Detector

Recently a problem was noted with high level of counts in darks when using the high-resolution (HR) camera. It was found that this was actually a feature related to the internal camera focus. The affect is there, independent of which camera is used, when the focus is set for the HR-camera imaging at a value of 20. The effect already starts to be noticeable at a focus value of 1000. The idea is that light from inside NOTCam can reach the camera when the focus mechanism is at low values, and the problem might be solved by improving the baffling. We are looking possible solution to be implemented during the next opening of NOTCam planned for January 2011.

The evolution of the array in terms of the increased amount of cold pixels (from 0.2% to 0.4% of the array) over 2008 - 2009 is clear and means it is getting difficult to find clean vertical areas for the locations of the spectra obtained in ABBA mode. It is noted that some of the ``bad'' areas disappear with time, and we intent to clean the array (by blowing dry air) on the next opening of NOTCam.

There are various ways in which the performance of the array can be improved the readout can be optimized and a document was produced with suggestions to provide some extra functionality on the new array controller.