Present: Chris Allgower, Andy Bacher, Ed Stephenson, Hermann Nann, Paul Pancella, Mark Pickar, Adam Smith
The meeting came to order at about 3:15 pm.
We should submit an abstract for the upcoming DNP meeting in Hawaii. It should be a report on the two test runs that have occurred this year, and should probably appear in an instrumentatin session. The deadline is 6/29. Ed is going anyway, so he will try to draft something for circulation. We discussed the author list, and decided to try to be inclusive at this stage. We were reminded about a prospective post-doc visiting tomorrow, and urged to meet him and/or attend his talk.
Ed made some comments about multiple scattering in connection with the size of detectors at channel end. Calculations would lead us to expect a multiple scattering width that is half as large for alpha particles as it was for the average 3He of the test run. Thus, while multiple scattering dominates the size of the 3He cone image at WC3, this effect may be smaller compared to the width due to kinematics and the optics of the quad lens for the alpha cone. It should be possible to use this information to make a better prediction of the size of the alpha image at channel end. This should take place before we decide whether to modify the existing detectors.
Hermann has completed a calculation of the shielding effect of two layers of steel with a 9" hole comprising the field clamp on the upstream side of the 6 degree magnet. The residual field just outside the shield is predicted to be 5 Gauss, decaying to 3 G or less at the location of the nearest lead glass phototube.
Mark has gotten the ray-tracing program "Turtle" up and running. This program traces charged particles through a system of magnetic elements specified exactly the same way that Transport does. The advantage is that unlike Transport, this program can predict distributions at any point, starting with a cone that exhibits the angle/momentum correla- tions we expect from pion production. Unfortunately, it appears that there is no way to calculate or output the path lengths of the rays, so Pickar will try to get his GEANT simulation up to date for this purpose.
Discussion turned again to possible tasks for REU and other under- graduate students, including the simulation work mentioned just above. Another possibility might be developing a visualization program for the gamma rays in the center of mass system. Documenta- tion and production of cables are also possible jobs.
Finally, we discussed the task of designing cosmic ray trigger scintillators to fit into the lead glass support structures.
Respectfully submitted,
Paul Pancella (with help from Ed Stephenson)