COSY Report

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COSY Report

December 6, 2013 | Andreas Lehrach, RWTH Aachen and FZ Jülich

December 6, 2013 | A. Lehrach KHuK Jahrestagung 2013 2

Content

Physics program

(ANKE, PAX, TOF, WASA)

Preparatory work for FAIR

(HESR and PANDA, CBM, NUSTAR, …)

Future plans

(EDM)


COSY ANKE

TOF

PAX

EDDApolarimeter WAS

A

COSY Overview

… the machine for hadron spin physics

Circumference: 183 m, max. beam momentum 3.7 GeV/c

Polarized proton and deuteron beams

Electron and stochastic cooling


ANKE exp., April 2013 (fast analysis, preliminary)

Ay for pp elastic (ANKE) at 6 beam energies:

Tp = 0.8, 1.6, 1.8, 2.0, 2.2, 2.4

Results from ANKE at COSY

NN scattering at ANKE: pp elastic (Ay)

Double-polarized experiments approved

(i) p n n p (spin observables) (ii) n p {pp}s - (Axz parameter) (iii) p p K+ p (CNN coefficient)

Openable storage cell (luminosity factor 5 more)


Results from WASA at COSY

Isospin decomposition of ABC resonance structurePhys. Lett. B 721 (2013) 229→ pure isoscalar effect If resonance in np system:→ effect should be present in np scattering

Most sensitive observable in np scattering:analyzing power Ay and its energy dependence near θCM ≈ 90°

First result:corresponding signalat resonance position

θCM ≈ 90°

isovector+

isoscalar

isoscalar

isovector

WASA

WASA

WASA

WASASAID

np → np→

Further analysisneeded


Results from COSY-TOF

Separation of singlet and triplet scattering length


Experiment with COSY / schematic

Spin-flipper

Results

COSY Cycle / schematic

Transverse polarization buildup of a stored beam by Spin-Filtering

Results from PAX at COSY

Preparation for longitudinal polarization build-up at COSY and PAX-at-CERN/AD

Siberian Snake

Physics Letters B 718, 64 (2012)


HESR Layout at FAIR

Main machine parameterMomentum range 1.5 to 15 GeV/cCircumference 575 m Magnetic bending power 50 TmDipole ramp 25 mT/sAcceleration rate 0.2 (GeV/c)/sGeometrical acceptances for βt = 2 m horizontal 4.9 mm mrad vertical 5.7 mm mradMomentum acceptance ± 2.5×10-3

Jülich is leading lab for design and construction


WASA

2 MeV e-Cooler (2013)

Barrier Bucket Cavity

Stochastic Cooling

Residual Gas Profile Monitor

Pellet Target

HESR accelerator component tests

HESR Prototyping and Beam Physicse-Cooler


2MeV Electron Cooler at COSY

Parameters demonstrated so far:•300mA @ 109kV•250mA @ 192kV•20mA @ 315kV•Voltage up to 1.3MV (5bar SF6)

Electron cooling achieved:for 200MeV Protons withe-beam up to 200mA @ 109kV

Initial beam profile | Vert. after cooling | Hor. after cooling | Gaussian fits | 108 protons in the Ring

Built at BINP, joint commissioning by BINP and COSY teams, to be installed at HESR


„Preassembly“ of PANDA parts (TOF area)

CBM, PANDA

CBM: Silicon Tracker Tests

GEM Detector Tests

RPC ToF-Detector Tests

HADES: Diamond Detector Tests

PANDA: Straw-tube Tests

Micro-vertex Detector Tests

(Disk DIRC Tests)

Preparatory Work for FAIR Detectors


Permanent EDMs violate parity P and time reversal symmetry T

Assuming CPT to hold, combined symmetry CP violated as well.

Electric Dipole Moments

EDM: Permanent spatial separation of positive an negative charges

EDMs are candidates to solve mystery of

matter-antimatter asymmetry


P. Harris, K. Kirch … A huge worldwide effort

EDMs – Ongoing / Planned


Storage Ring EDM Project

JEDIJülich Electric Dipole Moment Investigations

Goal:10-29 e cm

~ 100 members(Aachen, Dubna, Ferrara, Cornell, Jülich, Krakow, Michigan,St. Petersburg, Minsk, Novosibirsk, Stockholm, Tbilisi, . . . )

10 PhD students

… watch for development of vertical polarization

EDMChallenges:

Huge E-fieldsShielding B-fieldsSpin coherenceBeam position

Polarimetry(...)


R&D Work at COSY (preliminary)

Up-down asymmetry (~ horizontal polarization) as a function of time

Measured spin tune versus time in cycle

Precision of spin tune measurement:

10-8 per 4 seconds

Averaged spin tune can be determined to 10-10 in a single 100s cycle

High-precision spin physics !

