1 / 12

Electrostatic deflector development

This outline details the development of electrostatic deflectors for measuring Electric Dipole Moments in storage rings, including laboratory tests, large deflector development, and conclusions. It covers the Electric Dipole Moment Definition, alignment with spin, and spin motion in electromagnetic fields. Furthermore, it discusses the setup of a Cooler SYnchrotron ring for EDM measurements at Jülich, detailing the magnetic and electromagnetic rings, and existing and proposed setups. It also outlines the test stand for small electrodes in the vacuum chamber and measurement results with various electrode materials and coatings.

pspringer
Download Presentation

Electrostatic deflector development

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. Electrostatic deflector development 28.03.2019 I Kirill Grigoryev on behalf of the JEDI collaboration

  2. Outline Electric Dipole Moment Storage rings for EDM measurement Laboratory tests with small prototypes Large deflectors development Conclusion and outlook

  3. -q +q p - + d Electric Dipole Moment Definition : p = d · q Example : permanent EDM of H2O molecule p ~ 6 · 10-30 C·m ~ 4 · 10-9 e·cm

  4. no EDM (d = 0) Charge symmetricNOT Charge symmetric d aligned with spin EDMs: Discrete Symmetries Permanent EDMs violate P and T symmetry Assuming CPT to hold - CP violated also

  5. General case The spin motion for relativistic particles in electromagnetic fields is determined by the Thomas-BMT equation Ω : angular precession frequency d : electric dipole moment G : anomalous magnetic moment γ : Lorentz factor Ideal case Inject particles with spin pointing towards momentum direction „Frozen Spin“: without EDM spin stays aligned to momentum EDM couples to electric bending fields Slow buildup of EDM related vertical polarization Large electric fields (E = 17 MV/m at 2cm for 30m radius ring)

  6. COoler SYnchrotron ring for (polarized) protons and deuterons EDM measurements at Jülich Magnetic ring Electromagnetic ring Electric ring existing proposed future … an ideal starting point for precursor experiment Cyclotron

  7. 20mm Atmosphere 10-2 mbar 10-9 mbar -> 10-2 mbar -> 10-9 mbar -> 10-12 mbar Scroll fore pump Turbo-molecular pump Ion getter pump Test stand for small electrodes Electrodes in the vacuum chamber

  8. Test electrodes roughness Stainless steel Aluminum Material Stainless steel Aluminum Treatment Cleaning Polishing TiN coating Spacing between electrodes variable from 0.1 to 500 mm High Voltage up to 30 kV uncoated Average = 0.10 μm Maximum = 1.17 μm Average = 0.18 μm Maximum = 1.11 μm TiN coated Average = 0.10 μm Maximum = 2.54 μm Average = 0.08 μm Maximum = 1.78 μm

  9. Measurement results Uncoated stainless steel Coated Aluminum arXiv: 1812.07954

  10. 1400 mm 2700 mm Foil tighteners and actuators Deflectors HV - feed-thorough Necessary parts Parameters 2900 mm Electrode length = 1020 mmElectrode height = 90 mmElectrode spacing = 20 – 120 mmMax. electric field = ±200 kV on eachMaterial / coating = TiN coated Aluminum Deflector support Power supplies (200kV) Chamber protection foil Test deflectors Large deflector tests

  11. + - + - By Electron trajectories simulation Electrons initial energy: 50 eV Voltage: ±100 kV → 4MV/m B-field: 0.15 T B-field: 0 T

  12. Conclusion and outlook Achievements Small electrodes - Stainless Steel vs. TiN aluminum electrodes tests - Roughness measurements Large electrodes - Preparation for installation is almost finished Plans Small electrodes - Test all possible combinations of materials and coatings - Try gas conditioning and measure roughness again Large electrodes - Installation into vacuum chamber (indium sealing) - Mechanical and electrical tests - High voltage tests

More Related