The RHIC polarized H⁻ ion source

Area of Science:

• Nuclear Physics
• Particle Accelerators
• Beam Polarization

Background:

• High-intensity polarized ion sources are crucial for particle collider experiments.
• Previous methods faced limitations in achieving both high intensity and polarization.

Purpose of the Study:

• To implement and validate a novel polarization technique for the RHIC H(-) ion source upgrade.
• To enhance beam intensity and polarization for improved experimental capabilities.

Main Methods:

• Utilized a high-brightness proton beam ionized in a He-gaseous cell.
• Employed polarized electron capture from optically pumped Rubidium (Rb) vapor for proton polarization.
• Integrated the technique into the RHIC H(-) ion source.

Main Results:

• Achieved a high-intensity H(-) ion beam with 85% polarization.
• Successfully delivered reliable polarized beams during RHIC Run-2013 and Run-2015.
• Demonstrated 75% polarization at 23 GeV (AGS) and 60%-65% at 100-250 GeV (RHIC).

Conclusions:

• The novel polarization technique is effective for upgrading RHIC's polarized H(-) ion source.
• The enhanced beam characteristics enable higher polarization in collider experiments.
• This advancement supports precision measurements in heavy-ion and proton-proton collisions.