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

Attendees: Darren DePoy, Bruce Atwood, Mark Derwent, Jason Eastman, Paul Martini, Paul Byard, Dan Papallardo, Jerry Mason, Ray Gonzalez, Phil Covington, Dave Brewer, Dave Steinbrecher, Ross Zhelem, & Rick Pogge.

Via video from Tucson: Mark Wagner (LBTPO), Tod Boroson (NOAO/TSIP), Mark Trueblood (NOAO/TSIP), Richard Green (LBTPO), & Ray Bertram (LBTPO).

Between holidays and travel this is our first meeting of 2006.

Personnel Changes

Welcome Phil Covington to our team, Phil is an electronics specialist and is already at work on the boards for the MODS electroncs systems.

We also will soon say farewell to Ralph Belville who is retiring on February 28th. Ralph has been our master draftsman for nearly 16 years with the ISL.

We are also interviewing a candidate for our optical designer position, to succeed Paul Byard who has retired as of this year.

MODS Mechanical Systems

The MODS2 structure was safely delivered to OSU on January 17th from Indian Creek Fabricators in Tipp City Ohio. It is currently housed in our west campus facility (aka "The Birdhouse"). Mark Derwent reports that it looks great, in fact better than the MODS1 structure. They have it all cleaned up post-delivery, and are readying it for the initial fitting of the MODS components for starting the mechanical alignment process.

We received 5 dewar canisters for MODS at the end of December 2005, well ahead of the original March 2006 delivery estimate. Mark is working with Bruce to finish the design of the detector enclosure which will be mated to the dewars to complete the full CCD system.

Other work includes

1. Delivery and order of parts for MODS2 is proceeding, most of the MODS2 mechanical parts are already in hand.
2. Testing of the IMCS system on MODS1 proceeds apace, including the initial tests with the altitude drive for flexure testing. So far the system performs beautifully, keeping the optics aligned to within a few microns from horizon to nadir pointing of the instrument structure, despite have no measures taken to protect the long light path from air currents (the MODS1 structure is wide open).
3. Tom is working on the MODS Enclosure design, as well as a temporary dark fabric cover for work in the lab.

MODS Electronics

Dan Papallardo reports that Ed has completed the wiring and testing of 6 of the eventual 12 MODS collimator actuators (each collimator mirror has 3 tip/tilt/focus actuators), 2 copies of the darkslide mechanism, and the first of two calibration tower insert/retract mechanisms. A second copy of the 4-axis motor controller box has been ordered by Tom and Ray, and is beginning assembly in the electronics shop. Dan has also begun doing the preliminary layout of the full 32-axis motor controller box.

MODS Software

Ray Gonzalez reports that MODS low-level software is way ahead of schedule so far. All of the interprocess signalling and motion control modules are working, and have been extensively tested with the 4-axis IMCS system on MODS1 and a 2-axis Mask Select/Insert mechanism in the lab. All work with the ISL Manager system, which is the heart of the MODS Instrument Control System, and which will also provide the basic interfaces for the IIF, TCS, and GCS systems at LBT. Ray has also verified that the current MODS software package compiles and runs without problems on any Linux kernel, in particular, we have tested it on various flavors of RedHat (7.x and FCx systems), CentOS, Debian, Caldera, and etc. It's portable and robust.

Right now Ray is working on the documentation, including the architecture document that describes the overall system, as well as a programming guide to accompany the MODS Template Libraries, so any of our programmers can now begin working on modules for MODS.

We have not yet tried to get the LBT-provided IIF and TCS server simulators running at OSU. Ray has requested assistance from Alex at LBTO, but has heard nothing in about 2 weeks.

MODS Optics

Paul has received no word from Steve Miller at SOML since before Christmas, so we do not know the current status of the MODS large optics. We are approaching the target date for the delivery of some of these optics, but as yet have little data as to their progress. Richard Green mentions that there are management changes going on at SOML, and MODS optics are being given high priority, and hopefully we will see more regular reporting as these changes are implemented.

MODS Detectors

Bruce reports that he has sent out the printed circuit boards for the next-generation of the post-amplifier system, which includes provisions for fast- and slow-readout modes, 2 copies of analog processor and 2 ADCs, This lets us get around the problem of integrator reset time, which is the biggest bottleneck in signal processing. With dual processors and ADCs, one can be reading the video signal while the other is reseting, giving us essentially zero overhead on signal processing. the desiDesign goal is 40kps and 300kps per amplifier. This is definitely a prototype, we'll use it to check the ADC interface, analog processors, and different style of front end using existing clock-bias boards. Bruce has also finished a document describing the new digital interface, clock-bias boards, and power supply system, so we're on track. Additional tests with MODS will likely be done with the electronics that will become the CCD controller for the new MDM4K CCD camera. That's done waiting for something to do. The MDM4K system is being held up because of problems with our supplier for the mechanical parts. We're waiting for feedback from alternative suppliers.

The large MODS CCD request-for-bids have been sent out, and we have started receiving bids. This is a formality of our CCD procurment process.

E2V has beun the planning phases of the layout for the MODS CCDs, which will use 40-micron thick epitaxial deep-depletion devices.

Discussion of the MODS Red CCD coatings. E2V has provided 2 types of coatings:

1. A "Red" Coating that is optimized at a 750nm peak, and has good red response
2. A "Midband" coating, that is peaked out more like 500-550nm, and gives better QE in the 400-480nm range.

MODS Schedule

At present there is less than a year of work remaining on MODS1, and if we had the large optics, we could deploy something interesting this summer if we pushed it (and the telescope was actually ready). More realistically, given the considerable large optics delivery uncertainty and the status of the LBT AO Secondary deployment, we will not be able to deploy MODS1 until late 2007. As Richard Green notes, there are some programmatic issues about overlap with LUCIFER delivery and so there are other issues controlling when what goes where.

This change in schedule allows some priority shifts which may allow us to shift resources to other OSU projects with nearly no impact on the MODS delivery schedule. These are outside the scope of this MODS report, but the bottom line is that we can pursue some MDM projects that will allow us to do a lot of MODS prototyping while we are otherwise waiting for the large optics and the LBT to get ready.