Electron transfer in proton‐hydrogen collisions in dense semi‐classical hydrogen plasma

Abstract

Quantum mechanical calculations have been accomplished to study the dynamics of the reaction: p + H(1s) → H(nlm) + p in dense semi-classical hydrogen plasma. Interactions among the charged particles in plasma are represented by a pseudopotential which takes care of the collective effects at large distances and quantum effect of diffraction at small distances. Various capture cross sections are computed for the incident proton energy lying within 10 to 500 keV by applying a distorted wave method which uses a variationally determined closed-form wave function of hydrogen atom. Moreover, an inclusive study is made to explore the effects of screening of plasma and quantum diffraction on various capture cross sections for a wide range of thermal Debye length and de Broglie wave length. It has been found that various cross sections suffer considerable changes due to varying Debye length and de Broglie wave length. K E Y W O R D Scharge transfer, distorted wave method, proton-hydrogen collision, pseudopotential, semi-classical hydrogen plasma

Testing standard basis sets for direct ionizations: H+ + H at ELab = 0.1–100 keV

“…The MAPEs of total CT, total DI, and 1s à 2s TE integral cross-sections of H + + H from SLEND calculations with various basis sets and with respect to their experimental counterparts by McClure 43 (CT), Shah et al [44][45][46] (DI), and Higgins et al 47 number of considered ICSs values (sample size). In addition, Table 3 presents the ICSs MAPEs of the same three processes from SLEND and from alternative theoretical methods: TC-BGM by Leung and Kirchner, 12 OCC-CC by Abdurakhmanov et al, 11 FODWT by Das et al, 15 and CTMC and QCTMC by Ziaeian and T} okési, 14 all with respect to the aforesaid experimental data. [43][44][45][46][47] In Table 3, we report the lowest SLEND ICSs MAPEs per process and energy range; these MAPEs correspond to the most accurate SLEND calculations and are identified by the utilized basis set.…”

“…We consider low and high energy ranges (in addition to the full one) because some sets of experimental data lie entirely in either of them. Finally, Figures 4-6 plot the best SLEND ICSs values for the total CT (SLEND/aug-cc-pVTZ), total DI (SLEND/aug-cc-pVDZ and /q-aug-cc-pVDZ) and 1s à 2s TE (SLEND/6-311++G**) processes, respectively, versus the collision energy E Lab and along with their counterparts from the theoretical methods considered in Table 3 11,12,14,15 and from numerous experiments. [43][44][45][46][47] Before proceeding to analyze the obtained SLEND ICSs, we should point out once again that the tested STO/CGFs basis sets were originally designed for the time-independent prediction of bound-state molecular properties, and not for the time-dependent simulation of electronic processes; this is particularly the case for the demanding DI processes involving unbound states.…”

“…In the field of molecular physics, simulations of ion-molecule reactions mostly concentrated on electronic processes (CTs, DIs, and TEs), with little consideration, if not neglect, of nuclear processes (fragmentations, rearrangements, substitutions, etc.). [5][6][7][8][9][10][11][12][13][14][15] To treat electronic processes, numerous and diverse methods have been developed, such as the numerical solution of the time-dependent Schrödinger equation on a lattice, 5 the numerical solution of the time-dependent two-center Dirac equation with Dirac-Sturm basis functions, 6 various versions of the quantum close-coupling (CC) method [e.g., two-center atomic orbital CC (TCAO-CC), 7 molecular orbital (MO) CC (MO-CC), 8 semiclassical-atomic orbital CC (SC-AO-CC), 9 quantum mechanical convergent (QMC) CC (QMC-CC), 10 and one-center convergent (OCC) CC (OCC-CC) 11 ], the two-center basis generator method (TC-BGM), 12 the continuum distorted wave scattering method, 13 the first-order distorted wave theory (FODWT), 15 and classical and quasi-classical trajectory Monte Carlo methods (CTMC and QTMC, respectively). 9,14 These methods provided valuable insight into the investigated processes and predicted accurate properties.…”

Stability of the helium atom embedded in classical nonideal plasmas

“…The pseudopotential () includes the collective events and the screening effects in it, and properly describes particle interaction in CNP for 0 ≤ γ ≤ 4.0. Note that this potential takes the form of the Debye‐Huckel potential, when γ → 0, that is, in the weak limit of non‐ideality. The pseudopotential () has been used in a number of studies relating to CNP [32–35]. In this paper, we use the pseudopotential () to describe the interaction potential among the charged particles in He embedded in CNP.…”

Spherically confined hydrogenic atoms under classical non‐ideal plasmas: Scaling law for the critical cage size

“…It is to be mentioned that equation () reduces to the DHP () in the weak limit of (that is ) and pure Coulomb potential for . Of late, a number of theoretical investigations relating to non‐ideal classical plasmas (NICP) used the pseudopotential () to represent the organized effect of the plasmas [33–50].…”