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

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) 16.11.2005 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 16.11.2005 Ralf Engels @ PST 05

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

ABS beam profile σ = 2.85 ± 0.42 mm 16.11.2005 Ralf Engels @ PST 05

Lamb-Shift Polarimeter layout 16.11.2005 Ralf Engels @ PST 05

ABS beam polarization measurements Ly-α spectra of hydrogen and deuterium measured with LSP 16.11.2005 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 16.11.2005 Ralf Engels @ PST 05

LSP results 16.11.2005 Ralf Engels @ PST 05

LSP results 16.11.2005 Ralf Engels @ PST 05

How to measure polarization 16.11.2005 Ralf Engels @ PST 05

PIT at COSY hall 16.11.2005 Ralf Engels @ PST 05

PIT transportation 16.11.2005 Ralf Engels @ PST 05

PIT @ ANKE 16.11.2005 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 Polarized internal gas target setup at ANKE ABS Storage cell Polarimeter 16.11.2005 Ralf Engels @ PST 05

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 16.11.2005 Ralf Engels @ PST 05

Polarization test with D2 field Pz ~ 0.80 16.11.2005 Ralf Engels @ PST 05

Apertures tests at COSY beam XY-table Frame with apertures Vacuum chamber 16.11.2005 Ralf Engels @ PST 05

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 2 + Distance 3 ) Beam intensity is maximum Beam intensity starts to decrease Distance 2 Distance 2 Distance 3 16.11.2005 Ralf Engels @ PST 05

Estimated COSY-beam profile 36x16 mm 9x12 mm 16x15 mm with cluster target (density ~ 1014 at/cm2) no target at injection with an accelerated beam 16.11.2005 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 16.11.2005 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 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 !!! 16.11.2005 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 16.11.2005 Ralf Engels @ PST 05

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 (http://www.fz-juelich.de/ikp/anke/en/proposals.shtml) Polarized fusion 16.11.2005 Ralf Engels @ PST 05

ISTC project 1861 16.11.2005 Ralf Engels @ PST 05

Polarized fusion 16.11.2005 Ralf Engels @ PST 05