Axion dark matter search: 23 July 2014 Lepton Moments, Cape Cod The Storage Ring Proton EDM experiment Yannis Semertzidis, CAPP/IBS at KAIST Strong CP-Problem Axion dark matter search: State of the art axion dark matter experiment in Korea Collaborate with ADMX, CAST… Proton Electric Dipole Moment Experiment Storage ring proton EDM Muon g-2, mu2e, etc.

Korean Alphabet (Hangul, 1443AD) 24 characters, consonants and vowels Easy to read, understand short sentences, orient yourself at public places Hard to understand complicated sentences Many people understand English

Center for Axion and Precision Physics Research: CAPP/IBS at KAIST, Korea Four groups 15 research fellows, ~20 graduate students 10 junior/senior staff members, Visitors Engineers, Technicians Future: IBS building at KAIST

CAPP Group http://capp.ibs.re.kr/html/capp_en/ Three more Research Fellows signed up already…

Storage Ring Proton EDM

Proton storage ring EDM experiment is combination of beam + a trap

Yannis Semertzidis, CAPP/IBS, KAIST Stored beam: The radial E-field force is balanced by the centrifugal force. E Yannis Semertzidis, CAPP/IBS, KAIST Yannis Semertzidis, BNL 7

Yannis Semertzidis, CAPP/IBS, KAIST The proton EDM uses an ALL-ELECTRIC ring: spin is aligned with the momentum vector at the magic momentum E Momentum vector Spin vector Yannis Semertzidis, CAPP/IBS, KAIST Yannis Semertzidis, BNL 8

The proton EDM ring Total circumference: 300 m Bending radius: 40 m Straight sections are instrumented with quads, BPMs, polarimeters, injection points, etc, as needed.

Feasibility of an all-electric ring Two technical reviews have been performed at BNL: Dec 2009, March 2011 Fermilab thorough review. Val Lebedev considers the concept to be sound. First all-electric ring: AGS-analog Ring radius 4.7m Proposed-built 1953-57 It worked!

srEDM International Collaboration COSY: Strong collaboration with Jülich/Germany continues We’ve been doing Polarimeter Development, Spin Coherence Time benchmarking, Syst. Errors, Beam/Spin dynamics simulation, etc. for >5 years w/ stored pol. beams. JLAB: breakthrough work on large E-Fields KOREA: We are forming the EDM group and getting started with system developments. ITALY (Ferrara, Frascati,…) TURKEY (ITU,…) GREECE (Demokritos, …) Three PhDs already: KVI, Ferrara, ITU

The proton EDM ring evaluation Val Lebedev (Fermilab) Beam intensity 1011 protons limited by IBS , kV

pEDM polarimeter principle (placed in a straight section in the ring): probing the proton spin components as a function of storage time Micro-Megas detector, MRPC or Si. “defining aperture” polarimeter target Extraction: lowering the vertical focusing carries EDM signal increases slowly with time carries in-plane (g-2) precession signal

Polarimeter design, rates: Beam rates ~102 Hz/cm2 on average, higher at small radius. Design: ~1KHz/pad. Store bunches with positive/negative helicity for pol. syst. errors. 70 cm

The EDM signal: early to late change Comparing the (left-right)/(left+right) counts vs. time we monitor the vertical component of spin M.C. data (L-R)/(L+R) vs. Time [s] Opposite helicity bunches result to opposite sign slopes

Large polarimeter analyzing power at Pmagic! Yannis Semertzidis, BNL

Our proton EDM plan Develop the following systems (funded by IBS/Korea, COSY/Germany, applying for NSF support, and DOE-HEP/NP): SQUID-based BPM prototype, includes B-field shielding (UMass, CAPP/Korea, BNL,…) Polarimeter development (Ind. Univ., CAPP, COSY,…) Electric field prototype (Old Dom. Un. (NSF), JLab,…) Study of systematic errors (BNL, FNAL, Cornell,…) Precision beam and spin dynamics simulation (BNL, CAPP, Cornell, COSY,…) Lattice optimization, beam diagnostics (MSU (NSF),…)

Clock-wise (CW) & Counter-Clock-wise Storage Any radial magnetic field sensed by the stored particles will also cause their vertical splitting. Unique feature among EDM experiments… Equivalent to p-bar p colliders in Magnetic rings 18

Distortion of the closed orbit due to Nth-harmonic of radial B-field Clockwise beam Y(ϑ) The N=0 component is a first order effect! Counter-clockwise beam Time [s]

Vertical tune modulation frequency: 10 kHz Noise level: 0.9 fT/√Hz Vertical tune modulation frequency: 10 kHz

SQUID gradiometers at KRISS

SQUID gradiometers at KRISS

B-field Shielding Requirements No need for shielding: In principle, with counter-rotating beams. However: BPMs are located only in straight sections  sampling finite. Nyquist theorem limits sensitivity to low harmonics of Br. Hence the B-field needs to be less than (1-10nT) everywhere to reduce its effect. We are building a prototype!

Peter Fierlinger, Garching/Munich Issues: demagnetization, effect of holes, etc.

Peter Fierlinger, Garching/Munich

International srEDM Network Common R&D srEDM Coll. pEDM Proposal to DOE HEP, NP SQUID-based BPMs B-field shielding/compensation Precision simulation Systematic error studies E-field tests … JEDI (COSY/Jülich) Pre-cursor EDM exp. Polarimeter tests Spin Coherence Time tests Precision simulation Cooling E-field tests …

What has been accomplished? Polarimeter systematic errors (with beams at KVI, and stored beams at COSY). Precision beam/spin dynamics tracking. Stable lattice, IBS lifetime: 7500s. Spin coherence time >300s, role of sextupoles (with stored beams at COSY). Feasibility of required electric field strength ~40kV/cm – 100kV/cm, 3cm plate separation Analytic estimation of electric fringe fields and precision beam/spin dynamics tracking. Stable! Already published or in progress.

