Subject: HRI-SIM TV2 Flash report                                             
Date: Fri, 30 Aug 2002 21:30:04 -0400                                         
From: Dennis Wellnitz <wellnitz@astro.umd.edu>                                
                                                                              
Hi all,                                                                       
                                                                              
Note that yesterday's Flash report contained an error: the date was           
August 29, not August 19 as stated in the second paragraph.                   
                                                                              
Today (Friday, August 30), we met at 9:00 am MDT to plan the day's            
activities.  After reviewing the list of remaining activities, we             
concluded that we would not be able to finish everything by a reasonable      
hour this evening, so we split the list into two groups: one to be done       
today, and one to be done Saturday.  We hope to be able to finish all         
work for TV2 by mid-afternoon on Saturday.                                    
                                                                              
After taking our usual darks, our first work for today was gas cell           
measurements: CO, N2 (the reference), and CH4.  We then continued with        
the JPL black body at 190 C, and decided to interspersed it at                
increasing temperatures between other measurements throughout the day,        
because it takes a considerable time to equilibrate to each new               
temperature.                                                                  
                                                                              
After the JPL black body at 190 C, we worked with the tungsten lamp with      
the sapphire window through various ND filters, through the silica            
window, and through the Astronomy H, J, L, and M filters.  These              
filters, especially the M and J filters, gave us very interesting             
information about the stray light at shorter wavelengths that we had          
seen in black body images.  It appears that these are internal                
reflections in the spectrometer, probably reflections from the surface        
of the detector bouncing back to the detector via the focus mirror.  We       
have imported a continuously variable filter from JPL to investigate          
further the wavelength dependence of this stray light.  With the              
information we have gathered and the additional information from the          
continuously variable filter, we should obtain enough information to          
calibrate the effects and thus be able to remove these effects from           
calibrated spectra.                                                           
                                                                              
We then did the latent image test and polystyrene absorption, followed        
by the JPL black body at 300 C.                                               
                                                                              
Next we measured the tungsten lamp with the sapphire window and the gold      
integrating sphere.                                                           
                                                                              
Finally, we measured the JPL black body at 440 C.                             
                                                                              
We recorded 2081 files today, a new record!                                   
                                                                              
For Saturday we have a few more tests to run for the IR spectrometer:         
two more JPL black body temperatures, linearity, the meteorite sample,        
scattered light, and positioning the lamps at the window of the chamber       
to by-pass the telescope optics.  Also, to improve short wavelength           
signals to obtain good data for flat fields, we have obtained a small         
quartz halogen lamp with a 3200 K effective black-body temperature,           
which we plan to use with the gold integrating sphere.  We also have a        
halon screen which, when used with the NIST-traceable tungsten lamp with      
sapphire window at a known distance and angle of illumination, will           
provide us with an absolute irradiance calibration.  We also have a few       
CCD tests to run, including noise from the LVPS as a function of              
phasing, imaging through those filters which have transmission longwards      
of 600 nm (the cut-off of the zinc selenide chamber window, and tests of      
read-outs with the identified and tested changes in patchable constants,      
which were tested over the past few days using the EM CCD and                 
electronics.                                                                  
                                                                              
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