ARC 3.5-m Instrument News Page

Apache Point Observatory
New Mexico, USA

DIS

Important note concerning the red camera flat field lens. It has significant and noticable water spots that are affecting data collection. Extended object science is not recommended with the red channel at this time. We will not be able to address the problem until late fall or it may return quickly.

2024-03-18: Report from Russet: did a DIS contamination check today. Blue is the same as 3 weeks ago. Red is resuming progress in a direction that I think should resolve contamination, hopefully sometime in April or May.

2024-03-14: Report from Russet: did a DIS contamination check today. Blue is the same as 3 weeks ago. Red is resuming progress in a direction that I think should resolve contamination, hopefully sometime in April or May.

2024-03-11: No recent report of contamination. There was a partial warmup and softening of the blue camera vacuum last night. Attempting to resolve without need to pump on the camera. The instrument (both cameras) is available for science at this time.

2024-03-04: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). The instrument (both cameras) is available for science at this time.

2024-02-26: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). The instrument (both cameras) is available for science at this time.

2024-02-20: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). Recovered red camera from its failure in the Red Camera Electronics. Bias levels are now reading normal 122DN with normal pixel to pixel variation of all pixels. The instrument (both cameras) is available for science at this time.

2024-02-19: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). There was a failure in the Red Camera Electronics. Bias levels are reading 127 for all pixels. Investigating. DIS Blue is still available but useful science at this time is still questionable.

2024-02-12: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). There was a failure in the Red Camera Electronics. Bias levels are reading 127 for all pixels. Investigating. DIS Blue is still available but useful science at this time is still questionable.

2024-02-05: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). There was a failure in the Red Camera Electronics. Bias levels are reading 127 for all pixels. Investigating. DIS Blue is still available but useful science at this time is still questionable.

2024-01-29: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). This weekend there was a failure in the Red Camera Electronics. Bias levels are reading 127 for all pixels. Investigating. DIS Blue is still available but useful science at this time is still questionable.

2024-01-22: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2024-01-15: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2024-01-08: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2024-01-02: No recent report of contamination. Last report from Russet: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2023-12-18: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2023-12-11: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2023-12-04: Contamination on the blue side of DIS (across the 2/3 chip was recent report from Russet) is now usable. Red side has degraded further but still is acceptable (from excellent). DIS is still available but useful science at this time is still questionable.

2023-11-27: Contamination on the blue side of DIS (across the entire chip) is now usable. Red side has degraded but still ins good (from excellent). DIS is still available but useful science at this time is still questionable.

2023-11-20: Contamination on the blue side of DIS (across the entire chip) is now usable. Red side has degraded but still ins good (from excellent). DIS is still available but useful science at this time is still questionable.

2023-11-13: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-11-06: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-10-30: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-10-23: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-10-16: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-10-09: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-10-02: Contamination on the blue side of DIS is still poor but improving. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-09-25: Last week the red camera had a few temperature warmups. THis is likely from partial blockage of the cold head (Ice in the PCC lines). The red compressor was recharged and it took about 2 days for temperatures to stabilize. The affect to contamination on the redcamera has not been determined. Contamination ion the side of DIS is still rather poor. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-09-18: Contamination on blue side of DIS is still rather poor. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-09-11: Contamination on blue side of DIS is still rather poor. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-09-04: Contamination on blue side of DIS is still rather poor. Red side looks good. DIS is still available but useful science at this time is still questionable.

2023-08-28: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable. This past week andweekend very warm ambient temperatures was causing the Red camera to run quite warm (>220K). The past two days CCD temp has dropped somebecause of cooler weather but red camera is still running around 190K.

2023-07-14: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable. This past week andweekend very warm ambient temperatures was causing the Red camera to run quite warm (>220K). The past two days CCD temp has dropped somebecause of cooler weather but red camera is still running around 190K.

2023-07-10: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-07-03: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-06-26: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-06-19: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-06-12: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-06-05: Contamination on both sides of DIS are now rather poor. DIS is still available but useful science at this time is still questionable.

2023-05-30: The red side of DIS has now shown the expected rate of change of improvement. It is still poor but improving at a greater rate. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-05-22: The red side of DIS has now shown the expected rate of change of improvement. It is still poor but improving at a greater rate. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-05-15: The red side of DIS has now shown the expected rate of change of improvement. It is still poor but improving at a greater rate. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-05-08: The red side of DIS has now shown the expected rate of change of improvement. It is still poor but improving at a greater rate. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-04-24: The red side of DIS has improved some more but only a little. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-04-17: The red side of DIS has improved some more but only a little. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-04-10: The red side of DIS has improved some more but only a little. There has been not much change on the blue side. Russet considers it to be borderline usable. DIS is still available but useful science at this time is still questionable.

