Overcoming depolarizing resonances with dual helical partial Siberian snakes

Area of Science:

• Particle Physics
• Accelerator Physics
• Nuclear Physics

Background:

• Accelerating polarized protons to medium energies (5-25 GeV) presents challenges due to depolarizing spin resonances.
• Full Siberian snakes are often infeasible in medium energy accelerators due to space constraints and large orbit excursions.

Purpose of the Study:

• To investigate the effectiveness of helical partial Siberian snakes in mitigating polarization loss during proton acceleration.
• To demonstrate a method for maintaining high-intensity polarized beams in medium energy synchrotrons.

Main Methods:

• Installation and operation of two helical partial Siberian snakes with a double pitch design in the Brookhaven Alternating Gradient Synchrotron (AGS).
• Careful optimization of accelerator optics at injection and during the energy ramp.
• Analysis of partial snake resonances, including higher-order effects.

Main Results:

• The implemented helical partial Siberian snakes effectively suppressed intrinsic and imperfection depolarizing resonances.
• High-intensity polarized proton beams were successfully maintained throughout the acceleration energy range.
• Observation and description of higher-than-second-order partial snake resonances.

Conclusions:

• Helical partial Siberian snakes offer a viable solution for accelerating polarized protons in medium energy accelerators.
• This technique enables the maintenance of high-intensity polarized beams, crucial for precision physics experiments.
• The findings contribute to the advancement of polarized beam technology in synchrotrons.