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The Polarized Internal Gas Target of ANKE at COSY. Ralf Engels Institute for Nuclear Physics (IKP) Forschungszentrum Jülich. PST 05 Tokyo, Japan November 16, 200 5. COSY COoler SYnchrotron. COSY: storage ring for (un-) polarized proton and deuteron beams
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The Polarized Internal Gas Targetof ANKE at COSY Ralf Engels Institute for Nuclear Physics (IKP) Forschungszentrum Jülich PST 05 Tokyo, Japan November 16, 2005
COSY COoler SYnchrotron • COSY: • storage ring for (un-) polarized proton • anddeuteron 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 Engels @ PST 05
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 Engels @ PST 05
Atomic Beam Source H beam intensity ~ 8.0x1016 at/s Ralf Engels @ PST 05
ABS beam profile σ = 2.85 ± 0.42 mm Ralf Engels @ PST 05
Lamb-Shift Polarimeter layout Ralf Engels @ PST 05
ABS beam polarization measurements Ly-α spectra of hydrogen and deuterium measured with LSP Ralf Engels @ PST 05
How to measure polarization in the cell ABS beam Target gas sample COSY beam Layout of the test setup at laboratory Ralf Engels @ PST 05
LSP results Ralf Engels @ PST 05
LSP results Ralf Engels @ PST 05
How to measure polarization Ralf Engels @ PST 05
PIT at COSY hall Ralf Engels @ PST 05
PIT transportation Ralf Engels @ PST 05
PIT @ ANKE Ralf Engels @ PST 05
Polarized internal gas target setup at ANKE PIT @ 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 ABS Storage cell Polarimeter Ralf Engels @ PST 05
90 G 150 G 135 G 40 G 26 G 300 G 30 G 33 G 55 G 30 G 25 G 55 G 200 G 550 G 300 G 150 G 48 G 6 G 15 G 30 G 30 G 17 G y 60 G 100 G 300 G x z y z x 30 G - measured field without shielding 17 G - measured field with shielding 30 G - maximum calculated field magnitude 45 G - measured field magnitude 55 G - allowed field for device Stray field measurements Ralf Engels @ PST 05
Polarization test with D2 field Pz ~ 0.80 Ralf Engels @ PST 05
Vacuum chamber Frame with apertures XY-table COSY beam Apertures tests at COSY Ralf Engels @ PST 05
Distance 2 Beam intensity is maximum Beam intensity starts to decrease Beam intensity starts to decrease Beam diameter = Aperture inner width - ( Distance 2 + Distance 3 ) 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 Distance 2 Distance 3 Ralf Engels @ PST 05
Estimated COSY-beam profile 36x16 mm9x12 mm 16x15 mm with cluster target (density ~ 1014 at/cm2) no target at injection with an accelerated beam Ralf Engels @ PST 05
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 Engels @ PST 05
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 ~ 3 – 4 PRELIMINARY Injected deuterons large/small cell Estimated target density H2 for the small cell ~3 * 1014 ~ 7 – 8 No cooling of the ion beam !!! Ralf Engels @ PST 05
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 Engels @ PST 05
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 (http://www.fz-juelich.de/ikp/anke/en/proposals.shtml) Polarized fusion Ralf Engels @ PST 05
ISTC project 1861 Ralf Engels @ PST 05
Polarized fusion Ralf Engels @ PST 05