DEVELOPMENT OF A ROGOWSKI COIL BEAM POSITION MONITOR

DEVELOPMENT OF A ROGOWSKI COIL BEAM POSITION MONITOR 20. 03. 2018 I KIRILL GRIGORYEV, ON BEHALF OF JEDI COLLABORATION NUCLEAR PHYSICS INSTITUTE, FORSCHUNGSZENTRUM JÜLICH K. Grigoryev | Rogowski coil BPM development

OUTLINE § Electric Dipole Moment (EDM) § Storage ring for the proton EDM measurement § Beam Position Monitors ¨ Comparison ¨ Development ¨ Installations ¨ Results § Summary 17. 06. 2021 2 Page 2

ELECTRIC DIPOLE MOMENT (EDM) Example : Definition : p = d · q permanent EDM of H 2 O molecule p ~ 6 · 10 -30 C·m ~ 4 · 10 -9 e·cm -q - p +q + d 17. 06. 2021 3 Page 3

EDMS: DISCRETE SYMMETRIES no EDM (d = 0) Permanent EDMs violate P and T Charge symmetric Assuming CPT to hold, NOT Charge symmetric CP violated also d aligned with spin 17. 06. 2021 4 Page 4

HISTORY AND FUTURE OF EDM Particle/Atom Current EDM Limit Future Goal < 8. 7 · 10 -29 Electron < 0. 9 · 10 -19 Muon < 3. 0 · 10 -26 Neutron < 7. 4 · 10 -30 < 4. 1 · 10 -27 < 2. 1 · 10 -25 Proton History of the EDM experimental limits Deuteron ? Upper limits of EDM searches No direct measurement of proton EDM available No measurements of deuteron EDM at all 17. 06. 2021 5 Page 5

EDM MEASUREMENT AT COSY (COOLER Cooler and storage ring for SYNCHROTRON) (polarized) protons and deuterons • p = 0. 3 – 3. 7 Ge. V/c • internal and external experiments • phase space cooled beams … an ideal starting point Require high precision… for precursor experiment Cyclotron 17. 06. 2021 6 Page 6

BEAM POSITION MONITORS (BPM) Conventional BPM - Easy to manufacture - Length ~ 20 cm - Resolution ~ 10 μm - Accuracy ~ 100 μm Not enough for an EDM measurement 17. 06. 2021 7 Page 7

BEAM POSITION MONITORS (BPM) Conventional BPM Rogowski coil BPM - Easy to manufacture - Length ~ 20 cm - Resolution ~ 10 μm - Accuracy ~ 100 μm 17. 06. 2021 Excellent rf-signal response - Length ~ 1 cm - Resolution ~ 1. 25 μm - Accuracy ~ 150 μm 8 Page 8

MECHANICAL CONSTRUCTION Coil parameters R = 58. 625 mm a = 6. 375 mm n = 434 s = 0. 15 mm 17. 06. 2021 9 Page 9

POSITION DETERMINATION Segment 4 Segment 1 Segment 3 Segment 2 Coil parameters R = 58. 625 mm a = 6. 375 mm n = 434 s = 0. 15 mm 17. 06. 2021 10 Page 10

CALIBRATION 17. 06. 2021 11 Page 11

INSTALLATION AT COSY Offsets Coil 1: x = 2. 058 mm y = 1. 385 mm Coil 2: x = 3. 196 mm y = 2. 157 mm Coil 1 17. 06. 2021 Coil 2 12 Page 12

RESULTS • Coils were calibrated • Installation at accelerator finished successfully • No vacuum problems • Beam positions were correctly monitored during COSY operation 17. 06. 2021 13 Page 13

CONCLUSION & OUTLOOK • Rogowski BPM concept was checked and working • Calibration procedure was established • Can be used with limited installation space • Ground loops problems with electronics should be solved • Better alignment of the individual parts is necessary • Next versions have to be ready for summer shutdown • Readout will be used by the orbit control software 17. 06. 2021 14 Page 14