Line spectroscopy with spatial resolution of laser–plasma X-ray emission

Abstract

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.

X-ray emission from plasma generated by nanosecond laser irradiating tantalum

“…Fast photon emission with an energy of the order of 100 keV has been obtained with picosecond laser pulse intensities of the order of 10 15 W/cm 2 [1]. Generally, photon emission is isotropic, characterised by a continuum and characteristic atomic peaks [2].…”

“…Some research groups are operating with Bragg diffractometric techniques that have high-energy resolution to resolve characteristic emission peaks, and others with fast solid state detectors that integrate the X-ray yield and resolve the energy on the basis of the photon absorption in thin films placed in front of the detectors [1,2].…”

Differential absorption imaging for elemental analysis of thin samples using a soft laser-plasma X-ray source

“…The focal spot diameter was measured to be about 20 mm; which leads to an intensity on the target of about 10 13 W=cm 2 : The 48 Â 12 mm 2 ; spherically bent crystal (Mica, 2d ¼ 19:9 ( A) had a radius of curvature R ¼ 150 mm and was used in the second order of diffraction. The detection of X-rays was carried out using Princeton Instruments, highdynamic range, cooled CCD equipped with a SiTE back-illuminated chip consisting of 1100 Â 330 pixels, each of 24 Â 24 mm 2 and is described in detail in [18]. Finally, the crystal was placed on a remote controlled mount to perform rotation on the Rowland circle which enabled the diffracted X-ray wavelength to be tuned.…”

Study of the X-ray emission from Ta plasma obtained by ns laser ablation

“…Emission of photons with energy of the order of 100 keV was obtained with ps laser pulse intensities of the order of 10 15 W/cm 2 [1]. Generally, the photon emission is isotropic, characterised by continuum and characteristic atomic peaks and has high intensity [2].…”

“…Some research groups are operating with Bragg diffract-meters techniques, which have high-energy resolution to resolve characteristic emission peaks, and others with fast solid state detectors, which integrate the X-ray yield and resolve the energy on the base of the photon absorption in thin films placed in front of the detectors [1,2].…”