An extraction system for low-energy hydrogen ions formed by electron impact (original) (raw)

Extraction of hydrogen ions by penetrating E-field in the presence of perpendicular B-field

A new system is developed for extraction of low-energy Hand Dions formed by dissociative electron attachment. It is essential part of the new set-up for vibrational spectroscopy of hydrogen molecules where the guiding magnetic field is used for incident electron beam. Ion extraction is performed by field penetration technique in the presence of magnetic field and takes advantage of obvious but commonly not recognised fact that weak B-field does influence the trajectories of low-mass ions.

Electron capture by multicharged ions from hydrogen atoms at eV energies

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1991

To quantitatively study electron capture during collisions of multiply charged ions with neutral atoms at near-thermal energies. keV-energy multicharged ion beams are merged with ground-state beams of H or D atoms of chosen velocity such that collisions in the relative energy range l-1000 eV/amu result. Recent data for 0 3* 04+ + H(D) are presented and compared with theoretical , predictions.

Determination of the ionization and dissociation energies of the hydrogen molecule

The Journal of Chemical Physics, 2009

The transition wave number from the EF 1 ⌺ g + ͑v =0,N =1͒ energy level of ortho-H 2 to the 54p1 1 ͑0͒ Rydberg state below the X + 2 ⌺ g + ͑v + =0,N + =1͒ ground state of ortho-H 2 + has been measured to be 25 209.997 56Ϯ ͑0.000 22͒ statistical Ϯ ͑0.000 07͒ systematic cm −1 . Combining this result with previous experimental and theoretical results for other energy level intervals, the ionization and dissociation energies of the hydrogen molecule have been determined to be 124 417.491 13͑37͒ and 36 118.069 62͑37͒ cm −1 , respectively, which represents a precision improvement over previous experimental and theoretical results by more than one order of magnitude. The new value of the ionization energy can be regarded as the most precise and accurate experimental result of this quantity, whereas the dissociation energy is a hybrid experimental-theoretical determination.

Electron Capture from Excited States of Hydrogen by Impact of Bare Ions

Physica Scripta, 2002

Electron capture from excited H(2s) and H(2p) targets by protons and alpha particles, at intermediate and high collision energies, is theoretically studied employing three distorted wave models.This study is carried out using the Continuum Distorted Wave, the Continuum Distorted Wave^Eikonal Initial State and the Continuum Distorted Wave^Eikonal Final State approximations, according to the symmetry of the collision reaction. Total and partial cross sections are calculated and compared with other existing theoretical results. The in£uence of the polarization of the initial states on the cross sections is also analyzed.

Electron capture from atomic hydrogen by multiply charged ions in low energy collisions

Journal de Physique, 1985

2014 On a mesuré et calculé les sections efficaces de capture dans l'hydrogène atomique par des ions multichargés. Les expériences ont été faites avec les ions Nq+, Oq+ et Neq+ comme projectiles dans la gamme d'énergie 2 q à 10 q keV. On obtient en général un bon accord avec les mesures antérieures quand celles-ci sont disponibles. Les calculs utilisent la méthode moléculaire, avec facteurs de translation. Ils concernent les projectiles complètement épluchés avec une charge comprise entre 5 et 10 ainsi que O6+(1s2) et N5+(1s2). Le rôle de l'interaction c0153ur-électron actif est discuté. On obtient un bon accord entre la théorie et l'expérience. Tant les résultats expérimentaux que les résultats théoriques sont exempts d'oscillations en fonction de la charge du projectile dans le domaine d'énergie couvert par les expériences. Abstract 2014 Cross section measurements and calculations are presented for electron capture by multiply charged ions from atomic hydrogen. The measurements were made for Nq+, Oq+ and Neq+ projectiles in the energy range 2 q to 10 q keV. Fair agreement is obtained with most earlier measurements when available. Molecular calculations, including translation factors, have been carried out for the case of fully stripped projectiles with charges between 5 and 10 as well as for O6+(1s2) and N5+(1s2) impact The role of the interaction between the core and active electron is discussed Good agreement is obtained between theory and experiment. It is worth noting that both experimental and theoretical results do not show any oscillation as a function of the projectile charge in the energy range covered by the experiments.

Determination of the Ionization and Dissociation Energies of Molecular Hydrogen, H_2

2009

The transition wave number from the EF ^1Σ _g^+(v=0,N=1) energy level of ortho-H_2 to the 54p1_1(0) Rydberg state below the X^{+} ^2Σ^+_g(v^+=0,N^+=1) ground state of ortho-H^+_2 has been measured to be 25209.99756±(0.00022)_{statistical}±(0.00007)_{ systematic} cm^{-1}. Combining this result with previous experimental and theoretical results for other energy level intervals, the ionization and dissociation energies of the hydrogen molecule have been determined to be 124417.49113(37) cm^{-1} and 36118.06962(37) cm^{-1}, respectively, which represents a precision improvement over previous experimental and theoretical results by more than one order of magnitude. The new value of the ionization energy can be regarded as the most precise and accurate experimental result of this quantity, whereas the dissociation energy is a hybrid experimental-theoretical determination.

The measurement of the electron impact ionization cross-sections of hydrogen-like ions

Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, 2003

We have measured electron impact ionization cross-sections of hydrogen-like iron and hydrogen-like molybdenum with an electron beam ion trap. The measurements were performed in the electron energy range between 13.5 and 40 keV for hydrogen-like iron and between 50 and 80 keV for hydrogen-like molybdenum.

Electron impact direct dissociation processes of vibrationally excited H2 molecules to excited atomic hydrogen H*(n=1–5).I. Cross sections

Chemical Physics, 1989

cross sections for the process e + H2( v) +e+ Ht +e+H+H*(n= 1-5) have been calculated by using the Gryzinski approximation in combination with the Franck-Condon density. A satisfactory agreement is found between the present v=O cross sections and corresponding theoretical and experimental results for the processes leading to unexcited H*( n= 1) and excited H* (n = 2-5 ) fragments. The role of vibrational excitation in affecting cross sections is such to decrease the threshold energy and to increase the maximum value of the cross section. This behaviour holds for all processes, with the exception of cross sections leading to H* (n = 2). In this last case the maximum value of the cross sections increases with increasing the vibrational quantum number v for vQ 5, having an opposite behaviour for v> 5.