The dissociative ionization in oxygen

Locht, Robert; Schopman, Joop

doi:10.1016/0020-7381(74)80035-5

Cited by 58 publications

(64 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The experimental setup used in the present work has been described in detail earlier [23] and only the salient features will be repeated here. The ions generated in a conventional Nier type ion source by the impact of electrons of controlled energy, are focused on an exit hole, energy analysed by a retarding lens and mass selected in a quadrupole filter.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A dissociative electroionization study of nitrous oxide. The no+ and N2+ dissociation channels

1982

Self Cite

View full text Add to dashboard Cite

The decay of N 2 O into NO + and N 2 + dissociation channels has been investigated by electron impact using ions kinetic energy and mass analysis. The appearance energies of NO + and N 2 + are measured as a function of the released translational energy. Both decay channels are mainly reached through predissociation of the N 2 O + ionic states. In the NO + decay channel, only one dissociation limit is involved, i.e. NO + (X 1 Σ + , υ) + N( 4 S) and hence the repulsive 4 Σ -state is responsible for all the observed phenomena. In the N 2 + decay channel, several dissociation limits are involved. Dissociative ionization involving doubly excited states of N 2 O in both dissociation channels are briefly discussed.

show abstract

Section: Methodsmentioning

confidence: 99%

“…The operating conditions maintained during this work are identical to those described elsewhere [23], unless otherwise stated.…”

Section: Methodsmentioning

confidence: 99%

A dissociative electroionization study of nitrous oxide. The no+ and N2+ dissociation channels

1982

Self Cite

View full text Add to dashboard Cite

show abstract

“…The apparatus as well as the experimental conditions have been described in detail elsewhere [16]. Briefly, the experimental set-up consists of four basic units: the ion source, the ion kinetic energy analyzer, the mass spectrometer and the detection system.…”

Section: Apparatus and Operating Conditionsmentioning

confidence: 99%

“…Unless otherwise stated, the operating conditions maintained during this work are strictly identical to those described in the previous studies of the dissociative ionization of O 2 [16] andN 2 [17]. The carbon monoxide gas, purchased from Air Liquide, is of 99.997% purity.…”

Section: Apparatus and Operating Conditionsmentioning

confidence: 99%

“…As far as ionization efficiency curves are concerned, averaged during 8 h at least, the threshold is measured at the intercept of the linear extrapolation of the highest slope of the one time differentiated ionization efficiency curve and the electron energy axis [16,18]. All threshold energies have been measured independently five times.…”

Section: Data Handling and Significant Figuresmentioning

confidence: 99%

See 1 more Smart Citation

The dissociative ionization of carbon monoxide

Locht

1977

Chemical Physics

Self Cite

View full text Add to dashboard Cite

The dissociative ionization of CO by low energy electron impact into C + + O (or O -) and O + + C (or C -) is investigated using ion energy and mass analysis. The kinetic energy distributions are studied as a function of the impinging electron energy. The threshold energies of C + and O + are measured as a function of the released kinetic energy. The formation of the products in their ground level and with a small amount of kinetic energy mainly occurs through predissociation. The CO + electronic states involved in these processes are tentatively identified. New evidences have been found for the importance of dissociative ionization via autoionization.

show abstract

Three-dimensional kinetic energy distributions of ions using a retarding potential analyser. Analysis of discrimination effects by ion trajectory simulations

Hoxha

Leyh

Locht

1999

Rapid Commun. Mass Spectrom.

View full text Add to dashboard Cite

This paper presents a method of extracting three-dimensional kinetic energy distributions from retarding potential curves, suitable for analysing low kinetic energy releases. Trajectory calculations were performed which led to an analytical function correcting for the influence of discrimination against ions with velocity components perpendicular to the retarding field direction. The analysis of the thermal kinetic energy distribution of molecular vinyl bromide ions confirms the computed correcting factor. Copyright # 1999 John Wiley & Sons, Ltd. Received 29 September 1998; Revised 22 November 1998; Accepted 27 November 1998 When an ionised molecule breaks up, part of its internal energy is converted into translational energy of the fragments. The kinetic energy release distribution (KERD) during the fragmentation process contains valuable information about the reaction dynamics, and provides us with a test for the validity of the statistical theories of mass spectra. 1Retarding field analysers (RFAs) have been used by several groups 2-5 to analyse dissociations characterised by relatively high kinetic energy releases (KERs), i.e. of the order of 1 eV. Their main advantages are simplicity and compactness. However, the analysis of low KERs (comparable to kT) is not straightforward because of severe discriminating effects which depend on the value of the kinetic energy of ions.Kinetic energy spectra are measured in the laboratory framework. Differentiating a retarding potential curve leads to a one-dimensional kinetic energy distribution (KED) corresponding to the particular direction of the field, distorted by discrimination effects.In this paper we propose and discuss, based on ion trajectory simulations, a procedure to extract from raw retarding field data, three-dimensional KEDs which are free from discrimination effects. EXPERIMENTALThe experimental setup was designed for photoion-photoelectron coincidence measurements at fixed wavelength and is described in more detail elsewhere.6 It consists of a Lindau-type electron analyser and of an ion analyser based on a quadrupole mass spectrometer. It is also possible to run experiments in a simple retarding analyser mode. We will describe here only the most relevant features concerning the kinetic energy analysis. The ionisation chamber (IC) and the ion optics are shown schematically in Fig. 1. The effusive gas sample is ionised by photons produced from a He(I) discharge lamp, along a direction perpendicular to the figure plane. The photoion source is shielded by a mu-metal cylinder in order to avoid magnetic fields.In our particular scheme the ions are retarded within the chamber by scanning the voltage of the EXE lens, while the potentials of the IC and of the EXI extractor are maintained constant. The L 1 ,L 2 and the L 3 ,L 4 lenses form two triplets, while F is a focusing lens.The C 2 H 3 Br sample gas (98% inhibited with 200 ppm

show abstract

The dissociative ionization in oxygen

Cited by 58 publications

References 26 publications

A dissociative electroionization study of nitrous oxide. The no+ and N2+ dissociation channels

A dissociative electroionization study of nitrous oxide. The no+ and N2+ dissociation channels

The dissociative ionization of carbon monoxide

Three-dimensional kinetic energy distributions of ions using a retarding potential analyser. Analysis of discrimination effects by ion trajectory simulations

Contact Info

Product

Resources

About