2023-04-03: The red side of DIS has improved but only a little. The blended core+shoulders profile went from 24 pixels wide in February to 20 pixels wide tonight. 5 minutes on spectro standard Feige 66 gave counts only a few thousand above background, where we would normally expect about 20K. I consider it to be borderline usable. The blue side of DIS is still pretty much at its worst, with shoulders distinct from the core but very close and very broad. I consider this to be probably not usable for science. DIS is still available but useful science at this time is questionable at thie time.

2023-03-27: Contamination appears to be bad on both cameras as reported by Russet. Red progression is improving and is borderline usable for science. Blue is still quite bad and likely will not be usable for more science cases. DIS is still available but useful science at this time is questionable at thie time.

2023-03-20: Contamination appears to be bad on both cameras as reported by Russet. Red progression is improving and is borderline usable for science. Blue is still quite bad and likely will not be usable for more science cases. DIS is still available but useful science at this time is questionable at thie time.

2023-03-13: Contamination appears to be bad on both cameras as reported by Russet. Red progression is improving and is borderline usable for science. Blue is still quite bad and likely will not be usable for more science cases. DIS is still available but useful science at this time is questionable at thie time.

2023-03-06: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is barely measureable and expected to be slow for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-02-27: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is barely measureable and expected to be slow for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-02-20: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is barely measureable and expected to be slow for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-02-13: No further update this week from Russet. Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is unmeasureable for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-02-06: No further update this week from Russet. Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is unmeasureable for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-01-30: No further update this week from Russet. Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is unmeasureable for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-01-23: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned around however improvement is unmeasureable for the next few weeks. Red lines still have 3 peak profiles however the wings are close enough to the central core that Russet believes that theamount of signal can be coadded for science purposes. Blue is showing signs of continued degredation but the rate appears to have slowed and is close to turn around. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science at this time is questionable at thie time.

2023-01-17: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has turned aroud however improvement is unmeasureable for the next few weeks. Blue is showing signs of continued degredation. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available but useful science atthis time is questionable at thie time.

2022-12-12: Contamination appears to be horrible on both cameras as reported by Russet. Red progression has slowed and may start turning aroud and improve in the next few weeks. Blue is showing signs of continued degredation. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available for use.

2022-12-05: Contamination appears to be horrible on both cameras as reported by Russet. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available for use.

2022-11-28: Contamination appears to be horrible on both cameras as reported by Russet. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available for use.

2022-11-21: Contamination appears to be horrible on both cameras as reported by Russet. The hope is with a few weeks to months (based on previous experience) it will level off enough that the energy distributed in the wings of the PSF will be redirected back into the core. DIS is still available for use.

2022-11-14: Contamination may be degrading slowly over the next few weeks to months on the red camera but expected (historically) to turn around and improve. The blue camera contamination seems steady at this time. No recent report fromRusset on contamination status. DIS is available for use.

2022-11-07: Contamination may be degrading slowly over the next few weeks to months on the red camera but expected (historically) to turn around and improve. The blue camera contamination seems steady at this time. No recent report fromRusset on contamination status. DIS is available for use.

2022-10-31: The instrument vacuum servicing is complete. Contamination may be degrading slowly over the next few weeks to months on the red camera but expected (historically) to turn around and improve. The blue camera contamination seems steady at this time. DIS is available for use.

2022-10-24: The instrument vacuum servicing is complete. The water spots on the red camera have been cleaned. Contamination however is moderate from a partial warmup on Friday. DIS is available for use.

2022-10-21: The instrument vacuum servicing is complete. Waiting on Russet's report

2022-10-17: The instrument is undergoing vacuum servicing. It is unavailable for use until the 4th week of October.

2022-10-10: The instrument is undergoing vacuum servicing. It is unavailable for use until the 4th week of October.

2022-10-03: The instrument is undergoing vacuum servicing. It is unavailable for use until the 4th week of October.

Important note concerning the red camera flat field lens. It has significant and noticable water spots that are affecting data collection. Extended object science is not recommended with the red channel at this time. We will not be able to address the problem until late fall or it may return quickly.

2022-09-26: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-09-19: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-09-12: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-09-06: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-08-29: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-08-22: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-08-15: The instrument is operating nominally. Blue scattered light is quite good but worse than in July. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-08-01: The instrument is operating nominally. Blue scattered light is quite good. Water spots on red have not gotten worse but have not improved. Servicing is currently planned for October.

2022-07-25: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-07-18: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-07-11: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-07-05: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-06-27: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-06-20: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-06-13: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-06-06: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-06-01: The instrument is back to operating nominally. Blue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-05-23: The instrument is back to operating nominally. Bue scattered light has improved. Water spots on red have not gotten worse but have not improved.

