The new L3 Technology CCDs from E2V allow detector read noise to be decoupled from readout speed. If operated at sufficiently high gain, the read noise drops to sub-electron levels and photon counting becomes possible. At ING we have incorporated CCD60 , CCD87 and CCD97 L3 detectors into cryogenic cameras coupled to SDSU controllers for a variety of tests both in the lab and on-sky using the 4.2m William Herschel Telescope. These detectors have been operated in proportional and photon-counting mode using an in-house Linux based DAS. We have gained a number of insights into photon counting optimisation, how to cope with the effects of the L3 pipeline delay and the reduction of internal device-generated spurious charge. We have also discovered a statistical method for determining the gain of an L3 system from pulse height analysis of the individual photon events. Our on-sky test program has consisted to date of high frame rate photometry of the Crab Nebula Pulsar.

Date Published: 30 September 2004
PDF: 11 pages
Proc. SPIE 5492, Ground-based Instrumentation for Astronomy, (30 September 2004); doi: 10.1117/12.550353

Published in SPIE Proceedings Vol. 5492:
Ground-based Instrumentation for Astronomy
Alan F. M. Moorwood; Masanori Iye, Editor(s)