Fig. 5
Slice analysis of the final electron beam, with slice thickness of 20 nm. The current (black line) reaches the peak value of 13 kA. The energy spread (blue line) is limited in the interval 1.0–1.25 × 10−3 inside the beam bulk. The 6D-Brightness (green line) exceeds \(3.5\times 10^{18}\textrm{A}/\textrm{m}^2/0.1\%\textrm{BW}\) at the current maximum, and reaches the peak value of \(5.1\times 10^{18} \textrm{A}/\textrm{m}^2/0.1\%\textrm{BW}\) on the head of the beam, where both the energy spread and the emittances are lower. On the right (red) axis the normalized emittances along x (hash-dot line) and along y (dot line) are shown. The right axis also shows the deviation of the slice energy from the average beam energy (red full line) expressed in \(10^{-3}\) as \(\delta \gamma = (\gamma /\langle \gamma \rangle -1)\times 10^{3}\). The upper and lower bounds of the red band encode the local energy spread \(\sigma (E)/E\), and are evaluated as \(\delta \gamma +2\sigma (E)/E\) and \(\delta \gamma -2\sigma (E)/E\) ,respectively. The orange band shows the region of the beam where the particles energy does not change more than \(\pm 0.25\%\).
