IMACS progress report no. 56

B. Bigelow						17 December 2002

I)	Project Status

Currently scheduled tasks:					Status:


a)	DSS drive assembly/testing (Hare, Kowal)		IP
b)	DSS new grating tilt fab. (Kowal)			Done
c)	DSS new grating cell fab (Kowal)			Done
d)	Calibration system mech. des. (Hare)			IP 
e)	CCD array assembly (Thompson/Burley)			Done
f)	CCD array testing (Thompson/Burley)			IP
g)	Grism procurement (Sutin)				IP
h)	Grism cell fabrication (Kowal)				IP
i)	Entrance hatch fabrication (Kowal)			Done
j)	Short Camera shutter assembly (Hare)			Done
k)	Instrument electronics assembly (Bagish)		on sched.
l)	Control software design (Birk)				on sched.
m)	Short Camera opto-assembly (Bigelow)			IP
n)	IFU design and build (U. Durham)			IP

Project events in November:

 - Short camera aspheres AR coated and delivered!
 - Grating flexure testing successfully completed! 
 - Echellette mode: grating delivered, prism out for RFQ
 - Laser mask cutting started in Chile
 - Short camera filter server installed on structure
 - Utility wrap installed

Latest project images:

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

II)	Optics (Sutin)

* S01 and S08 have been coated and delivered.

* The replacement S04 and the 300 grism substrate are both now at STF,
  waiting to be coated.  (S04 delivered 12/17/02 BCB)

* The 600 grism is about to be glued together at Harold Johnson OL.

* The dewar window was returned with a small chip of unknown origin
  under where the o-ring sits.  We decided to make a backup window.
  The backup dewar window material is here and is about to be shipped
  to TORC for figuring.

* The echellette prism is designed and Zygo is about to quote.

III)	Electronics (Bagish)

No report for November

IV)	Software (Birk/Clardy)

Birk:

- Disperser Wheel:  We tested the disperser motor and associated
  limit-switches and position sensors. Except the hardstop-limits and
  the encoder, everything works. During December we plan to test the
  disperser server on the structure.

- TCP/IP Serial Converter (terminal server): All adapters
  successfully tested. All system are now controlled using the network
  and the terminal server.

- Long Camera Focus: Brian and I aligned the long-camera lens (LO5)
  using the alignment telescope. The offset for the 3 motors are: +110
  um, +335 um, -440 um.

- Science Array: For the first time we read all 8 chips
  simultaneously.  I fixed a bug (scaling-routine) in the quick-look
  GUI (QLTtool).

- Calibration Lamps: I added lamp-control to the software.

- Piezo Flexure Stage: I re-adjusted the internal control-loop of the
  PI-controller. That stopped the vibrations we saw earlier. Before we
  cool down the next time we should test it again with the copper
  straps connected.  We checked the max. motion that the stage can
  control: @90 deg: 0-180 (20-200) um @45 deg: 0-200

- Slit-Mask Server, (PR-,SH-CF-) Guiders: While running all (3)
  guiders, the slit-mask server and filter1-server we discovered a
  couple of interferences. (Mask-Server/PR-guider and
  SH-guider/CF-guider).  More tests will be done in December.

- Shutters: Both shutters will be re-assembled in December

Clardy:  

For November, 2002:

Specifications for the Astronomer's GUI were improved in a meeting
with users on Nov. 15th.  Most of the time was taken by refining the
mask cutting file generation.  The Z-axis control proved particularly
intricate, the logic for auto-focus use had to be revised at least 4
times to finally agree with how the machine actually works.  Also,
conversations by phone and e-mail continue to improve how the cutting
machine set-up and the program interact.  The test mask has been
generated, except for an unknown problem near the end which prevented
cutting of the features on the flange.

The file for cutting the center field guider mask has been revised to
include cutting most of the perimeter of the mask except for a small
tab in the center of each side; the new file has been sent south for
cutting.

V)	Detector Systems (Thomson/Burley)

1) multiple software updates to the code we use in the lab for testing
the CCD's: (a) rewrote the display code to use the client display
library, which fixed some major bugs, (b) modified the DSP code to
read all 8 chips, and dma the data each pixel period, (c) changed the
display code to down-load all 8 chip data, and display one chip at a
time, (d) revised the .fits code to save multiple .fits files per
readout (eg ccd01a.fits .... ccd01h.fits), (e) revised voltage update
code to handle 8 chips.

2) re-programmed eplds for 17-bit scrambler on optical link, and tested
with the lab camera + IMACS electronics.
 