2022-05-16: The instrument is back to operating nominally. Blue scattered is improving.

2022-05-09: The instrument is back to operating nominally.

2022-05-02: The instrument is back to operating nominally.

2022-04-25: The instrument is back to operating nominally.

2022-04-20: The instrument is available at this time. Replaced a failed powersupply. Instrument CCD controller now powers up and everything checks out.

2022-04-18: The instrument is NOT available at this time. There has been a failure of the CCD controller. We suspect that the problem may be a failed powersupply. A spare is on order and should arrive by Tuesday of this week.

2022-04-14: The instrument is NOT available at this time. There has been a failure of the CCD controller. We suspect that the problem may be a failed powersupply. A spare is on order and should arrive by Tuesday of next week.

2022-04-04: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-03-28: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-03-21: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-03-14: The instrument is available at this time. A problem on Wednesday night with the ICC not being able to write images to disk. Resolvedthe next morning with just a restrt of the ICC software. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-03-07: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-02-28: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-02-21: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-02-14: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-02-07: The instrument is available at this time. Scattered light seems consistent with the many past weeks. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-01-31: The instrument is available at this time. Contamination on both cameras are moderate to excellent. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2022-01-26: The instrument is available at this time. Contamination on both cameras are moderate to excellent. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2021-12-20: The instrument is available at this time. Contamination on both cameras are moderate to excellent. The red camera still has large water spots across the field but as long as those are avoided the contamination is excellent. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still wide.

2021-12-13: The instrument is available at this time. Contamination on both cameras are moderate to ok. The red camera still has large water spots across the field. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-12-06: The instrument is available at this time. Contamination on both cameras are moderate to ok. The red camera still has large water spots across the field. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-11-29: The instrument is available at this time. Contamination on both cameras are moderate to ok. The red camera still has large water spots across the field. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-11-22: The instrument is available at this time. Contamination on both cameras are moderate to ok. The red camera still has large water spots across the field. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-11-15: The instrument is available at this time. Contamination on both cameras are moderate to ok. The red camera still has large water spots across the field. The boresight of the telescope has been adjusted to minimize or miss these areas for point sources. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-11-08: The instrument is available at this time. Contamination on both cameras are moderate to poor. The fog on the red camera covering most of the image is gone but there are still water spots across the field. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-11-01: The instrument is available at this time. Contamination on both cameras are moderate to poor. The fog on the red camera covering most of the image is gone but there are still water spots across the field. The blue camera continues to slowly improve but the wings in the spectra are still quite wide.

2021-10-25: The instrument is available at this time. Contamination on both cameras are moderate to poor. Coming out of vacuum servicing there were numerous problems with the grating turret and its detent. Believe we have reolved those.

2021-10-18: Vacuum servicing of red camera in progress. The instrument is not available at this time.

2021-10-11: Vacuum servicing of red camera in progress. The instrument is not available at this time.

2021-10-08: Vacuum servicing of red camera started today. Warmed. Replaced ion pump. Put on vacuum pump.

2021-10-04: Blue contamination is still poor.

2021-09-27: Blue contamination is slowly improving.

2021-09-20: Cooled down blue camera. Contamination for blue looks far worse than when we started. The next few days will tell if it improves.

2021-09-18: Started vacuum serving of Blue camera. Instrument is not available during servicing.

2021-09-18: Started vacuum serving of Blue camera. Instrument is not available during servicing.

2021-09-16: Attempted to start DIS Blue vaccum servicing however ran out of time in the evening before start of observations due to techincal problems with vacuum pumping station.

2021-09-13: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.

2021-09-06: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.

2021-08-30: Recent measurements show both red and blue cameras have significantly worse performance with regard to contamination. Instrument is still usable but much light is scattered into the wings of the psf for both cameras.

2021-08-09: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable. The cryotiger for the RED camera died Friday. It was replaced with a new compressor. Today a power brownout caused the BLUE cryotiger to hiccup and have a partial warmup. It is recovering from the partial warmup. Placed the BLUE ionpump on the old blue varian controller this afternoon (off the gamma vacuum controller).

2021-08-02: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable.

2021-07-27: Recent measurements show both red and blue cameras are showing somewhat worse performance with regard to contamination. Instrument is still usable.

2021-07-12: Recent measurements show both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-07-05: Red camera had a partial inadvertant warmup yesterday. Restored cooling. Russet checked pinhole images and determined both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-06-28: Both red and blue cameras are showing good to excellent performance with regard to contamination. The red camera is running unseasonably warm as well.

2021-05-24: Both red and blue cameras are showing good to excellent performance with regard to contamination. The red camera is running unseasonably warm as well.

2021-05-17: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.

2021-05-11: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.

2021-05-04: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.

2021-04-19: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.

