NRLMSIS 2.0: A whole‐atmosphere empirical model of temperature and neutral species densities

Ultraviolet Absorption of Refractory Elements by a Dual Laser Plasma Method

International Astronomical Union Colloquium ◽

10.1017/s0252921100107821 ◽

1988 ◽

Vol 102 ◽

pp. 243-246

Author(s):

J.T. Costello ◽

W.G. Lynam ◽

P.K. Carroll

Keyword(s):

Absorption Spectra ◽

Laser Plasma ◽

Optical Pulse ◽

Ionic Species ◽

Neutral Species ◽

Plasma Method ◽

Plasma Technique ◽

Refractory Elements ◽

Delay Times ◽

Dual Laser

AbstractThe dual laser-produced plasma technique for the study of ionic absorption spectra has been developed by the use of two Q-switched ruby lasers to enable independent generation of the absorbing and back-lighting plasmas. Optical pulse handling is used in the coupling cicuits to enable reproducible pulse delays from 250 nsec. to 10 msec, to be achieved. At delay times > 700 nsec. spectra of essentially pure neutral species are observed. The technique is valuable, not only for obtaining the neutral spectra of highly refractory and/or corrosive materials but also for studying behaviour of ionic species as a function of time. Typical spectra are shown in Fig. 1.

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Radiation-induced surface decomposition

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100075592 ◽

1983 ◽

Vol 41 ◽

pp. 368-369

Author(s):

M. L. Knotek

Keyword(s):

Ionizing Radiation ◽

Atomic Structure ◽

Chemical Bonding ◽

Neutral Species ◽

Radiation Induced ◽

Physical And Chemical ◽

Surface Decomposition ◽

The Relationship ◽

Electron And Photon ◽

Surface Bond

Modern surface analysis is based largely upon the use of ionizing radiation to probe the electronic and atomic structure of the surfaces physical and chemical makeup. In many of these studies the ionizing radiation used as the primary probe is found to induce changes in the structure and makeup of the surface, especially when electrons are employed. A number of techniques employ the phenomenon of radiation induced desorption as a means of probing the nature of the surface bond. These include Electron- and Photon-Stimulated Desorption (ESD and PSD) which measure desorbed ionic and neutral species as they leave the surface after the surface has been excited by some incident ionizing particle. There has recently been a great deal of activity in determining the relationship between the nature of chemical bonding and its susceptibility to radiation damage.

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