[dsg-hallb_rich] [EXTERNAL] Re: d0 tests repeated for mirror 5 and 5C

[Marco Mirazita]

Hi Tyler,
can you put the raw data some where I can get them? I would also like to 
have the sequence of your measurements.
Thank you
Marco


Il 2021-10-05 19:36 Tyler Lemon ha scritto:
> Hello,
> 
>  This morning Mindy and I repeated d0 tests for RICH spherical mirror
> 5 and 5C with both mirrors in the horizontal and vertical position
> while testing whether the ambient light background or time CCD is
> active have an effect on the measurement.
> 
>  Before each set of mirror measurements, we took a new background
> image for use with that set of data.
> 
>  The first measurement was taken of mirror 5C in the horizontal
> position with the room in the same conditions as the last week's
> measurements.
> 
>  Next we eliminated as many sources of ambient light as possible,
> repeated the measurement of 5C in horizontal position, then measured
> 5C in the vertical position, switched mirror to measure 5 in the
> vertical position, and finally measured 5 in the horizontal position.
> 
>  When comparing background images for without and with ambient light
> sources covered, CCD pixel counts were an average of 0.13 +/- 2.39
> counts lower when ambient light was eliminated (histogram in Fig 1).
> 
>  When comparing the first no-ambient-light background with the last
> no-ambient-light background (~1 hour 15 minutes later), the CCD pixel
> counts for the last background measurement were an average of 0.36 +/-
> 2.38 counts lower (histogram in Fig 2).
> 
>  From these results, I do not think that leaving the ambient light in
> the room affects the background data too much. However, I do think
> that it is a good idea to take the multiple background measurements
> for each set of measurements.
> 
>  The table below has the results of the d0 test for each mirror.
> 
>  Mirror
>  Position
>  Ambient Light Eliminated?
>  Lowest d0 Observed [mm]
>  Fit d0 [mm]
>  Fit Mirror Radius of Curvature [mm]
> 
>  5C
>  horizontal
>  No
>  		 1.969
>  2.12
>  2708.1
> 
>  5C
>  horizontal
>  Yes
>  2.008
>  2.16
>  2708.23
> 
>  5C
>  vertical
>  Yes
>  2.989
>  3.01
>  2702.15
> 
>  5
>  horizontal
>  Yes
>  2.468
>  2.81
>  2709.8
> 
>  5
>  vertical
>  Yes
>  2.670
>  2.69
>  2704.26
> 
>  Because the PDFs of the results are each ~10 MB, I have put them on
> my JLab userweb page at the link below.
> 
>  https://userweb.jlab.org/~tlemon/RICH/RICHII_mirrors/
> 
>  -Tyler
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