The Ohio State University College of Mathematical & Physical Sciences Department of Astronomy

Attendees: Darren DePoy, Jen Marshall, Bruce Atwood, Jerry Mason, Paul Byard, Dan Pappalardo, Tom O'Brien, Mark Derwent, & Rick Pogge.

Paul reports that SOML is in the process of creating a new Shack-Hartmann cube to get better illumination (i.e., better f-ratio matching) and better fringe contrast for testing the blue corrector lens. In the current system, the entire piece is not uniformly illuminated, and the fringes are hard to see (low contrast).

Rework on the blue corrector lens parent to remove 1mm of material from the spherical surface to erase the ball-bearing dings (see the 2004 Oct 20 Report). Paul is planning to go to Tucson when there is something to see regarding what we hope will be the final figuring of the blue corrector lenses.

Other news from SOML is that they have not yet flowed UV-cured epoxy into the cracks in the supports of Camera Primary Mirror #4 (CPM4), which we intend to use as an optical and mechanical test sample, replacing CPM4 with CPM5 in the 4th MODS camera which SOML has in hand.

Paul has continued work on two projects:

1. The alignment procedure to use for the blue camera. He is currently in the midst of developing the test protocol. Initial alignment looks relatively straightforward, so the next tasks are to work on the correct procedures for refinement of the alignment.

2. A specification is being developed for the bypass gratings that will be used in the IMCS system. It turns out we will need it for the R=1800 gratings with the initial 4Kx4K CCDs in order to tune the central wavelength. It is absolutely required, even with an eventual 8KxnK detector for the R=8000 modes. Tom is checking the spec now, and they will prepare a bid package in the coming weeks.

Tom reports that we plan to take delivery of the MODS1 steel structural frame in February. Currently they are putting together the rigging equipment (lifting beams, load spreaders, chains, shackles, etc.) needed to lift the MODS structure and move it around for shipping. This gear will be sent to Indian Creek Fabricators and used to load the MODS1 frame and its cart onto a low-boy truck for shipping to Columbus, then used to lift it off the truck and into the McPherson Lab shop. It looks like we will have no problem shipping it in one piece.

We have received parts from Marquardt Machine in Worthington, Ohio, a small shop that has fabricated the lens mounts for the AGW stage and a number of other small parts. They are a good shop, and gave us a good price and early delivery. Both Marquardt and COW will be making the parts for the AGW filter wheel next.

In the McPherson shop the crew has been busy cranking out all of the grating-select turret frame parts for the #2 thru #4 grating turrets. Dave Brewer is also churning out the invar camera trusses for cameras #2 thru #4, which will take some time, but the work is going very well (Red Camera #1 truss parts on 2004 Dec 7 - 436k JPEG).

The only mechanism remaining that needs detailing is the Dichroic Beam Selector. Otherwise, Tom is turning his attention to developing a specification document for the overall instrument enclosure which will be circulated for comments once an initial draft is complete.

Darren reports that he has received no word from Mike Lesser regarding MODS 4K CCD or the AGW WFS cameras.