Publications of Christian Servais
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See detailHow complex can be the Unimolecular Decomposition of a simple Molecule? The case of Acetylene. An Electron Impact and PIPECO Investigation.
Locht, Robert ULiege; Servais, Christian ULiege

in Zeitschrift für Physikalische Chemie (1996), 195

The dissociative ionization of C2H2, C2D2 and C2HD is presented in this work. Excepting the H2+ formation, all dissociation channels are thoroughly investigated by electron impact. The translational ... [more ▼]

The dissociative ionization of C2H2, C2D2 and C2HD is presented in this work. Excepting the H2+ formation, all dissociation channels are thoroughly investigated by electron impact. The translational energy distribution as a function of the impinging electron energy and the appearance energy as a function of the translational energy are measured for all fragment ions. KE versus AE diagrams are obtained and the isotope effect is examined. All observed thresholds are analyzed in detail and dissociation mechanisms are proposed. For the C2H+ ion the PIPECO technique has also been used. From these discussions the H-C2H, HC-CH and H-C2 binding energy values are proposed, i.e. 5.33+/-0.23 eV, 9.83+/0.10 eV and 5.44+/-0.40 eV respectively. The fragmentation path leading to C+, CH2+ and C2+ are discussed in terms of dissociation mechanisms involving the transient vinylidene structure of the molecular ion as an intermediate. [less ▲]

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See detailVertical column abundance and profile retrievals of water vapor above the Jungfraujoch.
Demoulin, Philippe ULiege; Schmid, Beat; Roland, Ginette et al

in Proceedings of Atmospheric Spectroscopy Applications, ASA Reims 96 (1996)

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See detailVertical Column Abundances of COF2 measured above the Jungfraujoch Station from ground-based infrared solar observations.
Mélen, F.; Mahieu, Emmanuel ULiege; Zander, Rodolphe ULiege et al

in Proceedings of Atmospheric Spectroscopy Applications (1996)

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See detailThe appearance energy of C2H+ from C2H2 revisited. A Photoion-Photoelectron Coincidence Spectroscopic Determination.
Servais, Christian ULiege; Locht, Robert ULiege

in Chemical Physics Letters (1995), 236

The dissociative ionization of C2H2 in the C2H+-producing channel has been reconsidered. The photoion-photoelectron coincidence (PIPECO) technique has been used. The C2H+/e coincidence rate has been ... [more ▼]

The dissociative ionization of C2H2 in the C2H+-producing channel has been reconsidered. The photoion-photoelectron coincidence (PIPECO) technique has been used. The C2H+/e coincidence rate has been recorded between 16.2 and 21.2 eV. The lowest appearance energy determined for C2H+ is 17.35+/-0.04 eV. A second appearance energy is measured at 18.40+/-0.04 eV. At both energies ethynyl ions are produced through a predissociation mechanism at the expense of the C2H2+(A2Ag) state at 17.35 eV and C2H2+(B2Sigma+/g) at 18.40 eV. These results are in good agreement with the most recent TPIPECO experiments and dissociative electroionization results. This comparison leads to the exclusion of any contribution of autoionization phenomena to the C2H+ ion production between 16.2 and 21.2 eV. Investigations of C2H+ through the ion-pair formation channel (and dissociative electron attachment producing C2H- and H-) in C2H2 are reported and its contribution to C2H+ ion production below 17.3 eV must be discarded. [less ▲]

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See detailThe solar Spectrum between 16 and 35 µm.
Farmer, C. P.; Delbouille, L.; Roland, Ginette et al

in Sauval, A. J.; Blomme, R.; Grevesse, Nicolas (Eds.) Astronomical Society of the Pacific Conference Series (1995)

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See detailStratospheric changes monitored above the Jungfraujoch - The budgets of inorganic chlorine and fluorine since 1985.
Zander, Rodolphe ULiege; Mahieu, Emmanuel ULiege; Demoulin, Philippe ULiege et al

in Proceedings of the 3d International Symposium on Polar Stratospheric Ozone Research (1995)

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See detailA new analysis of the OH radical spectrum from solar infrared observations.
Mélen, F.; Sauval, A. J.; Grevesse, Nicolas ULiege et al

in Journal of Molecular Spectroscopy (1995), 174

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See detailA new analysis of the OH radical spectrum from solar Infrared observations.
Mélen, F.; Grevesse, Nicolas ULiege; Delbouille, L. et al

in ASP Conference Series (1995)

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See detailThe solar spectrum between 16 and 35 µm.
Sauval; Blomme, R.; Grevesse, Nicolas ULiege et al

in Sauval, A. J.; Blomme, R.; Grevesse, Nicolas (Eds.) ASP Conferences (1994)

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See detailThe solar spectrum between 16 and 40 microns. Atlas solaire et atmosphérique.
Farmer, C. B.; Delbouille, L.; Roland, Ginette et al

Report (1994)

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See detailSpectroscopic Measurements of Atmospheric Changes (SMAC), Belgian Impulse Programme GLOBAL CHANGE
Delbouille, L.; Roland, Ginette; Zander, Rodolphe ULiege et al

in Proceedings of the Symposium of Belgian Impulse Programme "Global Change" (1993)

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See detailPROCEDE ET DISPOSITIF DE PERMEABILISATION DE CELLULES VIVANTES
Servais, Christian ULiege; Louette, Joël

Patent (1991)

A method and a device for making cell membranes permeable using electrical discharges (electroporation), wherein at least one short electrical discharge is applied to a suspension containing cells to be ... [more ▼]

