Notes and Action Items from Hall C Compton meeting: 4/21/2009 Attendees: Ron, Katherine, Butch, Chris, and Dave 0. We will meet by phone again next Tuesday (April 28) at 1:30 pm. 1. We spent most of the time looking at Chris' latest layout, which included supports for beam pipe as well as pump ports and a "keep out" for the interaction region. Comments during the meeting: a. Interaction region in model contained only keep out for laser region and some bellows (because that's all Dave drew). We would like to add short, 2 inch BPMs on either side as well as valves if room allows. For reference, the Hall A system looks like: Dipole->valve->bellows->BPM->laser region->BPM->bellows->valve->Dipole b. Beam pipe stands in interaction region may conflict with laser table. We will likely use a table similar in size to the Hall A polarimeter, i.e., 4 feet wide x 5 feet long. These stands are likely not needed anyway. c. L-shape pump access ports likely not needed. The pump ports can stick out at 90 degrees on the wall side of the chicane and cause no conflict. d. A pipe attached to the downstream side of dipole 3 would be nice for transport of backscattered photons to photon detector. Dave needs to provide detector position and dimensions. I may have have missed a few other points. 2. Chris has not heard from Joyce regarding STEP file for laser cavity. Dave is bugging the Hall C designers to download and generate the file. 3. After the meeting, there was some discussion regarding the 3 inch BPMs. There is some re-design work required for these - it may be easier if we can switch to 2 inch BPMs. Dave is consulting with Users to see if this is acceptable from a physics perspective (at first glance it is): Ernie and Chris can comment on whether this is acceptable from a design perspective. 4. For reference, some photos of the Hall A Compton can be found here: http://www.jlab.org/~gaskelld/halla_laserin_laserout/ Pictures of interest: http://www.jlab.org/~gaskelld/halla_laserin_laserout/p000361.jpg http://www.jlab.org/~gaskelld/halla_laserin_laserout/p000369.jpg http://www.jlab.org/~gaskelld/halla_laserin_laserout/p000374.jpg http://www.jlab.org/~gaskelld/halla_laserin_laserout/p000424.jpg http://www.jlab.org/~gaskelld/halla_laserin_laserout/p000469.jpg -- ------------------------------------------------------ Dave Gaskell Jefferson Lab Suite 6 gaskelld@jlab.org 12000 Jefferson Ave. OFFICE:(757) 269-6092 Newport News, VA 23606 PAGER: (757) 584-6092