Subsystem Summary

Ca H&K Spectrometer

• Throughput requirement met by calculation

  • measurement deferred to on-sky

• Met all other requirements

• Trouble with trigger signal to start exposures (troubleshooting underway)

• Does spectrum need to be moved?

• Has on-sky throughput been checked?

Calibration Unit

• Could not fully test the Calibration Unit at SSL since compensator motors had very long lead and were not in-hand.

• Calibration Unit was set into a state that allowed use but was not the final configuration.

• New plan is to not use motors but purchase filters with higher tolerances.  Filter purchase waiting on funding; will install filters during servicing mission.  This will make for a simpler system going forward (and one easier to maintain as 4 less motors involved, no look-up table to maintain)

• Lamp issues, power supply issues

  • Now perhaps solved with Green Scientific lamps and supplies?

LFC

• LFC availability was sparse.  A combination of sub-optimal thermal variations in the high-bay (10’s of degrees F thermal variation over 12 hours) and incomplete software automation precluded extended operation of the LFC at SSL.

• Comb has been operational but there has been significant down-time due to Menlo hardware and software issues.

Etalon

• Was not available for tests at SSL.

• SuperK failing

• Is this our final etalon?  Plans for a replacement?

Cryostats/CCDs

• Fully passed majority of requirements

  • Some requirements were just missed but deemed OK.

• Fringing was significantly worse than requirement, plan was to correct in software

• Noise issues (procedure in-hand for better grounding)

• Has fringing correction been looked at yet?  (science impact not operational)

• CTE issue on one Green quadrant

Environmental Control System

• Vacuum Chamber met requirements

• Thermal enclosure not designed/built

• Thermal enclosure to be installed later this year.

• Linear potentiometers not in regular use (will be re-initialized during servicing mission)

• Gate valve position monitoring not yet implemented (will occur during servicing mission)

Exposure Meter

• Throughput requirement met by calculation

  • measurement deferred to on-sky

• Met all other requirements

• Have we checked this?  “The flux at the EM detector shall be at minimum 1% of the flux at the main spectrometer CCD”

• Above also needed for automatic exposure termination

• Has that been done tried yet??

Fiber Injection Unit

•Optical performance and alignment requirements met

• On-sky acquisition and guiding requirements met? – check list sent to Josh for CAPS

• FVCs have been more challenging to use than expected.

• ADC prism counter-rotation offsets likely not correct

Optical Fibers

•All requirements met

• Backup Simulateous Cal fiber was damaged during installation. There are no current plans to build a replacement.

Agitator

•Was not tested at SSL

• No issues; has been in routine operation on the summit

• Have we done an agitator on / agitator off performance verification test??

Instrument Control Software

•Nearly all dispatchers written (only exposure meter, LFC, and etalon TBC)

•Minimal alarms in place

Update:

• All dispatchers now operational

• “testall” script operational and in use

• Alarm system fully functional with important alarms in place

To-do:

• Plan to add more alarms

• Archon trigger issues

• Backup computer in-hand but not operational (needs OS installed)

Observing GUI

• Sketches and plans but no code

• Fully operational??

Spectrometer

• Throughput requirement met by calculation

  • measurement deferred to on-sky

• Met all other requirements

• Throughput matches model except at bluest end of full bandpass

  • could be a symptom of incorrect ADC correction

SoCal

• Not included within PSR scope