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

Attendees: Darren DePoy, Pat Osmer, Jen Marshall, Paul Byard, Jerry Mason, Mark Wagner (from LBTPO), Ray Gonzalez, Bruce Atwood, Ed Teiga, & Rick Pogge.

LBT Rotator

Mark Wagner reported that Sean Callahan has been tasked with design work on the Gregorian Rotator in collaboration with ADS/Italia. It should be done soon so that fabrication can proceed. An engineer from Germany has been attached to LBTPO for a year to assist with various tasks, including the rotator, and ADS will do the detailed design work and fabrication drawings.

MODS CCD Detectors

Bruce reported on further discussions with Peter Poole and colleagues at E2V regarding possible MODS CCD projects. Despite disclosing our budget for the project, they're still at least interested in talking to us about various design issues. Peter and two others (TBD) will be coming to visit briefly on the morning of July 27 to discuss things. Even though we might not eventually go with E2V, the simple fact is that they are currently the world's leading supplier of astronomical CCDs, and we have a lot we could learn, and the contacts will be good for future ventures.

MODS Space

Darren reports that the space at 1315 Kinnear Road on West Campus for MODS2 has been cleared out and in the process of being cleaned. We can start doing our work there around August 1. The door is broken, but thereis a working winch. The space is somewhat dirty, so we'll be doing some cleaning and painting as required. We're still on track to have most of our work done around the first week of September. No word yet from Indian Creek on a delivery date for the MODS2 structure, but it is looking like late-September/early-October.

MODS Mechanical

Tom reported on progress on many fronts of the MODS mechanical design, assembly, and testing.

Mark has the CCD dewar bid package done and is sending it out to vendors this week. The requested bids ask for two different options: a completely assembled dewar and a dewar "kit". We look forward to seeing the response.

Tom successfully mounted the invar flexures in the mechanical-sample Camera Primary Mirror, and will be integrating it with the focusing mechanism later this week. If all goes well, he'll then repeat the process with the first actual Camera Primary and keep the process moving along. The flexures and mounting procedure are very similar to those used in the Collimator mirros, so the first collimators will be done after successful work on the two Camera Primaries. Gratings and flats, however, are quite different, and will be done later.

Dave Brewer has been working on an electroforming tool to be sent to our blank mask vendor. Mask materials will be electrodeposited on the the metal tool as part of making the first prototype samples.

Andy Krygier has finished the design of the elevation drive for the MODS cart and various associated handling fixtures. Work on the drive itself is moving along, and should be ready in early September for testing.

The tasks for the rest of the summer will be mainly focussed on getting all of the components mounted to test the IMCS on the instrument proper. This includes basic optics (less corrector lenses) with simple silver coatings, prototype motor controls, sensors, etc. Lots of work to do, the tests will likely occur in late-September/early-October if all goes well.

MODS Optics

Paul reports that Newport (aka Richardson Grating Lab) has received our order for the Red and Blue Low-Resolution gratings for MODS2. We are also expecting to receive the bypass gratings for the IMCS from HOLO-OR (Israel) soon, and are waiting for quotes on the double-pass prisms for the very-low-resolution modes of MODS.

MODS Software

Ray reported progress on the motor control system. He has spent the last week or so on what has proven to be a relatively fruitless attempt to get the MicroLYNX motors to work in their "party" serial communications mode. The main problem has been that motor error messages are not correctly propagating back through the signal chain and getting missed, as well as problems with indexing in the controller microcode getting off by a few addresses and branching randomly.

The bottom line is that while party mode was attractive in some applications on paper, it is not acceptable and we are going back to the direct-addressing with comm ports (hub-and-spoke instead of daisy-chain topology) as in the original design documents.

Ray also reported that he has begun to test the WAGO I/O module with the ethernet interface using Dan's quad-cell setup. We are going to purchase their "FieldTalk" software (API library) for some of the work. So far, the WAGO hardware is proving to be very nice and looks like a great solution for us.

Overall, the MODS Engineering/Service Interface (MESI) software has been coming together nicely in tests with a 2-axis test with the slit mask mechanism. Ray will continue work on this and start setting up Mark and Tom to use it in the lab for subsequent tests.

MODS Guiders

The "phantom" Magellan CCD controllers are still something of an issue, so the project is going ahead and ordering more ARC GenIII controllers and the guider and off-axis wavefront camera CCDs from Steward plus spares.

To bring about more centralized coordination of the Guider Control Software efforts in the US and Germany, Jesper Storm in Potsdam will be acting as effective PI. We will begin working with Jesper later this summer on the MODS AGW system.