ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
We are incorporating a system of fast, variable apertures in our designs for the x-ray, neutral, and ion spectrometers for plasma diagnostics on Mirror Fusion Test Facility B (MFTF-B). The purpose of these apertures is to maintain optimized count rates, and thus optimized measurement statistics during an experimental shot, where flux variations as large as 104–105 may occur in periods as short as 0.1 s. We shall discuss the application of the fast apertures to the x-ray spectrometer in particular, and to the other diagnostic instruments in general. The particular design requirements for the optimized aperture system will be discussed, as will be the influence the system has on the data-handling process. We have performed experiments to test this new concept and shall present the results, including the details of the closed-loop feedback circuit controlling the apertures, optimization of the loop gain, and the engineering issues of the system, such as the effect of vacuum feedthrough, position sensitivity, and alignment criteria.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1138515
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