Subject: APO 3.5m users committee minutes, August 2011

From: Suzanne Hawley

Submitted: Tue, 6 Sep 2011 15:13:12 -0700 (PDT)

Message number: 1242 (previous: 1241, next: 1243 up: Index)

 		APO 3.5-m Users Committee Phonecon, 8/8/11

Attending:  Suzanne Hawley, Mark Klaene, Bill Ketzeback, Bob O'Connell 
(for Remy Indebetouw), Jon Holtzman, Michael Strauss, Scott Anderson, Sean 
Moran, and Bruce Gillespie

Absent:  Al Harper, John Bally, Remy Indebetouw, Russet McMillan


User feedback and comments from institutional representatives:

o Washington (Scott Anderson) - Scott mentioned the recent question about 
drifts in the echelle wavelength stability (see topic discussed below).

o Colorado (John Bally) - No report.

o Johns Hopkins (Sean Moran) - Sean had nothing new to report.

o New Mexico State (Jon Holtzman) - Jon had nothing new to report.

o Princeton (Michael Strauss) - Michael had nothing new to report.

o Virginia (Bob O'Connell) - Bob had nothing new to report.

o Chicago (Al Harper) - No report.


Discussion of telescope/instruments report:

Mark Klaene and Bill Ketzeback gave an overview of the past month's 
activities.  The July summer shutdown is over.  The primary mirror was 
realuminized, and got a good coating.  The echelle upper tank was opened 
for maintenance.  The DIS dewars were pumped, and power supplies were 
replaced.  The NA2 instrument rotator was serviced.  With the help of 
student and temporary staff, we kept schedule; the telescope is up and 
running well.

The new camera for the Shack-Hartmann instrument was installed and 
commissioned.  DIS vacuum and detector temperatures are a little higher 
than we like, but DIS seems to be working fine.  The blue 400 grating for 
DIS acquired a chip during handling.  It is not in the beam so the grating 
is in service, but we plan to replace it soon.  SPIcam, Agile, TripleSpec, 
and the echelle are all operational, but the echelle slit viewer camera 
computer is crashing.  It is an old computer that needs to be upgraded. 
The ThAr calibration lamp for the echelle was replaced and the new lamp 
has a quartz envelope that attenuates the UV lines -- we will get a 
replacement lamp.  There have been reports of jumps in the calibration 
lines, which is under investigation.  The NIC-FPS upside-down problem was 
addressed by replacing all the cables in the dewar, and the Leach 
controller was replaced to fix excessive read noise.  The upgraded GFP is 
still in commissioning.

Mark Klaene's detailed report for the reporting period follows:


 	3.5-m Telescope, Instruments, and CIF Projects Highlights
  	                 6/2/11 through 8/2/11

0) Overview

The forest closure was lifted on July 21st after receiving a few inches of 
much-needed rain.  Some fire restrictions remain in effect.  The to-date 
rainfall at the observatory is still below normal -- only 4 inches so far. 
During the long, dry spring and early summer, numerous fires occurred 
around us.  All fires within 5 miles of the observatory were kept to under 
one acre.  The summer shutdown started on July 5th and ended on time, with 
July 28th being the first night of science observing.

A)  Summer Shutdown

The main task was to re-aluminize the primary mirror at KPNO.  Despite a 
major detour caused by road construction just outside Kitt Peak, the 
mirror arrived at KPNO on July 11 and returned to APO on July 15.  Many 
thanks to the Starfire folks in Albuquerque for the loan of their shipping 
crate again.  With the mirror removed, the mirror cell was serviced and 
the PMSS re-calibrated.  Additional work included:  Echelle upper-tank 
work and pumping, DIS camera pumping, new DIS robotic power supplies, 
top-end metrology, and Na2 rotator bearing service.

The shutdown went quite quickly and smoothly, in part due to additional 
temporary manpower.  This included 2 UW students (Conor Sayres and Nick 
Hunt-Walker) as well as a temporary APO summer helper, Tom Yuhosz.  Many 
thanks to them.

1) Telescope

The telescope is up and fully operational following the shutdown.

The new Shack-Hartmann camera is now working after considerable effort by 
Fritz and Russell to get the new camera into TUI and also by Bill to get 
the data-reduction procedure running.  It was used to confirm collimation 
of the telescope after the mirror was replaced in the mirror cell.

2) Instruments

DIS became quite troublesome during the shutdown.  New vacuum gauges that 
would have been a great addition to the cameras proved to leak and had to 
be removed.  Last-minute pumping was needed to get reasonable vacuum 
levels.  Both Cryotigers had to be purged and recharged.  Despite very 
good vacuums and nearly perfectly charged cryotiger systems, the cameras 
are running 5-10 Deg C warmer than before shutdown. Upon initial testing 
the blue-medium grating was found to to be chipped.  There are known 
deficiencies with the mounting of the gratings in the holder, and some 
were corrected but other more invasive fixes were not.  The grating has 
been glued back together and is serviceable (the chip is outside FOV).  A 
new grating has been ordered.  Other robotics issues were traced to 
corroded connections and appear to be OK after cleaning.  However, issues 
with grating initial calibrations are being investigated (see agenda 

SPICam operated with no new issues.  Agile is operational; a recent motor 
error is being investigated.  TripleSpec is operational. Echelle is 
operational.  Problems with the slitviewer are still appearing.  This is 
due to an old computer that needs to be upgraded, which is in work but may 
take a substantial amount of time.  If we cannot get the proper libraries 
built and working with MAC OS9 for this older camera, we will have to look 
at a new camera similar to what is being considered for the new DIS 
slitviewer camera.  A replacement of the ThAr lamp in early June was 
mentioned in the minutes for the June meeting.  Additional issues have 
recently surfaced with wavelength calibration (see agenda item below).

