Real Photon Collaboration Engineering Meeting

7/23/02 Minutes

Attendees: 

P Bosted, K Griffioen, M Olson, W Olson, S Rock, M Racine, 
C Wilder, D Walz

Items Discussed: 
1. 3DC2 is being designed for remote alignment by adding stepper 
   motors to a T-0 precision stage.  P Anthony will be consulted about 
   the control system.
2. D Walz will have Bruno design the dump collimator structural 
   support when he is finished with his current design project.
3. How the diamond is to be held was discussed.  D Walz will 
   look at some options to single edge clamping with epoxy.
4. D Walz said the C37 support/alignment system is ready to go.
5. D Walz believes the toroid will have to be destructively 
   opened and the cores rewound due to it having been under water, 
   with resulting corrosion damage likely.
6. Mo has talked with Sandy about where to store rad hot lead 
   that will be removed from E158.  It will be stored in building 413.
7. M Olson will use a scale drawing and wood blocks to model 
   the concrete shielding for E160, and as a design aid.  P Bosted 
   wants the concrete blocks to butt against the LASS dipole, without 
   walkways around LASS.  He is concerned about particles getting 
   back into the detectors.
8. P Bosted raised the question of accident scenarios.  M Olson 
   is looking at it.
9. Discussed hodoscope panels and how they should be indexed 
   to each other so they can be aligned as a unit rather than 
   independently, when installed in the support frame.  K Griffioen 
   and W Olson will work this design feature.
10. The Compton polarimeter collimator will be identified and 
   located by P Bosted and M Olson.  Pipe size between the target 
   and collimator will be 6" diameter and 3" diameter downstream of 
   the Compton detector.  It wasn't known whether the 18D36 magnet(s) 
   have a vacuum vessel, or what the pipe size should be between the 
   magnet and the detector.
11. P Bosted's rough calculation of backscattering neutrons from 
   the SEQ indicates 4-feet of concrete is required to shield the 
   detectors.  Because this was a rough calculation, he recommends 
   6-feet of concrete.  It should be located just downstream of the 
   Compton detector.

Decisions Reached
1. 3DC2 to be remotely alignable.

New Action Items
1. P Bosted and M Olson to locate the Compton collimator.

Ongoing Action Items
1. T. Weber will get prices for cast copper and tin.
2. P. Bosted to determine material to be in front of the middle 
   spectrometer detector panel. (In progress)
3. J. Weisend will work with D. Crabb and R. Principe to develop 
   a detailed drawing showing the dilution refrigerator and the 
   proposed superconducting magnet. 
4. P. Bosted will continue the physics simulations of the 
   proposed change to the RPC design. (In progress)
5. The interaction of the LASS magnet and all its iron with 
   the E161/ E159 7-T target magnet needs to be carefully modeled 
   using a 3-D field simulation. (In progress)
6. Serious engineering of the shielding and earthquake supports 
   associated with the LASS magnet must be started. 
7. T. Weber will investigate other E160 target materials to 
   replace the Pb and Au for example Tantalum or Platinum. (In progress)
8. L Keller will identify all forces on the magnet system, 
   and confirm the magnet configuration.

W. Olson