Steward CCD Guider Cameras

The Steward CCD guider cameras are 4-inch diameter by 2-inch high thermoelectrically-cooled dewars containing a 1024x512 thinned, back-illuminated CCD operating in frame-transfer mode.  As such, they can double as small-format "science cameras" for quick-look direct imaging.  Originally operated with Leach Gen 1-3 controllers, they have more recently been mated to more inexpensive Magellan-style controllers.  The controller is connected to a Windows 2000/XP host computer through a PCI interface, and the acquisition code is generalized through the use of network command/control interfacing.  A complete user GUI for guiding written in Tcl/Tk and compiled C is available.  More than 30 systems have been installed at Steward telescopes ranging in aperture from 1.5m to the twin 8.4m LBT.

Camera Characteristics

CCD	1024 x 512 pixel x 15µm square, masked to 512 x 512 and run in frame-transfer mode
	Thinned, back-illuminated with max QE > 90%.
	Readout time for full imaging area with Leach Gen-1 controller: 2 seconds (binned 2x2 on chip)
	Readout time for full imaging area with Leach Gen-2 controller: <0.5 sec; unbinned
Cooling	3-stage thermoelectric, requiring ~1.2 amp @ 12V
	Dewar back plate held at ambient temperature by circulating glycol and outboard radiator
	Demonstrated TCCD = -60°C at telescope with ambient of +9°C.
	Cooling time from ambient: less than 20 minutes
Vacuum	Miniature port. Window and housing are O-ring sealed.  Internal "getter" maintains vacuum for >1 yr.
Mechanical	4 inches (10.2 cm) diameter;  2 inches (5 cm) thick (plus connectors)
	All electrical, cooling, and vacuum connections are made through back plate
	Mounts from front, back, or any of the 6 flat side surfaces
	Usable as-is or behind a commercial camera lens
Performance	Accurate guiding on V = 19 stars  in 5 sec exposures  under 2 arcsec seeing on 2.3 m telescope
Software	Tcl/Tk + C. Click here for view of GUI
	Current guider.tcl code can be downloaded here