Bubble Chamber Beam Test May 2018

Bubble Chamber Turn On

• Fill with natural C₃F₈– test bubble chamber systems operation

• With beam on bubble chamber radiator:

1. How does CCD camera perform under beam-on conditions?
2. Count rates on bubble chamber. Do we get single or multiple bubbles from Bremsstrahlung beam exposure?
3. Measure gamma ray beam spatial profile as reflected by bubble distribution. Is collimator effective in defining the gamma-ray beam?
4. Test the bubble chamber laser shutter (gumby shutter)

• Background measurements:

1. Measure beam off environmental background in chamber-injector area
2. Measure beam on background by looking outside fiducial volume
3. Measure background with beam to Faraday Cup in CEBAF beamline (about two meters from chamber)
4. Measure neutron events in chamber. Neutron radiation detectors in injector region will indicate if any neutrons are generated (especially at beam kinetic energies higher than 5.5 MeV).

Bubble Chamber Beam Test

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Run Plan:

• Check if Bubble Chamber is working properly:

1. Start with K.E. of 5.2 MeV
2. Determine the initial operational pressure and temperature
3. Measure bubble rate. The expected rate is 1 bubble per sec at 10 µA
4. Measure rate vs beam current (0.01, 0.1 and 1.0 µA)
5. Measure the number of bubbles for 30 minutes per beam current

Beam Kinetic Energy (MeV)	Beam Current (µA)	Time (hour)
7.4	10	10
7.5	10	10
7.6	10	5
7.7	2	5
7.8	2	5
7.9	1	5
8.0	1	5
8.1	0.8	5
8.2	0.4	5
8.3	0.2	5
8.4	0.2	5

• Presentations

• MCC 8 am presentation