NIRSPEC Team:
Ian McLean, PI
George Brims, Systems
James Larkin, Faculty, Software
John Canfield, Mechanical
Nick Magnone, Mechanical
Don Figer, Optics
Michael Spencer, Electronics
Maryanne Angliongto, Electronics
Mavourneen Roberts, Grad Student
The NIRSPEC cargo was picked up from the airport, when it was found that most of the shock sensors had triggered on the dewar and baseframe crates, up to 20-g's in ALL 3 axes. The cargo was safely transported to the summit, and offloaded by 3pm. The dewar and baseframe was contained in inner crates, which were isolated from the outer crates by air cushions. Fortunately the inner shock sensors on the dewar crate did not suffer the same forces as the outer crate - one 5 and one 10-g vertical shock on one side of the inner crate were broken. We have decided to push forward and plan on conducting the full inner dewar inspection early next week as scheduled.
Today, the baseframe (with jacking hardware) was assembled,
and the electronics racks were filled after the baseframe+cart was moved to
the K2 mirror barn. The system has been powered up successfully. The
jacking system drive assembly will be added tomorrow morning; the baseframe
will then be ready to move. The cal unit was also unpacked and inspected.
The dewar was moved on its cart to the K2 dome floor.
The instrument handler was driven to RNAS, but it was discovered that the
gear train needs adjustment; too much backlash in one gear causes the
handler to jump when driven across the gap. The adjustment will be done
tomorrow, but NIRSPEC's two big parts cannot be brought to RNAS until
that work is complete, estimated to take 1/2 day+.
The handler gear adjustment was completed at 1500. The handler now drives
very smoothly across the gap. Baseframe detail work was done in the mirror
barn during the wait. The baseframe was rolled into the K2 dome, rigged
up, and lifted to the handler on RNAS. One problem surfaced: the locating
pins for the jacking pads didn't match up to the baseframe. The pins
were removed, and the frame placed on the handler; the pin locations
will be marked and moved tomorrow. We noted that the dewar kinematic
adjuster screws lined up by eyesight to the elevation crosshair, a
nice visual. About 1/2 of NIRSPEC is on the telescope today!
On the computer front, the host accepts the operating account logins
on its console and from 3-headed kua. We are also ready to test the
laptop connection roundtrip from RNAS.
The NIRSPEC team grew with Ian and James on site. The baseframe was lifted
off the handler to relocate the jacking pad pins. The pins were installed,
and the handler driven to the KM's. The KM top screws were nominally
adjusted at the installed position, and the jacking upper limit switch
was set.
The dewar was flown from the dome floor, and installed on the baseframe!
The operation was very smooth.
The cable boom was rotated around, power and fiber were connected, and
after a bad fiber jumper was discovered (should we be surprised?), we
successfully communicated from the computer to the on board transputer
control. The first (no)data was taken (dewar is not cabled).
The dewar vacuum was checked - it's at 1.8 T, good considering the rubber
packing material inside of it.
The computer host 'waimea' required a change in a network configuration
file, listing itself as a local network machine. Also, it was booting
of disk 3 (the Y2k test boot disk); the configuration was changed
to boot off the internal disk.
NIRSPEC IS ON THE TELESCOPE TODAY!
Image of NIRSPEC on RNAS
The heat exchangers were removed first thing, after NIRSPEC was placed on the RNAS KM's and the frame loosened; it was discovered that the internal plumbing is very deteriorated, and new units will be shipped from UCLA tomorrow. NIRPSEC was driven to the deck, and the AO enclosure was prepared for entry. Removal of the floor panels requires some study to streamline the procedure, for the future. The dewar lid was lifted off at the deck; no shipping damage was evident. NIRSPEC was driven into the AO enclosure, and the cold shield removed. There were two 5-g shock sensors installed before shipping; one fell off and both axes were broken, and the other was still on with both axes intact. Packing material was removed from the image rotator and the echelle assembly. Preliminary inspection of wiring, mounting hardware, and the visible stages showed good condition overall. The cold shield was reinstalled, and NIRSPEC has been left in the AO enclosure until tomorrow. We are a bit more relieved about the state of the instrument, but there is much more testing and inspection to go.
