JLab Polarized He3 Target System
Introduction to the JLab Polarized 3He Target:
Status of the Polarized 3He Target
- A polarized 3He target was built in 1998 and has been undergoing upgrade and improvement continuously.
- A permanent polarized 3He target lab (a laser room and a control room) was built in 1998 in EEL
building. The target system was initially built and tested in the lab. Subsequent upgrades, R-and-Ds and numerous
tests were performed here.
- A 2nd laser building was built in 2005 next to the Hall A counting house to allow setting-up and testing the
polarized 3He target for experiment(s). An optical fiber system is used to transport the laser light
into the hall.
- The target was a critical part for 13 experiments in 6 GeV era.
- It is currently going through an upgrade for experiments in 12 GeV era, aiming to increase the FOM by
about a factor of 8 in two stages.
- If you would like to contribute to the polarized 3He target effort, please contact the polarized 3He target program coordinator
J. P. Chen at 269-7413.
- You will need laser training before you can work in the target lab. The training includes General Laser Safety Training (contact JLab laser safety officer Bert Manzlak at 269-7556), an eye exam and the system specific training (read the safety documents Laser Safety Operation Procedure (LSOP)
and Operation Safety Procedure (OSP), then contact the laser system supervisor
J. P. Chen at 269-7413).
Progress and Status of
the Polarized 3He Physics
- Thirteen experiments using the polarized 3He target have
successfully completed data taking from 1998 to 2009.
- The last series of experiments, leading by the transversity (E06-010) experiment, had
target polarized in vertical as well as tranverse and longitudinal directions. Fast spin reversal every 20 minutes
was established. Narrow-width lasers and hybrid (Rb-K mixture) cell helped the transversity experiment to reach
a maximum in-beam polarization ~60% with up to 15 uA and
fast spin reversal. The average polarization over the experiment was ~55%.
- Many papers were published or submitted for publication (listed for each experiment, see Completed Experiments below).
- A number of students got their PhDs from the polarized 3He
program (listed for each experiment), including J. Huang, MIT, on E06-010,
received the APS-GHP thesis award and three (X. Zheng, MIT, on E99-117 in 2002, K. Slifer, Temple, on E94-010 in 2004, and X. Qian, Duke, on E06-010) received JLab/SURA (JLab/JSA) thesis award,
- A number of experiments using the polarized 3He target are aprroved
to run in 12 GeV era and are key components of the physics program for the JLab 12 GeV upgrade. They require
further upgrade of the polarized 3He target to increase FOM by a factor of 3 to 8.
Polarized 3He Target Experiments in Hall A:
- E94-010: Measurement of the Neutron (3He) Spin Structure Function at Low Q2; a connection between the Bjorken and GDH sum rules.
E95-001: Transverse Asymmetry AT from 3He (e,e')at low Q.
E99-117: An1 at Large x using JLab at 6 GeV.
E97-103: Search for Higher Twist Effects in the Neutron Spin Structure Function gn2.
E01-012: Neutron (3He) spin structure functiuons in the resonance region - spin duality.
E97-110: The GDH Sum Sule and Spin Structure of 3He and the Neutron Using Nearly Real Photons.
E02-013: Neutron Electric Form Factor GEn at High Q2.
E06-010: Single Target-Spin Asymmetry in Semi-Inclusive Pion Electroproduction on a Transversely Polarized 3He Target.
E07-013: Normal Target Single-Spin Asymmetry in Inclusive n(e,e') with a Polarized 3He Target.
E06-014: Precision measurements of d2n: color polarizabilities.
E05-015: Target Single Spin Asymmetry in Quasi-Elastic 3He(e, e') Reaction.
E05-012: A_x and A_z in Quasi-Elastic 3He(e, e'd) Reaction
E08-005: Target Single-Spin Asymmetry Ay in Quasi-Elastic 3He(e,e'n) Reaction
Approved 12 GeV Experiments:
E12-06-122: A1n in the Valance Quark Region Using an 11 GeV Beam and a Polarized 3He target in Hall C
E12-06-122: Neutron g2 and d2 at High Q2 in Hall C
E12-06-122: A1n in the Valance Quark Region Using 8.8 GeV and 6.6 GeV Beam Energies and Bigbite Spectrometer in Hall A
E12-09-018: SIDIS Pion and Kaon Electroproduction on a Transversely
Polarized 3He Target using the Super BigBite and Bigbite Spectrometers in Hall A
E12-09-016: GEn/GMn at High Q2
E12-09-014:Target Single Spin Asymmetry in SIDIS (e,e'pi) Reaction on a Transversely
Polarized 3He Target at 8.8 and 11 GeV
E12-11-007:Asymmetries in SIDIS (e,e'pi) Reactions on a Longitudinally
Polarized 3He Target at 8.8 and 11 GeV
Collaborations and Related Sites:
- Collaborating Institutions:
Kentucky, Temple, UVa and William and Mary; earlier, also Caltech and MIT)
- Current active members: Supervisor: J. P. Chen, Students: Jie Liu, Jin Kai, Nguyen Ton.
- Former students: Alexandre Deur, Pibero Djawothi, Stenphen Jensen, Ioannis Kominis, Karl Slifer;
Kevin Kramer; Xiaochao Zheng; Patricia Solvignon; Vince Sulkosky, Jaideep Singh; Aidan Kelleher,
Ameya Kolarkar;Chiranjib Dutta, Jin Huang, Yi Zhang; Joe Katich; Yawei Zhang.
- Former postdocs:Sebastian Incerti, Meimei Liang, David Pripstein; Xiaofei Zhu; Yi Qiang; Zhiwen Zhao.
Polarized 3He Target Lab at University of Virginia.
Polarized 3He Target Lab at William and Mary.
This page is maintained by J. P. Chen. Last Update: August 31, 2015.