Scholarly Work - Physics
Permanent URI for this collectionhttps://scholarworks.montana.edu/handle/1/3458
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Item On-Orbit Performance and Calibration of the Soft X-Ray Telescope on Yohkohohkoh Satellite(2016-02) Acton, Loren W.This paper documents details of the on-orbit performance, data problem solving, and calibration of the Soft X-ray Telescope (SXT) experiment on Yohkoh. This information is important to a full understanding of the strengths and weaknesses of the SXT data set. The paper begins with summaries of SXT calibration issues and how they have been addressed, operational anomalies experienced during the mission, and a brief discussion of the SXT optical train. The following section on the accuracy of Yohkoh pointing determination provides information important for alignment of SXT images with each other and with other solar data. The remainder of the paper gives details of work by the experiment team to understand and ameliorate the many instrument anomalies and changes which impacted the scientific data.Item Recalibration of the Soft X-Ray Telescope Onboard Yohkoh(2018-10) Acton, Loren W.We present a new derivation of the X-ray spectral sensitivity of the Soft X-ray Telescope (SXT) experiment onboard Yohkoh. The recalibration is based upon the hypothesis that, during the first 15 months of the mission, an absorbing material gradually built up on the entrance filters of the telescope. We have also re-evaluated the times and sizes of ruptures of the SXT entrance filters. The impact of this recalibration on derived filter-ratio temperature, emission measure, and calculated spectral irradiance is substantial, especially for SXT data prior to November 1992.