5th Workshop on the Scientific Cooperation between German Research Centres and JINR

ANKE at COSY-JülichANKE at COSY-Jülich(ANKE goes double-polarized)

Frank RathmannInstitut für Kernphysik

Forschungszentrum Jülich

Physics accessible with the Polarized Internal Storage Physics accessible with the Polarized Internal Storage Cell Target at ANKECell Target at ANKE

• pd (+ spectator protons) – pn elastic scattering

– pd breakup

• dp charge exchange• ppppX• pnpnX• EM spin transfer p+ep+e

– polarized antiprotons for FAIR

ABS

LSP

Atomic Beam Source (a la HERMES)Atomic Beam Source (a la HERMES)

PI I ~ 10 mbar-6

PI ~ 10 mbar-4

PI II ~ 10 mbar-7

PIV ~ 10 mbar-8

1st group of 6-pole magnetsPole-tip fields are:

#1 1.654 T 10/14 mm

#2 1.684 T

#3 1.625 T

16/22 mm

mm28

2nd group of 6-pole magnetsPole-tip fields are:

#4 1.565 T

#5 1.621 T

#6 1.621 T

30 mm

30 mm

30 mm

Nozzle cooling systemTemperature range: 50-300 K

DissociatorPrimary flow (H /D ) range: 1 10 - 5 mbar l/s

Second2 2 -3

ary flow (O ) range: 1 10 - 0.5 mbar l/sRF power: 0 - 600 W @ 13.56 MHz

2 -3

Medium Field Transition unit (MFT)Frequency: 58.7 MHz (H )Magnetic field: up to ~ 2 kG

2

Strong Field Transition unit (SFT)Frequency: 1425.2 MHz (H )Magnetic field: up to ~ 3 kG

2

Weak Field Transition unit (WFT)Frequency: 14 MHz (H )Magnetic field: up to ~ 3 kG

2

Movable bafflesAl casting

Central reference platestainless steel (t ~ 50 mm)

Atomic beam intensity ~ 7.5x1016 at/s

Test Setup of PITTest Setup of PIT PIT installed at ANKEPIT installed at ANKE

Atomic Beam Source

TargetChamber

Lamb-shift Polarimeter

Atomic beam polarization from Lamb-Shift Polarimeter

Ly-α spectra of hydrogen and deuterium atoms

Hydrogen

P = 0.89±0.01z

P = –0.96±0.01z

300 350 400 450 500 550Magnetic field, a.u.

P

P

z

z

(Ly-a) = +0.78MFT 2-3teor= +1

mI=–1/2

50 100 150 200 250 300 350 400 450 500 5500

20406080

100120140160180

N(Ly

-)

P

P

z(Ly-a) = -0.86MFT 2-3WFT 1-3

= -1zteor

mI=+1/2

mI=–1/2

Deuterium

P = 0.73±0.05z P = –0.82±0.06z

500 550 600 650 700 750 800 85040

60

80

100

120

140

160 P

P

z(Ly- ) = +0.68

MFT 3-4SFT 2-6

P

P

zz

z

(Ly- ) = +0.68

= +1= +1

z

z

teor

teor

N(Ly

-)

mI=+1

mI=–1mI=0

500 550 600 650

40

60

80

100

120

140 P

P

z(Ly- ) = -0.76

MFT 3-4WFT 1-4 2-3

P

P

zz

z

(Ly- ) = +0.57

= -1= +1

z

z

teor

teorN(Ly

-)

mI=+1 mI=0

P = 0.77±0.06zz P = –1.17±0.08zz

500 550 600 650 700 750 800 850

40

60

80

100

120P

P

z(Ly- ) = 0

WFT 1-4SFT 2-6

P

P

zz

z

(Ly- ) = +0.72

= 0= +1

z

z

teor

teor

N(Ly

-) mI=+1 mI=–1

mI=0

500 550 600 650

40

60

80

100

120

140

N(Ly

-)

mI=+1

mI=0

Magnetic field, a.u.

Magnetic field, a.u. Magnetic field, a.u.

Magnetic field, a.u. Magnetic field, a.u.

150 200 2500

20406080

100120140160180

N(Ly

-)

mI=+1/2

700 750 800 850

mI=–1

700 750 800 850

P

P

z(Ly- ) = -0.06

WFT 1-4SFT 3-5

P

P

zz

z

(Ly- ) = -1.09

= 0= -2

z

z

teor

teor

mI=–1

New Equipment: Spectator DetectorNew Equipment: Spectator Detector

Features:– Three layers (double sided)

1st: 60 m2nd: 300 m3rd: 5 mm

– Ekin~2 MeV (60 MeV/c)

– 800 Channels– Self-triggering– On-board electronics

– UHV compatible– Large Acceptance

• 10% per telescope• 30 mm from the beam

Future Experiments: Future Experiments: Parity of Parity of θθ+ + PentaquarkPentaquarkDouble polarization fixes parity of θ+ free of any model!

