High dynamic range, space-resolved X-ray spectra, obtained using a TlAP crystal and a cooled CCD camera as a detector, were used to investigate the electron density and temperature profiles of an aluminum laser plasma with micrometer resolution. The electron density profile retrieved from the measurements is compared with numerical predictions from the two hydrodynamics codes MEDUSA (1D) and POLLUX (2D). It is shown that 2D density profiles can be successfully reproduced by 1D simulations using a spherical geometry with an ad hoc initial radius, leading to similar electron temperature profiles.

Recently, two novel techniques for the extraction of the phase-shift map (Tomassini et al. (2001). Applied Optics40, 35) and the electronic density map estimation (Tomassini P. & Giulietti A. (2001). Optics Communication199, 143–148) have been proposed. In this article, we apply both methods to a sample laser–plasma interferogram obtained with femtoseconds probe pulse, in an experimental setup devoted to laser particle acceleration studies.

High dynamic range, space-resolved X-ray spectra of an aluminum laser–plasma in the 5.5–8 Å range were obtained using a TlAP crystal and a cooled CCD camera as a detector. This technique was used to investigate the emission region in the longitudinal direction over a distance of approximately 350 μm from the solid target surface. These data show that the electron density profile varies by two orders of magnitude with the temperature ranging from about 180 eV in the overdense region to about 650 eV in the underdense region. Accordingly, different equilibria take place across the explored region which can be identified with this experimental technique. Detailed studies on highly ionized atomic species in different plasma conditions can therefore be performed simultaneously under controlled conditions.