Bacci, A. Faillace, L. Rossetti Conti, M. JACoW Publishing Geneva, Switzerland 2226-0366 978-3-95450-194-6 10.18429/JACoW-LINAC2018-TU1P01 English 314-319 TU1P01 cavity emittance electron space-charge bunching Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-LINAC2018-TU1P01 http://jacow.org/linac2018/papers/tu1p01.pdf The generation of ultra-short, low emittance and low energy spread electron bunches is nowadays a critical requirement for accelerators in plasma wave or for femto-second light sources. A new longitudinal compression scheme, based on velocity and ballistic bunching tech-niques in presence of space charge forces, allows to enter in a peculiar regime, so-called laminar bunching (LB). In this regime, the bunch is longitudinally compressed, at the expense of its transverse size, and the over-bunching is forbidden by the laminarity: going to the minimal longi-tudinal dimension the bunch is adiabatically frozen and transversally refocused. Furthermore this technique heats slightly the uncorrelated energy spread resulting in elec-tron distributions that, in case of bending paths, does not require Laser Heater devices.