摘要
In underdense plasmas, the transverse ponderomotive force of an intense laser beam with Ganssian transverse profile expels electrons radially, and it can lead to an electron cavitstion. An improved cavitation model with charge conservation constraint is applied to the determination of the width of the electron cavity. The envelope equation for spot size derived by using source-dependent expansion method is extended to including the electron cavity. The condition for self-guiding is given and illuminated by an effective potential for the laser spot size. The effects of the laser power, plasma density and energy dissipation on the self-guiding condition are discussed.
In underdense plasmas, the transverse ponderomotive force of an intense laser beam with Ganssian transverse profile expels electrons radially, and it can lead to an electron cavitstion. An improved cavitation model with charge conservation constraint is applied to the determination of the width of the electron cavity. The envelope equation for spot size derived by using source-dependent expansion method is extended to including the electron cavity. The condition for self-guiding is given and illuminated by an effective potential for the laser spot size. The effects of the laser power, plasma density and energy dissipation on the self-guiding condition are discussed.
基金
Project supported by the National High Technology Inertial Confinement Fusion Foundation （Grant No 10335020/A0506）, the National Natural Science Foundation of China （Grant Nce 10474081 and 10576035）, and Natural Science Foundation of Shanghai （Grant No 05ZR14159）.
