The IPCS is a blue-sensitive imaging detector, which counts individual photon events with zero readout noise and a dark current of only 4 counts/s/cm, which corresponds typically to 2 10 counts/s/pixel. The IPCS is therefore suited to detecting faint signals, which on a CCD would be dominated by the readout noise. The saturation characteristics of the IPCS mean that it is not suitable for observations at high count rates.
The only IPCS detector available is the UCL-RGO CCD-IPCS on the WHT. This has a four stage EMI Image Intensifiet, coupled by a tranfer lens to a thinned GEC CCD. This system is known by the name CCD-IPCS to differentiate it from the old Plumbicon-based system, which was available at the INT but has now been decommissioned. The CCD-IPCS is available as a detector option for the UES, for Taurus, and in exceptional circumstances for the blue arm of ISIS. Potential users must justify in the technical case for their projects their choice of the IPCS as detector..
This section briefly describes how the IPCS works. Useful references for further reading are:
Boksenberg, A., Proceedings of the ESO-CERN conference on auxiliary
* instrumentation for large telescopes, eds Lausten, S. & Reiz, A., p295, 1972.
* Boksenberg , A. & Burgess, A., 1973. Astronomical observations with
* television sensors, eds Glaspey, J.W. & Walker, G.A.H., p21, 1973
* Boksenberg A. Philosophical Transactions of the Royal Society of London A,
* vol 307, p531, 1982
* W.L. Martin & P.B. Taylor, IPCS Users Reference Manual.
* (A detailed description of the INT system)
* C.R. Jenkins, IPCS Cookbook.
* (Spectroscopy with the IPCS on the INT)
* C.R. Jenkins, Monthly Notices of the Royal Astronomical Society, vol 226, p341, 1987.
* (Saturation characteristics of the INT IPCS)