Following some difficulties in getting fiber and power to NIRSPEC in the AO
enclosure, the instrument was brought on line, and the first extensive
testing begun. Some more packing material was removed, and the interior
was vacuum and alchohol cleaned. Motor testing was very successful; all
the motorized stages work as expected, one more check off the anxiety list.
The CCR heads were installed, and manifold plumbing and interface panel
work continues. Images were taken with terminating resistors; the SCAM
electronics perform normally, but the InSb electronics do not read out
without saturating A/D with any range of applied offsets; this is being
investigated. Work will continue in the AO enclosure at least through
tomorrow mid-day.
The last two days have primarily been spent in the AO enclosure; NIRSPEC
left it at 2pm today, and driven to RNAS. There was some troubleshooting
required to locate the source of the Aladdin offsets problem; the DAC's
on the interface board were not responding to offset commands from the
transputer. It was
ultimately found to be due to a bent pin on the SPEC transputer board
connector to the interface cable. It was also discovered that the
SCAM and SPEC interface boards were spares and not the original operating
boards (the original boards were left at UCLA,
and were shipped today to us). Another problem remains, that of 2 unstable
channels on the Aladdin readout; a bad connector is suspected for this
too.
The cold shield was installed, NIRSPEC brought over to RNAS, and
NIRSPEC was jacked into its KM's there. Optical alignment began, and
took about 2 hrs; the result is quite good, with the instrument
aligned to about 1/2 the runout on the el-axis crosshairs (about 1/3 arcmin).
Tomorrow we will jack NIRSPEC off of the mounts, and test repeatability
of the alignment. We will make a decision about the day sky pupil
first thing in the morning.
Communication to NIRSPEC was re-established by changing to a different telescope fiber for the recieve line; fiber labeling is not logical nor well documented, by the way. Troubleshooting the intermittently bad twin-channel on the InSb continued throughout the day while alignment was in progress; the problem remains unresolved but it looks much like a cable fault seen at UCLA.
We found that NIRSPEC's position did not repeat well when jacking on and off the KM's. The rear screw on the flat was loose; after tightening repeatability was good (< 10 arcsec). The AT was realigned with the El-axis, and NIRSPEC was repeatedly adjusted to bring it into collimation and centering. The final result is, that NIRSPEC is aligned to the rotation axis of K2 to < 1/4 arcmin. The rotator introduces runout of about 20 arcsec. The positional centering accuracy is about 2 mm.
Late in the day the dewar lid was installed, a touchy procedure. Rough pumping began at 1715; at departure the vacuum was not dropping as fast as expected - it will be checked Saturday. NIRSPEC was left running; the front electronics panels were installed; cabinet temperatures will be monitored.
Days 12-15 Summary
This week the instrument cooling cycle began on schedule, beginning
Tuesday with connection and operation of the closed-cycle-cooling
system. The compressors were left running overnight, bring the
instrument down about 25 K running into the start of LN2 flow
into the 20 liter reservoir Wed morning. The LN2 service went only
until Wed evening, and Thursday, the can was topped off and the
roughing pump attached to bring it down solid. The pump will be
left on the LN2 reservoir until mid-next week.
The cooldown is going very well; as of Friday 16 Apr the detectors are cooled to operating temperatures, and the rest of the instrument is following.
The lingering problem with the dual-channel noise on the Aladdin was rectified by repair of the transputer DAQ-17 board, and reinstallation (thanks Rich!). Both detectors now function normally; images are being taken daily during the cooldown.
The glycol integration was interrupted with a leak in one of the heat exchangers; it was repaired and installed. Splash guards were added over the exchangers.
