Polarized 3He Target System

• Overview• Design • Vertical Polarization • Spin-Flip• Oven/Ladder/Enclosure/Access• Laser/Optics/Cells• Polarimetry• Safety/Documents• Installation/Switch-over• Milestone, Manpower and Responsibilities

3He Target Overview

Design Progress

• Progress: (Estimated >90 person-weeks 3 months ago)

Completed items:• Layout for all four experiments • New vertical Helmholtz coils and support• New RF coils for vertical polarization• New oven system• Oven support in the target lab• Target collimators• Replacement support for horizontal Helmholtz coils• New cells (with side pull-offs)• Extended magnetic shielding on BigBite fringing field • Conceptual design on laser optics lines • Conceptual design on vertical Compass

Oven System

Oven being assembled in the target lab

Target Cell

Laser Optics

Remaining Items for Design

• Remaining design items: (total < 20 person-weeks)• Main support Structure

Supports for

Target drive, Target Collimator, new RF coils, Ref. cell

Target enclosure and windows • Target ladder and pick-up coils • Laser optics lines (including EPR, spectra-analyzer) and support • Personnel access• Safety interlock• Compass mounts

Progress in the target lab

• Spin-flip test (mostly complete)• RF sweep NMR on 3He works• EPR works• New support for horizontal Helmholtz coils installed• New oven and support arrived, being assembled• Two new cells manufactured and to be tested• Cell characterization (density and window) setup ready• Optical fibers and combiners ordered• 5-to-1 combiners delivered, tested and problems found

Spin-Flip Test

RF sweep NMR on 3He

EPR

Planned tests in the target lab

• Install new oven, test• Test new cells • Characterizing new cells • Test new components • Test new optics• RF sweep water calibration • Combine polarization measurements with spin-flip• Spin-flip signal to DAQ• LabView communication with EPICS

Other Components

• Compass (Kentucky): Conceptual design complete complete design, manufacturing and test• Vertical coils (order placed, delivery next month): setup in new target lab, align and field mapping then move to EEL target lab, integrate with horizontal coils • Lasers: 9 in hand, 2 spare diodes; new vender: narrow lasers• Cells: new contracts with Princeton/Mike Souza medium size (3”) pumping chamber, production started, two in hand, plan to produce 1 cell every two weeks W&M and UVa groups

Vertical Compass Conceptual Design

Safety and documents

• There are a number of safety aspects for the target: • Laser safety: eye, skin, fire hazard, LSOP enclosure, alignment, eyewear, training• High pressure glass cells: explosion, radiation, OSP/RWP enclosure, windows, loop around pivot area cell handling: face mask, eye and hearing protection• Reference cell system: high pressure, hydrogen• Hot Surface/fire hazard from heating• Electrical from power supplies• Magnetic field

• All documents will be updated

Manpower

• Designer: A. Gavalya, S. Esp (and help from others)• Students: C. Dutta (KY), J. Katich (W&M), X. Zhan (MIT), • Physicists: T. Averett (W&M, part-time), W. Korsch (KY,

short-term visit), and J. P. Chen (JLab).• Postdocs: from W&M, Duke• Help from past students/postdocs.• Off-site

• Cell production/testing at W&M, UVa. • Compass design/testing at Kentucky.

Responsibilities

• Overall: J. P. Chen• Design: A. Gavalya/ J. P. Chen• Vertical coils, holding field, oven system, ladder, support, cell

characterization, reference cell, NMR: J. Katich/T. Averett• Spin-flip, EPR: C. Dutta/W. Korsch• Optics: C. Dutta/J. P. Chen• Software/Labview, communication with EPICS: X. Zhan/B. Moffit• Compass: A. Kolarkar/W. Korsch• Fringe field: P. Brindza• Safety, documents: J. P. Chen

Installation, commissioning, switchover

• Coordinate with Ed Folts for installation: 4-6 week for the target • Move to the hall, survey• Move to pivot, survey, install components, • Install optical line support, instrumentation, power cables• Checkout magnets, measure field direction/survey• Install ladder, cells, survey• Install reference cell system, cooling jets• Water calibration• Laser safety inspection, switch to 3He, laser alignment• Pumping up, check out spectra-analyzer, EPR

• Commissioning: elastic 3He asymmetry (T and L) • Switchover:

• change cell, water calibration• change optical line and check alignment, pump-up • EPR, temperature test

Milestones for Polarized 3He

• Spin-Flip test: done • NMR/EPR system working: done, keep improvement• New oven ready for cell testing/characterization: April 1• Vertical coils test: June 1 • Cell production: 10 by July 1, 20 by Dec. 1 • New target structure: Sept. 1• Compass: Sept. 1• Laser optics line: Oct. 1• NMR FM water (optional): Oct. 1• Complete system test: Nov. 1• Ready for installation: Jan. 1, 2008