Laser wakefield acceleration using wire produced double density ramps

• Published in: Physical review special topics. PRST-AB. Accelerators and beams Vol. 16; no. 1; p. 011301
• Main Authors: Burza, M., Gonoskov, A., Svensson, K., Wojda, F., Persson, A., Hansson, M., Genoud, G., Marklund, M., Wahlström, C.-G., Lundh, O.
• Format: Journal Article
• Language: English
• Published: American Physical Society 2013
• Subjects: Atom and Molecular Physics and Optics; Atom- och molekylfysik och optik; Fysik; Natural Sciences; Naturvetenskap; Physical Sciences
• ISSN: 1098-4402; 1098-4402
• DOI: 10.1103/PhysRevSTAB.16.011301

A novel approach to implement and control electron injection into the accelerating phase of a laser wakefield accelerator is presented. It utilizes a wire, which is introduced into the flow of a supersonic gas jet creating shock waves and three regions of differing plasma electron density. If tailored appropriately, the laser plasma interaction takes place in three stages: Laser self-compression, electron injection, and acceleration in the second plasma wave period. Compared to self-injection by wave breaking of a nonlinear plasma wave in a constant density plasma, this scheme increases beam charge by up to 1 order of magnitude in the quasimonoenergetic regime. Electron acceleration in the second plasma wave period reduces electron beam divergence by ≈25%, and the localized injection at the density downramps results in spectra with less than a few percent relative spread.