Wednesday June 11, 2014

We will meet in TL 2236 on Wednesday June 11 at 3:30 pm EST.

For those calling in we'll use the ReadyTalk audio conference system.

1. Dial Toll-Free Number: 866-740-1260 (U.S. & Canada)
2. Enter 7-digit access code 4402297, followed by “#”

Agenda:

1- Bubble Chamber progress at Argonne

2- (Grames) Beam line progress at JLab:

* Coordination meeting (May 28) media:140527_BubbleInstallKickoff.pptx media:140527_BubbleInstallKickoff.pdf

* Review final girder components

Assembly media:JL0015130 COLLIMATOR TABLE ASSEMBLY.pdf

Radiator media:JL0015733 CU RADIATOR WINDOW ASSY.pdf

Collimator media:JL0015777 CU COLLIMATOR.pdf

* BPM bench top calibration using Goubau surface wave transmission line (G-line) technique

3- (All) How to proceed with readiness review (beam line, safety, radiological, commissioning plan, ?) so the beam line is ready for commissioning at the end of summer ?

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Notes from this meeting:

• PAC41 selected the Bubble Chamber as a High Impact experiment.

• Bubble Chamber, filled with N₂O, is up and running.
• There is nucleation where the two liquids (buffer Hg and superheated N₂O) meet the glass and traced to the fact that Hg is not wetting the glass and is forming a negative meniscus. Now, searching for a solution ... .
• When attempted to vent the beamline to install the Fast Valve, it was found that the valve immediately after the 1/4 cryo-unit is leaking. It was decided to warm the 1/4 cryo-unit to room temperature and replace the leaky valve.
• The new magnet alignment fixture has been built.
• Dave and Brad will decide on who and where the collimator will be built. The design is complete and the drawing is ready.
• Radiator design has been completed.
• The chamber location may have to be pushed downstream by about an inch to allow for insulation housing. The chamber will be running at -12 to -14 °C. Instead of having the Survey and Alignment group marking 4 points on the floor for the chamber, they will mark two parallel line.
• We should keep the excess steel from the steel plate used to make the new dipoles. This steel will be used to widen the gap of the sweep dipole we have on hand.
• The beamline two BPMs will be calibrated using G-line technique. The goal is to improve the absolute beam position measurements needed for the energy determination.
• Rolf and Arne will decide on the exact framework of the Bubble Chamber Readiness Review but expected to be like PEPPo:

1. Conduct of Operations (COO)
2. Experiment Safety Assessment Document (ESAD)
3. Radiation Safety Assessment Document (RSAD)
4. Beamline Review (to allow for beamline commissioning)
5. Bubble Chamber Safety Review:
   1. Pressure System
   2. Mercury
   3. Laughing Gas
   4. Operational Safety Procedure (OSP)

• Must inform Rolf that we are having a commissioning (or an engineering) run this fall.

• Claudio, Simona, Darren, and Wouter have started the work on GEANT4 simulation of the Bubble Chamber.
• Claudio is planning on putting a germanium detector to measure the photon beam profile (before installing the chamber on the beamline).