Observation Of The Plasma Lens Effect

摘要: A direct observation of the wakefield self-focusing of an electron beam in a plasma is reported. The transverse beam sizes were measured at three different points downstream of the plasma. The Twiss parameters and the emittance were then derived as a function of the plasma density in the overdense region. Profiles in the horizontal-longitudinal plane were also measured using a streak camera. The experimental results in the vertical direction agree well with a prediction based on linear theory.