Bubble Chamber Meeting Wednesday June 3, 2015

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We will meet in TL 2221 on Wednesday June 3 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


1- Bubble Chamber progress at Argonne

2- Detection features of new bubble chamber: media:Detection_features_new_bubble_chamber.pdf

Notes from this meeting:

  • Bubble Chamber:
  1. Showed bubbles distribution from N2O with mercury as buffer liquid using PuC neutron source.
  2. Plan to measure temperature gradient across the glass cell.
  3. Test chamber with C2F6 as the super heated liquid.
  4. Chamber stand (support structure) for JLab injector beamline.
  5. What type of window on chamber high pressure vessel that is used for the camera?

  • Supper Heated Liquid:
  1. Regarding CO2: it is possible to suppress the 12C(γ,α)2α signal but 13C(γ,n)12C background is still significant - Not an option.
  2. For N2O: 15N can be enriched from 0.366% to 98% to help suppress 14N(γ,p)13C background. However, a factor of 50 suppression of 14N is still tiny when compared to 108 needed; have to rely on chamber efficiency vs temperature.

  1. Reconfigure bubble chamber beamline in the first two weeks of July.
  2. Chamber arrives JLab in middle of July, move to Injector, install and align.
  3. Mercury will be installed in chamber at Argonne.
  4. Brad arrives on August 3, 2015. Cool and pressurize with C2F6. Complete safety reviews.
  5. Beam on chamber in the second week of August. Beam kinetic energy = 4.0 – 5.5 MeV.
  6. Remove C2F6 and fill with N2O during the last two weeks of August.
  7. Beam on chamber in the first two weeks of September. Beam kinetic energy = 4.0 – 9.5 MeV.

  • In June - August: find the highest gradients for the 1/4 cryounit. Do we need to ask for helium processing of the unit? it is not planned.