Polarized 3 He Target Lab Update Presented by Xiaohui Zhan MIT Hall A Collaboration Meeting, Dec. 14, 2007

Outline: Oven/Support Structure NMR & EPR New Oven & Other Designs Optics Design & Orders Vertical Coils Test BigBite Frindge Field Investigation Software & Target Spin Sign Signal Cell Production To Do List Students: Chiranjib Dutta (UKY), Joe Katich (W&M), Xiaohui Zhan (MIT) Postdoc: Yi Qiang (DUKE)

Oven/Support Structure Support piece on the bottom was burned, install new support structure. Working well: ~250 o C. Old cell Carlos was installed for test. Oven Cell

NMR & EPR Tests Good NMR signal EPR underway…

New Oven/Optics Ordered from Technical Products, Inc.. New materical: CS85 Structural Insulation. Weigh 29lbs with supports (current oven ~ 45lbs). Oven and support design was done, installation in February. Optics design is done! Most optics components ordered and in house. 6 single FAP and 2 duo FAP in lab, one new duo and single were ordered. Alignment for 2 lasers was done for the tests.

Vertical Coils R = cm Z: Beamline Y: Vertically up X: Normal to YZ Measured Volume Vertical Coil With 16A current, the average field generated by vertical coils is ~31 Gaus in Y direction (vertical). Most field gradients inside < 10mG/cm (absolute value). Large gradients (~20mG/cm) only happen at the edge of the volume.

BigBite Fringe Field Transver sity g2/d2(e,ed) Angle of BigBite -7 o 8o8o 2.8 o dBx/dx (mG/cm) dBz/dz (mG/cm) dBz/dx (mG/cm) BigBite clamp reduces the gradients by half compared to previous measurements. But also introduce the mirror coils. Simulation was done (Yi Qiang).

Results of Simulation (Transversity) Gradient (mG/cm) dBx/dydBy/dzdBz/dxdBx/dxdBy/dydBz/dz By = 28 G Target Chamber 0.0± ± ± ±1.32.2± ±1.1 Pumping Chamber 0.7±0.67.9± ±0.49.7±0.60.8± ±0.6 By = -28 G Target Chamber -3.4± ± ± ±1.32.2± ±1.1 Pumping Chamber -4.6± ± ± ±0.52.8± ±0.9 Bx = 28 G Target Chamber -1.7± ± ± ±5.34.8± ±3.3 Pumping Chamber -2.4± ± ± ± ± ±1.8 Bx = -28 G Target Chamber -1.7± ±0.15.9±2.76.7± ± ±1.2 Pumping Chamber -1.5± ±1.47.2±1.45.5±1.34.5± ±1.6

Target Spin Sign Signal+DAQ Flip target spin every ~20min Hardware signal: goes to CODA datastream Software signal: LABVIEW to EPICS RF frequency monitoring & quarter-wave plate rotation monitor Cell Production 16 new cells were done! (8 from W&M and 8 from UVa) Most cell polarization > 40%, a few>50%, max~60% (W&M)

To Do List 1.New oven test with all new cells (NMR, EPR, Spin-Flip). 2.Cell characterization. 3.New pick-up coils inside the oven. 4.Target spin sign signal/DAQ. 5.Target IOC. 6.Software collection & analysis. Will be ready before installation in May 1st, 2008! Thanks to: Jian-Ping, Todd, Walfgang, Al, Susan, Jaideep, Ameya, Aidan…