The NIC-FPS problem of spontaneous reset of the Leach controller when 
rotated upside down has been addressed with a complete replacement of the 
in-dewar cabling.  This was accomplished at CU along with replacing the 
burned-out heater tape.  Upon return to APO the read noise was quite high. 
This was traced to bad Leach controller cards that were replaced with 
spares.  The suspect cards will be sent back for repair.  The read noise 
is now back at 11 DN with the spare cards.  Thanks to Stephane Beland for 
all his work on NIC-FPS this year.

GFP upgrade work has resumed on the mountain with engineering time this 
week.  All of the hardware for direct imaging and IFS mode is in place. 
Work continues on commissioning characterization and software development. 
The problem with thermal stability has been corrected and a fix is in work 
for the problem of image drift with rotation.  Robotics software has been 
completed and is operational.


DIS blue grating:

Suzanne emphasized that since the DIS blue low res grating (B400, the one 
with the chip) was removed and reinstalled, users should recalibrate 
wavelengths for data taken since the shutdown.  If there are any problems 
with the data or calibrations, let us know.


Echelle wavelength calibration:

The same is true for echelle data taken since the shutdown, and we would 
particularly like to hear about unexpected wavelength shifts.  Suzanne 
pointed out that since the new calibration lamp was installed around 6 
June, many lines in the blue and UV are gone or very weak.  We should have 
a new lamp in a few weeks, hopefully in September.  UW observer John 
Wisniewski has been doing radial-velocity studies with the echelle, and 
reports that he see more scatter in the RV residuals (~2 km/sec), and has 
also seen two instances of a calibration wavelength jump of ~15 km/sec. 
Echelle users are urged to look at their data carefully and report any 
problems.  Mark mentioned that we are looking in to replacing the echelle 
grating, and Jon Holtzman thinks we may have identified one with higher 


TUI support for old versions of operating systems:

Mark suggested that we make MacOS 10.6 the oldest operating system that 
will be supported for TUI.  Suzanne asked if anyone knows of users using 
older versions of MacOS.  We do want to maintain platform flexibility, but 
it is difficult to keep TUI consistent with several generations of 
operating systems.

===> ACTION:  We will plan to phase out TUI support for MacOS 10.4 by the 
end of the year, and phase out MacOS 10.5 by next summer.  Users committee 
members should query their users to see if this causes hardships.


PISCO instrument update:

Suzanne said that PISCO is a 4-color dichroic imager that is being built 
at CfA and was intended to go on Magellan.  If APO contributes some money 
and manpower, it is possible the instrument could be brought here.  There 
will be a meeting at APO in August with CfA personnel to discuss details. 
The camera has built-in griz filters, but options are being looked at for 
other filters.  However, it may be more practical to keep either Spicam or 
GFP for narrow band imaging.  The camera has a 12 arc minute FOV which 
will require some reworking of the NA2 port.  It is also a large 
instrument; one of our existing instruments will need to be moved or 
retired to make room for it.  Jon asked what the science case is for this 
camera.  The new capabilities are that it has a much wider field, with 
better sensitivity, and obtains four colors simultaneously.  Both 
Princeton and UW thought these capabilities were very interesting for 
future science programs including deep imaging of stellar populations and 
transient followup.  ReSTAR has also expressed interest in our having such 
an instrument.



[open from previous meeting]:

===> ACTION:  User committee members to try to find users who would be 
interested in helping develop exposure time calculators.

 	STATUS:  Closed.  UW students have been working with Bill 
Ketzeback on exposure time calculators for a class project.  Anyone who is 
interested in helping should contact Bill directly.

===> ACTION:  User Committee members to ask their users if MJD in TAI 
would be useful information to have written in the FITS headers.

 	STATUS:  Closed.  Michael asked if there is any down side in doing 
this.  Suzanne stated that all instruments should use TAI.  Scott said 
that as long as the time records are well-labelled, it doesn't matter. 
Suzanne thought that the hub could easily write the times as TAI, ignoring 
what the ICCs deliver.  Bill said that all the ICCs should have standard 
time keywords, but making them consistent is not an easy task.  Suzanne 
said we will look into exactly what the ICCs are writing, especially if 
they are only giving UTC times.

[new actions from this meeting]:

===> ACTION:  We will plan to phase out TUI support for MacOS 10.4 by 
January 2012, and for MacOS 10.5 by July 2012.  Users committee members 
should query their users to see if this causes hardships.


Next meeting:  The next Users Committee phonecon will be on Monday 12 Sept 
at 8:30 AM Pacific Time.  The agenda and other materials will be sent to 
the committee members during the preceding week.

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