Development of spatial filter for laser plasma cathode

We are developing two spatial filters for our 12 TW-50 fs laser system in order to improve a spatial profile of the laser. In our scheme of a laser plasma cathode, electrons are injected into further wake fields by relativistic wave breaking. Previous experiments clearly showed production of well collimated ∼40 MeV electrons, which is suggested having 40 fs pulse duration by a particle in cell (PIC) calculation. It was found from our recent research that the stability of the electron beam strongly depends on the plasma dynamics. With these spatial filters we expect that we can stabilize the femto-second electron bunch generation and plasma dynamics