Virginia Tech Update for Tracking Group, Mar. 12, 2008

1. CODA and F1TDC setup at VT:
We have been setting up the F1TDC system to take data with our first production HDC. A lot of problems have been encountered just getting all CODA components working properly in our environment, but we have resolved those now. The primary cause of the problems was our choice of using two Ethernet cards in the computer (one for talking to the outside world, one for the private local network with the VME CPU). This gave several of the CODA components problems that weren't immediately apparent. We've resolved it by going to a configuration with a single ethernet card. Currently we are working on getting the actual F1TDCs to read out properly.

2. Region 2 Rotator
Work has been progressing at JLAB on designing the Region 2 rotator. Roger called to say last week that some drawings are going through final approval, and then we can have a meeting to look it over and discuss any needed modifications. I haven't seen the drawings yet, so I don't know further details, but they did find a way to do the rotation with no magnetic parts.

3. Simulation - new inelastic generator
As discussed at an earlier meeting, the inelastic generator we have been using (legacy from G0) wasn't really being used properly. It didn't have a huge impact on our estimates of the inelastic rate for small angular ranges, but became progressively more incorrect as the angular range became larger (like when we study inelastic backgrounds from sources besides the inelastics that pass directly through the collimators). Juliette has written a new generator that is like our elastic generator with the additional variable of the scattered energy. So it throws uniformly in theta, phi, and scattered energy and then uses the cross section weighting. The systematic decrease in the inelastic rate on the bar as the upper thrown theta value is increased is now gone.