Fig. 1. Electron density interferometric measurement. (a) Schematic overview of the experimental diagnostic setup. (b) Temporal evolution of the electron density at the rear surface of the target. All pictures are shifted +200 fs due to the logarithmic timescale. Figure from Ref. [24].

Fig. 2. Magnetic pulse measurement. Schematic of the pump–probe experimental diagnostic setup for probing the megagauss magnetic fields at the (a) front and (b) rear target surfaces. (c) Magnetic field pulse profile for p- and s-polarized pump lasers with an intensity of $1.1\times 10^{16}~\text{W}/\text{cm}^{2}$. Solid line shows the fit for the p-polarized case using a phenomenological model. The inset shows the reflectivity and induced ellipticity of the probe as a function of delay time. Figure from Ref. [25].

Fig. 3. THz pulse detection. (a) Experimental setup. The THz radiation emitted from the target rear surface is collected and sent to a calibrated THz energy meter or to a single-shot TDS system with a dual reflective echelon pair. The beamlets produced by the echelon pair arrive at the ZnTe with different time delays. Via the electro-optic effect induced by the THz electric field, the temporal evolution of the THz field is retrieved. (b) Experimentally detected THz time-domain signals and (c) corresponding spectra from Cu targets with different thicknesses. The laser energy is 600 mJ. The blue dashed line gives the calculated sheath lifetime. Figure from Ref. [17].

Fig. 4. Moebius loop antenna layout. Figure from Ref. [14].

Fig. 5. Electron energy spectrum measurement. (a) Experimental setup. The magnetic spectrometer $(B=1700~\text{G})$ is used to measure the energy of electrons ejected from a $30~\unicode[STIX]{x03BC}\text{m}$ thick CH target at different observation angles (0 and 22 deg). (b) Electron distributions from 0.4 to 3 MeV, for $9\times 10^{18}~\text{W}/\text{cm}^{2}$, $3\times 10^{18}~\text{W}/\text{cm}^{2}$, and $2\times 10^{18}~\text{W}/\text{cm}^{2}$ laser intensities, at normal incidence, measured along the laser propagation axis. Hot temperatures are, respectively, 891, 420, and 374 keV, assuming a Boltzmann distribution (solid lines). The vertical axis is the number of electrons per units of keV and steradians. The horizontal error bar takes into account the spatial extension of the diodes. Figure from Ref. [37].

Fig. 6. (a) Sketch of the experimental setup at the PHELIX sub-picosecond laser facility. (b) Spatial distribution of ion current density using a double-layer target with Al on the front side and PET on the rear side irradiated with 516 J of laser energy.

Fig. 7. Electron bunches with different energies stopped in different films within the detector. Figure from Ref. [41].

Fig. 8. (Left) Schematic for a three-color proton beam spatial profiler. Higher-energy protons are stopped in the shorter-wavelength scintillators located further downstream in the stack. The combined optical signal is collected and relayed to a CCD camera via a fiber optic bundle. (Right) Proton (half) beam profile for a 100 nm Al target irradiated at $5\times 10^{20}~\text{W}/\text{cm}^{2}$ with high contrast (${>}10^{9}$).

Fig. 9. Thompson parabola. (Left) Schematic for a three-color proton beam spatial profiler. Higher-energy protons are stopped in the shorter-wavelength scintillators located further downstream in the stack. The combined optical signal is collected and relayed to a CCD camera via a fiber optic bundle. (Right) Proton (half) beam profile for a 100 nm Al target irradiated at $5\times 10^{20}~\text{W}/\text{cm}^{2}$ with high contrast (${>}10^{9}$).

Fig. 10. Optical streaking technique for proton beams. TNSA accelerated protons are blocked in a high-purity $\text{SiO}_{2}$ sample. The corresponding transient opacity (gray) is recorded using a synchronized chirped probe pulse. This allows one to observe the interaction over a large temporal window. In (a) and (b), the incident proton bunch is collimated using an aluminum slit (CS). Different frequency components of the chirped pulse, coming from the left, traverse the irradiated region at different times. (c) The optical streak is obtained using an imaging spectrometer. The region of interest (ROI in (d)) for the ion beam interaction is a ${\sim}10~\text{mm}$ scale slice along the central axis of laser. This is imaged onto the entrance slit of the spectrometer. Figure from Ref. [54].

Fig. 11. Sketch of the experimental setup. The FLAME laser is focused on a stainless steel target ejecting a relativistic electron beam able to escape from it as well as EMPs. These two interaction products induce local birefringence on a ZnTe electro-optic crystal, such that a linearly polarized laser, crossing the crystal, can probe them^[28].

Fig. 12. Calibration of the diagnostics relative to TOF measurements. Each point corresponds to one delay line step (3 fs).

Fig. 13. Spatial encoding process: (a) the coulomb field, relative to the electron bunch, makes the crystal birefringent; (b) while the E-field propagates into the crystal, the local birefringence shifts downwards; (c) the probe laser crosses the crystal and its polarization is rotated: the resulting signal comes from the region where the local birefringence and the probe laser are temporally overlapped^[29].

Fig. 14. Fast electron bunches for different target shapes. Experimental measurements of the longitudinal fast electrons’ charge profile from (a) planar, (b) wedged and (c) tip targets. The emitted charges are, respectively, (a) 1.2 nC (B1) and 3 nC (B2); (b) 2 nC (B1) and 0.3 nC (B2); (c) 7 nC (B1) and 3 nC (B2). The Gaussian envelopes represent the extrapolated charge profiles of each bunch. A $10^{2}$ neutral density filter has been used in (b) and (c) to avoid saturation of the CCD camera^[28].

Fig. 15. Electro-optical encoding. (Left) EO crystal (yellow square) acquires a local birefringence when the electric field (dashed arrows) reaches it. (Right) The probe laser, starting with a well-defined linear polarization, crosses the crystal while the charge propagates on target, increasing the source size^[31].

Fig. 16. Evolution of the EM radiation pulse emitted by the target. By focusing the main laser onto a wedged target, the probe laser is sent onto the ZnTe crystal with different delays. The horizontal axis represents the relative probe arrival time ($t$) associated with each pixel^[31]. $\unicode[STIX]{x0394}t_{0}$ is the delay between the main and probe laser pulses. From Ref. [31].