Prerequisites to get long SCT:

Beam bunchingBeam coolingSextupole correction SCT 400s

Envelop of 120 kHz spin precession


EDM Prototyping and Spin Physics

RF ExB Spin Flipper (2014)

EDM accelerator and detector component tests

Electrostatic Deflector

(2017)SQUID and Cavity BPMs

(≥2014)

Prototype Polarimeter

(≥2015)


COSY has a strong physics program:

spin physics and symmetries

COSY is an ideal test machine for FAIR

preparatory work:

accelerator and detector components

COSY is the ideal starting place for charged-particle EDMs and precision measurements:

R&D work, first direct measurement and dedicated storage ring

ZusammenfassungSummary and Outlook


Future HESR Upgrade Options

Spin FilteringAntiproton Polarizer (APR)Asymmetric Collider

15 GeV/c – 3.5 GeV/c

Polarized Proton-Antiprotons Collider

Linac

eSynchrotron

eRing (3.3GeV)

HESR(15GeV/c,

= 16)

SIS18

new 70MeV linac

P tune jump Quads,partial snake

eCool, 8.2MVfull snake

spin rotatorsaround IR

e

Polarized Electron-Nucleon Collider ENC

Accelerator Working Group:


Siberian Snake at COSY

Superconducting 4.7 Tm solenoid is ordered. Overall length: 1 mRamping time 30 s

Spin dynamics and longitudinal polarized beams for experiments

Installation at COSYin spring 2013


EDM searches - only upper limits up to now (in ecm):

Huge efforts underway to improve limits / find EDMs

Limits for Electric Dipole Moments

Particle/Atom Current EDM Limit Future Goal

Neutron 3 10-26 10-28

199Hg 3.1 10-29 10-29

129Xe 6 10-27 10-30 – 10-33

Proton 7.9 10-25 10-29

Deuteron ? 10-29

An EDM can have different sources. To disentangle different sources of CP valuation,

it is important to measure neutron and proton and deuteron, and light nuclei EDMs


Timeline: Stepwise approach all-in-one machine for JEDI


RF ExB Spin Flipper

Commissioning and first beam tests in January 2014

B-Field: 560mm long coil out of 6mm copper tubes with 8 windingsIntegral B field on axis: 0.33Tmm.E-Field: stainless steel electrodes inside the vacuum chamber by 50 μm thin foil Field gradient: 0.1 MV/mFrequency range: 100 kHz to 2000 kHz.


Precursor Experiments: Resonance Method with „magic“ RF Wien filter

Avoids coherent betatron oscillations of beam. Radial RF-E and vertical RF-B fields to observe spin rotation due to EDM.Approach pursued for a first direct measurement at COSY.

Observable:Accumulation of vertical polarization during spin coherence time

Polarimeter (dp elastic)

stored d

RF E(B)-fieldIn-plane

polarization


ANKE

TOF

WASA

COSY Overview

PAX

EDM

… the machine forhadron spin physics


Vorarbeiten für HESR

Entwicklungen an COSY:

Barrier BucketKavität

StochastischerKühltank

Budker-Institut(Novosibirsk)Tests 2011

Lieferung I/2012

Komponententests; COSY Hochenergie e-Kühler 1. Stufe für HESR

Elektronen-Kühler (2 MV)


Jülich Center for Hadron Physics

Cooler Synchrotron COSYCircumference: 183 m, magnetic rigidity 12 Tm

Polarized proton and deuteron beams

Electron and stochastic cooling

High-Energy Storage Ring HESR at FAIRCircumference: 576 m, magnetic rigidity 50 TmAntiproton and ion beamsElectron and stochastic cooling

Cooperation with Universities: COSY Association of Networking Universities (CANU)COSY F&E programJülich-Aachen Research Alliance (JARA-FAME)Physics lectures at Aachen, Bonn, Cologne, Bochum, Wupertal, …Student summer school with Univ. of Bonn, Gießen and BochumBachelor/Master and PhD theses


Preparatory Work for FAIR Detectors

Komponententests an COSY (PANDA-Targets, Central Tracker)

COSY as test bench

Pellet Target (Lab)

Pellet Target (WASA)

Cluster Jet Target (ANKE)

Straw Detektoren alszentraler PANDA-Tracker

Straw Det. (TOF)


Neutron Electric Dipole Moment

Adapted from:Nature,

Vol 482 (2012)

Neutron

No EDM yet, only limits


Storage Ring EDM Project

Options:

All-electric ring (proton, electron): only E-fieldAll-in-one ring (proton, deuteron, 3He): E- and B-fields

Requirements:

Clockwise and

counterclockwise beams

Dedicated precision storage ring

Challenges:

Huge E-fieldsShielding B-fieldsSpin coherenceBeam position

Polarimetry(...)

srEDM Collaboration - JEDI Collaboration


EDM Sensitivity

Time

R&D, test measurements at COSY

Precursor expt. w/ COSY

Dedicated SR

Now

10-24 e cm

10-29 e cm

First directmeasurements

for p, d

First directmeasurements

for p, d

Time scale: R&D and Precursor experiment: < 5 years

Dedicated storage ring: > 5 years

JEDI – Stepwise Approach


Results from WASA at COSY

Phys.Rev.Lett.106, 242302 (2011)

Resonance structure with I(JP) = 0(3+)m = 2370 MeV, = 70 MeV

If a resonance in np system, then resonance effect also in np scattering:

Most sensitive observable in np scattering:Analyzing power Ay and its energy dependence near cm 90

cm = 83

resonance in 3G3

resonance in 3D3

Further analysis needed !


Rohrhälften (1.4301) mit 0,1 mm Wandstärke und Detektoren werden von speziell entwickelten Piezotischen bewegt.

COSY Report

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