2021-04-12: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on both cameras. The red camera is running unseasonably warm as well.

2021-04-05: Both red and blue cameras are showing good to excellent performance with regard to contamination. Russet does report she can now measure the contamination on the red camera. The red camera is running unseasonably warm as well.

2021-03-29: Both red and blue cameras are showing good to excellent performance with regard to contamination. However Russet does report that she is seeing the beginning signs of return of contamination. The red camera is running unseasonably warm as well.

2021-02-22: Both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-02-15: Both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-02-08: Both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-02-01: Both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-01-25: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-01-18: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-01-11: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.

2021-01-05: Russet reports both red and blue cameras are showing good to excellent performance with regard to contamination.

2020-12-07: Red and Blue cameras are doing well, scattered light is considered to be minimal for most of area on both chips. The blue camera is showing some degradion in the scattered light in the lower left portion of the detector.

2020-11-30: Red and blue camera scattered light is remaining relatively steady and acceptable for most science. There is some degradation of scattered light in the corners and lower left of the blue CCD.

2020-10-26: Red and blue camera scattered light is remaining relatively steady. There is some degradation of scattered light in the corners and lower left of the blue CCD.

2020-10-19: Red camera scattered light is much improved and is holding steady. The Blue camera scattered light improved greatly after thevacuum servicing however has started degrading slowly especially at the bottom and left side of the image. It is unclear how long it will remain with lower scattered light levels.

2020-10-12: Red camera scattered light is much improved and is holding steady. The Blue camera scattered light improved greatly after thevacuum servicing however has started degrading slowly especially at the bottom and left side of the image. It is unclear how long it will remain with lower scattered light levels.

2020-10-05: Russet reports that the Blue Scattered light is much improved.

2020-10-04: Vacuum servicing of Blue Camera complete. Instrument is now available.

2020-09-30: Vacuum servicing of Blue Camera. Instrument is not available until completed..

2020-09-28: Vacuum servicing of Red Camera completed. Instrument is available.

2020-09-04: Vacuum servicing of Red Camera completed. Instrument is available.

2020-08-28: Vacuum servicing of Red Camera. Instrument is not available until completed..

2020-08-17: No change in instrument status.

2020-08-11: No change in instrument status.

2020-08-04: No change in instrument status.

2020-06-22: No change in instrument status.

2020-06-20: No change in instrument status.

2020-06-01: No change in instrument status.

2020-04-06: No change in instrument status.

2020-03-30: No change in instrument status.

2020-03-23: No change in instrument status.

2020-03-02: No change in instrument status.

2020-03-02: No change in instrument status.

2020-02-24: No change in instrument status.

2020-02-17: No change in instrument status.

2020-02-10: No change in instrument status.

2020-02-03: No change in instrument status.

2020-01-27: No change in instrument status.

2020-01-13: No change in instrument status.

2020-01-06: No change in instrument status.

2020-01-03: No change in instrument status.

2019-12-16: No change in instrument status.

2019-12-09: DIS Blue scattered light is rather poor. The blue camera is mostly unusable for most science. Red camera is still usable. The instrument is available for use. There are no current plans to vacuum service either camera.

2019-10-21: DIS Blue scattered light is rather poor. The blue camera is mostly unusable for most science. Red camera is still usable. The instrument is available for use.

2019-10-14: DIS Blue scattered light is rather poor. Red camera is still usable. The instrument is available for use.

2019-09-19: Concluded DIS Blue vacuum servicing. The instrument is available for use. No action was taken with the red camera due to humid weather this past week.

2019-09-15: Started DIS vacuum servicing of the cameras. Currently the blue camera is on the vacuum pump. It is not available for use.

2019-08-26: There have been multiple reports by the observing specialists of banding visiable in the bias frames of the red camera after the instrument sits idle for multiple hours. A reset has been fixing the issue. Please inspect any calibration images for unusual biases. Blue camera scattered light continues to be poor and the red camera scattered light is still slowly degrading but remains quite usable.

2019-07-08: DIS cameras are experiencing increasing scattered light from contamination (likely water vapor) in each of the dewars. Red is still at a low level. Blue is quite bad making this half of the instrument almost unusable for science. In the past we have found that vacuum servicing during this time of year (humid and warm) results in a very short amount of time before the contamination returns to an unacceptable level. Therefore we are not going to do a vacuum servicing this summer and wait until the science programs in Q3 can best benefit for this additional work.

2019-05-15: DIS Blue camera servicing complete. It is available for use.

2019-05-10: DIS Blue camera is being vacuum serviced. It will be available again after May 15.

2019-04-22: DIS Blue camera is again cold and ready for science. It is available for use.

2019-04-16: DIS Blue camera is being vacuum serviced. It will be available again next Monday.

