ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A compact multichannel scintillator probe is described, which has been used to make spectral measurements of energetic electron end-loss (E∼400 keV) from an electron cyclotron resonance-heated mirror plasma. The probe utilizes entrance foils of various thicknesses for energy discrimination, and photomultiplier tubes that are used in current mode with linear amplifiers for fast response (Δt∼0.1 μs) or logarithmic amplifiers for wide dynamic range (10−8–10−4 A). The probe is used to obtain spectra in the energy range 10–500 keV, and is sensitive to power densities above 0.1 mW/cm2. The energy dependence of the response of a low-energy channel (sensitive to electrons above 10 keV) has been measured, and agrees very well with a calculation of the foil discrimination. Calibration results and sample data from the mirror plasma experiment are presented. Uses other than the measurement of electron end-loss in mirror experiments include measurement of runaway electron populations at the edge of tokamak plasmas and direction-sensitive measurement of high-energy electron populations in tokamak plasmas with lower hybrid current drive.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1139962
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