Tracking results using realistic (analytic estimations of) fringe fields E. Metodiev et al., to appear in PRSTAB The radial position away from the ideal orbit as a function of ring X and Y coordinates.

Jlab E-field breakthrough Large grain Nb, no detectable dark current up to (max avail.) 18 MV/m and 3cm plate gap TiN coated Al plates reach high E-field strength Jlab to develop large surface plates

Field Emission from Niobium Work of M. BastaniNejad Phys. Rev. ST Accel. Beams, 15, 083502 (2012) Buffer chemical polish: less time consuming than diamond paste polishing DPP stainless steel Fine grain niobium Large grain niobium Single crystal niobium Field strength > 18 MV/m Conventional High Voltage processing: solid data points After Krypton Processing: open data points

Work of Md. A. Mamun and E. Forman What about TiN-coated Aluminum? No measureable field emission at 225 kV for gaps > 40 mm, happy at high gradient Bare Al TiN-coated Al the hard coating covers defects Work of Md. A. Mamun and E. Forman

Technically driven pEDM timeline 13 14 15 16 17 18 19 20 21 22 Two years system development One year final ring design Three years beam-line construction and installation

Jülich, focus on deuterons, or a combined machine EDMs: Storage ring projects pEDM in all electric ring in the USA Jülich, focus on deuterons, or a combined machine (from A. Lehrach) CW and CCW propagating beams

The Proton EDM experiment status Support for the proton EDM: CAPP/IBS, KAIST in Korea, R&D support for SQUID-based BPMs, Prototype polarimeter, Spin Coherence Time (SCT) simulations. COSY/Germany, studies with stored, polarized beams, pre-cursor experiment. After the P5 endorsement DOE-HEP requested a white paper to establish the proton EDM experimental plan. Large ring radius is favored: Lower E-field strength required, Long SCT, 1-10nT B-field tolerance in ring. Use of existing ring preferred.

The JEDI experiment status Helmholtz Foundation evaluation, early 2014. The pre-cursor experimental program is approved: Use of the existing COSY ring, slightly modified to become sensitive to deuteron EDM (RF-Wien filter). EDM sensitivity moderate, but significant as first direct measurement. Asked to prepare a CDR for a sensitive storage ring EDM experiment.

Summary The storage ring proton EDM has been developed. The breakthrough? Statistics! Best sensitivity hadronic EDM method. Both efforts (USA and COSY) received encouragement to produce an experiment plan. pEDM first goal 10-29 ecm with a final goal 10-30 ecm. Complementary to LHC; probes New Physics ~102-103 TeV.

Extra slides

Peter Fierlinger, Garching/Munich

Why now? Exciting progress in electron EDM using molecules. Several neutron EDM experiments under development to improve their sensitivity level. Proton EDM could be decisive to clarify the picture.

Storage ring proton EDM method All-electric storage ring. Strong radial E-field to confine protons with “magic” momentum. The spin vector is aligned to momentum horizontally. High intensity, polarized proton beams are injected Clockwise and Counter-clockwise with positive and negative helicities. Great for systematics Great statistics: up to ~1011 particles with primary proton beams and small phase-space parameters.

Large Scale Electrodes, New: pEDM electrodes with HPWR Parameter Tevatron pbar-p Separators BNL K-pi Separators pEDM Length 2.6m 4.5m 3m Gap 5cm 10cm 3cm Height 0.2m 0.4m Number 24 2 102 Max. HV 180KV 200KV 150KV

Physics reach of magic pEDM (Marciano) Sensitivity to new contact interaction: 3000 TeV Sensitivity to SUSY-type new Physics: The proton EDM at 10-29e∙cm has a reach of >300TeV or, if new physics exists at the LHC scale, <10-7-10-6 rad CP-violating phase; an unprecedented sensitivity level. The deuteron EDM sensitivity is similar. 44

The grand issues in the proton EDM experiment BPM magnetometers (need to demonstrate in a storage ring environment) Polarimeter development: high efficiency, small systematic errors Spin Coherence Time (SCT): study at COSY/simulations; Simulations for an all-electric ring: SCT and systematic error studies Electric field development for large surface area plates

1. Beam Position Monitors Technology of choice: Low Tc SQUIDS, signal at 102-104Hz (10% vertical tune modulation) R&D sequence: Operate SQUIDS in a magnetically shielded area-reproduce current state of art Operate in RHIC at an IP (evaluate noise in an accelerator environment); Operate in E-field string test

2. Polarimeter Development Polarimeter tests with runs at COSY (Germany) demonstrated < 1ppm level systematic errors: N. Brantjes et al., NIM A 664, 49, (2012) Technologies under investigation: Micro-Megas/Greece: high rate, pointing capabilities, part of R&D for ATLAS upgrade MRPC/Italy: high energy resolution, high rate capability, part of ALICE development

3. Spin Coherence Time: need >102 s Not all particles have same deviation from magic momentum, or same horizontal and vertical divergence (all second order effects) They cause a spread in the g-2 frequencies: Present design parameters allow for 103 s. Cooling/mixing during storage could prolong SCT (upgrade option?).

The miracles that make the pEDM Magic momentum (MM): high intensity charged beam in an all-electric storage ring High analyzing power: A>50% at the MM Weak vertical focusing in an all-electric ring: SCT allows for 103s beneficial storage; prospects for much longer SCT with mixing (cooling and heating) The beam vertical position tells the average radial B-field; the main systematic error source

With coordinate mapping inversion

Tracking results To achieve storage we had to “clip” the inner plates by theta~1mrad