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).