%0 Journal Article
%T Downramp-assisted underdense photocathode electron bunch generation in plasma wakefield accelerators
%A Alexander Knetsch
%A Oliver Karger
%A Georg Wittig
%A Henning Groth
%A Yunfeng Xi
%A Aihua Deng
%A James Benjamin Rosenzweig
%A David Leslie Bruhwiler
%A Johnathan Smith
%A Dino Anthony Jaroszynski
%A Zheng-Ming Sheng
%A Grace Gloria Manahan
%A Guoxing Xia
%A Steven Jamison
%A Bernhard Hidding
%J Physics
%D 2014
%I arXiv
%X It is shown that the requirements for high quality electron bunch generation and trapping from an underdense photocathode in plasma wakefield accelerators can be substantially relaxed through localizing it on a plasma density downramp. This depresses the phase velocity of the accelerating electric field until the generated electrons are in phase, allowing for trapping in shallow trapping potentials. As a consequence the underdense photocathode technique is applicable by a much larger number of accelerator facilities. Furthermore, dark current generation is effectively suppressed.
%U http://arxiv.org/abs/1412.4844v1