Minutes SHMS MC 8

Minutes of SHMS MC working group meeting 12/01/2011

Participants: Dave, Dipangkar, Howard, John, Mark, Peter and Rolf

1. Mark went over the list of all the changes made to the spectrometer design over the last few meeting. The most important of these changes are the raising of the dipole central axis with respect to the horizontal axis (changed from 20cm to 26cm). The the re-centering of the drift chambers with respect to the detector stack central axis. Rolf asked that we check a few more things to make sure that the optics are still good. The first is to check the simulated sieve slit distributions. This has now been done and shown here: https://hallcweb.jlab.org/wiki/images/c/c3/Sieve1.png

2. Dipangkar showed the plots of collimators using 28x14 and a 28x18 and 23x13 collimators. The 28x18 collimator seems to be give the largest acceptance. A few more issues need to verified, such as delta dependence and verify the losses in the dipole etc are consistent with the earlier studies. Once these are completed the collamator design will be complete. Next items to finish are the sieve slits.

3. Still to do are the simulations of adding GEMs in front of the HB to verify how they will help disentangle the HB from the rest of the spectrometer.