title: Improvements to the calibration of the MST Thomson scattering diagnostic.
abstract: Calibration of the Madison Symmetric Torus Thomson scattering system has been refined to improve temperature fluctuation measurements. Multiple avalanche photodiodes have been directly calibrated for use as reference detectors during calibration, improving accuracy and ease of use. From the absolute calibration we calculate corrections to the gain for variation in detector operating temperature. We also measure the spatial uniformity of detector responsivity for several photodiodes, and present a method of accounting for non-uniformity in the calibration process. Finally, the gain and noise enhancement are measured at multiple wavelengths to improve temperature and uncertainty measurements.
authors.affiliation: Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA. eparke@wisc.edu
authors.forename: E
authors.initials: E
authors.lastname: Parke
authors.forename: D J
authors.initials: DJ
authors.lastname: Den Hartog
authors.forename: L A
authors.initials: LA
authors.lastname: Morton
authors.forename: H D
authors.initials: HD
authors.lastname: Stephens
authors.forename: C P
authors.initials: CP
authors.lastname: Kasten
authors.forename: J A
authors.initials: JA
authors.lastname: Reusch
authors.forename: W H
authors.initials: WH
authors.lastname: Harris
authors.forename: M T
authors.initials: MT
authors.lastname: Borchardt
authors.forename: A F
authors.initials: AF
authors.lastname: Falkowski
authors.forename: N C
authors.initials: NC
authors.lastname: Hurst
authors.forename: A
authors.initials: A
authors.lastname: Plunkett
authors.forename: J
authors.initials: J
authors.lastname: Goglio