Evaluation of magnetic field error in ExtendedEBIS

Area of Science:

• Nuclear Physics
• Accelerator Physics

Background:

• The Electron Beam Ion Source (EBIS) at Brookhaven National Laboratory is undergoing an upgrade to ExtendedEBIS.
• This upgrade utilizes two 5T-superconducting solenoids in series to increase trap capacity and improve polarized 3He ion production.

Purpose of the Study:

• To estimate the magnetic field error introduced by the two series superconducting solenoids in the ExtendedEBIS upgrade.
• To assess the impact of these field errors on the alignment and spin direction of polarized 3He ions.

Main Methods:

• Magnetic field simulations were performed to estimate field errors.
• The deviation of magnetic field lines from the central axis was calculated.
• The effect of misalignment on the spin direction of polarized 3He ions was analyzed.

Main Results:

• Simulations indicated a potential magnetic field line offset of up to 17 mm from the center axis at the collector entrance.
• Three types of correction coils were identified as effective in adjusting this magnetic field offset.
• The estimated mismatch in the spin direction of polarized 3He ions due to misalignment was found to be minimal.

Conclusions:

• The ExtendedEBIS upgrade, despite using superconducting solenoids, can effectively manage magnetic field errors.
• Correction coils are crucial for maintaining beamline accuracy and ensuring high-quality polarized 3He ion production.
• The upgrade is expected to successfully enhance polarized 3He ion generation capabilities.