ARC 3.5-m Instrument News Page

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Apache Point Observatory
New Mexico, USA

SPICAM

2016-11-01: The instrument has been removed from the observing floor, disassembled and crated up for shipment to Chris Stubbs at Harvard.

2016-10-03: SPIcam is no longer available for use. It has been decommissioned and is not to be requested even as a backup instrument.

2016-09-26: SPIcam will be decommissioned on October 1.

2016-08-01: SPIcam has been wrmed and shutoff over the summer shutdown. IT is still on the observing level until some of the issues with ARCTIC can be solved then we will start disassemble of it.

2016-02-22: Spicam will be retired this coming summer shutdown. Wit the successful commissioning of ARCTIC, we plan to retire spicam likely at the end of Quarter 2 or 3. An offical date has yet to be announced.

2016-02-22: Spicam will be retired this coming summer shutdown. With the successful commissioning of ARCTIC, we plan to retire spicam likely at the end of Quarter 2 or 3. An offical date has yet to be announced.

2015-11-02: Report from last night of images with all pixels having zero values. An instrument reset cleared the problem.

2015-10-20: Fiber replaced, instrument is again available.

2015-10-19: Bad fiber. Will run a replacement tomorrow.

2015-10-19: Still no answers. Could not find problem remotely with observing specialists help over weekend. Will investigate further today.

2015-10-17: Instrument in non-responsive. First report in nightlog of 10/15. Investigating.

2015-06-15: No further drop outs of ion pump controller communications. Will monitor at a less frequent rate.

2015-05-18: Evaluating the ion pump controller for the past 6 weeks has shown no dropouts of data or repeats of symptoms where the controller has shut itself down. Will continue to monitor but its unclear if their is a problem at all.

2015-03-30: Working with the manufacturer of the ion pump and controller to determine why the SPCe ion pump controller is going off line periodically. This will not affect data collection of the instrument.

2015-03-18: The instrument vacuum was soft as evidenced by the ion pump controller and independent MKS vacuum guage. Pumped on the dewar for 6 hours during the day today. Ion pum is again regulating the vacuum.

2014-06-18: Still no evidence that discharges of the ion pump result in a glow on the ccd. We believe the problem has been resolved.

2014-06-02: There is no evidence of light on the detector from ion pump discharge from small to moderate spikes in vacuum pressure, however we have yet to catch a large spike (> 4.5e-5 torr)

2014-05-09: SPIcam is cold again and available for science. I am still investigating the ion pump spikes, which still exist. During the servicinga 90 degree elbow and a screen were placed between the ion pump and dewar in hopes this will dispate the glow discharge from the ion pump when it spikes.

2013-05-02: SPICAM is still unavailable

2013-04-21: SPICAM is being warmed for vacuum and ion pump servicing. Hopefully we can address the high dark current spikes that occur on the order of once per day. This is a major servicing session and is planned to take the instrument out of use for science for several weeks.

2014-03-26: Ion pump controller returned to intermediate level. Instrument is again usable. Test did not disclose a change in behavior.

2014-03-20: Ion pump controller moved to inside instrument enclosure. Because cable lengths are short the instrument is not available until the night of March 27th. This test will eliminate cable length and age as a possible cause of the current spikes.

2014-01-12: There is still an intermittent dark current problem, we have yet to find a solution. The instrument is usable, but extra darks may be needed.

2013-11-21: Instrument is cold and operational.

2013-11-12: Replaced ion pump with different style of pump from Gamma Vacuum

2013-11-10: Instrument is being warmed to replace ion pump

2013-09-30: Instrument is cold

2013-09-24: Instrument is being warmed to replace ion pump

2013-09-04: Russet has shown the dark current source originally appeared to be correlated with ion pump current but last night showed this is not always the case. Source of the noise is still under investigation

2013-08-17: There is an unknown source of dark current. It appears intermittent. See PR/1453 for details.

2012-09-28: Spicam is back with its new ion pump and controller. There is an electrical noise problem seen in biases and darks. Looks like a grounding problem from the ion pump through the coldhead and cold strap. Will address asap.

2013-01-25: Checked for contamination. None found. Back in service.

2013-01-24: Instrument cryotiger lost refrigerant last night and warmed. Pumped and recharged.

2013-01-04: Lowered heater setpoint to 160K.

2012-11-28: New instrument block. Instrument appears to be behaving fine. Lowered heater setpoint to 165K.

2012-11-21: Pressure transducers on the PCC was swapped. I relabled the connectors and corrected this problem. For monitoring purposes only but there will be a discontinuity in the logs. This does not affect instrument use.

2012-11-19: SPIcam is back together and ready for tonights observations. The instrument has a new window and the CCD is better electtically isolated from the vacuum vessel.

2012-11-08: UPDATE: We expect the new window to be shipped to APO from the coater on or before November 15. We also will be looking for a shipment of aluminum nitride electrical isolation disks to arrive on or before this date as well to help with the noise issue earlier described.

2012-10-06: A chip in the dewar window appears to be the source of the vacuum leak. The instrument will be down until further notice until a replace window can be made and AR coated.

2012-10-04: Appears to have a vacuum leak. System warmed for leak check and to replace vacuum fittings to ion pump. Instrument unavailable until these issues fixed

2012-10-01: Parts on order to address noise issue.

2012-09-21: The ion pump for SPIcam failed this evening. The instrument is warming for a replacement. It will not be available for use until this repair is done

2012-08-28: The cryotiger was serviced over shutdown. Temperatures continue to be running consistently 10 - 15 degrees warmer than expected. APO has a call in with Brooks Polycold for input.

2012-05-17: Returned to service today. Still needs an instrument block due to the amount of disassembly that was performed.

2012-04-26: Removed from service for maintenance

2012-04-24: Servicing scheduled starting Thursday April 26. The instrument will be unavailable after that date until further notice.

2012-04-09: SPicam's cold head appears to be partially restricted, limiting its cooling capacity. It is running 20 degrees above nominal. We therefore strongly recommend that users take darks to accompany their data. The following page gives more information of the problem. Plans are in progress to replace the coldhead the end of April and beginning of May.

2012-04-09: SPicam's cold head appears to be partially restricted, limiting its cooling capacity. It is running 20 degrees above nominal. We therefore strongly recommend that users take darks to accompany their data. The following page gives more information of the problem. Plans are in progress to replace the coldhead the end of April and beginning of May.

2012-04-03: Instrument returned to service.

2012-03-30: Instrument removed from service while we service the Cryotiger, lines and coldhead

2012-03-28: Camera partially warmed again. Still usable but darks are recommended. Will address the cryogenics system in the next few days

2012-03-06: Camera again cold. Contamination appears to be gone.

2012-03-01: Warmed and placed on vacuum pump to remove contamination. Not available until next week when we can take off pump and cool.

2012-02-27: Contamination on the CCD has reappeared. We were able to get the frost to partially sublimate off the chip by raising the chip heater a few degrees. Both visual and flat fields show evidence of contamination. About 400 counts above background. We are attempting to reduce the amount further however we will need several days to warm and pump on the instrument. For an example of what we are seeing look here.

2012-02-09: Spicam User Guide updated with new recommended exposure times for flat fielding using the truss lamps.

2012-01-24: SPIcam exhibits a low level pattern noise as seen in biases. This noise is very intermittent and has existed for the life of this instrument. Cause has never been determined. Examples of the SPIcam pickup noise as seen in biases can be seen here.