Difference between revisions of "MOLLER Pion Background Meeting Wednesday, November 2, 2016 3:00pm EST"
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** Paul: Do you really need the lead glass calorimeter? David: Probably won't be used in the main pion rate analysis. Can be used as a cross-check. | ** Paul: Do you really need the lead glass calorimeter? David: Probably won't be used in the main pion rate analysis. Can be used as a cross-check. | ||
** KK: Need to keep the 1:1 pion to electron ratio for keep the desired stat. reach. | ** KK: Need to keep the 1:1 pion to electron ratio for keep the desired stat. reach. | ||
+ | ** David: Pion dilution will be open closed dependent do to the electron open closed dependence. | ||
+ | * Single collaboration meeting talk for the pion detector concept. | ||
+ | * KK: Should review pion treatment from prior science review along with exploring more of this hyperon work. | ||
+ | ** Should collect all of the previous science info for the end of the collaboration meeting. | ||
+ | * How much distance in Z do we need? Javier will ask. David: Quick estimate 1.5 meters, KK: Try to push it down to 1 meter. | ||
+ | * Are the other detectors (not the Moller ring) exposed to line of sight to the beam pipe? Need to continue to think about shielding. |
Latest revision as of 16:08, 2 November 2016
MOLLER wiki home:MOLLER_at_11_GeV_E09-005
Previous Meeting: MOLLER_Pion_Background_Meeting_Wednesday,_October_26,_2016_3:00pm_EST
Meeting Information
BlueJeans Call Information
URL: https://bluejeans.com/624029893
Phone Number: 1-888-240-2560
Meeting ID: 624029893
Agenda
- 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: https://dilbert.physics.wm.edu/MOLLER+Simulation/72:
- Kurtis: Quick search on radiation hardness of Lucite - Radiation Effects pg. 167 (pg.192 pdf doc)
- Lucite unaffected by radiation to 0.82 Mrads (total absorbed dose?)
- 91% to 56% light reduction at 5.5 Mrads (total absorbed dose?)
- Kurtis: Quick search on radiation hardness of Lucite - Radiation Effects pg. 167 (pg.192 pdf doc)
- Any new business?
Minutes
Attendees: David, Jacob, Mark P., Seamus, Kurtis, Wouter, Paul, Scott, KK, Dustin, Rakitha
Not Attending:
Scribe: Kurtis
- Looking at W&M ELOG 72.
- Paul: 50% of the pion get through? I thought they were low energy. David - Will not be an unbiased measurement of the incident pions. Will need to use Monte Carlo to de-tangle.
- Can we produce an efficiency plot? Energy spectrum of the pions that make it through the lead.
- Any detector system will have some energy range. David - Shower Max is very much pion blind. Going to be difficult to unfold this background.
- KK: We have never really worried about the momentum/energy dependence on the asymmetry. Has it changed at this point? Paul - Not really sure at this point.
- Might be worth while to confirm with a theorist if the asymmetry dramatically changes between 1 Gev and lets say 3 GeV pions. If so, this pion detector method wouldn't work for this application.
- Make sure you take into account the radiation length of the shower max detector. David - Estimate the lead wall thickness to account for presence of Shower max, later the lead wall can be reduced by 7 X_0 as the Shower Max will be there.
- Paul: What about the hyperon asymmetry? Currently not in the simulation.
- Open and closed sectors for each pion detector will bin two different pions energies, will also have two different pion fractions.
- David: Really want a MIP detector, the best would be Quartz, however it is to pricey. Plan to use Lucite, the poor man's substitute.
- Concerns:
- Backgrounds in lucite
- Differential sensitivity across pion energy
- No major reason for azimuthial dependence on the pion dilution.
- Should be able to measure dilution in a single septant, for the open and closed sector in that given septant.
- KK: Could use two sets of dilution measurement devices. David: GEMS the cost driver in the dilution apparatus.
- Could attempt to check energy spectrum of the exiting pions with a calorimeter.
- Looking at Wouter's diagram
- David: Distances will change over time.
- KK: This first image is great to pass on to Javier for engineering of super structure costing.
- David: Also should include trigger scintillators, as learned by Qweak.
- Paul: Are you basically tracking to the center of the lead donut.
- KK: Tracking resolution depends on matching tracks before and after the lead.
- David: Tracking beam current should be low, so that we don't have signal pile-up.
- David: From a dilution costing perspective, planning to still with GEMS. Straw-chambers could be another option.
- KK: With straw-chambers have to be careful of hadronic background. Floating protons, ...
- David: What does it mean to measure the pion rate? Maybe a relative measurement, ratios before and after lead wall.
- KK: You are responsible for the lead donut.
- David: More cost effective to go with lead for wall/donut.
- Cost driver is the GEMS right now. KK: If straw-chambers would work, then GEMS could be removed. Need to look at the cost of straw-chambers.
- Paul: What is the approximate size of the rate? David: Guess around 10kHz per septant.
- Next step is to look at the energy spectrum of the electrons that come out of the lead donut.
- Paul: Do you really need the lead glass calorimeter? David: Probably won't be used in the main pion rate analysis. Can be used as a cross-check.
- KK: Need to keep the 1:1 pion to electron ratio for keep the desired stat. reach.
- David: Pion dilution will be open closed dependent do to the electron open closed dependence.
- Single collaboration meeting talk for the pion detector concept.
- KK: Should review pion treatment from prior science review along with exploring more of this hyperon work.
- Should collect all of the previous science info for the end of the collaboration meeting.
- How much distance in Z do we need? Javier will ask. David: Quick estimate 1.5 meters, KK: Try to push it down to 1 meter.
- Are the other detectors (not the Moller ring) exposed to line of sight to the beam pipe? Need to continue to think about shielding.