Difference between revisions of "He3 / H3 e,e'p experiment E12-14-011"
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== Meetings == | == Meetings == | ||
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| + | === Bi-weekly Tritium SRC Analysis Meetings (Every Other Tuesdays 10:00 ET)=== | ||
| + | * [[SRC Analysis Meetings]] | ||
=== Weekly SRC Meetings (Wednesdays 9:30 ET) === | === Weekly SRC Meetings (Wednesdays 9:30 ET) === | ||
* [[Files (SRC Meetings)]] | * [[Files (SRC Meetings)]] | ||
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Revision as of 10:22, 15 May 2019
The SRC Tritium Experiment (E12-14-011) is an (e,e'p) experiment in Hall A, comparing the momentum distribution of protons in tritium and helium-3. These nuclei have a large proton-neutron asymmetry, but are also isospin-mirror nuclei, meaning that the proton distribution in tritium can tell us about the neutron distribution in helium-3.
Contents
Publications and results
- Comparing proton momentum distributions in A = 3 nuclei via 3He and 3H(e,e'p) measurements
- R. Cruz-Torres, S. Li, F. Hauenstein, A. Schmidt, et al., (Jefferson Lab Tritium Collaboration)
- arXiv:1902.06358 (2019)
Important codes
- replay script can be found here:
- https://github.com/reynier0611/HallA-Online-Tritium/tree/coincidence
- (Make sure to be in the "coincidence" branch)
- bash scripts to submit jobs to the farm can be found here:
- skimmer and combiner codes can be found here:
- skimmer keeps events based on the database: elist_database.
- This event list was created with the following code by Shujie:
- https://github.com/reynier0611/TritiumAnalysis/tree/master/beam
During the experiment
The information that was more relevant for activities during the data-taking period will be moved from this page to the following new page:
Beam Energy Calibration
Done by D. Higinbotham (This is a 'pass-dependent' statement)
For second pass beam, use the Tiefenbach energy multiplied by 1.0025(5)
(That is, replace the value Ebeam in db_run.dat by 1.0025xEbeam)
After this correction, the measured Ebeam (before Eloss corrections) is ~ 4.3255 GeV
Raster Calibration
Target Information
- Tritium Target Tech. Note
- Target Ladder Alignment Survey January 2018
- Information from Jesse
- Target Densities (TGT-CALC-17-020)
- Target Densities (TGT-CALC-17-020) <- NEW ONE
- Helium contamination in tritium target - by Tyler Kutz
| Target | density [mg/cm2] |
|---|---|
| Hydrogen | 70.8 +/- 0.4 |
| Deuterium | 142.15 +/- 0.8 |
| Tritium | 85.1 +/- 0.8 |
| Helium-3 | 53.4 +/- 0.6 |
Kinematics
These are the nominal values we got by optimizing in simc (these are not the actual values from the experiment)
| Kinematics | LHRS momentum [GeV] | LHRS angle [deg] | RHRS momentum [GeV] | RHRS angle [deg] |
|---|---|---|---|---|
| Fast | 3.543 | 20.88 | 1.4805 | 48.80 |
| Slow | 3.543 | 20.88 | 1.246 | 58.50 |
| Parallel (Hydrogen) | 3.543 | 17.80 | 1.4805 | 48.80 |
HRS Angles, Surveys, and Mispointings
- Spectrometer Surveys
LVDT retults
| Kinematics | Run number | L mispointing [mm] | R mispointing [mm] | LHRS angle [deg] | RHRS angle [deg] |
|---|---|---|---|---|---|
| Fast | 100085 | 1.18245 | -0.70915 | 20.8837 | 48.8207 |
| Hydrogen | 100100 | 0.9882 | -0.7113 | 17.8017 | 48.8207 |
| Slow | 100532 | 0.48765 | -0.65395 | 20.8812 | 58.5031 |
| Fast2 | 100658 | 0.49145 | -2.9875 | 20.8812 | 48.8187 |
| Hydrogen2 | 100685 | 0.8831 | -3.00255 | 17.8053 | 48.8188 |
HRS Momenta
Values taken from db_run.dat file.
| Kinematics | Run number | LHRS p_cent [GeV] | RHRS p_cent [GeV] |
|---|---|---|---|
| Fast | 100085 | 3.54334 | 1.48051 |
| Hydrogen | 100102 | 3.54334 | 1.4805 |
| Slow | 100532 | 3.54331 | 1.246 |
| Fast2 | 100658 | 3.5433 | 1.48051 |
| Hydrogen2 | 100685 | 3.5433 | 1.4805 |
Optics
More information can be found here
Other information
- BCM calibration
- run number: 100172
- target: carbon foil
- currents and attenuator values:
- 3uA ---> 140
- 7uA ---> 163
- 12uA ---> 184
- 18uA ---> 204
- 22.2uA ---> 214
- These are nominal values for the beam current. Gotta get the actual values from epics info.
- See example in the halog, entry number: 3505501
- Unser calibration
- run number: 100451
- target: dummy
- current values: 0,2,0,3,0,5,0,10,0,25,0,40,0,60,0,80,0,90,0,100,0,2,0,3,0,5,0,10,0 uA
- Ideally we would have completed two full cycles from 0 to 100 uA, but the beam came back and we decided to go back to production.
- See example in the halog, entry number: 3499263
Root files on Tape
Actual raw data: /mss/halla/triton/raw/
July 10th, 2018: /mss/halla/triton/prod/coinc_eep/pass2.1/all/
July 27th, 2018: /mss/halla/triton/prod/coinc_eep/pass2.2/all/
August 10th, 2018: /mss/halla/triton/prod/coinc_eep/pass2.3/all/
Documentation
- Run List
- For collimator cut (this cut ended up not being used)
- Experiment seminar slides
- Run and online analysis slides
- Boiling paper
- Raster
- HRS DAQ Resources
- Simulation
- Tel Aviv University SRC group
- MySQL Database
Reference Reading
- Proposal for E12-14-011, approved by PAC-42
- Hall-A NIM paper (2004)
- Tech notes on HRS optics calibration
- Hall A Coordinate systems (Ye Zhihong PhD thesis)
- HRS info
