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arXiv · 1201.1115

Investigation of slow collisions for (quasi) symmetric heavy systems: what can be extracted from high resolution X-ray spectra

Martino Trassinelli·Christophe Prigent·Emily Lamour·Férid Mezdari·Jacques Merot·Regina Reuschl·Jean-Pierre Rozet·S. Steydli·Dominique Vernhet
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Abstract

We present a new experiment on (quasi) symmetric collision systems at low-velocity, namely Ar$^{17+}$ ions ($v=0.53$ a.u.) on gaseous Ar and N$_2$ targets, using low- and high-resolution X-ray spectroscopy. Thanks to an accurate efficiency calibration of the spectrometers, we extract absolute X-ray emission cross sections combining low-resolution X-ray spectroscopy and a complete determination of the ion beam - gas jet target overlap. Values with improved uncertainty are found in agreement with previous results \cite{Tawara2001}. Resolving the whole He-like Ar$^{16+}$ Lyman series from $n=2$ to 10 with our crystal spectrometer enables to determine precisely the distribution ${\mathcal{P}_n}$ of the electron capture probability and the preferential $n_{pref}$ level of the selective single-electron capture. Evaluation of cross sections for this process as well as for the contribution of multiple-capture is carried out. Their sensitivity to the $\ell$-distribution of $n$ levels populated by single-electron capture is clearly demonstrated, providing a stringent benchmark for theories. In addition, the hardness ratio is extracted and the influence of the decay of the metastable $1s2s\ ^3 S_1$ state on this ratio is discussed.

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Martino Trassinelli, Christophe Prigent, Emily Lamour, Férid Mezdari, Jacques Merot, Regina Reuschl, Jean-Pierre Rozet, S. Steydli, Dominique Vernhet. 2012-01-05. Investigation of slow collisions for (quasi) symmetric heavy systems: what can be extracted from high resolution X-ray spectra. https://doi.org/10.1088/0953-4075/45/8/085202

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