Subject: HRI-SIM TV2 Flash report Date: Wed, 28 Aug 2002 23:15:02 -0400 From: Dennis Wellnitz Hi all, Today (Wednesday, August 28), we met briefly at 9:00 am MDT to plan the day's activities. We then continued the IR spectrometer calibration at the "warm" bench temperature of 142 K, commencing with the tungsten lamp with the sapphire window and the gold integrating sphere. We then used the same setup with the CCD system to perform a linearity test, followed by imaging of two test targets to verify placement and orientation of the CCD quadrants with respect to the outside world. Following on this we used the SIRTF black body and gas cells filled with CH4, N2 (as a reference), and CO. The shifts of the CH4 and CO absorption lines for this bench temperature as compared to the previous bench temperature confirmed expectations from the Code V model. We then performed the filter wheel EMI test (running the filter wheel for about 100 seconds while taking IR-FPA darks). We saw no EMI associated with the filter wheel, but did see motion of the end of the slit on the array (due to the black body emission of the room at long wavelengths), in the amount of about one third of a pixel in the spatial direction. There was also a small motion in the spectral direction, but the amount has not yet been determined. Before the end of this Thermal Vac, we plan to run an additional test of motion using the Argon lamp as a source, to better quantify the spectral motion due to filter wheel movement. We again attempted the scattered light test, but got puzzling results, with increased background throughout the field of view. It may be that we are seeing reflections of our off-slit sources, so we may need to control the reflective background better. We then tried a test of a quartz halogen lamp with a higher color temperature than any source previously tried, in an attempt to boost the short wavelength response. This was tried with both the gold and the white integrating spheres, but provided somewhat disappointing results. Though this lamp provided a test source with a roughly solar spectral signature in the near infrared, we still saw minimal signal in the short wavelength channels. This data will be reviewed more extensively tomorrow in hopes of understanding why we have this low response. We finished the day with the SIRTF black body placed near the chamber window, to provide a reference without the telescope optics. While pursuing these tests, a few of us continued to work on the CCD overscan anomalies. Towards the end of the day, we believe we understood what was happening and how to fix it. Tests will be run soon (hopefully tomorrow) on the EM CCD system in the lab to see whether the changes we propose will solve the problem. When we finished these tests, we began cooling the system to the "cold" bench temperature which will be in the range 128-130 K, possibly warmer than HRI-SIM Thermal Vac 1 due to increased parasitic heat loads. John Ferguson believes we could be at the new stable temperature around noon tomorrow, so we hope to start the cold bench calibration at that time. We plan to meet briefly at 9:00 am MDT tomorrow, and then commence a careful version of the co-focus and co-alignment of the IR spectrometer and CCD system in the morning, and then continue with the IR spectrometer calibration in the afternoon and evening. If everything goes well, we may be able to finish the calibration work sometime between late Friday and mid-day Saturday, and then begin warming up. Please let me know if you have any comments or questions. If you would prefer not to receive these Flash reports on HRI-SIM TV2, please let me know. Dennis