Fig. 1. Temporal profile of the PHELIX pulse in 2010 before the application of pulse cleaning techniques, measured with a third order cross-correlator (Sequoia, Amplitude Technologies). The curve has been scaled to a peak intensity of $10^{20}~\text{W}~\text{cm}^{-2}$. The shaded area illustrates the ionization threshold for typical target materials. The red dashed line shows a Gaussian function with the same FWHM as the pulse (blue).

Fig. 2. Simulated electron density for two different ASE levels.

Fig. 3. Schematic of the PHELIX short pulse beamline.

Fig. 4. Temporal profile of the PHELIX pulse in 2012 using the uOPA with a gain of $10^{4}$. The pulse was measured with a third order cross-correlator (Sequoia, Amplitude Technologies). The right graph shows an enlargement of the red framed region of the left graph.

Fig. 5. Temporal profile of the PHELIX pulse in November 2015 using the uOPA with a gain of $10^{5}$. The pulse was measured with a third order cross-correlator (Sequoia, Amplitude Technologies).

Fig. 6. Schematical setup of the focus and target alignment system. (a) The laser focus is imaged on the camera while the target is moved to the side. A transparent target is mapped on the camera by transmitting the light from the LED inside the target chamber through the target. (b) For alignment of opaque targets the LED light is coupled into the diagnostics beamline using a beamsplitter cube and light coming back from the target is imaged onto the camera.

Fig. 7. (a) Image of a micrometer thick plastic target attached to a thicker supporting foil with a free aperture of 1 mm. (b) Image of the focal spot.

Fig. 8. Selection of RCF which were exposed to laser-accelerated proton beams. The energy of protons which are fully stopped in the particular foil are written underneath each layer. Shown are examples for: (a) a shot with a ns-prepulse with a contrast ratio around $10^{6}$, (b) a shot after removing the prepulse and (c) a shot using the full aberration control.