Ultralow-emittance measurement of high-quality electron beams from a laser wakefield accelerator

Zhiyong Qin, Changhai Yu, Wentao Wang, Jiansheng Liu, Wentao Li, Rong Qi, Zhijun Zhang, Jiaqi Liu, Ming Fang, Ke Feng, Ying Wu, Lintong Ke, Yu Chen, Yi Xu, Yuxin Leng, Cheng Wang, Ruxin Li, Zhizhan Xu

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)
48 Downloads (Pure)


By designing a cascaded laser wakefield accelerator, high-quality monoenergetic electron beams (e beams) with peak energies of 340–360MeV and rms divergence of <0.3 mrad were produced. Based on this accelerator, the e-beam betatron radiation spectra were measured exactly via the single-photon counting technique to diagnose the e-beam transverse emittance in a single shot. The e-beam transverse size in the wakefield was estimated to be ~0.35 lm by comparing the measured X-ray spectra with the analytical model of synchrotron-like radiation. By combining the measured e-beam energy and divergence, the normalized transverse emittance was estimated to be as low as 56 um mrad and consistent with particle-in-cell simulations. These high-energy ultralow-emittance e beams hold great potential applications in developing free electron lasers and high-energy X-ray and gamma ray sources.
Original languageEnglish
Article number023106
Number of pages7
JournalPhysics of Plasmas
Issue number2
Publication statusPublished - 15 Feb 2018


  • cascaded laser wakefield accelerator
  • emittance measurement
  • electron beams
  • single photon counting


Dive into the research topics of 'Ultralow-emittance measurement of high-quality electron beams from a laser wakefield accelerator'. Together they form a unique fingerprint.

Cite this