Bubble Chamber Meeting Wednesday January 20, 2016

We will meet in TL 2221 on Wednesday January 20 at 3:30 pm EST.

For those calling in we'll use the Blue Jeans [1] audio conference system.

Phone number: 1-888-240-2560
Meeting ID: 3528502673#
Meeting URL: http://bluejeans.com/3528502673

Agenda:

1- GEANT4 Simulation:

1. Gamma Flux: media:G4Flux_Sept2015.pdf media:G4Flux_Sept2015.pptx
2. Expected Rates:
   1. ¹⁸O(γ,α)¹⁴C with no ThrCut: media:O18ga_rate_G4.txt
   2. ¹⁷O(γ,n)¹⁶O with:
      1. ThrCut = 90 keV: media:O17gn_rate_G4_90keV.txt
      2. ThrCut = 130 keV: media:O17gn_rate_G4_130keV.txt
   3. ¹⁴N(γ,p)¹³C with:
      1. ThrCut = 20 keV: media:N14gp_rate_G4_20keV.txt
      2. ThrCut = 50 keV: media:N14gp_rate_G4_50keV.txt

2- Sept beam test data analysis: media:Analyses_Rashi_Jan2016.pdf media:Analyses_Rashi_Jan2016.pptx

3- Discussion of June 2016 beam test

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Notes from this meeting:

• My previous statement [2] about beam energy being 5% lower than set value is not correct. The quarter cryo-unit RF gradients were found to be lower by 5%. During the September test, we set the energy using the dipole so we should be very close to the quoted energy. Complete analysis of the beam energy measurements is forthcoming.

• In the simulation, the collimator inner radius is correct (8.0 mm).

• Bubble chamber simulation remaining tasks:

1. Complete geometry: add stainless steel cube and flanges
2. Add electron beam energy spread and beam size
3. Measure fraction of photons that are absorbed in the N₂O target as a function of E_γ

• Next Bubble Chamber beam test will measure ¹⁹N₂O F(γ,α)¹⁵N

• Old fluorine chamber has a height of 36 inches. Beamline height on the concrete platform is 27 inches. Beamline height before the step is 42 inches.