A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hyb...A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hybridCPA/OPCPA VULCAN laser system(500 J,500 fs beamline;250 J,ns regime beamline)based on Nd:glass amplification.Its pulse duration(20 times shorter)combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for longer pulses and their interactions with targets.The newly designed system will be mainly dedicated to electron beam generation,but could also be used to perform a variety of particle acceleration and optical radiation detection experimental campaigns.In this communication,we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section.Finally,we present experimental results and details of our commissioned NOPCPA picosecond front end,delivering 1.5 mJ,~180 nm(1/e^(2))of bandwidth compressed to sub-15 fs.展开更多
The collective response of electrons in an ultrathin foil target irradiated by an ultraintense(~6×10^(20)W cm^(-2)) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown ...The collective response of electrons in an ultrathin foil target irradiated by an ultraintense(~6×10^(20)W cm^(-2)) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown that if the target is sufficiently thin that the laser induces significant radiation pressure, but not thin enough to become relativistically transparent to the laser light, the resulting relativistic electron beam is elliptical, with the major axis of the ellipse directed along the laser polarization axis. When the target thickness is decreased such that it becomes relativistically transparent early in the interaction with the laser pulse, diffraction of the transmitted laser light occurs through a so called ‘relativistic plasma aperture', inducing structure in the spatial-intensity profile of the beam of energetic electrons. It is shown that the electron beam profile can be modified by variation of the target thickness and degree of ellipticity in the laser polarization.展开更多
基金financial support of the European Union’s Horizon 2020 research and innovation programme under grant agreement No.654148(Laserlab Europe)the Euratom research and training program 2014–2018 under grant agreement No.633053+1 种基金the Fundacao para a Ciencia e a Tecnologia(FCT,Lisboa)under grants No.PD/BD/114327/2016framework of the Advanced Program in Plasma Science and Engineering(APPLAuSE,sponsored by FCT under grant No.PD/00505/2012)at Instituto Superior Tecnico(IST)。
文摘A petawatt facility fully based on noncollinear optical parametric chirped pulse amplification(NOPCPA)technology,Vulcan OPPEL(Vulcan OPCPA PEtawatt Laser),is presented.This system will be coupled with the existing hybridCPA/OPCPA VULCAN laser system(500 J,500 fs beamline;250 J,ns regime beamline)based on Nd:glass amplification.Its pulse duration(20 times shorter)combined with the system design will allow the auxiliary beamline and its secondary sources to be used as probe beams for longer pulses and their interactions with targets.The newly designed system will be mainly dedicated to electron beam generation,but could also be used to perform a variety of particle acceleration and optical radiation detection experimental campaigns.In this communication,we present the entire beamline design discussing the technology choices and the design supported by extensive simulations for each system section.Finally,we present experimental results and details of our commissioned NOPCPA picosecond front end,delivering 1.5 mJ,~180 nm(1/e^(2))of bandwidth compressed to sub-15 fs.
基金supported by EPSRC (grants:EP/J003832/1,EP/M018091/1,EP/L001357/1,EP/K022415/1 and EP/L000237/1)EPSRC grant EP/G054940/1+2 种基金STFC (grant number ST/K502340/1)the US Air Force Office of Scientific Research (grant:FA8655-13-1-3008)the European Unions Horizon 2020 research and innovation programme (grant agreement No 654148 Laserlab-Europe)
文摘The collective response of electrons in an ultrathin foil target irradiated by an ultraintense(~6×10^(20)W cm^(-2)) laser pulse is investigated experimentally and via 3D particle-in-cell simulations. It is shown that if the target is sufficiently thin that the laser induces significant radiation pressure, but not thin enough to become relativistically transparent to the laser light, the resulting relativistic electron beam is elliptical, with the major axis of the ellipse directed along the laser polarization axis. When the target thickness is decreased such that it becomes relativistically transparent early in the interaction with the laser pulse, diffraction of the transmitted laser light occurs through a so called ‘relativistic plasma aperture', inducing structure in the spatial-intensity profile of the beam of energetic electrons. It is shown that the electron beam profile can be modified by variation of the target thickness and degree of ellipticity in the laser polarization.
