Radiative double electron capture (RDEC) in collisions of bare fluorine ions with carbon foils

Radiative double electron capture (RDEC) is a charge exchange process involving the capture of two target electrons into a bound state of the projectile simultaneously with the emission of a single photon. RDEC is the time reversed process of double photoionization if the target electrons are loosely bound. This approach provides us with a clean tool to explore the problems involved with electron-electron correlations and a proper description of a two-electron-continuum wave function in various atomic systems. In this work, we investigate both radiative electron capture (REC) and RDEC in collisions of 42 MeV singly- and doubly-charge changed fluorine ions with carbon targets. The experiment was performed at the tandem Van de Graaff accelerator of Western Michigan University in which emitted x rays were measured at 90\r{ } to the beam line in coincidence with projectile charge-changing of bare and H-like fluorine. The first evidence to see the RDEC process in O$^{8+}$ + C collisions\footnote{A. Simon \textit{et al}., Phys. Rev. Lett. \textbf{104} (12), 123001 (2010)} was the motivation to conduct the current work for the sake of the comparison between both observations and with recent theoretical calculations.\footnote{A. I. Mikhailov \textit{et al}., Phys. Lett. A \textbf{328}, 350 (2004)}$^,$\footnote{A. I. Mikhailov \textit{et al}., Phys. Rev. A \textbf{69}, 032703 (2004)}$^,$\footnote{A. Nefiodov \textit{et al}., Phys. Lett. A \textbf{346}, 158 (2005).}