Electron acceleration and electron-positron pair production by laser in tunnel ionized inhomogeneous plasma

A high intensity laser short pulse causes rapid tunnel ionization of an inhomogeneous gas. The tunnel ionization of the gas causes a defocusing of the laser pulse. The electron experiences an unequal ponderomotive force due to the trailing and rising part of the laser pulse, hence, gains net energy. The net acquired electron energy is reduced due to the inhomogeneity in gas density. If the accelerated electrons are targeted to a low-Z material nucleus, the electron-positron pair will be created via a trident process. (C) 2005 American Institute of Physics.