Phasing multi-segment undulators

Area of Science:

• Physics
• Engineering

Background:

• Manufacturing multi-segment undulators for synchrotron radiation and free-electron lasers (FELs) faces challenges in phasing successive segments.
• Current phasing methods can be complex and require active current control.

Purpose of the Study:

• To present a novel, passive permanent magnet phasing section for multi-segment undulators.
• To evaluate the impact of this new phasing section on mechanical independence, positioning tolerance, and spectral properties.

Main Methods:

• A pure permanent magnet phasing section was designed and implemented.
• The section introduces a 6 mm longitudinal gap between undulator segments.
• Magnetic interactions and spectral performance were analyzed and compared to conventional methods.

Main Results:

• The novel phasing section provides complete mechanical independence between segments.
• It reduces the tolerance for longitudinal positioning by a factor of 2.8 compared to conventional phasing.
• The spectrum and useful harmonics remain largely unchanged across various gap sizes.

Conclusions:

• The passive permanent magnet phasing section offers a significant improvement for multi-segment undulator fabrication.
• It enhances precision and simplifies construction without compromising performance.
• This innovation is crucial for advancing synchrotron radiation sources and FELs.