Wednesday, October 14, 2015 1:00pm EDT

Last meeting: Wednesday, September 23, 2015 11:00am EDT

Agenda

• Field comparisons between TOSCA and MAXWELL [1]
• Status of the CDR text
  • Comments from KK
  • Report from MIT
• Next meeting

Minutes

Attending: Rakitha, KK, Jim, Ernie, Juliette, Seamus

• Field comparisons between TOSCA and MAXWELL
• Power on collimators
  • After reviewing the collimator fin concept in SolidWorks, it doesn't look like the fins will cause any problems.
  • Only the upstream face of the collimator fin will be visible to the target.
  • The other faces of the fin are hidden by the collimator. Since the upstream face is perpendicular to the beamline, it's impossible for a particle to scatter from the fin and continue moving along the beamline (positive z direction). Therefore no single-bounce particles will be able to pass through the acceptance-defining collimator. I attached an annotated diagram that should make this clear.
  • From KK - I generally agree with this. However, I want to point out that since the fin will contain water, it will effectively have a terrible Moliere radius (transverse extent of a showering particle). If there are several radiation lengths of material, then particles will leak out of the side of the fins, have a small but finite angle to make it through the acceptance petals and then potentially have line of sight to the detectors.
  • After thinking about this a bit, I think our best bet is to minimize the number of radiation lengths of this material i.e. make it as transparent as possible except for the water. Also, make each fin as narrow as feasible in phi rather than use all the available (1/14th) phi.

But good news is that this will have no other effect on the physics. We should use it to get the temperature down at the front end.

• Status of the CDR text
  • Comments from KK
  • Report from MIT
• Next meeting

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