IMACS progress report no. 50

B. Bigelow						10 June 2002

I)	Project Status

Currently scheduled tasks:				Status:

a)	DSS redesign (Hare)				IP
b)	DSS drafting (Cleary)				IP 
c)	DSS fabrication (Kowal, Castillo)		IP 
d)	Calibration system mech. des. (Hare)		IP 
e)	Principal Guider Camera testing			IP
f)	Shack-Hartmann Guider Camera testing		IP
g)	Science Array controller fab (Burley)		95% compl.
h)	CCD array assembly (Thompson/Burley)		on sched.
i)	Filter procurement (Sutin)			IP
j)	Grism procurement (Sutin)			IP
k)	Instrument electronics assembly (Bagish)	on sched.
l)	Control software design (Birk)			on sched.
m)	Instrument enclosures design (Gunnels)		on sched.

Project events in May:

 - First light achieved with long camera and guide camera detector!
 - First flexure measurements - promising!
 - Mask cutting laser installed at LCO

Latest project images:

Final Assy:        http://www.ociw.edu/instrumentation/imacs/devel/final/index.html
Laser:		   http://www.ociw.edu/instrumentation/imacs/devel/laser/index.html
Collim. assy:	   http://www.ociw.edu/instrumentation/imacs/devel/coll/index.html
Electronics:	   http://www.ociw.edu/instrumentation/imacs/devel/electronics/index.html

II)	Optics (Sutin)

Things done:

* S07 is finished and here at OCIW.  No work is currently at TORC.

* Tinsley has pretty much finished the spherical sides of S01 and
  S08, and the aspheres are within 1 micron rms.  I have not yet
  gotten a call back from them this month.

* STF is supposed to start test runs this week.  We'll see...

* Barr delayed the R filters again, until 2002-06-07.

* Still no response from Schott about L05 replacement material.

* 200 l/mm grism replacement glass has been shipped to Thermo RGL.

* 300 l/mm grism glass is at HJOL, in polish on one side.

* 600 l/mm grism glass is at HJOL awaiting the arrival of the
  appropriate cutting saw blade.

* An RFQ was sent to Thermo RGL for rulings on the 300 and 600
  grisms.  No response yet.

* Second fold mirror was coated at Denton and is now at OCIW.

* A preliminary model of IMACS was computed and given to Ken.
  At some point Ken's program, with my fit, should be compared
  to my ray-trace model.

III)	Electronics (Bagish)

 - Designed IMACS bulkhead connector panel

 - Redesigned shutter controller, ordered parts came in and ready for build.

 - Powered up Chassis' 3 & 4. Successful rotation of instrument. Disperser
   tilt A moving.  Altera hardstop logic needs debugging.

 - Heat exchanger mounted on rear panel of Rack #2.

 - Designed microphone preamp, line driver and line receiver. Parts on order.

 - Designed Physik Instrument encoder signal repeater. PCB designed. 

To do:

 - Debug hardstop logic.

 - Build mic preamp, line driver and receiver. Design PCB's and order fab.

 - Order fab of Physik Instrument encoder repeater PCB and build.

IV)	Software (Birk/Clardy)

Birk:

- Structure rotator:
  The rotator GUI (rotest) has been tested and is working fine.

- PR-/SH-guider theta motion:
  Preliminary tests demonstrate that a control-loop can stabilize
  the theta (and radial) axis of the guiders to about +-0.05" from 
  an uncontrolled motion of about +-1" while rotating the structure.
  More tests will be conducted after the guiders are back from
  anodizing to address a small problem while moving close to the 
  zenith.

- Disperser server:
  We have started testing the first grating-tilt mechanism. All
  limits/near/home sensors and the motor/brake are working fine.
  During June I plan to measure backlash, resolution and stability
  of the grating mechanism.

- Shutter-electronics:
  The shutter electronics design has changed in a way that one
  'Jackrabbit/Linmot' controller moves both shutters instead of having
  one micro-/motor-controller per shutter.  I plan to change the shutter 
  software during June, as soon as the electronics are assembled.

Clardy: 

During May, we had a series of meetings with Skip Schaller, which
produced an improved understanding of how the IMACS system will
interface with the Magellan Telescopes.

The result of these meetings is that I will produce an enhanced
version of the "gmap" program which the telescope operators use to
select guide stars.  It will include the IMACS specific things, and
a feature to select the current telescope, guider and camera from
a menu rather than editing file names as at present.

The optical data for the focusing elements has been received from
Brian Sutin, and a method of testing my programming and use of this
data with respect to Brian's design program will be devised.

Several extensions of the mask cutting software were discussed.
A need is perceived to exist for software which will produce a plot
of the tool movements contained in the "G-code" file output by the
cutting program; a search for such software is underway.  In the
unlikely event affordable commercial software is not found, such a
program could be written.

The cutting software will need to include the ability to avoid
several hold-down fixtures, the positions and sizes of which will
be provided to me in a drawing.

Control of the Z-axis movements during mask cutting will be revised
to allow following the surface within a sufficient tolerance to
allow the auto-focus to stay engaged.  This will be done by making
each move in a linear 3-dimensional fashion, and with sufficiently
small length that the auto-focus limit is not exceeded; long moves
will be split up into a series of smaller moves with proper Z-axis
positions to assure this.

With the above enhancements, the cutting software will be used in
the next few weeks to produce some LDSS-2 masks.  That should be
entirely possible, if input for the desired masks is available.

V)	Detector Systems (Thomson/Burley)

No report this month.  Thermal testing of the IMACS dewar with
two cryotigers was started in May.  Initial results are positive.

VI)	Mechanics (Bigelow/Hare)

Bigelow:

In May:

1) Finished potting and opto-mechanical assembly of LCAM
2) Finished assembly and installation of imaging mirror
3) Completed laser support (ventilation, tooling) work
4) Repaired LCAM scale control actuators

In June:

1) Complete instrument hatch design
2) Complete 2nd imaging mirror cell
3) Progress grism cell design
4) Correct Dewar solid models and re-work dewar parts as necessary
5) Release slit mask carrier drawings for fabrication

Hare:

Current Work

* Redesigned drive mechanism on Principle and Shack-Hartmann guide cameras to 
  resolve mechanical issues.
* Continued opto-mechanical and electro-mechanical assembly and testing of the 
  Principle and Shack-Hartmann Guide Cameras.
* Assembly and testing of first Grating Tilt Mechanism.
* Partial assembly and testing of the clamping, taper pin, and disperser server 
  assemblies.
* Review design of the Disperser Server Drive Mechanism.

Future Work

* Continue assembly, testing, and rework of all guide cameras as necessary.
* Continued Testing of the Grating Tilt Mechanism.
* Continued assembly and testing of the clamping, taper pin, and disperser server 
  train.
* Fabrication DSS Drive Assembly
* Assembly and testing of the Disperser Server System.
* Fabrication of the second shutter.
* Resume design work of the Calibration Unit.

VII)	Fabrication (Kowal)

1) New Parts and Modifications to G.T.M. completed.
2) EFT Base for SMS is done.
3) Steel base for CFG is finished.
4) Made more electronic panels for Alan Bagish.
5) New clamps for guider drive chains were made.
6) Made grating installation jig.

Expectations for June:

1) Modify bases of filter servers.
2) Carousel drive mechanism?
3) Shutter v2.0?
4) Pick up work

VIII)     Other Business

Next meeting:  10:15, 7/3/02