Sarri, G. and Schumaker, W. and Di Piazza, A. and Vargas, M. and Dromey, B. and Dieckmann, M. E. and Chvykov, V. and Maksimchuk, A. and Yanovsky, V. and He, Z. -H. and Hou, B. X. and Nees, John A. and Thomas, Alexander George Roy and Keitel, C. H. and Zepf, M. and Krushelnick, Karl (2013) A table-top laser-based source of short, collimated, ultra-relativistic positron beams. Proceedings of SPIE, 8779. ISSN 0277-786X
Full text not available from this repository.Abstract
An ultra-relativistic electron beam passing through a thick, high-Z solid target triggers an electromagnetic cascade, whereby a large number of high energy photons and electron-positron pairs are produced. By exploiting this physical process, we present here the first experimental evidence of the generation of ultra-short, highly collimated and ultra-relativistic positron beams following the interaction of a laser-wakefield accelerated electron beam with high-Z solid targets. Clear evidence has also been obtained of the generation of GeV electron-positron jets with variable composition depending on the solid target material and thickness. The percentage of positrons in the overall leptonic beam has been observed to vary from a few per cent up to almost fifty per cent, implying a quasi-neutral electron-positron beam. We anticipate that these beams will be of direct relevance to the laboratory study of astrophysical leptonic jets and their interaction with the interstellar medium.