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 wall with Teflon
   2. Tried tapping on glass cell
   3. Tried strong magnet to move the droplets
   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. Each time and before running CW beam, BCM0L02 FSD has to be set with beam to FC2. We need to measure water flow to Faraday Cup and radiator/dump (these are in series) to be allowed to run up 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.