2019-03-25: DIS Blue camera is back and looks to be operating as it was back in October. The spectragraph appears to be back in working order but we will monitor for increasing contamination.

2019-03-07: DIS Blue camera is reassembled and on the vacuum pump. Voltages check out within spec when tested warm and at atmosphere when connected to saddlebag.

2019-03-01: DIS Red is still available. DIS blue is currently unavailable.

2019-02-18: The blue camera has been removed from the instrument and is in the clean room for further evaluation. A counter weight has been installed in its place and the red camera is functional and available.

2019-02-12: The red camera is working again. The blue camera is still not working.

2019-02-04: After troubleshooting the blue clock board. The Red camera is also experiencing strange electical noise and odd behavior. The instrument is not useable while we try to solve what happened.

2019-01-29: The DIS Blue camera is not currently detecting light. It is unavailable while we troubleshoot. The Red camera is working and the the instrument is available for use.

2019-01-28: The DIS Blue camera has excessive noise and is likely dead. We are investigating a torubleshooting scheme and have ordered parts however consider the blue camera unavailable for sometime.

2019-01-14: DIS scheduled servicing run. Instrument is unavailable.

2019-01-02: DIS Blue noise issue likely in the dewar. It will be addressed during the next scheduled servicing run.

2018-12-28: DIS is returned to service however there is a noise issue with the blue camera.

2018-12-17: Start December vacuum servicing of the instrument. Scheduled to return Dec 29.

2018-12-03: Dis is operating nominally.

2018-11-29: Dis is back in service.

2018-11-19: DIS Red and Blue Camera vacuum servicing. The instrument is scheduled to return to service November 29.

2018-11-01: Return DIS Red camera to service. Cooled, initial focus and alignment. May require additional refinement.

2018-10-16: Took instrument out of service to work on red camera. DIS is currently unavailable.

2018-10-15: Both cameras continue to show contamination. We will be removing the instrument from service on Wednesday for intervention and vacuum servicing.

2018-10-08: Both cameras were cooled last Wednesday. Blue looked good for about the first 24 hours and then rapidly degraded from contamination. The Red camera could not be properly focused. We are discussing options and may be removing the instrument from service again in a week or so.

2018-09-27: Both cameras are on vacuum pumps. The instrument is unavailable at this time.

2018-09-11: The instrument is unavailable while we are trying to solve a vacuum leak. Waiting on parts to be manufactured.

2018-07-02: Red camera vacuum pumping complete. Instrument i again available.

2018-06-26: Red camera vacuum is soft, warming and cooling.

2018-06-05: Completed vacuum servicing of blue camera. Instrument is available for use.

2018-05-28: The blue camera is warm and on the vacuum pump for servicing. The instrument is not currently available.

2018-04-30: Completed vacuum servicing of blue camera. Instrument is available for use.

2018-04-24: The blue camera is warm and on the vacuum pump for servicing. The instrument is not currently available.

2018-04-13: Russet reports that the scattered light on the blue camera has increaded to about 1/3 of what it was before pumping.

2018-04-05: DIS blue camera servicing is complete. THe instrument is again available. There was a market reduction in scattered light for the blue camera. Red is holding steady at a low level.

2018-04-02: Blue camera is on the vacuum pump. Instrument is not available currently.

2018-03-30: Removed instrument from service to work on the vacuum system. Warming and pumping on the blue camera for the next week.

2018-03-19: Blue camera scattered light is far worse now than it has been prior to the last several vacuum servicings. Will attempt another vacuum pumping on the camera near the end of the month as the schedule allows.

2018-03-01: Finished serving the blue camera vacuum again. Small improvement in the scattered light.

2018-02-27: Started serving the blue camera vacuum again

2018-02-02: Instrument servicing went well. The Red camera cleaned up very well and we are monitoring for how quickly the contamination is returning. The blue camera had the same amount of pumping time but removed perhaps 50 - 75% of the contamination only. We will continue to monitor for the next time servicing will need to be done.

2018-01-26: The instrument is being serviced and is unavailable for the next week. This planned servicing will hopely improve vacuum and reduce the scattered light seen in users spectrums.

2018-01-11: The DIS slitviewer shutter appeared to be sticky. Replaced with spare. No alignment needed.

2017-11-03: The DIS slitviewer spare was installed. Sending the noisy camera off to the factory of evaluation.

2017-11-01: The blue camera has been checked out and is operational.

2017-10-30: Cooling the camera back down. It is still unavailable until it stabilizes. The pattern noise on the slitviewer camera continues but we have a spare camera to swap in when the first oppurtunity presents itself.

2017-10-27: Serving the blue camera in hopes to reduce the scattered light. The camera was warmed and is on the vacuum pump.

2017-10-23: Continued to try to isolate pattern noise. Contacting Andor for followup.

