A new photon-counting spectrometer for the COAST

Electron multiplying CCDs, e.g. as delivered by E2V Technologies and Texas Instruments, have the potential to become the detectors of choice for all future optical interferometers, replacing expensive fibre-fed arrays of APDs. We report here on the development of a new 500-channel spectroscopic back end for the COAST interferometer that exploits such a device. An E2V Technologies CCD97 (back illuminated) EMCCD with sub-electron readout noise is used as the detector, and can be read out at pixel rates of up to 30~MHz. We present software and hardware approach used to integrate a new CCD controller with the COAST as well as results from lab tests of the detector and controller.