The information contained here is reproduced from release notes on the LRIS Red upgrade that were provided by the LRIS red upgrade team.

3.0 LRIS-R CCD MOSAIC PERFORMANCE CHARACTERISTICS

3.1 CCD Gains and read noise as a function of readout speed

The noise measurements tabulated below correspond to the results that are achieved when the serial clock delay parameter (keyword LSERCLKD) has been optimized for the particular combination of:

• LRIS-R CCD Controller operating temperature (as reported by UTBTEMP keyword)
• CCD readout speed (as reported by CCDSPEED keyword)
• CCD Binning (as reported by BINNING keyword)

Normally, this optimization will be performed by the support astronomer before LRIS is released to the observer. When properly adjusted for each such combination, the gain and noise at a particular readout speed (CCDSPEED) and preamplifier gain select setting (CCDGAIN) will be the same regardless of the operating temperature or binning.

3.1.1 CCDSPEED=normal and CCDGAIN=high:

The following measurements were obtained on June 7, 2009 with LRIS mounted in the telescope. A series of dark and dome-imaging-flat exposures were obtained and a photon transfer curve generated from those images.

Vidinp    Amplifier    gain (e-/DN)       noise (DN)    noise (e-)
------    ---------    ---------------    ----------    ----------
   1      1-12L        1.022 +/- 0.005          4.57          4.67
   2      1-12R        0.955 +/- 0.005          3.97          3.79
   3      1-13L        0.877 +/- 0.006          3.39          2.97
   4      1-13R        0.916 +/- 0.005          3.38          3.10

3.1.2 CCDSPEED=fast and CCDGAIN=high:

The following measurements were obtained on June 5, 2009 with LRIS sitting on the Nasmyth Deck. A series of dark and internal flat exposures (using the Halogen lamp) were obtained and a photon transfer curve generated from those images.

Vidinp    Amplifier    gain (e-/DN)       noise (DN)    noise (e-)
------    ---------    ---------------    ----------    ----------
   1      1-12L        1.121 +/- 0.006	       6.50           7.28
   2      1-12R        1.024 +/- 0.008         6.23           6.38
   3      1-13L        0.946 +/- 0.008         5.89           5.57
   4      1-13R        0.971 +/- 0.009         5.96           5.79

3.1.3 CCDSPEED=slow and CCDGAIN=low:

The following measurements were obtained on May 5, 2009 with the LRIS-R dewar in the UCO/Lick CCD Lab in Santa Cruz. These measurements need to be repeated now that the dewar is installed in the LRIS instrument.

Vidinp    Amplifier    gain (e-/DN)       noise (DN)    noise (e-)
------    ---------    ---------------    ----------    ----------
   1      1-12L        1.434 +/- 0.017	        2.92          4.19
   2      1-12R        1.328 +/- 0.022          2.53          3.36
   3      1-13L        1.253 +/- 0.015          2.10          2.63
   4      1-13R        1.304 +/- 0.027          2.03          2.65

3.1.4 CCDSPEED=slow and CCDGAIN=high:

The following measurements were obtained on May 3, 2009 with the LRIS-R dewar in the UCO/Lick CCD Lab in Santa Cruz. These measurements need to be repeated now that the dewar is installed in the LRIS instrument.

Vidinp    Amplifier    gain (e-/DN)       noise (DN)    noise (e-)
------    ---------    ---------------    ----------    ----------
   1      1-12L        0.587 +/- 0.014          6.85          4.02
   2      1-12R        0.547 +/- 0.009          5.89          3.22
   3      1-13L        0.510 +/- 0.003          4.89          2.49
   4      1-13R        0.525 +/- 0.002          4.76          2.50