We obtained a E2V/Marconi 2048x2048 CCD (CCD42-40 backside illuminated) with 13.5 micron pixels through an internal grant at Los Alamos National Labs written by Tom Vestrand. The CCD was obtained and put in an Infrared Labs dewar by Bob Leach at UCSD, who supplied the controller. The dewar is a model WD5, serial number 3538, job number ARMF28H.
Some drawings and photos for dewar/electronics can be found in http://control1m.apo.nmsu.edu/1m/leach. Leach says "I think the attached drawings are the applicable ones. We built a similar system for Wyoming, so don't get misled by that label. The heater is terribly simple, just a 25 ohm resistor connected to the utility board."
Library software was provided by Leach, and LANL provided a simple command line interface to this. The library stuff is inserted as a kernel module. LANL supplied a computer with the camera; we have subsequently reinstalled OS/software to make it compatible with other computer systems; however, the RedHat 9 LANL installation+software was left on an unmounted partition on the computer ccd1m; see this manual LaTeX source for account information.
Leach provides application interface routines (astropci), as well as a Linux JAVA control program called VOODOO. We have used the interface routines to implement our own software. Leach's software can be obtained from astro-cam.com; access control information can be found in the LaTeX source for this manual. Various Leach documentation from this web site can be found at http://control1m.apo.nmsu.edu/1m/docs/leach.
The Leach astropci software is installed under the 1m/tcomm source directory. There are different versions for different kernels, see the documentation for more information.
The dewar developed some leaks in 2007, and upon opening, several chips were discovered in the dewar window. Inquire to Infrared Labs revealed that we had a non-standard sized window, so a new top plate was purchased with a standard size window and installed.
We had some issues with the shutter failing to open and opening incompletely in December 2008. At that time, we ordered and received a replacement shutter assembly from Leach; the shutter is a Pronto Magentic E64 (141176 2570) shutter. The shutter comes with a small electronics board (to transition from opening voltage to hold voltage???), but Leach told us to remove the board and connect the solenoid directly to the HIROSE connector from the pins connected to a power supply through the timing card. We also discovered that the shutter needs to be physically modified to fit in our mounting scheme: the solenoid is farther from the shutter than in the Prontor default, and several bolt holes need to be redrilled to allow for flush bolts to be put in. Instead of making this modification, we simply replaced the old solenoid with the new one, and redid the wiring (made the cable significantly shorter. In fact, the old solenoid is probably still OK, problems may have just been electrical with perhaps some small mechanical alignment of the solenoid issues. We have retained the spare shutter and the old solenoid for potential future use.
The guider was built around the format of an old Spectrasource CCD camera (Spectrasource is no longer in business). This constrains the physical dimensions of a guide camera to be cylindrical in shape within a diameter of a few (?) inches.
The current guider camera is a Finger Lakes Instrumentation MaxCam CM2-1, which has a 1024x1024 thinned backside illuminated sensor, with 13 micron pixels. Mechanical interface drawings can be found at http://control1m.apo.nmsu.edu/1m/docs/fli. This camera was purchased/installed in summer/fall 2005.
The guider camera is controlled via a USB interface. To minimize the number of computers in the dome, we purchased a fiber/USB converter kit made by Icron, so that the control computer, ccd1m, is located in the main computer room. A pair of fibers run from the 1m dome patch panel through the cone to the receiver box, into which the FLI camera is connected.
Power is supplied by a small DC supply that is located up on the arm by the camera. Communication to the camera is by a custom 10-pin cable (looks like and Ethernet connector, but isn't) which goes to a small box with a control card that is attached to computer via USB.
We sometimes have some trouble with the shutter not closing fully, especially during cold weather. As a result, normal operation is to command the shutter open at the beginning of the night and just leave it open; the small trails created during readout don't significantly affect the centroids. The camera was opened in November 2006, and the shutter blades were cleaned with isopropyl alcohol and reassembled.
The guide camera stopped functioning in September 2008. It was returned to FLI and they repaired and cleaned it. Specifically, they replaced components on the A/D and internal power supply board, baked the camera, replaced o-rings and dessicant packs, cleaned the sensor, and purged the camera.
FLI no longer makes this model, and their newer models do not appear to have the same form factor.
Before obtaining the Leach E2V CCD camera, we used an Apogee camera as the main science instrument. This is now again being implemented as the acquisition/guide camera for the high speed photometer.
On the photometer port (also used for SDSS/APOGEE fiber feed), the camera looks at the focal plane. This is accomplished using a Nikon macro lens. To achieve maximum magnification, the lens needs to be focussed for the closest possible object, which is about 10 inches away. This requires that the camera be located as far down as possible in order to achieve focus. Even still, the pixel scale is between 1.5 and 2 arcsec/pixel - it would be better to have a camera with smaller pixels.
