Bubble Chamber Meeting Tuesday May 12, 2015

We will meet in TL 2221 on Tuesday May 12 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- Bubble Chamber progress at Argonne

2- JLab Summer 2015 Schedule:

• Timeline: media:SAD_Summer2015_Timeline.pdf media:SAD_Summer2015_Timeline.pptx
• Task List: media:SAD_Summer2015_TaskList.pdf media:SAD_Summer2015_TaskList.docx

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Notes from this meeting:

• Bubble Chamber:

1. Tried few possible solutions to get rid of the mercury droplets on the inner wall of the glass cell but with no luck so far:
   1. Tried coating the inner glass with Teflon
   2. Tried tapping on glass window
   3. Tried strong magnet
   4. Will try laser beam to heat mercury droplets
2. There is a discussion of using CO₂ instead of N₂O (now we have to deal with ¹²C(γ,α)2α background instead of ¹⁴N(γ,p)¹³C background).
3. We may want to use C₃F₈ for our engineering run this summer. This gas has very similar operational parameters as either N₂O or CO₂.

• The State of Virginia reporting limit for mercury brought on-site is 10.0 lbs. This is about 4536 grams or 336 mL.
• How are we going to ship mercury to JLab? (i.e., in glass cell or in reservoir).
• In Virginia, N₂O is considered a drug.
• For the time being, there is 10 μA CW and 10 MeV administrative limit on beam to Bubble Chamber beamline. This limit has to be increase to 100 μA.
• A new laser shutter will be used to terminate the beam while the Bubble Chamber is processing an event. The Bubble Chamber will generate a TTL signal, Low: beam ON, High: No beam. The TTL signal will stay high for the period with no beam.