Readout electronics and fast photometry with the Canarias InfraRed Camera Experiment (CIRCE)

We present the design for a high-speed readout imaging mode for the Canarias InfraRed Camera Experiment (CIRCE), a visitor-class near-IR imager, spectrograph, and polarimeter for the 10.4 meter Gran Telescopio Canarias (GTC). This mode, along with the polarimetric and spectroscopic capabilities of the instrument will provide a powerful and unique instrument for the study of fast variability objects. Modification in the firmware of the readout control electronics of the HAWAII-2 2048×2048 detector will allow us to select the effective detector size and hence reduce the readout time. We present a description of the final design along with a discussion of potential future improvements.