1 Preparation for the 3 He Injection Test 11/2007 MIT/BATES D. Dutta*, H. Gao, M. Busch, Q. Ye, X. Qian, W. Zheng, X. Zhu ( Duke University) ASU, BU, Caltech, LANL, MIT, MSU, NCSU, SFU And others in nEDM collaboration *Mississippi State University.

2 Outline Introduction Magnets Glassware design Cryogenics pNMR & Calibration Summary

3 The Goal of Injection Test 3 He, out of ABS, collected within superfluid 4 He at 0.3K pNMR to demonstrate that polarization loss is acceptable

4 Magnets system Superconducting tri-coil – Central axial field uniformity<16ppm By Cryomagnetics – Liquid 4 He container By MIT Superconducting solenoid – Ready, to be installed – design of coil support finished Conduction cooled » To be made by Boston Univ. Tri-coil Solenoid coil 4545 o

5 3 He Spin Rotation Spin follows the field direction – AFP condition: Monte-carlo simulation: – Average spin rotation ~ 3.35±0.30 deg – Polarization ~98.8% 3 He trajectory

6 3 He Spin Rotation Test at 300K Parallel mag. field – FID signal drop by ~12.11 Curved mag. field – FID signal drop by ~11.9 B B Polarization loss due to curved field is negligible 45 o 1.5m

7 Pyrex Collection Cell Pyrex collection cell – Glass to copper adaptor thermal cycle<20 times – Jacket design works – Coating with Cs ampule Started with CsN 3 /Cs-Spencer coating » S. Lamoraux and E. Ihloff – Hard to control contamination In situ Coating with Cs ampule – Cs port not needed – Space is accessible » J. Boissevain and M. Busch 10/ / /2007

8 Coating with CsN 3 Hard to know/control contamination above 400 deg C.

9 Cs Coating with Cs Ampule Torch to chase Cs Vapor Cs ampule is detachable Coating successful Before After

10 Cryogenics Filling of 4 He – Jacket – 3 He collection cell » J. Boissevain Location of temperature sensors – Film burner

11 Gas/Liquid Filling & Temperature Monitoring 1.0K--1K port of DR 0.3K -- MC of DR 4.0K --Al 4K thermal shield 4.0K He tank Top flange at 300K Film burner Heater 0.5k 0.3k Temperature sensor

12 pNMR for Injection Test pNMR setup at Duke – An existing magnet modified for this test: 1kG Uniformity ~ 80mG/cm – Tank circuit tuned ~ 3.89MHz – Proton FID signal is observed at room temperature Comparable to 3 He density during injection test ~1X10 14 polarized protons/cc magnet Tank circuit magnet Tecmag Apollo console Tank circuit

13 Trying to improve S/N on 1 H Spin tipping angle at room temp. – RF duration time Spin echo signal – For calibration purpose RF shielding – Au plated mylar A. Matlachov FID signal T 2 measurement on water sample

14 Inside dewar at 4K 1.5m, 50 ohm coax cable Single coil setup Tuning of Cs and Cp:

15 Separate RF: Saddle Coil Coil design – diameter=2.54cm – length =5cm – angular aperture: 135 deg ( not 120 deg, due to big region of interest) – rung width: 15 deg Saddle coil increases the signal size by ~1.4 – Disadvantage Smaller RF field Longer pulse duration – RF heating and T 2 limitation

16 Polarization Calibration Calibration carried out after injection test mol of 3 He will be filled – ~5x10 15 polarized atoms/cc at 0.5K, 1.2 kG 3 He / 4 He gas filling panel is under construction

17 Injection Test Pumping Station Volume from MIT Going to make a gas handling system

18 Summary Magnets are ready, to be assembled with cryostat – Curved field passed spin rotation test Cryogenics and collection cell are under fabrication – Coating with Cs ampule pNMR system under optimization Injection test will be carried out at LANL this winter

19 Thanks!