2017-10-20: DIS slitviewer is experiencing worsening pattern noise. We are investigating possible solutions.

2017-10-05: DIS is back in service. Red camera warmup, pumping and cooldown was successful. Will attempt the Blue camera in the near future.

2017-09-29: To try to reduce the contamination rise on the red camera it has been taken out of service, the red camera warmed and on the vacuum pump. Expected down time approximately 1 week.

2017-09-18: Russet reports that there is a rapid rise in contamination on both cameras since the servicing. Users are asked to report any effect to their science to the observatory staff.

2017-09-13: The instrument is once again available for use. The instrument servicing went well. We added 0.010" shims to the front of both CCDs to bring the focus adjustments closer to the middle of its range of travel. We replaced the ion pump on the blue camera. We installed the new red field flattener lens holder. We replaced all o-rings on both cameras and dewars. Inspected but id not clean the field lenses (they both appeared spotless). Verified the full range of the rotary micrometers for focus on each camera for documentation purposes. Last night Russet was able to redo the instrument blocks (x3) on the instrument as well as measuring scattered light and getting throughput data.

2017-09-13: The instrument is once again available for use. The instrument servicing went well. We added 0.010" shims to the front of both CCDs to bring the focus adjustments closer to the middle of its range of travel. We replaced the ion pump on the blue camera. We installed the new red field flattener lens holder. We replaced all o-rings on both cameras and dewars. Inspected but id not clean the field lenses (they both appeared spotless). Verified the full range of the rotary micrometers for focus on each camera for documentation purposes. Last night Russet was able to redo the instrument blocks (x3) on the instrument as well as measuring scattered light and getting throughput data.

2017-09-01: DIS is unavailable. It is being warmed over the weekend in preparation for vacuum and contamination servicing next week. It is scheduled to return on Sept 12.

2017-08-22: UPDATE: The red ion pump still is having periodic dropouts but once restarted the vacuum recovers rather quickly. New High Voltage cables are on order but have a long lead time for mfg. As long as vacuum remains good the ccd temp will not raise effecting darks and science.

2017-07-12: Ion pump is still dropping out. Track problem to high voltage cable. Parts will be on order.

2017-07-11: DIS is back up.

2017-07-10: Cooling red camera. Will verify ion pump operation and vacuum stability before released back for science.

2017-07-08: On June 21, we had a failure of the ion pump on DIS red. The vacuum gauge and ion pumps were incorrectly reading good vacuums at this time and the cause went unnoticed, attributed to a problem with warm ambient temperatures or the compressors on the cryotigers. Gas pressure was checked and adjusted multiple times without any affect. It was guessed that there likely was a partial blockage of the capillies of the cold head. Plans to warm the camera and flush the cold head was made. While setting up for this procedure the ion pump failure was discovered. The camera was put on the vacuum pump and reached excellent pressures in a few hours and the camera temps dropped 20K. Unfortunately once the vacuum valve was closed pressures did not hold. Even with pressures in the 10^-2 Torr the ion pump was reading 10^-7. This morning I changed out the ion pump and put the camera back on the vacuum pump. Plans to check for a vacuum leak and cool early the coming week are in place.

2017-06-22: Due to very warm ambient temperatures the cryocoolers that chill the CCDs are failing to maintain temperatures. Suggest users monitor the dark current.

2017-06-19: Contamination is increasing at the same rate as this time last year. Users should expect to see light scattering from the main psf into the wings of emmision line spectra. Servicing of the instrument is expected in September of 2017. For more information speak with Russet McMillan.

2017-04-17: Engineering data last week shows the contamination is holding steady to only a slight increase on both cameras.

2017-02-27: Russet took some additional pinhole data over the weekend. No big changes even though the ion pump for Red appears to have been working harder over the past week. Only a marginal addition in the contamination.

2017-01:30: Ran several tests of opening and closing the turret bay doors with internal metrology. No indication that the contamination got any worse from these tests.

2016-11-18: Russet reports that the contamination is still present in pinhole spectra however nearly unmeasurable with slit spectra.

2016-11-01: Russet reports that the red camera is just starting to show a halo around line spectra. It is still too weak to be measurable but it is starting. It became visible on October 30 but not on October 29th

2016-10-24: The past week and a half the instrument was warmed and the cameras were pulled. The cryostats were opened in the cleanroom where Bill Ketzeback and Sarah Tuttle inspected and cleaned the field flattener lenses in each dewar. They were then reassembled, pumped for 5 to 6 days in the instrument lab before being reinstalled on the instrument. This past Friday alignment and focusing of the cameras were accomplished by Bill and Russet respectively. The instrument is again available and clear of contamination. Nothing was done to eliminate future occurance of the problem however, the blue camera has a new lens holder to make it safer for future cleaning. The holder for red needs remachining. Sarah evaluated possible causes for the contamination and a team is being formed to work through options for a possible upgrade to the instrument that will eliminate future occurances.

