EUROPEAN SOUTHERN OBSERVATORY FEROS on the MPG/ESO-2.20m Telescope
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CCD#60 with FIERA Controller in readout mode 225kHz,1,low (norm). Blue LED (LAMP7) Light Source

General Information

Since November 2003 the CCD camera has been operated with an ESO standard FIERA CCD controller. The FIERA controller is capable of delivering the full performance of the CCD in terms of readout noise, CTE, immunity from interference, crosstalk, etc., and provides the image files with the necessary header information. Typical ReadOut Times (ROT), ReadOut Noise (RON) and Conversion Factors (CF, i.e. inverse Gain) characteristics, for the three defined readout modes are given in table 1.

The performance figures given were derived in the initial characterisation tests performed when the CCD controller was chnaged from the previous BIAS system to the FIERA system in November 2003. This page provides a database of characteristics derived from regular monitoring of the CCD performance.

The camera uses an EEV CCD detector of the design specified for FEROS, i.e., 2048x4096 pixels of 15x15microns, mounted in a continuous-flow cryostat. The CCD can only be mounted with the columns in the main dispersion direction. The CCD is operated at a temperature of -135 degrees Celsius

The thinned 2kx4k CCD and the standard ESO-VLT continuous-flow cryostat are provided by ESO.

Derivatives

Standard CCD Test

Long CCD Test

Time Evolution

The below plot shows the variation of the bias level, standard light-source (note that often a beta-light is used which, due to radioactive decay, will fade. It is also possible that the phosphor can be poisoned, but our data show no evidence for such an effect), gain, read-out noise, shutter error, and linearity error as a function of time. The values for the bias, gain and read-out noise are plotted along with the associated measurement error. The blue dashed line in the plots shows the mean value of all the points, while the dotted blue line shows the standard deviation of this distribution. The blue and red points in the bottom plot show the maximum deviations in a positive and negative sense wrt the least-squares fit of the linearity data. Plotted vertically on the bottom of the graph is the date (dd/mm) on which the test was made.

For printing, the above plot is also available in postscript format . The raw data can also be viewed in a tabular format.

Standard CCD Test

Below we show the most recent test.

*** MIDAS logfile (07SEPpl1.1) *** Mo, 21 Jul 2014   11:52:18   Page 1
 
 
*** MIDAS logfile (vers. 07SEPpl1.1) *** Mo, 21 Jul 2014   11:52:31   Page 2
 
     ============================================================
     SUMMARY STANDARD TEST CCD#60 TAKEN ON 20140721T105537 IN norm MODE
     ============================================================
 
      BIAS
      ====
 
      5 biases at start test: average = 248.59 stddev =   1.71
 
      There were 0 hot pixels/columns detected
 
 
      TRANSFER FUNCTION AND LINEARITY DATA
      ====================================
 
  Table : Std_norm_60_20140721T105537 
 Sequence Exp_tim1  Med_cnt1  Med_cnt2  Variance  Frc_cnt1  Frc_cnt2  el_adu1  
 -------- --------- --------- --------- --------- --------- --------- ---------
        1      7.93    1623.3    1624.7     599.1      0.13      0.14      2.71
        2     15.85    3231.3    3232.1    1200.4     -0.15     -0.15      2.69
        3     31.68    6457.6    6456.1    2407.0     -0.14     -0.17      2.68
        4     47.51    9682.7    9682.7    3571.4     -0.15     -0.15      2.71
        5     71.26   14531.4   14530.5    5230.9     -0.08     -0.09      2.78
        6     95.01   19382.3   19382.3    6898.9     -0.03     -0.03      2.81
        7    118.76   24243.0   24242.8    8572.1      0.03      0.04      2.83
        8    158.33   32340.4   32337.1   11304.8      0.09      0.09      2.86
        9    197.91   40450.9   40450.6   13836.2      0.16      0.16      2.92
       10    237.49   48533.8   48534.5   16178.7      0.15      0.15      3.00
 -------- --------- --------- --------- --------- --------- --------- ---------
Table : Std_norm_60_20140721T105537
Column #   5 Label :Med_cnt1       
Total no. of entries :      10, selected no. of entries :      10
Minimum value :    1623.315    , Maximum value:    48533.79
Mean value    :   20047.662    , Standard dev.:   16130.387
Table : Std_norm_60_20140721T105537
Column #   6 Label :Med_cnt2       
Total no. of entries :      10, selected no. of entries :      10
Minimum value :    1624.656    , Maximum value:    48534.51
Mean value    :   20047.340    , Standard dev.:   16130.117
 
      Dynamic range explored: from 4852 to 145019 e-
      Average count rate measured: 204 ADU/sec.
 
      CONV. FACTOR AND RON
      ====================
 
      C.Fact =   2.99 +/-   0.04 e-/ADU
 
      RON    =   5.12 +/-   0.06 e- RMS
 
 
      SHUTTER ERROR
      =============
 
 Average shutter error derived from fractional count rate =  0.014 sec
 
 
      LINEARITY ERROR
 
*** MIDAS logfile (07SEPpl1.1) *** Mo, 21 Jul 2014   11:52:31   Page 3
 
      ===============
 
 Average linearity error after shutter correct. = + 0.16/-0.16 %
 
 These errors represent maximum deviation in % from the average
 count rate after correction for shutter delay

In addition, the previous standard tests are available. Click in the table below to access these files.