Paper | Title | Page |
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MOPE072 | Electron Beam Quality Measurements on the ALPHA-X Laser-plasma Wakefield Accelerator | 1146 |
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The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme at the University of Strathclyde is developing laser-plasma wakefield accelerators to produce high energy, ultra-short duration electron bunches as drivers of radiation sources. Coherent emission will be produced in a free-electron laser by focussing the electron bunches into an undulator. To achieve net gain, a high peak current, low energy spread and low emittance are required. A high intensity ultra-short pulse from a 30 TW Ti:sapphire laser is focussed into a helium gas jet to produce femtosecond duration electron bunches in the range of 80 - 200 MeV. Beam transport is monitored using a series of Lanex screens positioned along the beam line. We present measurements of the electron beam energy spread as low as 0.7% (at 90 MeV) obtained using a high resolution magnetic dipole spectrometer. We also present pepper-pot measurements of the normalised transverse emittance of the order of 1 pi mm mrad. With further acceleration to 1 GeV, the beam parameters indicate the feasibility of a compact X-ray FEL with a suitable undulator. |