Temporal profile of the LCLS photocathode ultraviolet drive laser tolerated by the microbunching instability ∗
نویسندگان
چکیده
The high quality LCLS electron beam generated in the photoinjector is subject to many instabilities in the downstream acceleration and compression. The instability can be initiated by any density modulation of the electron beam generated at the photocathode. In this paper, we prescribe the tolerance on the initial electron beam density modulation possibly introduced by the ultraviolet (uv) laser at the cathode. Our study shows that with a matched Landau damping laser-heater, the initial rms density modulation of the electron beam at the photocathode must be less than 5% to ensure the FEL lasing and saturation.
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