permalink