IMACS progress report no. 52

B. Bigelow						12 August 2002

I)	Project Status

Currently scheduled tasks:					Status:

a)	DSS drive design (Hare)					IP				
b)	DSS drafting (except drive) (Cleary)			Done 
c)	DSS assembly/testing (Hare, Kowal, Castillo)		IP
d)	DSS Grating Tilt Mech testing (Hare)			IP
e)	Calibration system mech. des. (Hare)			on hold 
f)	CCD array assembly (Thompson/Burley)			IP
g)	Filter procurement (Sutin)				Done
h)	Grism procurement (Sutin)				IP
i)	Instrument electronics assembly (Bagish)		on sched.
j)	Control software design (Birk)				on sched.
k)	Instrument enclosures fab (Gunnels/Paragon)		IP
l)	Instrument utility wrap design (Gunnels)		done
m)	Utility wrap fabrication				IP

Project events in July:

 - First Light on 4 of 8 CCDs with long camera!
 - 2/3 of enclosure panels delivered in July

Latest project images:

Final Assy:        http://www.ociw.edu/instrumentation/imacs/devel/final/index.html
Dewar Assy:        http://www.ociw.edu/instrumentation/imacs/devel/dewar/index.html
Enclosures:	   http://www.ociw.edu/instrumentation/imacs/devel/enclosures/index.html

II)	Optics (Sutin)

No report this month.

 - Aspheres due from Tinsley in August.
 - SO1 is "finished", and undergoing final testing.
 - S08 is close behind.
 - As-built update for short camera is scheduled for August

III)	Electronics (Bagish)

In July:

- Assembled and successfully tested the new Altera hard stop logic, PI
  encoder repeater, Microphone preamp, line driver and line receiver. 
  Final quantities of all PCB's have been ordered.
- Two MCS Rack bulkhead panels have been engraved and connectors installed.
- Assembly of 35 foot long cables has begun. Additional cable ordered and
  received.
- TCIP/IP to serial interface break-out schematic complete and parts ordered.
- Two RTD thermal sensors ordered for initial test.
- One-half of two-rack insulating panels have been cut and mortised to size.
- Bypassed thermostat on heat exchanger.

To do:

- Parts ordered and ready to test fluid flow of heat exchanger.
- Populate and test all remaining PCB's. 
- Upgrade MCS Chassis 3 & 4 with new Altera hard-stop logic.
- Send MCS front panels out for final finish, anodizing and engraving.
- Upgrade MCS Chassis 1 & 2 with Altera hard-stop logic and new front panels.
- Test RTD thermal sensors w/ HP data acquisition unit.
- Assemble cables.

IV)	Software (Birk/Clardy)

Birk:

- Long Camera focus: We tested the Long Camera focus motors and were
  able to focus an image of a round slit. Moving the focussed image in
  X and Y turned out to greatly defocus the image. It does not seem
  feasible to me to use LO5 for flexure control, but moving all 3
  motors in parallel to correct for scale/focus changes works fine.

- Shutters:  The shutter was connected to the DSP for the first time
  and we were able to take pictures using the IMACS dewar.

- Gratings/Disperser-wheel:  Lots of flexure tests were done this month
  and major hardware changes are going on. I hope to continue with
  software test on the disperser mechanisms in August.

- DSP/Science Array Software: For the first time I read CCD (MIKE)
  data from the DSP. The full array mode works fine. There are onle
  small changes necessary in the DSP code, eg. removal of prescan
  pixels.  The sub-raster- and shuffle-modes and reading more than one
  CCD chip simultaneously, requires to update the DSP code.  Greg and
  I are trying to make those changes by email while he is in Canada.

- Graphical IMACS Status Display: I continue to add parts to the
  graphical status display GUI.  It now shows the hatch, all three
  guiders, the slit-mask server, disperser server, both filter-servers
  and shutters.

Clardy:  (Clardy)

V)	Detector Systems (Thomson/Burley)

First of all, the bad news -- one of the IMACS cryotigers had an
o-ring blow-out in the cooling head.  Not much gas escaped, but it did
mean that one out of two IMACS cryotigers was out of action.  It has
been sent back for servicing, along with the other cryotiger system
which needed the cooling gas exchanged from PT-13 to PT-30.

Also, we accidentally discovered a somewhat nasty thermal short in the
IMACS dewar.  When the dewar was evacuated, the focus stage was pushed
towards the faceplate, and smashed the ball-bond covers on the SITe
detectors into the faceplate.  This could have been a real disaster if
the ball-bond covers weren't there.  There is a retaining nut on the
focus motor shaft that should prevent this happening, but the focus
motor assembly wasn't installed at the time.

And then, the good news -- both the Red MIKE + Blue MIKE ccd cameras
were installed and working on the spectrograph.  And, roughly half the
IMACS mosaic was working with the long camera optics on that
spectrograph -- 4 chips + 1 cryotiger.

The single cryotiger was able to cool the detectors to about -90C,
which is much colder than might be expected.

In Sept:

1) putting the MIT/LL chip in blue MIKE
2) getting the fiber link to work (prereq for the 8-chip readout)
3) populating the rest of the chips in the IMACS array

VI)	Mechanics (Bigelow/Hare)

Bigelow:

In July:

1) Complete 2nd imaging mirror cell - done, parts in shop
2) Progress grism cell design - no progress
3) Designed and received spool which allows the long camera to
   mount on the short camera end of the structure - flexure testing
4) Measured lens motions in cells - found to be within allowances
5) Completed final layout of cables and selected IGUS chain for
   utility wrap
6) Wrote two papers for SPIE Astronomy 2002 meeting in August

For August:

1) Progress grism cells
2) On vacation 8/5 - 8/11
3) Short camera as-built update - tooling design
4) Order long camera baffles
5) SPIE meeting 8/19 - 8/29

Hare:

In July:

* Continued optomechanical and electro-mechanical assembly and testing of the Principle 
  and Shack-Hartmann Guide Cameras.
* Assembly and testing of the Grating Tilt Mechanism.  Investigating flexure issues.
* Review of the Disperser Server Drive Mechanism design complete.  Revising solid 
  models.

For August:

* Continue assembly, testing, and rework of all guide cameras as necessary.
* Continued testing of the Grating Tilt Mechanism.
* Fabrication DSS Drive Assembly.
* Assembly and testing of the Disperser Server System and Cable Wrap Subassembly.
* Fabrication of the second shutter.
* Resume design work of the Calibration Unit.

VII)	Fabrication (Kowal)

In July:

1) Made new drive wheel on IMACS structure
2) Made new Drive Plates for Shack and Prin. Guiders
3) Made assorted Shutter parts.
4) Built test fixtures for Tilt Mechanism
5) Modified Tilt Mechanism Part for rigidity
6) Modified supports for mask server to clear enclosure panels

For August:

1) Shutter v2.0
2) New Imaging Mirror Cell
3) Pick up work


VIII)     Other Business

Next meeting:  10:15, Wednesday 9/4/02