1 / 7

Transverse RF Spin Rotator for the n- 3 He experiment

Transverse RF Spin Rotator for the n- 3 He experiment. Christopher Crawford University of Kentucky for the n- 3 He Collaboration n-3He Technical Review ORNL, TN 2013-01-08. Transverse RF spin rotator. Resonant RF spin rotator

lynley
Download Presentation

Transverse RF Spin Rotator for the n- 3 He experiment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Transverse RF Spin Rotatorfor the n-3He experiment Christopher Crawford University of Kentucky for the n-3He Collaboration n-3He Technical Review ORNL, TN 2013-01-08

  2. Transverse RF spin rotator • Resonant RF spin rotator • P-N Seo et al., Phys. Rev. S.T. Accel. Beam 11, 084701 (2008) • Properties suitable for n-3He expt. • Transverse horizontal RF B-field • Longitudinal or transverse flipping • No fringe field - 100% efficiency • Real, not eddy currents along outsideminimizes RF leaked outside SR • Doesn’t affect neutron velocity • Compact geometry • Matched to the driver electronicsof the NPDGamma spin flipper • Construction • Development in parallel with similar design for nEDM neutron guide field • Few-winding prototype built at Uky; Real RFSF being built now field lines end cap windings NPDGamma windings n-3He windings

  3. Inner / outer coil design • Windings calculated using scalar potential • Uniform transverse RF field inside • Zero leakage field enforced by B.C.’s • Copper wires run along equipotentials • Inner region: • Intermediate: • Outer region: • 4:1 inside / outside winding ratio • By choosing appropriate radii • Perfect cos theta windings inside & out • 48 inner loops of 18 AWG wire

  4. Status • Waiting for winding grooves to be machined in nylon forms

  5. Alternate winding patterns • Three possibilities all give same field in high-frequency limit INNER INNER/OUTER OUTER easiest to wind no eddy currents no copper in beam • All three wound using same grooves • R&D: test RF fields of each winding

  6. Electrical specifications • Holding field: • Resonant frequency: • Inductance: 4.5 mH • Capacitance: 7.5 nF • Resistance: 5.1 Ω • Maximum voltage: • Stored energy: • Dissipated power: • Quality factor: Q=151

  7. Electrical specifications • RF field strength depends time spent in RFSF. • High energy neutron beams (~20 meV) will be travelling upwards of 1000 m/s • These neutrons will spend approximately 398 microseconds inside the RFSF and need to rotate π-radians • Flip rate: • The maximum value of the required rotational field is then, • The maximum value of the required RF field is exactly twice this, • To produce this field, we calculate the maximum value of required current given the winding spacing of the inner coils. • Proportionally Constant:

More Related