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

Attendees: Jerry Mason, Ross Zhelem, Jason Eastman, Paul Martini, Dan Pappalardo, Mark Derwent, Bruce Atwood, Andy Gould, & Rick Pogge.

MODS Optics

Ross reported on the status of the Red Corrector Lens fabrication at SOML. After 3 days of polishing the part up, they discovered a number of bad scratches made during polishing. The largest scratch is >50mm long (curved) and 200um wide. The others are shorter but average about 100um wide. This means they will have to go back to loose abrasive polishing to piston down the surface, which adds another 2 weeks to the delivery schedule. In the meantime, Ross has completed an analysis of their optical testing procedure, particularly with regards to alignment tolerances (important for testing apheric surfaces). Ross will continue to work closely with SOML as this develops.

CSIRO reports that they are done with the dichorics, and will be packing them along with witness samples for shipment. We should receive them within a couple of weeks of sending them the shipping info.

The Integrating Sphere exit port windows have arrived from Sydor Optics, and they look great. The cells are fabricated and ready for anodization. We still need to fabricate the pupil mask (which mounts in the central hole in the window), and then we can mount them on the integrating sphere and baffle tube mounting piece. The projector lenses are ready for mounting, and this remains to be done to then complete the calibration system optics (more on lamps below).

The Blue Corrector Lenses arrived safely at ZC&R for coating, and should be back to us in 6-8 weeks.

Ross has quotes on order separation filters, so Rick & Paul are tasked with making the final selections so we can make up an order. They will cost about $1K apiece, so we need to choose well.

MODS CCDs

Bruce reported that the 3x8K electrical sample CCD arrived from e2v today and appaers to be intact. He currently has no data sheet for the device (a fully wired front-side device) so as to know what does and does not work yet, etc. He will contact e2v to acquire this.

Phil Covington has been making some progress on the Altera system, but they've hit a few snags that they are working out with engineering personnel at Altera (e.g., the PC won't boot when the card is installed without some trickery).

MODS Electronics

Dan has finished the preliminary layout of the Lamp Box (which mounts the power supplies for the calibration lamps, the IMCS and alignment lasers, and their interface electronics). He needs to iterate with Tom about where this will mount on MODS and how to finalize the choice of the NEMA box, and then he can proceed to doing the detailed layout and the box penetration design. We will also order the box and parts. So far we have orders in for the lamp power supplies (pen-ray and QTH), plus 1 set of spares for each power supply type (3 pen-ray flavors and 1 QTH supply), the WAGO node and associated hardware, and a complete set of Pen-Ray line lamps for MODS2. We will decide later on sparing these lamps.

In other progress, Ed has completed the second AGW Stage/Calibration Tower hardware interlock harness and pigtails. Dave Brewer has finished the 4 MicroLYNX mounting panels for the IEBs and will keep working on other parts as we can schedule his time. Dan will be ordering the parts from item for the 4 IEB frames and other parts later this week.

The next major wiring task is the multislit mechanism.

Now that we have data on multi-mechanism performance with the 16-axis box, we need to decide if we need 1 or 2 power supplies in each IEB. There is space for 2 but we've only installed 1. Rick has been tasked with reviewing the MODS operating modes to determine how many mechanisms need to be able to move a the same time for efficient configuration of the instrument. The working number from the lab testing is that we can move 2 big and 3 small motors at once on a single power supply. Ray will provide Rick with the latest conceptual layout (how the mechanisms are distributed between the two IEBs), and the motor ratings for each mechanism. This analysis is to be done in 3 weeks when Dan and Bruce return from the LBT aluminization run. At that time we will review the proposed mechanism control distribution and results of the MODS operating-mode configuration analysis to decide on what power supplies we need in the IEBs. While we can put 2 power supplies in, it adds substantial weight, complexity, and heat load, so we need to know we really need to do it before we commit.

MODS Enclosure and Mechanical Systems

Mark reported that they are currently waiting on parts to arrive for the MODS2 enclosure framework, but Justin and Dave Steinbrecher have been about finished mounting the fixed hexagon ring on MODS2. The panels for MODS1 are on order, but the PO is slow getting into the OSURF purchasing system and will be delayed. We can expect to receive the panels a few weeks after receipt of the PO.

In the meantime Mark has been working on the mounting of the IEBs to the framework, and will be putting together an order for the parts needed from item. He has also done the initial programming for the dichroic beam selector mechanism.

Dave Steinbrecher has been tasked with working on modifications to the detector boxes for the changes in field flattener lens positioning found during earlier work. Justin is available in the meantime for small projects, he's currently tasked with doing the light-leak testing on the proximity sensors, and the necessary but unglamorous task of washing down the MODS1 structure, which has been getting dirty with all the enclosure work.

MODS Software

Ray reported on general software issues. The CVS for LBT recently changed, and Ray has been busy getting our local copy of the TCS/IIF software updated. He is awaiting word on when he will be doing field testing of the MODS TCS/IIF interface on the mountain. It will be after the LUCIFER team does their live interface tests.

In instrument control software work, Ray has written a lamp control widget that allows individual control of the lamps and has been testing it with simulated lamps. It will be ready for when the Lamp Box is assembled. He has also been running all of the mechanisms in the Solarium hooked up to the 16-axis control box (IEB#1). So far the Red Filter Wheel has been through 6000 cycles, the grating select and dark slide through 3000 and 2000, respectively, and less than 1000 cycles each on the AGW, Calibration Tower, and Slit Mask system. A problem has emerged with some interference when doing an insert/retract operation on a slit mask loaded into the 24th (final) slot. Ray needs to work with Tom on characterizing it and finding a fix.

Ray has written a IEB power-logging function for the Instrument Control System and been testing it with the main supply voltage readout. Adding the eventual current readout will be straightforward. This includes a nice real-time plotting display for engineering. Data from this has been used to setup the concurrent motion analysis described above. In addition, Ray has been putting together a series of Engineering Interface widgets for all of the MODS mechanisms, and should have them ready for general use in testing soon.