Excitation of atomic hydrogen by protons and multiply charged ions at intermediate velocities

Abstract

We have investigated the collisional excitation of hydrogen atoms by protons and multiply charged ions at intermediate velocities applying the optical method. The population or the np levels (n = 2,. . . ,6) has been determined for a variety of projectiles with charge states q ranging from I + to I I + and scaled velocities U/& between 0.7 and 5.6au. The cross &ions are shown to fulfil the scaling relation o / q = f ( d / q ) with respect to the projectile charge q and velocity U for q>3. The relevan= of scaled intermediate velocities for a classification o f excitation mechanism is pointed out.

Electron excitation of hydrogen atom by ions impact in the energy range 20–1000 keV/amu

“…For comparison experimental results of Stebbings et al [29], Morgan et al [27], Kondow et al [30], Detleffsen et al [29] in the low energy region (10-20 keV) departure from the present results is quite sharp. Results of Detleffset et al [23] overestimate our results in the whole energy region. In this Figure1 (b), we overlooked the uncertainties of the experimental results, it may be the reason for the said departure.…”

“…Ramirez et al [22] noticed the distortion effects in electron excitation of ground state hydrogen atoms by impact of protons, alpha particles and He + ions in the projectile energy range of 50 to 1000 keV/amu. Total excitation cross sections for final np states are calculated using symmetric eikonal approximation and results are compared with the experimental data Detleffsen et al [23], Hughes et al [24]. This work supports the existence of distortion effect in electron excitation to bound states of the target as predicted by Bugacov et al [25].Tong et al [26] studied the excitation and charge (including resonant charge transfer) transfer processes of H + and H collisions in a wide range of collision energies by solving the time-dependent Schrodinger equation which is solved by the split-operator method with a generalized pseudospectral (non uniform grid) method.…”

“…[23] are included. Results of Morgan et al and Kondow et al are restricted to a narrow velocity region of 10 keV to 26 keV.…”

Compact homogeneous manifolds with integrable invariant distributions, and scalar curvature

“…Experimentally, the main difficulty is to provide targets of dissociated hydrogen in combination with an efficient dispersion and detection system for the ion impact induced fluorescence radiation and with the limited flux of highly charged ions. In fact, we are only aware of the recent work by Detleffsen et al [1], who, for the first time, presented a systematic investigation of hydrogen excitation at intermediate velocity, v, using a large variety of projectile charges (q = 1-11). From the theoretical side, most of the literature has been devoted to the analysis of models and scaling laws (for a review, see for instance [2]).…”

“…Thus, it is quite clear that the computation of excitation cross sections for the simplest H target is highly desirable in order to analyse the appropriateness of close-coupling methods for these kind of problems. Detleffsen et al [1] were able to measure hydrogen excitation cross sections, σ , for the optically-allowed transitions 1s → np with n = 2-6, and analysed the validity of the Janev-Presnyakov (JP) [8] scaling rule…”