Bubble Chamber Beam Test May 2018
Beam Setup and Measurement - May 2018
Bubble Chamber Turn On
- Fill with natural C3F8 – test bubble chamber systems operation
- With beam on bubble chamber radiator:
- How does CCD camera perform under beam-on conditions?
- Count rates on bubble chamber. Do we get single or multiple bubbles from Bremsstrahlung beam exposure?
- Measure gamma ray beam spatial profile as reflected by bubble distribution. Is collimator effective in defining the gamma-ray beam?
- Test the bubble chamber laser shutter (gumby shutter)
- Background measurements:
- Measure beam off environmental background in chamber-injector area
- Measure beam on background by looking outside fiducial volume
- Measure background with beam to Faraday Cup in CEBAF beamline (about two meters from chamber)
- Measure neutron events in chamber. Neutron radiation detectors in injector region will indicate if any neutrons are generated
Bubble Chamber Beam Test
- Bubble Chamber Run Plan
- Draft Run Plan: media:bubble_runplan.pdf
- Systematics:media:bubble_systematics_May2018.pdf
- (Joe) Dispersive and Non-Dispersive Optics for last week's beam study data
Run Plan:
- Prebeam Checkout:
- Neutron source test at 0.7, 1, 2, 5m
- Establish background rate with no beam
- Check if Bubble Chamber is working properly:
- Establish high rate checkout beam: 5.74 MeV/c, 1uA (1 event per 5s)
- Determine the initial operational pressure and temperature
- Establish fiducial region for beam
- Measure activity with beam in high pressure
- Move beam +/-3 mm and search for 10% lower rate
- Change spot size to 2, 3mm; observe 30% lower rate at 3mm
- Current scan: 0.5 uA for 1 hour, 0.25 uA for 2 hours
- Normalized yields should be identical
- Run high energy to low energy:
Beam Momentum (MeV/c) | Beam Kinetic Energy (MeV) | Beam Current (µA) | Time (hour) |
5.24 | 4.75 | 50 | 31 |
5.34 | 4.85 | 50 | 40 |
5.44 | 4.95 | 20 | 13 |
5.54 | 5.05 | 10 | 6 |
5.64 | 5.15 | 4 | 3 |
5.74 | 5.25 | 1 | 3 |
Nominal Daily Plan
Thurday, May 10
- Swing: p = 5.74 MeV/c, T = 5.25 MeV
- Establish beam in the injector
Friday, May 11
- Owl: p = 5.74 MeV/c, T = 5.25 MeV
- Start commissioning plan
- Day: No beam
- Swing: p = 5.74 MeV/c, T = 5.25 MeV
- Continue commissioning plan
- Data for T = 5.25 MeV point
Saturday, May 12
- Owl: p = 5.74 MeV/c, T = 5.25 MeV
- Day: p = 5.64 MeV/c, T = 5.15 MeV
- 3+ hours for this point
- Swing:
- Set up for p = 5.24 MeV/c, T = 4.75 MeV when previous point done
- 5.24 will be used to test if rates can be determined
Sunday, May 13
- Owl: p = 5.24 MeV/c, T = 4.75 MeV
- Day: p = 5.54 MeV/c, T = 5.05 MeV
- Call Mom
- 6 hours data
- Swing: p = 5.44 MeV/c, T = 4.95 MeV
- 16 hours data
Monday, May 14
- Owl: p = 5.44 MeV/c, T = 4.95 MeV
- Day: p = 5.44 MeV/c, T = 4.95 MeV
- Swing: p = 5.34 MeV/c, T = 4.85 MeV
- 48+ hours
Tuesday, May 15
- Owl: p = 5.34 MeV/c, T = 4.85 MeV
- Day: p = 5.34 MeV/c, T = 4.85 MeV
- Swing: p = 5.34 MeV/c, T = 4.85 MeV
Wednesday, May 16
- Owl: p = 5.34 MeV/c, T = 4.85 MeV
- Day: p = 5.24 MeV/c, T = 4.75 MeV
- 24+ hours
- Swing: p = 5.24 MeV/c, T = 4.75 MeV
Thursday, May 17
- Owl: p = 5.24 MeV/c, T = 4.75 MeV
- Day: p = 5.24 MeV/c, T = 4.75 MeV
- Swing: p = 5.24 MeV/c, T = 4.75 MeV
Friday, May 18
- Owl: p = 5.24 MeV/c, T = 4.75 MeV
- Day: ~fin~
Presentations
- MCC 8 am presentation