1. Polarized 3He ++ ion source development for RHIC. Check the Bjorken Spin Sum Rule (the difference between the 1st moments of the proton and neutron spin structure function). Violation of that would be a very big deal. If we find the rule to be CONFIRMED, i.e. no violations, then these evaluation will give the BEST value of the strong coupling constant Alpha-S and its running. A.Deshpande Polarized 3He ++ ions can be accelerated in RHIC with the present “siberian snakes”. Electron Beam Ion Source is being constructed at CAD. A.Zelenski. J.Alessi, E.Beebe, A.Pikin, A.Kponou, D.Steski

2. EBIS ionizer for polarized 3 He gas. He(2S)→ He(1S) He(2S)→ He(1S) He-3 metastability -exchange polarized cell P - 80-90%. Pumping laser 1083 nm. EBIS-ionizer, B~ 50 kG EBIS-ionizer, B~ 50 kG RFQ He-transfer line. Valve. ~50·10 11, 3 He /pulse. 2.5·10 11 He ++ /pulse

3. EBIS ionizer for polarized 3 He gas. Polarized 3 He gas is produced by a “metastability exchange” technique. P ~ 70-80% (pressure ~ 1 torr). 3 He gas is injected in the EBIS ionizer. Pulsed valve? The ionization in EBIS is produced in a 50 kG field. This field will greatly suppress the depolarization in the intermediate He + single charge state, B c (He + ) = 3.1 kG The charge ratio He ++ /He + >> 1. The number of He ++ ions is limited to maximum charge which can be confined in EBIS (about 2.5 ·10 11 of 3 He ++ /store). It is sufficient to obtain ~10 11 He ++ /bunch in RHIC.

4. Electron Beam Ion Source at RHIC E-Gun (10 A) Drift Tube Structure Electron Collector Superconducting Solenoid (6 T) Acceleration Tube What intensity is expected? Capacity will be 10 12 charges/pulse  ~ 2-3 x 10 11 3 He ++ ions per pulse ?

5. EBIS Preinjector Layout in lower equipment bay of 200 MeV Linac Beam port Booster Linac RFQ EBIS 17 keV/u 300 keV/u 2 MeV/u 100 MHz Ion He - U Q/m≥1/6 Current> 1.5 emA (for 1 turn inj) Pulse Length 10  s Rep. Rate5 Hz Time to switch species1 second Polarimeter

6. SUMMARY Expected Results. Building of the He –3 polarizing setup. Study the limitation on the maximum attainable nuclear polarization in the metastability-exchange technique. Study the possible depolarization effects during polarized 3 He gas injection to EBIS and multi-step ionization process. 3He++ beam polarimeter development for polarization measurements and optimization. Requested budget: $545 k/ 3 years (2 years postdoc is included).