A method and a device for making cell membranes permeable using electrical discharges (electroporation), wherein at least one short electrical discharge is applied to a suspension containing cells to be made permeable and molecules to be accommodated therein, in order to generate in said suspension a high-value electric field, whereafter at least one longer electrical discharge is applied thereto to generate a lower-value electric field therein. [less ▲]

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See detailAbout the Double Ionization of NH3 and CO2. A Comparison between Photoionization and Electron Impact.
Locht, Robert ULiege; Servais, Christian ULiege; Davister, M. et al

in Dalagarno, A.; Freund, R. S.; Lubell, M. S. (Eds.) et al 16th Internatioanl Conference on the Physics of Electronic and Atomic Collisions: Abstracts of Contributed Papers. (1989)

Using synchrotron radiation the double ionization of NH3 and CO2 is measured. The results are compared with those obtained by electron impact.

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See detailThe Dissociative Electroionization of Ammonia and Ammonia-d3. II. The H+ and H2+ Dissociation Channels.
Locht, Robert ULiege; Servais, Christian ULiege; Ligot, M. et al

in Chemical Physics (1988), 125

The dissociative electroionization of NH3(ND3) in the H(D)+ and H(D)2+ dissociation channels is investigated in the 18-50 eV electron energy range. The H(D)+ translational energy distribution spectrum ... [more ▼]

The dissociative electroionization of NH3(ND3) in the H(D)+ and H(D)2+ dissociation channels is investigated in the 18-50 eV electron energy range. The H(D)+ translational energy distribution spectrum shows several components and that of H(D)2+ is continuous. The thermal energy component of the latter distribution is entirely ascribed to H2+/H2. For both ions the kinetic energy-versus-appearance energy diagram is obtained and discussed. The H+ ion at the lowest onset is probably formed at the expense of the NH3+(A2E) state. In the 22.5 eV electron energy range both H+ and H2+ are formed by dissociative autoionization. Evidence is also brought for H+ and H2+ formation at 22.5 eV and 26.5 eV through spontaneous decomposition of NH2+. Above 35 eV dissociation of doubly ionized states by Coulomb repulsion is mainly involved. [less ▲]

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See detailThe Dissociative Electroionization of Ammonia and Ammonia-d3. I. The NH+ and NH2+ dissociation channels.
Locht, Robert ULiege; Servais, Christian ULiege; Ligot, M. et al

in Chemical Physics (1988), 123

The dissociative electroionization of NH3 (ND3) in the NH2+ (ND2+) and NH+(ND+) dissociation channels is investigated in the 15-50 eV electron energy range. The translational energy distributions of ND2 ... [more ▼]

The dissociative electroionization of NH3 (ND3) in the NH2+ (ND2+) and NH+(ND+) dissociation channels is investigated in the 15-50 eV electron energy range. The translational energy distributions of ND2+ (NH2+) exhibit several components whereas NH+ only shows a continuous broad distribution. For both ions a kinetic energy-versus-appearance energy diagram is obtained and discussed. The predissociation of the Jahn-Teller split NH3+(A2E) state produces both ions at their lowest threshold. At higher energies dissociative autoionization (in the 22 eV region), dissociative ionization through the NH3+(B2A1) state (in the 24-30 eV region) as well as by Coulomb repulsion of doubly ionized states (in the 35-50 eV region) produce NH2+(ND2+) and NH+ with large amounts of kinetic energy. Some arguments are brought forward to indicate that the former value of the NH2-H dissociation energy is overestimated. [less ▲]

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See detailThe Dissociative Electroionization of NH3. The NH+ Dissociation Channel.
Locht, Robert ULiege; Servais, Christian ULiege; Ligot, M. et al

in Gilbody, H. B.; Newell, W. R.; Read, F. H. (Eds.) et al Electronic and Atomic Collisions: Abstracts of Contributed Papers. 15th International Conference on the Physics of Electronic and Atomic Collisions. Brighton, United Kingdom, 1987. (1987)

The dissociative electoionization efficiency of Nh3 in the NH+ channel is reported. The kinetic energy of this fragment ion is measured as a function of the impinging electron energy. Several dissociation ... [more ▼]

The dissociative electoionization efficiency of Nh3 in the NH+ channel is reported. The kinetic energy of this fragment ion is measured as a function of the impinging electron energy. Several dissociation limits are detected. [less ▲]

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See detailThe Dissociative Photoionization of O2 and N2O.
Locht, Robert ULiege; Hagenow, G.; Rühl, E. et al

Book published by Berliner Elektronen Speicherring für Synchrotron Strahlung m.b.H. (BESSY) - Jahresbericht/Annual Report (1987)

The dissociative photoionization of O2 and N2O is investigated using synchrotron radiation. The results on the O+ and NO+ dissociation channels are reported.

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See detailA versatile low-cost Automation System for an Electroionization Experiment.
Servais, Christian ULiege; Locht, Robert ULiege; Momigny, J.

in International Journal of Mass Spectrometry and Ion Processes (1986), 74

A cheap complete automation system designed for an electoionization experiment is described. This system is based on a Sinclair ZX Spectrum computer and a modular architecture. The control program and ... [more ▼]

A cheap complete automation system designed for an electoionization experiment is described. This system is based on a Sinclair ZX Spectrum computer and a modular architecture. The control program and general building blocks diagrams are discussed and give a general idea of how to build modules or procedures adapted to different applications. [less ▲]

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