A beam energy feedback for ultrafast electron diffraction facility

Zhang Junqiang; Li Lin; Liu Yajuan; Jiang Tao; Xiao Chengcheng; Gu Qiang; Xiang Dao

doi:10.11884/HPLPB202032.190415

Volume 32 Issue 6

May 2020

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Article Navigation > High Power Laser and Particle Beams > 2020 > 32(6): 064001

Zhang Junqiang, Li Lin, Liu Yajuan, et al. A beam energy feedback for ultrafast electron diffraction facility[J]. High Power Laser and Particle Beams, 2020, 32: 064001. doi: 10.11884/HPLPB202032.190415

Citation:

Zhang Junqiang, Li Lin, Liu Yajuan, et al. A beam energy feedback for ultrafast electron diffraction facility[J]. High Power Laser and Particle Beams, 2020, 32: 064001. doi: 10.11884/HPLPB202032.190415

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A beam energy feedback for ultrafast electron diffraction facility

doi: 10.11884/HPLPB202032.190415

1.
Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Chinese Academy Sciences, Shanghai 201204, China
2.
School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China

Received Date: 2019-10-23
Rev Recd Date: 2020-01-14
Publish Date: 2020-05-12

Abstract

Abstract

The ultrafast electron diffraction (UED) facility located in Shanghai Jiao Tong University, driven by a linear electron accelerator, has a photocathode RF gun. Sometimes an RF gun arc might happen during the accelerator running, causing a cavity detuning and beam loss, then resulting in a beam energy change. It will take a long time for the beam to restore its previous energy, which will influence utilization of the facility. An energy feedback is applied to low level RF (LLRF) system after improvement of amplitude-phase loop, using a real-time feedback of the beam center position to regulate the output amplitude of LLRF, to ensure the stability of beam energy and RF gun accelerating field. A long period of stability testing indicates, that beam energy can return to its original value quickly after arc occurence, energy jitter is improved from 4.293 3×10⁻⁴ (RMS) to 2.855 7×10⁻⁴ (RMS), realizing a long term stability of beam energy.
- ultrafast electron diffraction,
- photo cathode RF gun,
- energy feedback,
- MicroTCA,
- low level RF

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References(15)

References

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