Apache Point Observatory
New Mexico, USA

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ARC 3.5-m Instrument News

News Worthy Items

• AGILE is out of service to return camera to manufacturer. See below for updates.
• The new ARCES grating was successfully installed during summer shutdown. Do not use calibrations older than August 1, 2012. Ask the Observing Specialist for the new iraf wavelength and dispersion solution files.
• UT1 and likely LST in several instrument headers was intermittently wrong from fall 2012 by a significant amount (+12 hours). Other time stamp keywords in the various instrument headers is correct. It was fixed on 2012-11-16.

Current problems and technical issues

Instrument issues which our users should be aware of before taking data. For historical information go here. For future planned upgrades go here.

• 2013-04-10: External trigger circuit for the camera appears to have failed. Sending the camera back to Princeton Instruments for repair.
• 2013-04-05: Camera is failing when commanded to take a sequence of triggered exposures.
• 2013-01-18: The instrument appears to be functional again. Waiting on Anjum to perform timing testing.
• 2013-01-17: The instrument control computer (ICC) is back up but only for slow readout rates (>10.8s). Hopefully this is just a library or driver issue. Fritz is working on the problem.
• 2013-01-07: The RAID (HDD) controller card in the instrument control computer (ICC) failed this weekend. A spare is on order. The instrument is unusuable. We will not be able to discover the full extent of the damage to the system until this card arrives.
• 2012-01-24: APO still does not recommend taking dome flats with AGILE. More information can be found here.

• 2013-03-20: External driver circuit is working. Back in service.
• 2013-03-18: After multiple reports of shutter problems with the echelle, we believe we have narrowed the trouble down to an intermittent shutter driver circuit for the instrument. This circuit is not repairable. Ed Leon intends to build a custom driver circuit to replace this portion of the instrument controls. The new driver circuit will be built and tested today and tomorrow. It is our hope to have the instrument ready for science Tuesday evening.
• 2013-02-05: The echelle is again cold with a good vacuum. It still is unclear at this time the true cause of the vacuum failure and warmup. Some additional characterization testing still needs to be done tonight but it should be ready for use tomorrow night.
• 2013-01-28: The instrument warmed over the weekend. It is unclear at this time if it was a failure of the autofill system or a loss of vacuum. We are investigating and will pumping on it this week.
• 2012-11-29: Installed shorter cables. Saw improved performance in echelle cal mirror performance but hope to get further improvement from reduceing cable length further. Another cable is on order.
• 2012-11-09: Replacement cables arrived but want to schedule the next round of repairs until there is a break in the echelle schedule.
• 2012-11-05: We are trying a number of possible solutions for the calibration mirror. Software and various hardware solutions are proving difficult due to the age of the equipment and the lack of spares. Our next attempt will be to replace some of the more key cables in the system. Those are on order.
• 2012-09-20: We believe the problem with varing QTH lamps is related to a problem with the calibration mirror. We have changed the stepper controlling this mirror, inspected the driver board and have aligned calibration light path. We will continue to work on this problem. Replacing the stepper driver board will be next during next weeks engineering time.

• 2013-01-10: Binning of the chips do not work for odd number of rows and odd number of columns. Odd number of one or the other or even number of both work. This is a lower priority problem. Recently it was also discovered that the TAI time in the headers is wrong due to the hardwiring of the UTC-TAI offset on the ICC. UTC time is correct in the headers. We will address these problems when we find the manpower. Users should be aware they exist though.
• 2013-01-04: Lowered heater setpoint to 160K.

• 2013-01-17: The instrument is currently not usable for Fowler Sampling modes > 8. NFS 8 and below still work fine.
• 2012-10-30: A report of a glowing obstruction as seen in the K-band was tracked down to a loose wire harness. That harness was re-secured
• 2012-01-24: NICFPS still experiences intermittent failures since the fall of 2010. Please coordinate with the observing specialist for monitoring of failures and recovery modes as you take data. More information can be found here.

• 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.

• 2013-03-15: The ICC was found powered down yesterday. Recovery was a major undertaking requiring power cycles of both tspec and tcam leach controllers and reloading the dsp code. Most likely a gap in the documentation which will get updated.
• 2012-11-08: A reminder to users. Since the slitwheel is locked in place at the 1.1 arcsec slit, true instrument darks are not possible at this time.

• 2012-08-28: Users should be reminded that there are scripts available on Newton to match up science image numbers to respective guider images. These scripts can be run after your scheduled time for a log matching the two data sets. For more information can be found here

The information on this page is up to date as of April 10, 2013. This page is maintained by the 3.5-m Telescope Engineer .