ULTRASPEC on the 2.4m TNT
During 2011-2012, we converted ULTRASPEC into a brand new imaging instrument. We kept the original EMCCD in its cryostat, but added an opto-mechanical chassis housing custom-made re-imaging optics and an updated data acquisition system based on the latest version of the ULTRACAM system. The new ULTRASPEC saw first light at the 2.4m TNT on 2013 November 5, and is now permanently mounted on this telescope for at least the next 2 years. Just to re-emphasize, ULTRASPEC is now a high-speed imager - essentially a one-armed ULTRACAM - and hence does not currently have any spectroscopic capability, although it would be trivial to convert it back for spectroscopic use on EFOCS2 on the NTT if we wanted to.
ULTRASPEC on the TNT provides imaging photometry over a field of view of 7.7'x7.7' with a pixel scale of 0.45 "/pixel. A selection of 14 different broad-band and narrow-band filters can be accommodated in its 6-position filter wheel, covering the wavelength range 300-1000 nm. Zero readout noise is available via the avalanche output, or 2.5 e- readout noise via the normal output. The detector is liquid-nitrogen-cooled to 160 K, providing dark current of less than 10 e-/pixel/hr. The maximum frame rate using small, binned windows in drift mode is approximately 200 Hz.