title: A compact tunable polarized X-ray source based on laser-plasma helical undulators.
abstract: Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 10(19) photons/s/mm(2)/mrad(2)/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications.
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: J
authors.initials: J
authors.lastname: Luo
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: M
authors.initials: M
authors.lastname: Zeng
authors.affiliation: GoLP/Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.
authors.forename: J
authors.initials: J
authors.lastname: Vieira
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: L L
authors.initials: LL
authors.lastname: Yu
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: S M
authors.initials: SM
authors.lastname: Weng
authors.affiliation: GoLP/Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade de Lisboa, Lisbon, 1049-001, Portugal.
authors.forename: L O
authors.initials: LO
authors.lastname: Silva
authors.affiliation: SUPA, Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.
authors.forename: D A
authors.initials: DA
authors.lastname: Jaroszynski
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.|SUPA, Department of Physics, University of Strathclyde, Glasgow, G4 0NG, UK.
authors.forename: Z M
authors.initials: ZM
authors.lastname: Sheng
authors.affiliation: Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.|Collaborative Innovation Center of IFSA (CICIFSA), Shanghai Jiao Tong University, Shanghai, 200240, China.
authors.forename: J
authors.initials: J
authors.lastname: Zhang