1. Overview of Polarized 3He Target
Jian-ping Chen, Jefferson Lab
A1n/d2n Collaboration Meeting, Dec. 10, 2018
Polarized 3He target: introduction and 6 GeV performance
Target for A1n/d2n
Upgrade
Current status and plan
Engineering/mechanical
Target system
Summary

2. Polarized He3 Target Upgrade for A1n/d2n
Hall C A1n/d2n goals:
30 uA on 40 cm , ~10 atm, L ~ 2.2x1036 cm-2s-1
In-beam polarization ~ 55-60%,
Polarization measurement precision ~ 3%
Design, components and plan
Updated design and installation design all complete (Bert Metzger)
Mechanical parts ordered/arrived or arranged to be available for installation
Lasers/long fibers in target lab. Spare lasers ordered
4-1 combiners tested (Junhao Chen)
Tests, calibrations and studies on going at JLab target lab:
Cell characterization, testing components (Junhao Chen (W&M))
Pulse NMR (Mingyu Chen (UVa))
EPR Melanie Rehfuss (Temple))
Installation plan and preparation
Documents: target OSP and LSOP approved

3. Peoplepower/User Contributions
At JLab: students + engineer/designer + JP (supervisor/coordinator)
Three graduate students
Junhao Chen (W&M, Todd’s group)
Mingyu Chen (Uva, Xiaochao’s group)
Melanie Rehfuss (Temple, Zein-Eddine’s group)
At user target labs :
UVa (Gordon Cates):
cell fabrication (one at JLab, several at UVa, Gordon’s talk)
k0 measurement
W&M (Todd Averett)
Reference cell system/cooling jets
Kentucky (Wolfgang Korsch)
field direction measurement

4. Plan Establish fully functional target system at JLab target lab
Pulse NMR with Lock-in/DAQ fully calibrated
Fully function EPR with final configuration
Water calibration in target lab cross calibration with EPR
Establish cell density/thickness measurements
Fully characterize 1st target cell
cell production at UVa continue to reach total of 10 cells
Fully characterize all cells
Establish field direction (COMPASS) measurements (Uky)
Reference cell system (W&M)
Test existing components
EPICS work for control system
Prepare for target field mapping with compensation coils/Bender magnet
Assistant with installation
Have some tasks done during April-June down time