1. The Polarized Internal Gas Target of ANKE at COSY
Ralf Engels
Institute for Nuclear Physics (IKP)
Forschungszentrum Jülich
PST 05
Tokyo, Japan
November 16, 2005

2. COSY  COoler SYnchrotron
storage ring for (un-) polarized proton
and deuteron beams
with momentum up to 3700 MeV/c
COSY used for:
internal experiments - with the circulating
beam (ANKE, COSY-11, EDDA, PISA)
external experiments - with the extracted
beam (BIG KARL, JESSICA, NESSI, TOF)
Ralf PST 05

3. PIT setup Polarized internal gas target setup
at the laboratory consist of:
Atomic Beam Source
Test chamber with storage
cell prototype
Lamb-Shift Polarimeter
Setup at the laboratory
Ralf PST 05

4. Atomic Beam Source H beam intensity ~ 8.0x1016 at/s 16.11.2005
Ralf PST 05

5. ABS beam profile
σ = 2.85 ± 0.42 mm
Ralf PST 05

6. Lamb-Shift Polarimeter layout
Ralf PST 05

7. ABS beam polarization measurements
Ly-α spectra of hydrogen and deuterium measured with LSP
Ralf PST 05

8. How to measure polarization in the cell
ABS
beam 
Target gas
sample
COSY
beam
Layout of the test setup at laboratory
Ralf PST 05

9. LSP results
Ralf PST 05

10. LSP results
Ralf PST 05

11. How to measure polarization
Ralf PST 05

12. PIT at COSY hall
Ralf PST 05

13. PIT transportation
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14. ANKE
Ralf PST 05

15. Polarized internal gas target setup at ANKE
ANKE
Technical constraints
Installation time of the PIT is
limited to 3-4 days
D2 is movable → needs
sophisticated supporting
bridge between D1 and D2
Tunnel width is limited
→ 60° angle between LSP
components
ABS axis is 50 cm away from
D2 yoke → shielding from the
stray field is needed
Polarized internal gas target setup at ANKE
ABS
Storage cell
Polarimeter
Ralf PST 05

16. Stray field measurements
30 G
17 G
150 G
48 G
30 G measured field without shielding
17 G measured field with shielding x y z x y z
90 G
150 G
135 G
6 G
15 G
30 G
25 G
55 G
40 G
26 G
300 G
200 G
550 G
60 G
100 G
33 G
30 G maximum calculated field magnitude
45 G measured field magnitude
55 G allowed field for device
Ralf PST 05

17. Polarization test with D2 field
Pz ~ 0.80
Ralf PST 05

18. Apertures tests at COSY
beam
XY-table
Frame with apertures
Vacuum chamber
Ralf PST 05

19. Principle of the apertures tests at COSY
1. Beam in the center
of the aperture
50 mm
2. Aperture moves to the
right until intensity drops
+5 mm
3. Aperture moves to the
left until intensity drops
11 mm
Beam diameter = Aperture inner width - ( Distance Distance 3 )
Beam intensity is maximum
Beam intensity starts to decrease
Distance 2
Distance 2
Distance 3
Ralf PST 05

20. Estimated COSY-beam profile
36x16 mm x12 mm x15 mm
with cluster target
(density ~ 1014 at/cm2)
no target
at injection
with an accelerated beam
Ralf PST 05

21. Cell test preparation Aperture → 40 x 25 mm
Big cell → 30 x 20 x 220 mm
entrance 600 mm2
Small cell → 15 x 15 x 220 mm
entrance 225 mm2
Ralf PST 05

22. Results of the cell test
Tests were carried out with unpolarized hydrogen gas flux ~ 10-3 mbar l/s
Target density
for the large cell
Ratio target/background
for the large cell
9.4 * 1013
PRELIMINARY
~ 3 – 4
Injected deuterons
large/small cell
Estimated target density
H2 for the small cell
~3 * 1014
~ 7 – 8
No cooling of the ion beam !!!
Ralf PST 05

23. Summary PIT moved to COSY hall since December 2004
PIT installed at ANKE in June-July 2005
PIT is running since September 2005
Cell tests without cooling in Spring 2005
Cell tests with electron cooling shifted to November 2005
LSP will be used to measure direct beam of the ABS
Polarization in the cells determined by the Spectator counters
Ralf PST 05

24. Polarized fusion Outlook
November ’05 – next cell tests with cooling and stacking of the COSY beam
November ’05 – commissioning of the ABS-jet target at COSY
Winter ’05-’06 – ANKE target exchange from PIT to Cluster target
May ’06 – one more week for cell test at COSY
Until June ‘06 – more tests with LSP in COSY hall
new cell production with teflon coating
ISTC project 1861 : “Measurement of the nuclear
polarization in H2 / D2 molecules”
Summer ’06 – PIT reinstallation at ANKE
Autumn ’06 – first data production with jet target at ANKE (
Polarized fusion
Ralf PST 05

25. ISTC project 1861
Ralf PST 05

26. Polarized fusion
Ralf PST 05