Difference between revisions of "Bubble Chamber Beam Test May 2018"
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= '''EPICS Data'''= | = '''EPICS Data'''= | ||
| − | The following command dumps the archived data – | + | The following command dumps the archived data – Dipole field (G.cm), Dipole Hall probe (G), Current readback from BCM0L02 Gigatronics (µA), High channel readback from BCM0L02 new receiver (µA), Low Channel readback from BCM0L02 new receiver (µA), 5D Dump current (A) and Beam positions (mm) – every second to a file: |
mySampler -b "2018-05-10 00:00:00" -s 1s -n 86400 MDL0L02.BDL dtm151:field IBC0L02Current IBC0L02MAGA IBC0L02MAGB IFY5D04K6485dataRead IPM5D00.XPOS IPM5D00.YPOS IPM5D01.XPOS IPM5D01.YPOS > BubbleChamber_EPICS_10May2108.txt | mySampler -b "2018-05-10 00:00:00" -s 1s -n 86400 MDL0L02.BDL dtm151:field IBC0L02Current IBC0L02MAGA IBC0L02MAGB IFY5D04K6485dataRead IPM5D00.XPOS IPM5D00.YPOS IPM5D01.XPOS IPM5D01.YPOS > BubbleChamber_EPICS_10May2108.txt | ||
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'''Notes:''' | '''Notes:''' | ||
# The nominal momentum is calculated from the dipole field with: p [MeV/c] = BdL [G.cm] / 1412 (when beam is in 5D line). | # The nominal momentum is calculated from the dipole field with: p [MeV/c] = BdL [G.cm] / 1412 (when beam is in 5D line). | ||
| − | # Use IBC0L02MAGA | + | # Use IFY5D04K6485dataRead for beam currents in 5D line. Unfortunately, the KEITHLY 6485 picoammeter was on fixed gain during part of the run, then use IBC0L02MAGA instead. The picoammeter saturates if beam currents are higher than the fixed current value. You may want to examine both current readbacks and use the one that gives currents close to what in the shift logs. |
Latest revision as of 15:24, 20 July 2018
Beam Setup and Measurement - May 2018
Bubble Chamber Turn On
- Fill with natural C3F8 – test bubble chamber systems operation
- Thresholds code for C3F8: media:ThresholdsC3F8.xlsx
- 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's 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
- Composite image python script: media:combinebubbles.txt (rename file, change ".txt" to ".py")
- 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 |
Shift Schedule
media:ShiftSchedule_Bubble_May2018.pdf media:ShiftSchedule_Bubble_May2018.pdf
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 | p = 5.64 MeV/c, T = 5.15 MeV |
| 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
Run Summary
- Summary of run information: media:Jlab_Bubble_May18_RunSummary.pdf
Analysis
- Composite image of all bubbles:
- Composite image of all bubbles:
- Tarball of composites for each run (change .txt to .tar.gz): media:Bubble_May2018_composite.txt
EPICS Data
The following command dumps the archived data – Dipole field (G.cm), Dipole Hall probe (G), Current readback from BCM0L02 Gigatronics (µA), High channel readback from BCM0L02 new receiver (µA), Low Channel readback from BCM0L02 new receiver (µA), 5D Dump current (A) and Beam positions (mm) – every second to a file:
mySampler -b "2018-05-10 00:00:00" -s 1s -n 86400 MDL0L02.BDL dtm151:field IBC0L02Current IBC0L02MAGA IBC0L02MAGB IFY5D04K6485dataRead IPM5D00.XPOS IPM5D00.YPOS IPM5D01.XPOS IPM5D01.YPOS > BubbleChamber_EPICS_10May2108.txt
Notes:
- The nominal momentum is calculated from the dipole field with: p [MeV/c] = BdL [G.cm] / 1412 (when beam is in 5D line).
- Use IFY5D04K6485dataRead for beam currents in 5D line. Unfortunately, the KEITHLY 6485 picoammeter was on fixed gain during part of the run, then use IBC0L02MAGA instead. The picoammeter saturates if beam currents are higher than the fixed current value. You may want to examine both current readbacks and use the one that gives currents close to what in the shift logs.
- Data file for May 10 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_10May2108.txt
- Data file for May 11 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_11May2108.txt
- Data file for May 12 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_12May2108.txt
- Data file for May 13 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_13May2108.txt
- Data file for May 14 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_14May2108.txt
- Data file for May 15 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_15May2108.txt
- Data file for May 16 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_16May2108.txt
- Data file for May 17 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_17May2108.txt
- Data file for May 18 (00:00:00 - 23:59:59): media:BubbleChamber_EPICS_18May2108.txt