ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
We describe the x-ray diagnostics employed on the Tandem Mirror Experiment-Upgrade (TMX-U) to measure the x-ray emission from plasma locations where electron cyclotron radio frequency heating is applied. At each potential minimum of the TMX-U plasma, broadband spectra are obtained with NaI scintillation and cooled HPGe detectors that are coaligned to view the same plasma volume. The high-energy sensitivity of the NaI detector is necessary for studying x rays emitted by hot runaway electrons with energies exceeding 200 keV. The spectral response of the HPGe detector complements the NaI performance. Its higher resolution at energies below 100 keV is the key to determining what fraction of ECRH power is transferred to a bulk density of cooler (∼50 keV) mirror-confined electrons. X-ray spectra from the TMX-U end cell, where a potential peak produced by sloshing ions and ECRH create a localized plasma with Te ∼1.6 keV, will be measured with a Si(Li) detector. The geometrical configuration, shielding requirements, data handling systems, and recent results will be presented.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1138066
Permalink