The upgraded GMOS-N detector array will consist of three ~ 2048x4176 Hamamatsu chips arranged in a row. Two of the detectors (CCDr and CCDg) will have an enhanced red response, these CCDs are referred to by the ITC as "Hamamatsu Red". The right-most CCD (CCDb, the blue end of spectral dispersion dispersion) in the focal plane array has improved blue response in addition to red response very similar to the Hamamatsu Red CCDs. This third CCD is referred to by the ITC as "Hamamatsu Blue". The orientation of the CCDs will remain unchanged and will continue to support the Nod and Shuffle observing mode. Commissioning of these new GMOS-N detectors has unfortunately been delayed. See the Status and Availability webpage for more details. The plot below gives the anticipated QE comparison to the current E2V CCDs in GMOS-N. These QE plots are taken from general Hamamatsu information and will be updated with the QE curves measured for each specific GMOS-N CCD once they are available.

QE Comparison for the GMOS-N CCDs upgrade. Click to view full image.

The table below summarizes some of the expected Hamamatsu detector/controller characteristics.

Values we be updated as detectors are characterized.

Readnoise and Gain Values

The table below will give gain/read-noise values for the new GMOS Hamamatsu CCDs operating with the SDSU controller once the detectors have been characterized. The values are averaged over all 12 amps. The full table of read-noise and gain values at all settings and for all amps is not yet available.

The Slow Read / High Gain mode will not be offered for the Hamamatsu CCDs as it has been deemed to be of little scientific use. Slow Read / Low Gain is the primary mode for science use. Fast Read / Low Gain may be of use, for example, with acquisition observations or for time resolved observations. Fast Read / High Gain is expected to be used primarily for very bright targets.