Monitoring the HARPS Detector Performance

In June 2003 we started a monitoring programme for the HARPS detector. Currently we regularly measure the conversion factor/gain of both chips comprising the detector mosaic.

Here are the latest data for chip # 77 and # 78

*** MIDAS logfile (03SEPpl1.2) *** Mo, 01 Nov 2004   12:38:46   Page 1
 
 
*** MIDAS logfile (vers. 03SEPpl1.2) *** Mo, 01 Nov 2004   12:39:19   Page 2
 
     ==========================================================
     SUMMARY STANDARD TEST CCD#77 TAKEN ON 041101 IN F417 MODE
     ==========================================================
 
      BIAS
      ====
 
      5 biases at start test: average = 286.54 stddev =   3.55
 
      There were 0 hot pixels/columns detected
 
 
      TRANSFER FUNCTION AND LINEARITY DATA
      ====================================
 
  Table : Std_F417_77_041101 
 Sequence Exp_tim1  Med_cnt1  Med_cnt2  Variance  Frc_cnt1  Frc_cnt2  el_adu1  
 -------- --------- --------- --------- --------- --------- --------- ---------
        1      3.18    4470.6    4488.5    2902.4     -8.60     -8.06      1.54
        2      6.34   10083.3   10098.6    7275.6      3.23      3.58      1.39
        3      9.49   14163.5   12675.2    9333.7     -3.29    -13.28      1.52
        4     12.65   18433.5   20109.4   14209.4     -5.58      3.21      1.30
        5     15.81   24547.9   24655.2   17704.2      0.62      1.25      1.39
        6     18.97   29905.3   30038.0   21438.1      2.16      2.81      1.39
        7     22.12   35396.8   35557.1   26005.9      3.65      4.32      1.36
        8     25.28   39566.9   38169.0   28154.6      1.38     -2.01      1.41
        9     28.44   46526.8   46730.5   33940.1      5.97      6.64      1.37
       10     31.60   49006.0   49447.5   34900.2      0.46      1.56      1.40
 -------- --------- --------- --------- --------- --------- --------- ---------
 
      Dynamic range explored: from 6188 to 68003 e-
      Average count rate measured: 1543 ADU/sec.
 
      CONV. FACTOR AND RON
      ====================
 
      C.Fact =   1.38 +/-   0.02 e-/ADU
 
      RON    =   4.90 +/-   0.07 e- RMS
 
 
      SHUTTER ERROR
      =============
 
 Average shutter error derived from fractional count rate = -0.010 sec
 
 
      LINEARITY ERROR
      ===============
 
 Average linearity error after shutter correct. = + 6.31/-10.94 %
 
 These errors represent maximum deviation in % from the average
 count rate after correction for shutter delay
*** MIDAS logfile (03SEPpl1.2) *** Mo, 01 Nov 2004   12:39:25   Page 1
 
 
*** MIDAS logfile (vers. 03SEPpl1.2) *** Mo, 01 Nov 2004   12:39:57   Page 2
 
     ==========================================================
     SUMMARY STANDARD TEST CCD#78 TAKEN ON 041101 IN F417 MODE
     ==========================================================
 
      BIAS
      ====
 
      5 biases at start test: average = 217.58 stddev =   3.65
 
      There were 0 hot pixels/columns detected
 
 
      TRANSFER FUNCTION AND LINEARITY DATA
      ====================================
 
  Table : Std_F417_78_041101 
 Sequence Exp_tim1  Med_cnt1  Med_cnt2  Variance  Frc_cnt1  Frc_cnt2  el_adu1  
 -------- --------- --------- --------- --------- --------- --------- ---------
        1      3.18    5603.8    5620.7    4315.4     -1.02     -0.14      1.30
        2      6.34   11402.7   11407.1    8791.9      0.85      1.48      1.30
        3      9.49   16974.8   15181.7   12399.7      0.14     -9.92      1.37
        4     12.65   20993.9   22819.6   16668.7     -7.09      1.58      1.26
        5     15.81   28467.5   28483.2   21237.1      0.81      1.45      1.34
        6     18.97   34252.4   34268.6   25430.0      1.08      1.72      1.35
        7     22.12   40059.4   40079.5   29621.7      1.34      1.98      1.35
        8     25.28   45675.7   43879.7   32922.6      1.11     -2.30      1.39
        9     28.44   51697.8   51725.5   38098.4      1.73      2.38      1.36
       10     31.60   57061.3   57134.4   41823.9      1.06      1.78      1.36
 -------- --------- --------- --------- --------- --------- --------- ---------
 
      Dynamic range explored: from 7747 to 78817 e-
      Average count rate measured: 1782 ADU/sec.
 
      CONV. FACTOR AND RON
      ====================
 
      C.Fact =   1.38 +/-   0.02 e-/ADU
 
      RON    =   5.04 +/-   0.06 e- RMS
 
 
      SHUTTER ERROR
      =============
 
 Average shutter error derived from fractional count rate = -0.010 sec
 
 
      LINEARITY ERROR
      ===============
 
 Average linearity error after shutter correct. = + 2.05/-8.51 %
 
 These errors represent maximum deviation in % from the average
 count rate after correction for shutter delay

Archive information available:

• http://www.ls.eso.org/lasilla/sciops/3p6/CCDs/HARPS contains the listings produced by the MIDAS script used for performing the test. The file names give the information needed to access the desired information: Std_F<readspeed>_<chipnumber>_<yymmdd>.txt. These are ascii files. Chip number 77 is Linda, the "blue" chip, chip number 78 is Jasmin, the "red" chip.
• http://www.ls.eso.org/lasilla/sciops/3p6/CCDs/HARPS/plots contains postscript plots generated by the same script. The file naming convention is sililar as abov: Std_F<readspeed>_<chipnumber>_<yymmdd>_<plottype>.ps.

In case you need further information, please contact ls-harps.