3) got all 8 array CCD's working in the lab and produced a map of the
array. The images were simple darks, with over-scan + cosmic rays.
 
4) reassembled lab dewar with spare ccd, started noticing dark defects
on the chip.  These might be small AR coating defects.
  
5) revised and tested the barnacle for the dual-slope trim voltage and
applied it to the MIKE pcbs and lab pcbs.
 
6) designed and built cables for testing the wing chips, and MIT/LL
chips

7a) put the ccd array on IMACS -- chips A,D,E,F,G,H are OK, some
troubles with chip B (only left half working) and chip C (always
saturated).
 
7b) after taking the array off IMACS and warming it up, Ian and Bruce
noticed a film on the surface of some of the chips.  Pumping the dewar
removed the film,

8) tried to balance the ccd array, something not quite right.

9) started to test the wing chips in the lab dewar. All have been
tested at room temperature, and about half of the 8 chips look
promising as imagers.

VI)	Mechanics (Bigelow/Hare)

Bigelow:

In Nov:

1) Assembled instr. hatch - minor tweaks needed for screen
2) Assembled grating cell in new tilt mechanism for testing
3) Installed filter servers for both cameras with new mounts
4) Finished lens mounting for short camera, but S04 must be re-mounted
5) Completed fab drawings for echellette prism RFQ
6) Designed many new parts for dewar - cooling, mounting, dewar fixture
7) Tested flexure of CCD array in dewar - OK with PI stage "on"
8) Long camera baffles received (installed 12/16/02)
9) Investigating options for thermal enclosure for instrument testing

For December:

1) Fill and strain-relieve hoses and cables in utility wrap
2) Assemble short camera
3) Finish instrument cooling system design (plumbing)
4) Revise filter server insertion mechanics, shuttle carriages

Hare:

Current Work

* Fabricate and assemble counterbalance for the Shack-Hartmann Guide Camera.
* Continue to examine the performance of the Grating Tilt Mechanism.  
  Preliminary tests of the redesigned assembly appear positive.
* Assembly and testing of Disperser Server, including drive assembly, 
  all limit switches, encoder, and cable wrap.
* Modify Clamp Assembly with symmetric guide components to attempt to 
  improve repeatability performance.
* Assembly and testing of the second shutter.

Future Work

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

VII)	Fabrication (Kowal)

Done in November:

1) Grism cells are in progress.
2) Hatch is finished.
3) Completed one copy of new G.T.M. parts.
4) Finished delrin guides and installed into 2nd shutter.
5) Made new latch parts for DSS.

Expectations for December:

1) Finish Grism cells and base plates
2) Finish Imaging Mirror cells and base plates.
3) Make FC controller saddlebag.
4) New stainless latch mounting blocks for DSS.

VIII)   IFU (J. Schmoll, U. Durham)

1) Faulty output lenslet arrays sent back to AOA for rework. Got 1st
sample of eight arrays mid November. Investigation shows that they are
sufficient in position and quality.  Complete delivery is expected for
mid December now.

2) Fiber bundles glued to output blocks, using glue jig to achieve
angular tolerances.

3) 42 fiber bundles polished (40 required). One bundle lost in
polishing process. Angular tolerances okay and all fiber surfaces
polished out. Final quality check coming soon.  There are nine spare
bundles left for replacing possible broken ones.

3) Cover 1 arrived and accepted. Cover 2 arrived and accepted for
dummy (craftsmanship of cover 2 not as good but sufficient for the
volume and mass dummy).
 
4) Mechanical parts mounted on final base plate.

5) Volume and mass dummy: Weights finished and cover 2 bolted
on.  Problems with stress on base plate solved (some threads redone by
workshop). Next step is spray painting. Shipping is expected within
the next two weeks. (received 12/16/02 BCB)

5) IFU mounted to alignment and assembly jig. Fit is acceptable.

6) Green laser module for lenslet alignment purchased.

7) Input block fiber glue: Armstrong C4 production discontinued. There
is a replacement product with similar properties. Nevertheless a check
of FRD performance and viscosity is required. A sample will reach us
within the next days.

8) IAD coating: Will be ordered and the arrays sent in when output
arrays arrive and quality is sufficient.

9) The schedule has been upgraded (MS project file
IMACS_20021128). Delivery is still to be expected at the end of
February, albeit the time-line is quite tough. Smaller jobs
(e.g. painting of the IFU housing) and effects of the Christmas week
on delivery times are not accounted for.

IX)     Other Business

Next meeting:  10:15 AM, 1/7/03