MOLLER Pion Background Meeting Wednesday, November 16, 2016 3:00pm EST
MOLLER wiki home:MOLLER_at_11_GeV_E09-005
Previous Meeting: MOLLER_Pion_Background_Meeting_Wednesday,_November_2,_2016_3:00pm_EST
BlueJeans Call Information
Phone Number: 1-888-240-2560
Meeting ID: 624029893
-------- WWWW ------- G4Exception-START -------- WWWW ------- *** G4Exception : GeomNav0003 issued by : G4Navigator::GetGlobalExitNormal() WARNING> Expected normal-global-frame to be valid, i.e. a unit vector! - but |normal| = 0 - and |normal|^2 = 0 which differs from 1.0 by -1 n = (0,0,0) Global point: (-549.2642695,-978.7146481,31450) Volume: pionDetectorGEMOpenSector_logical_PV Solid: pionDetectorGEMOpenSector_solid, Type: G4Tubs -----------------------------------------------------------
- Scott: Implementation of lead wall and strawman pion detector.
- Separate pion development branch
- Initial detector prototype.
- Jacob: Starting to work on pion simulations.
- David: present detector concept.
- Any new business?
Attendees: Kurtis, Wouter, Seamus, David, Mark Pitt, Jacob, Scott
Not Attending: KK(traveling)
- Wouter- Detector concept in simulation
- David: Any concern with detector concept. KK did discuss the possibility of some type of counting mode asymmetry measurement, which would lead to better particle ID.
- David: Biggest concern from the collaboration meeting is that we wont be able to definitely know the pion rate and energy spectrum before and after the wall.
- David: No need to really looking into some special asymmetry measurement for the directors review.
- Wouter: Implemented the objects from the cad drawing into gdml using primitives. Looking at the images taken from gdml.
- The geometry tree shows the volumes that Wouter has implemented. Note that this currently doesn't show the really main detectors volumes.
- The GEMS should be places in one open sector and 180 degrees into the opposite closed sector. This would simplify the support structure you would need for these detectors.
- Wouter: Looking at a complete detector package about 2 meters long. Still flexible, can be compressed depending on requirements.
- David: Should confirm with KK the actual available space for the detector system.
- Wouter: Optical photons are being generated via the Cerenkov process. Still not being collected by the pseudo PMT photo-cathode. Work in progress.
- Wouter: Red electrons, green neutrals. Incident electrons with lead wall set to vacuum. Simply for testing purposes.
- Wouter: Still working on optical surfaces, no overlap in the geometry or memory leaks. Still a problem with the geometry around the GEMs and trigger scintillator. Seamus: Could be a problem with parallel faces.
- Wouter: Had to disable Scott's geometry to implement this geometry.
- Wouter: This is all implemented in GDML. Could implement reflective material in between the lucite sheets. Can change from a 5 layers to single layers.
- David: Scott should move to this new geometry? Wouter: No, because it is more difficult to look at the energy distributions. A good middle ground would be to implement a simple sensitive volume into the more complete geometry. Wouter will add it.
- Once the optical properties are a bit more farther along Jacob can start working on optimizing the lucite detectors.
- David: Major physics questions for directors review
- Thickness of lead? Looking for 45 X_0 (including Shower max),
- Energy spectrum of the electrons and pions before and after the lead wall.
- Back of envelop calculation of the total absorbed dose for the lucite over the life time of the experiment.
- Dilution in the open and closed sectors.
- Particle multiplicity, really need more detectors than just GEMS. Really worry about particle track identification.
- Possible scintillator fiber detector might help instead of GEMS.
- Calorimeter, would help with background identification. Need to identify the specs regarding this detector system.