He3 / H3 e,e'p experiment E12-14-011

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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.

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:

• Data-taking period

Other information

• Kinematics MORE DETAILS HERE

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

• 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

Documentation

• Run List
• For collimator cut
• Experiment seminar slides
• Run and online analysis slides
• Raster
• HRS DAQ Resources
• Simulation
  • Using MCEEP
  • Using SIMC
  • Using COSY
• Tel Aviv University SRC group
• MySQL Database

Target Information

• Tritium Target Tech. Note
• Target Ladder Alignment Survey January 2018
• Information from Jesse
• Target Densities (TGT-CALC-17-020)

Target	density [g/cm3]
Hydrogen	0.002832
Deuterium	0.005686
Tritium	0.003065
Helium-3	0.002

Beam Energy Calibration

Done by D. Higinbotham

Use the Tiefenbach energy multiplied by 1.0025(5)

check this too

HRS Surveys and Mispointings

• Spectrometer Surveys
  • LHRS Survey, April 17 (during slow and fast2 kinematics)
  • RHRS Survey, April 17 (during slow kinematics)
  • RHRS Survey, April 30 (during fast2 and hydrogen2 kinematics)
  • LHRS Survey, May 2 (during hydrogen kinematics 2)

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

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

Previous (e,e'p) studies

• Hall-A E89-003 16O(e,e'p) experiment
• Hall-A E07-006 4He(e,e'p) experiment

Weekly SRC Meetings (Wednesdays 9:30 ET)

• Files (SRC Meetings)

Bi-weekly SRC Analysis Meetings (Every Other Tuesdays 10:00 ET)

• SRC Analysis Meetings