Experiments with longitudinally polarized electrons in a storage ring using a siberian snake

Area of Science:

• Nuclear Physics
• Particle Physics
• Electron Scattering

Background:

• Maintaining electron polarization in storage rings is crucial for spin-physics experiments.
• Previous experiments lacked simultaneous polarized electron and polarized target capabilities.

Purpose of the Study:

• To report the first measurements using polarized electrons stored in a medium-energy ring.
• To investigate the electrodisintegration of polarized helium-3 with unprecedented precision.

Main Methods:

• Injection of polarized electrons (442 MeV, 653 MeV) into a storage ring.
• Utilized a partial/full Siberian snake to preserve electron polarization.
• Employed laser backscattering to measure longitudinal polarization and lifetime.
• Simultaneous detection of scattered particles (electrons, protons, neutrons, deuterons, 3He) for spin observable determination.

Main Results:

• Successfully stored and maintained polarized electrons in the medium-energy ring.
• Measured longitudinal polarization and polarization lifetime of stored electrons.
• Acquired spin observable data for polarized helium-3 electrodisintegration across a wide phase space.

Conclusions:

• Demonstrated the feasibility of using polarized electrons in a medium-energy storage ring for advanced nuclear physics experiments.
• The developed techniques enable precise measurements of spin-dependent nuclear structure and reaction mechanisms.