The Nikon lens has an adaptor for a C-mount that screws into the camera. The APOGEE camera has a large bolt circle, to which a snout that is 3 inches in diameter is mounted. This is barely large enough to fit around the Nikon lens. The snout goes into a 3-inch diameter JMI focuser. This is controlled using a JMI SmartFocus unit.
The Apogee AP7P is a thermoelectrically cooled CCD. Documentation for this camera is located on the documentation shelf in the 1-meter control room at Apache Point. The camera has a 512x512 thinned back-side illuminated CCD. The camera is plugged into the parallel port of the Linux machine, eyeball, which must be located in the 1-meter enclosure. Power to the Apogee is supplied by its own power supply and special cable. Follow instructions in the manual for safely connecting and disconnecting the Apogee.
If the camera window fogs over, it is time to replace the Apogee's desicant. Consult the Apogee manual for detailed instructions. Replacement desicant is located in the upper most of the big file drawers in the 1-meter control room.
Apogee has kept some documentation for their AP series at http://www.ccd.com/tech.html.
The original science CCD camera was was purchased from Princeton Instruments of Trenton, New Jersey. This camera was retired in the late 90s (?) and is now on long term loan to New Mexico Tech, via Bill Ryan, for their MRO observatory (I don't know if they are actually using it).
Princeton Instruments was bought out and is now Roper Scientific. Roper Scientific's technical support number is (609) 587-9797. The people who seem to be most familiar with our system are Paul Sandyck and Rob Allen.
There are several things to be familiar with when mounting and dismounting the PI CCD camera. First off, the shutter assembly on the camera screws on and off with a flanged collar. This collar needs to be tight, otherwise, the camera can turn, changing the camera's orientation on the sky. Make sure not to rotate the shutter housing when tightening the collar - the mechanical solenoid that holds the shutter open can bind inside, on the camera housing. After tightening the shutter housing, run a test exposure to make sure the shutter opens cleanly. Next, assuming you are looking at the shutter and the camera's fill tube is upright, there is a scratch on the shutter housing at roughly the 10 o'clock position. This scratch lines up with a scratch on the filter wheel. This allows you to mount the camera such that north is approximately at the top of the chip.
The camera is held to the filter wheel with a set of three cleats that screw into the filter wheel. Since the camera is only clamped in place, it is critical that the cleats be very snug to make sure the camera does not rotate.
The camera control hardware consists of three components: the camera head, which is mounted to the telescope; the camera controller which is in the left-hand side of the rack; and the computer interface card which is installed in the Dell 486 Computer that is housed in the left-hand side of the computer rack. The camera operates at -110 Degrees C. There is a temperature control knob on the front of the camera controller. Next to that is an LED that shows green when the camera is at the correct temperature and amber when not at the correct temperature.
Between the Dell 486 and the camera controller is a pair of roughly 4-foot long "Parallel" cables. Care must be taken when plugging these cables into the back of the camera controller so that the pins do not bend. These cables have a tendency to pull free of the controller as the rack is moved or as the temperature in the dome shifts. Check periodically to make sure the cables are firmly seated.
Fast readout mode capability has been added to the Princeton Instruments camera controller in-house. Inside the camera controller unit, on the left hand side of the largest board visible from the top is a set of jumper pins labeled with speeds (e.g. 200 KHz, 50 KHz, etc.) This set of jumper pins determines the readout speed of the Princeton CCD. Note, the faster the selected speed, the higher the dark current. Under the front plate of the camera controller again on the inside is a box with a relay. This box contains a relay that alternately connects the common (right-hand) side of the jumpers with either the 200 KHz or the 50 KHz pin. The relay is triggered when 12-volts are applied to pins 1 and 2 of a 9-pin D-connector run out the back of the Camera Controller. The default (i.e. power off) state of the relay runs at the 50 KHz rate.
Vacuum pumping the Princeton Camera may be done on-site at Apache Point Observatory. It should only be done with the assistance of APO personnel who are familiar with the operation of the vacuum pump. Those people include Mark Klaene, Jon Davis, and Jon Brinkmann.
The following are guidelines to follow when pumping the camera.
Three Logitech QuickCam 4000 Pro web cams, with USB interface are connected to the ccd1m computer, via the USB/fiber interface boxes. These require the pwc driver.
We also have a Panasonic eggcam with its own PCI interface card, but this requires a computer in the dome to run (eyeball was used for this purpose).