EUV_BACKGROUND.DOC	Jan 20, 1994 

The folowing material was provided by Wayne R. Pryor, UVS/EUV Co-I,
on Jan 12, 1994.
===================================================================

   Typical cruise files, EUV_748148_22.MRO  (Mar 5,91)
                 and   EUV_742540_20.MRO  (Mar11,91)

     yield 160 counts per sector per pixel in background pixel 21 in
     340,219 seconds

     each sector integrated for 340,219/35 = 9720 seconds

     so counts per detector per second =    160 cnts
                                         ____________   * 128 pixels
					 9720 pixel sec


                                       =  2.1 cnts per sec per detector
    *********************************************************************

    Broadfoot (JGR 86,8259-8282) finds Voyager has

       (2.5 x 10^-2 cnts per sec per anode) x (128 anodes) 

             =   3.2 cnts per sec per detector,  in space

    *********************************************************************

    Broadfoot (Space Science Rev 21, 183-205) found Voyager has 

       (3 x 10^-3 cnts per sec per anode) x (128 anodes)

             =   0.38 cnts per sec per detector,  in the lab

    *********************************************************************

                        EUV GEOTAIL BACKGROUND

    In Encounter mode, in deep space, we typically use 1/2 of the
    available data rate, or about 500 counts per RIM, 0r 8.2 counts/sec,
    of which 3.2 counts per sec is background.

    Telemetry saturation occurs at 1092 counts per RIM, or 18 counts/sec.
    Subtract 5 counts per sec signal to get 13 counts per sec background
    at saturation.  WE SATURATED AT EARTH 1.