2016-09-26: Contamination is still present but has not significantly gotten worse. Plans to go into the dewars to clean up the field flatterner lenses is scheduled for middle of October.

2016-08-01: The red camera contamination seen before shutdown has gotten worse. We tried during shutdown to eliminate it by heating and pumping on the dewar when we changed out ion pumps however this does not appear to have been successful on this try. The next step would be to open the dewar and clean off the flat field lens. We are delaying action on this until the wet weather we often see in the fall passes and we can have a new lens holder manufactured
2016-03-23: The dcamera shutter was swapped out with a spare. We finally saw and identified the failure mode. The bad shutter has been RMA'ed and we have a spare on order as well. Operation with the new shutter has been performing well.

2015-06-04: A new version of TUI (2.4.0 or higher) is required to display the new slitviewer. DIS Users should install this new version of TUI. Most users will find binning the slitviewer camera 1x1 is fine for guiding and display however in the event of poor seeing or slow image downloads consider switching to 2x2 mode. Users will also notice a much faster readout time and increased sensitivity for the new camera.

2016-03-23: The dcamera shutter was swapped out with a spare. We finally saw and identified the failure mode. The bad shutter has been RMA'ed and we have a spare on order as well. Operation with the new shutter has been performing well.

2016-01-14: The sticky shutter on the slitviewer is still a problem. We hope to resolve it soon with an in house shutter driver.

2015-10-05: Sticky bit issue resolved. The instrument with both cameras is available

2015-10-05: Cooled the red camera again on Friday. Cool down biases looked great. However once I started putting light on the detector a sticky bit (2E14) appeared. We will have to investigate further this week. Simple resets of the electronics did not fix or resol ve it. Otherwise, we were able to focus the camera by moving the actuators all the way to the forward most end of their range and moving the red collimator lens near the forward end of its range.

2015-08-01: Potential slitviewer shutter problem with short exposures on the slitviewer and bright stars. Vertical bleeding of stars seen in short (less than 2 second) readouts. Does not appear to be a problem with guiding.

2015-06-04: A new version of TUI (2.4.0) is required to display the new slitviewer. DIS Users should install this new version of TUI. Most users will find binning the slitviewer camera 1x1 is fine for guiding and display however in the event of poor seeing or sl ow image downloads consider switching to 2x2 mode. Users will also notice a much faster readout time and increased sensitivity for the new camera.

2015-10-05: Sticky bit issue resolved. The instrument with both cameras is available

2015-10-05: Cooled the red camera again on Friday. Cool down biases looked great. However once I started putting light on the detector a sticky bit (2E14) appeared. We will have to investigate further this week. Simple resets of the electronics did not fix or resolve it. Otherwise, we were able to focus the camera by moving the actuators all the way to the forward most end of their range and moving the red collimator lens near the forward end of its range.

2015-09-21: Red camera is on the vacuum pump and baking out water vapor. This will take a few more days with the water vapor content that is still in the dewar.

2015-09-16: Installed the spare red CCD42-20. Initial images taken warm look like the chip is alive but thermal signal is too great to tell much. Currently pumping on the dewar to remove as much water vapor as possible before cooling. We will make every effort to make the instrument available for blue science requests in the mean time.

2015-09-11: Preamp PCD boards check out. In discussions with E2V wether the chip can be RMA-ed. The instrument was made available for Blue science only.

2015-09-08: Removed DIS red ccd from dewar, preparing (waiting on parts) to test the pre-amplifier board. Attempting to RMA the red CCD with E2V. Waiting for RMA number. Working to make the instrument available for blue camera only.

2015-09-03: DIS is currently unavailable until further notice. The red CCD (or preamp) was damaged during the most recent vacuum servicing (to remove contamination from the field lens). APO staff are troubleshooting further.

2015-08-24: Warming the DIS cameras to clean contamination off the field lenses. It will be unavailable for science all week.

2015-08-01: Potential shutter problem with short exposures on the slitviewer and bright stars. Vertical bleeding of stars seen in short (less than 2 second) readouts. Does not appear to be a problem with guiding.

2015-06-04: A new version of TUI (2.4.0) is required to display the new slitviewer. DIS Users should install this new version of TUI. Most users will find binning the slitviewer camera 1x1 is fine for guiding and display however in the event of poor seeing or slow image downloads consider switching to 2x2 mode. Users will also notice a much faster readout time and increased sensitivity for the new camera.

2015-06-01: New slitviewer camera installed. Commissioning this next 2 nights. User manual to be updated as well this week.

