Figure 2
From: Efficient plasma electron accelerator driven by linearly chirped multi-10-TW laser pulses
(a) Representative measurements of electron spectral images obtained by the interaction of 826 mJ chirped laser pulses with He gas-jet targets. The spectral images cover a kinetic energy range from 62 to 122 MeV, as allowed by the magnetic spectrometer geometry and scintillating screen dimensions. Note that electron spectra for negative chirp values showed no measurable electron signals, a fact that is attributed to their lower than 62 MeV kinetic energies. The spectral image for the \(-100\) fs\(^2\), shown at the top panel, is typical for all the negatively chirped laser pulses used in this study. (b) The corresponding to the measurements of (a) FTL and chirped laser pulses intensity temporal shapes. (c) Reproducibility measurements of the maximum electron energy (measured at 1/e) for FTL and chirped laser pulses. The black filled squares correspond to the individual measurements. Note that identical maximum energy values have been closely separated in the chirp axis for better visibility. Large red filled circles correspond to the averaged values for each chirp.
