摘要:

This paper is divided into three parts. In the introduction, we discuss the history and makeup of ICPEAC. In the second part, we discuss the extent of applicability of atomic collision physics. In the third part, we chose one subject (dielectronic excitation) to show the interrelationship of various sub‐branches of atomic collision physics.

ISSN:0094-243X    

DOI:10.1063/1.39216

出版商:AIP    

年代:1990

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.39194

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The transition state region for several chemical reactions of the type A+HB→Ha+B has been investigated via photodetachment of the stable negative ion AHB−. The photoelectron spectra of BrHBr−and BrHI−show resolved vibrational structure attributable to the transition state region of the Br+HBr and Br+HI reactions, respectively. The photoelectron spectra of IDI−and the cluster ion IDI−(N2O) are compared; these spectra probe different parts of the I+HI potential energy surface. Finally, a high resolution threshold photodetachment spectrum of one of the IHI−features shows evidence for reactive resonances in the I+HI reaction.

ISSN:0094-243X    

DOI:10.1063/1.39273

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Some commonly used theoretical approaches to the low‐energy molecular collision dynamics are briefly reviewed. The present status of theoretical calculations of intermolecular potential is summarized. Taking examples from the systems relevant to the physics and chemistry of the interstellar molecular clouds, recent calculations of the rotational and vibrational cross sections and rate constants are surveyed. Efforts of finding scaling and fitting laws are briefly mentioned. Recent studies of vibrationally excited H2molecules, including collision‐induced dissociation, are reviewed. Finally, works on ion‐molecule collisions are discussed.

ISSN:0094-243X    

DOI:10.1063/1.39268

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

A review is given of recent advances in the theory of electron‐atom collisions. The first part deals with elastic and inelastic scattering and the second part with ionization. Positron‐atom collisions are also considered.

ISSN:0094-243X    

DOI:10.1063/1.39245

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Experimental studies on giant resonances in heavy atoms and ions by electron impact, carried on in our laboratory at Sophia University, are described. Three topics are discussed; the first one is measurements of the double ionization cross sections of singly charged alkaline‐earth ions by means of the crossed electron‐ion beams experiment. The second topic is measurements of partial cross sections for the inner shell ionization of rare‐gas atoms by means of the Auger electron spectroscopy. The third one is measurements of partial cross sections for the outer s‐subshell ionization of rare‐gas atoms by means of the VUV spectroscopy. Experimental results are discussed in relation to the giant resonance effect.

ISSN:0094-243X    

DOI:10.1063/1.39246

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Product distributions for the electron‐ion dissociative recombination of HCO+, O2H+, HCO2+, N2OH+and H3O+have been determined at 300 K using a flowing afterglow/Langmuir probe apparatus. Electron (and thus ion) densities were determined using the Langmuir probe and the OH products of the reactions were detected using laser induced fluorescence spectroscopy. The OH fluorescence was quantitatively related to the OH number density by using the calibration reaction H+NO2→OH+NO and by determining the H‐atom number density using vacuum ultraviolet absorption spectroscopy. Preliminary determinations of the H atom and O atom contributions to the product distributions are also described.

ISSN:0094-243X    

DOI:10.1063/1.39219

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Recent calculations of low energy electron scattering by diatomic molecules, using the R‐matrix method, are reviewed. These include the vibrational excitation of HF and HCl, and the electronic excitation of H2and N2. Calculations, using similar methods, of positron scattering by H2and HF are discussed briefly.

ISSN:0094-243X    

DOI:10.1063/1.39272

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

The use of state‐selection techniques has added greatly to our fundamental understanding of electron‐atom collision phenomena. In particular, measurements of atomic orientation and alignment in electron impact excitation, and measurements of spin dependence in both elastic and inelastic scattering, provide substantially more detail about collision processes than conventional measurements of differential cross sections alone. This work reviews recent experiments which, through the use of spin dependence and atomic orientation and alignment, attempt to provide the most complete characterization possible of electron‐atom collision phenomena.

ISSN:0094-243X    

DOI:10.1063/1.39201

出版商:AIP    

年代:1990

数据来源: AIP

摘要:

Detection of the Lyman alpha, Lyman beta and Balmer alpha photons and near‐threshold energy loss electrons enables the determination of excited state lifetimes, total and differential excitation functions and various angular and polarization correlation parameters. Data are given for the summed n=2 and 3 states as well as the separate 2P, 3S, 3P and 3D states.

ISSN:0094-243X    

DOI:10.1063/1.39202

出版商:AIP    

年代:1990

数据来源: AIP