%0 Figure %A B Borisov, Alex %A C McCorkindale, John %A Poopalasingam, Sankar %A W Longworth, James %A K Rhodes, Charles %D 2013 %T Spectral details of Kr(L) amplification are presented %U https://iop.figshare.com/articles/figure/_Spectral_details_of_Kr_L_amplification_are_presented/1012344 %R 10.6084/m9.figshare.1012344.v1 %2 https://iop.figshare.com/ndownloader/files/1480166 %K beam diameter %K zone centred %K von %K mm %K kr %K position Z %K ev %K Thomson image %K Composite spectra %K electron density %K spectrometer %K Atomic Physics %K Molecular Physics %X

Figure 7. Spectral details of Kr(L) amplification are presented. These data correspond to file 677/18 May 2012. (a) Composite spectra are shown illustrating the axial (red) and transverse (brown) spectra. The transverse Kr(L) spectrum corresponding to Z = 0.3 mm is practically null; the axial von Hámos spectrometer, with the focal plane located at Z = 0.3 mm, as shown in panel (b), reveals sharp spectral structure with a width δλ,l  3 eV that is particularly obvious on the dominant Kr26+ 3s → 2p transition at λ 7.5 Å. The depth-of-field of the axial von Hámos spectrometer is estimated to be ≤ 300 µm, as indicated by the shaded zone centred at Z = 0.3 mm in panel (b). Compare these spectra to those presented in figure 6(a). (b) Transverse x-ray camera image of Kr(L) emission profile with a spatial resolution estimated to be ~50 µm. The axial position Z = 0.3 mm corresponds to the location of the focal plane of the axial von Hámos spectrometer.

Abstract

Experimental evidence demonstrating amplification on the Kr26+ 3s→2p transition at λ 7.5 Å (~1652 eV) generated from a (Kr)n cluster medium in a self-trapped plasma channel produced with 248 nm femtosecond pulses is presented. The x-ray beam produced had a spectral width of ~3 eV and a corresponding beam diameter of ~150 µm, properties that were simultaneously determined by a two-dimensional x-ray spectral image formed with an axially placed von Hámos spectrometer and a matching Thomson image of the spatial electron density generated by the x-ray propagation.

%I IOP Publishing