Spin-correlation coefficient Axx in pp θ++

+1

-1

50 Q [MeV]0

neg. Parity

pos. Parity

Axx

C. Hanhart et al., PLB,590,(2004)

WASA-COSYWASA-COSY with a polarized

jet target

PIT at ANKE

pursue a strong spin physics program

ConclusionConclusion

Single and Double Polarization Experiments•NN Interaction (pn)•pd Dynamics•Meson Production in pp and pn Collisions•Parity of Θ+ Pentaquark

FAIR offers unique oportunities for spin physics (PAX)•Expertise gathered at COSY essential for success at FAIR

-Polarized Antiprotons-Measurement of Transversity distribution of the nucleon

Apertures tests at COSY

COSYbeam

XY-table Frame with apertures

Vacuum

camber

Apertures tests at COSY to find cell dimensions

d=w-(a+b)

0

100

200

300

400

500

600

700

800

-25 -20 -15 -10 -5 0 5 10 15 20 25

X coordinates, mm

beam

inte

nsity

, a.u

.

0

100

200

300

400

500

600

700

800

-25 -20 -15 -10 -5 0 5 10 15 20 25

X coordinates, mm

beam

inte

nsit

y, a

.u.

a

0

100

200

300

400

500

600

700

800

-25 -20 -15 -10 -5 0 5 10 15 20 25

X coordinates, mm

beam

inte

nsity

, a.u

.

w

b

d

COSY-beam diametersaccelerated beam

cluster target off

36x16 mm2

at injectioncluster target on

9x12 mm216x15 mm2

Target PolarimetryReactions for Pz

Reactions for Pzz

dp→dp dp→dp

np→dπ0 (quasi-free)

dp→3Heπ0

pp→pp (quasi-free)

dp→(2p)n

→

→

→

→

→

→

Deuteron beam polarimetry at ANKE well-understood:Diploma thesis D. Chiladze

Momentum and angle accuracies (from simulation) for protons (about 1.15 GeV/c) and deuterons (about 2.3 GeV/c). Cluster target 40 cm cell Δp/p [%] Δθ [deg.] Δp/p [%] Δθ [deg.] 1.0 0.15 1.6 0.36

dp elastic

ANKE

pp elastic more acurate data (SAID), dp reactions closer to the physics use both for target polarization determination

New Equipment: PIT + Spectator TelescopePIT: Polarized Internal Target::

- ABS- Lamb-Shift Polarimeter- Storage Cell

Spectator: Silicon telescope array

beam

Discussed Issuestopics responsible Remarks rating

np physics

CE Breakup

Two slow protons

np elastic

A. Kacharava

V. Leontiev

R. Schleichert

• Test of the spectator model• What do learn from dp(pp)Δ?• ‘‘ Polarization of Δ?

• Ay and Ayy easy without new instrumentation

pd dynamics

pd(pp)n Yu. Uzikov

S. Yaschenko • New Idea: T20 in (pp) from dp with side detector

Pion Production C. Hanhart

S. Yaschenko

• EFT needs Ayy in pn ppπ-

Additional Measurements in pn ppπo at small angles (Ayy, Ay)

• How: pd psppπ- or dp psppπ-

Heavy Meson Prod.

pp ppФ

pp (pp)?η

M. Hartmann

C. Hanhart

• Double Polarization needs high Lumi

• P-waves in pp System? Ayy

Discussed Issues IItopics responsible Remarks rating

Strangeness Production Yu. Waldau

V. Koptev

+ S. Belostotski

Λ N Scattering LengthK+ near 900 cmAy and Ayy

Looks feasible from rate estimates• pp pK+Λ0 difficult, better

pn nK+p π-(Vertex)

Symmetry TestsPentaquark

Time-Reversal Inv.

Yu. Uzikov

C. Hanhart

D. Eversheim

Mention, but with low weight• pn Λ0 θ+

• Ayy not sufficient for model-independent determination

–needs σ0(1+Ayy)

Difficult, Eversheim needs help

Do we from ANKE embark on this ship?

Once commissioned, use ANKE PIT?

ep spin transfer F. Rathmann Required for AP

Sequence of Actions

• PIT Commissioning during 2005• Experiments will proceed from high rate to low rate

reactions– Some optimization of Luminosity can be expected by making narrower cell:

• for now: L=1.6·106·1010·5·1013=8·1029 cm-2s-1

• Sequence of experiments will not necessarily follow physics priorities

• Proposal Deadline: End of February 2005

D1-D2 Section

Target Chamber (750x600x400 mm3)

Strip Targetmovable

Beam-Position Monitor

Storage Cell Frame

COSY Beam

Present System at ANKEPresent System at ANKE

Differential Pumping

ANKE

PIT presently assembled in LKW Hall

Movable Platform

Pillars mimic D1 and D2 magnets

Few crane movements to transport PIT to ANKE

Commissioning: Stray field of D2 Magnet

x

y

z

Field map cut at the storage cell center(COSY coordinate z = 0)

xx

yy

60-90 G135 G

5-6 G30 G

30 G55 G

35-45 G300 G

200 G300 G

50-60 G300 G

30 G55 G

30 G - calculated field magnitude55 G - permissible field of device

Target chamber with strip and cluster target Beam Position Monitor during testing

ANKE Target Chamber and Beam Position MonitorsANKE Target Chamber and Beam Position Monitors

The NN program at ANKE

Future double polarized ANKE Experiments:

1. Charge-Exchange breakup

2. np Elastic scattering

3. Deuteron breakup

dp→(pp)1S0 n

→→

pd→psp(pn)→→

pd →(pp)1S0 n

→→

Strategy: Begin commissioning of the Polarized Internal Target using high rate reactions that can be easily identified (e.g. CE).