摘要:

Source requirements for selective excitation and interrogation of physical and chemical processes are examined. The subjects discussed include UV and VUV lasers, synchrotron and undulator emission, harmonic generation, and free electron lasers of the Compton and Raman scattering types, as well as their associated equipment. Applications of these excitation sources to intramolecular dynamics studies are briefly considered.

ISSN:0094-243X    

DOI:10.1063/1.40549

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The main machine parameters of the synchrotron radiation under construction at Campinas, Brazil, are described. The 1.15 GeV ring is scheduled to become fully operational in 1993. Six beam lines will be initially available to the users. Fourteen experimental stations are already under construction or have been proposed by research groups from Brazil and Argentina. A 12‐pole normal magnet wiggler is also under construction.

ISSN:0094-243X    

DOI:10.1063/1.40540

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

Frequency conversion by four‐ and six‐wave mixing in gaseous media is a well established experimental method to generate tunable coherent light in the spectral region of the vacuum ultraviolet (VUV) and more recently in the extreme ultraviolet (XUV). Tunable coherent ‘‘laser like’’ radiation can be generated by nonlinear frequency mixing in the 62–200 nm spectral region, starting from the radiation of a pulsed dye laser pumped by a Q‐switched Nd:YAG laser. Because of the combination of high pulse power with narrow spectral width of the VUV/XUV radiation, the nonlinear frequency mixing becomes a powerful light source for spectroscopic studies. A short review of the field of nonlinear frequency mixing to obtain VUV/XUV radiation is made, together with a comparison of the spectral brightness of various radiation sources in this spectral region.

ISSN:0094-243X    

DOI:10.1063/1.40544

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

We present here in a format intermediate between a research‐revue paper and a student course some considerations about the calculation of the photoionization cross section for diatomic and small polyatomic molecular systems. Examples are taken from the work on diatomic molecules performed in Orsay, namely photoionization of CO, H2and HI and the work on small polyatomic molecules, namely H2O and CH4, performed in the framework of a joint project between California Institute of Technology and several Universities in Brasil.

ISSN:0094-243X    

DOI:10.1063/1.40548

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

The purpose of this article is to give a simple beginners introduction to the basic concepts of Multichannel Quantum Defect Theory (MQDT). This will be done by proceeding through a series of examples. Each example will add something to our understanding and will also illustrate an area in which the theory can be used. In particular MQDT is used to study Rydberg levels of atoms and molecules and the ionization continuum that lies above each Rydberg series. We will also see that MQDT can account for the interactions between the Rydberg series and continua that occur in an atom or a molecule. A short bibliography at the end includes references to several review articles to which interested readers are directed if they wish to deepen their knowledge.

ISSN:0094-243X    

DOI:10.1063/1.40550

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

One of the new challenging fields of half collision processes is the study of differential cross sections, polarization of the spin of the molecular electron and more generally orientation and alignment of light. This paper presents a discussion about the way the information contained in the differential cross sections and spin polarization of the molecular photoelectron can be unfolded and converted to a qualitative understanding of the underlaying process of ionization. It also contains a comprehensive explanation of the logical steps in the derivation of the differential photoionization cross section including spin orientation. Few examples will be given taken from the work done by the author during the last years.

ISSN:0094-243X    

DOI:10.1063/1.40551

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

A discussion is given to studies of Resonance Enhanced Multiphoton Ionization (REMPI) processes in molecules. (AIP)

ISSN:0094-243X    

DOI:10.1063/1.40552

出版商:AIP    

年代:1991

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.40553

出版商:AIP    

年代:1991

数据来源: AIP

ISSN:0094-243X    

DOI:10.1063/1.40554

出版商:AIP    

年代:1991

数据来源: AIP

摘要:

This paper highlights a number of characteristics resulting from the slow dissociations of metastable singly and doubly charged ions, as seen in a reflectron style mass spectrometer.

ISSN:0094-243X    

DOI:10.1063/1.40555

出版商:AIP    

年代:1991

数据来源: AIP