Progress of polarized ion sources at BNL

The OPPIS has undergone multiple upgrades since 2000, with the most recent completed in 2022. Improvements to the Rb and Na cells have reduced vapor dispersion in the beamline, significantly lowering consumption and improving source stability. Plasmatron modifications extended component lifetimes. These upgrades enabled reliable Run-24 operation, with a mean current of 350 μA, 300 μs pulse width, and ~80% polarization delivered at the 200 MeV linac exit. Development is also underway for a high-intensity (2×10¹¹ ions/pulse) polarized ³He⁺⁺ source for the future EIC. The approach uses metastability-exchange optical pumping of high-purity ³He gas in a strong magnetic field, followed by ionization in EBIS. In tests with an “open” cell, 80–85% polarization has been achieved. The final gas cell configuration is now being tested with a 5 T EBIS solenoid magnet.