2014-10-02: REd camera contamination significantly improved. We still do not have a quantitative measurement but visually using a pinhole mask it is nearly gone.

2014-09-30: Red camera is cold again. Investigating if contamination is still present. Instrument is usable at this time.

2014-09-26: Warmed Red camera to remove reported contamination. Instrument is not usable until this is resolved.

2014-07-15: Red and Blue cameras are cold. Instrument is ready for science

2014-07-07: Red and Blue cameras warm for vacuum servicing

2014-01-09: Grating 1 blue bay repaired. The problem was a bad/failed home switch. Some dis-assembly was required of that bay. After reassembly, the instrument robotics were rehomed and tested.
2014-01-03: DIS high res bay home switch has failed. Parts on order. The observing specialists will need to make grating swaps (sometimes in the middle of the night) until the problem is fixed. The Blue high resolution grating bay motor is not available until then.

2013-08-08: DIS Red camera is running 10 degrees warmer than prior to shutdown and servicing. Cause is under investigation. Currently there is no evidence that users will need to take extra darks with their calibrations.

2013-08-08: DIS Red camera was showing a light leak. The bolts that mount the camera to the instrument are not creating a good seal. Taped over the interface.

2013-08-05: DIS Red and Blue cameras were serviced during shutdown. The Red camera received a new field flattener lens, a new aluminum nitride disk and the tensioning springs holding the field lens was removed. This last item was installed during the summer of 2012 to protect the lens from thermal cycling which we believed may have stressed the glass. This was certainly the cause for the dark current because the CCD was no longer in good thermal contact with the coldplate (in a sense floating). The blue camera was opened to clean the field lens which showed signs of water spots. Some investigation of the cause of the contamination was discussed by several engineers. Both cameras had their ion pumps replaced as well.

2013-06-26: DIS red is once again cold. There was marked improvement in the contamination/ scattered light as seen in the large wings in the profiles of spectral lines. Nothing was done with the blue camera at this time. We will address it during the summer shutdown unless it gets much worse. An improvement in the red cameras dark current was also seen however still is not fixed. There is a small tilt in the red camera spectra(20 pixels across the width of the chip) that will be addressed during shutdown. This is just an alignment issue with reinstallation.

2013-06-18: Warming of the red camera. I will be placing it on the vacuum pump this week in hopes we can reduce the magnitude of the contamination / scattering of the spectral wings. Other issues of the cause of this contamination, replacing the field corrector lens, vacuum issues will be addressed (or at least investigated further) later this summer during shutdown when we can open up the camera itself.

2013-06-03: Verified that the red camera has contamination on the field lens. To remove we will need to bring the instrument down for a minimum of 4 days to warm and bake out the water vapor. Any vacuum leaks will be addressed later in the summer during shutdown.

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.

2012-08-28: Yesterday we added an Aluminum Nitrade electrical isolation disk between the cold head and cold strap block inside the dewar. The Red camera was pumped on for 24 hours and cooled this morning. Initial tests show that the biases look normal again and that dark current is low (< 0.02 DN/sec).

2012-08-24: The Red camera is experiencing excessive noise as in readout, possibly due to extra dark current. It was taken offline today and warmed in preparation for a more thorough investigation next week.

2012-08-10: Over summer shutdown both DIS cameras and cryotigers were fully serviced. The Blue camera with a new cryogenic cold head. Both camera showed water vapor spots on their field lenses. They were removed and cleaned. There was minor damage done to the Red camera field lens when it was reinstalled.

2012-05-07: DIS Blue contamination shown to be gone.

2012-05-04: DIS Blue retruned to service late in the day. Unable to determine yet is contamination is still present.

2012-04-30: DIS removed from service today to deal with contamination on the blue camera. Expect it to be out of service until Thursday of this week

2012-04-24: DIS blue is tracking ambient temperatures and is running about 7 - 10 degrees warm (-87C). Extended wings on the spectrum suggest a scattering source on optics or the ccd. Will monitor and address if it continues to worsen. Otherwise, servicing this summer is planned.

2012-03-28: NEW B400 grating installed and aligned today.

2012-03-26: DIS Blue camera ion pump replaced. It is warm and still needs more pumping this week. It is not in service until further notice. DIS B400 Grating has been removed for swap with new grating.
2012-02-17: DIS Blue camera temperature is back to normal.

2012-02-16: DIS Blue camera vacuum has gone soft and is experiencing temperature regulation issues today. We are putting it on the vacuum pump. THis will take DIS out of service until the vacuum issue is resolved. If all goes well it will still b e available for this evening.

2012-02-10: DIS Users Guide updated today with new recommended exposure times for flat fielding using the truss lamps.

2012-02-09: New recommended exposure times for flat field lamps can be found here.The DIS User Guide will be updated shortly.