Final-state-resolved charge exchange in C^{5 +}collisions with H

Abstract

We report charge exchange cross sections for the collision system C 5+ + H using the quantum mechanical molecular-orbital close-coupling method. The multi-reference single-and double-excitation configuration interaction method is used to produce potential and coupling data, and scattering calculations are performed for collision energies between 0.01 eV/u to 1 keV/u for all l,S-resolved states within the n = 3 and 4 manifolds. The n = 5 manifold is represented through the inclusion of the 5s state. To predict cross sections at higher energies, we include new results from atomic-orbital close-coupling and classical trajectory Monte Carlo calculations. We briefly discuss applications to x-ray emission within the solar system.

Plasma code for astrophysical charge exchange emission at X-ray wavelengths

“…As reported recently by Nolte et al (2012), the singlet-to-triplet ratio of the C 4+ ion, produced from a low-velocity C 5+ +H reaction, covers a broad range of 0.01−100 for different n, l, and v. The apparent bias from the commonly adopted statistical value 3 is probably caused by electron-electron interaction during the capture. A similar effect was also reported in other papers (e.g., Wu et al 2011 for N 6+ +H reaction), indicating that it could be a common property.…”

“…In the high-speed regime (v ∼ v 0 ), the collision dynamics become more important for the capture process, and the peak population level is gradually smeared out among several adjacent shells. We compiled the velocity-dependent, n-resolved cross sections for reactions involving Be, B, C, N, O, Ne, and Fe ions from theoretical calculations (Ryufuku 1982;Shipsey et al 1983;Fritsch & Lin et al 1984;Belkić et al 1992;Toshima & Tawara 1995;Harel et al 1998;Raković et al 2001;Errea et al 2004;Nolte et al 2012;Wu et al 2011Wu et al , 2012Mullen et al 2015). As shown in Fig.…”

“…As shown in Fig. 4, we compare the G ratio calculated based on the data from Nolte et al (2012) with that assuming statistical weight for the C 5+ + H reaction. The largest bias is seen at v ∼ 500 km s −1 , where the statistical weight is underestimated by about 30%.…”

Division B Commission 14 Working Group: Collision Processes

“…Charge transfer, excitation and ionisation in collisions between ions and neutral atoms play important roles in a number of astrophysical environments. New work on processes involving hydrogen atoms and protons include: excitation, ionisation and charge transfer in collisions between protons and He + , Li 2+ , Be 3+ , B 4+ , and C 5+ (Winter 2013), proton collisions with He , excitation and charge transfer in Li q + + H collisions (Liu et al 2014c), charge transfer in Be 3+ + H collisions (Liu & Wang 2013), charge transfer and ionisation of Be, Fe, Mo and W by H collisions (Tolstikhina et al 2014), charge transfer in C 5+ + H collisions (Nolte et al 2012b), charge transfer and ionisation in C 6+ , N 7+ + H collisions (Jorge et al 2014) (Tolstikhina et al 2012).…”

Line ratios for soft-x-ray emission following charge exchange betweenO8+and Kr

“…These include the classical trajectory Monte Carlo (CTMC), atomic orbital close coupling (AOCC) and semi-classical molecular orbital close-coupling (MOCC) methods along with the more recent two-center basis generator method (TC-BGM) . Atomic orbital close coupling (AOCC) approaches work well for calculating total cross sections of CX involving light ions [12,13].…”