Accession Number:

AD0262729

Title:

ABSORPTION, IONIZATION, AND ION FRAGMENTATION CROSS SECTIONS OF HYDROCARBON VAPORS FOR VACUUM ULTRAVIOLET RADIATION

Descriptive Note:

Corporate Author:

UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES ENGINEER WATERWAYS EXPERIMENT STATION*

Personal Author(s):

Report Date:

1960-06-15

Pagination or Media Count:

1.0

Abstract:

The vapors tudied were ethane, propane, n-butadiene, n-pentane, ethylene, propylene, cis-butene 2, 1,3-butadiene, acetylene, and cyclopropane. Monochromatic radiation in the energy range 9 to 25 ev was provided by a Seya type vacuum monochromator. With this radiation, absorption cross sections were determined and ionization cross sections were measured. All three kinds of cross sections had certain features in common. When plotted against energy, a typical cross section curve rose smoothly and monotonically with increasing energy to a single maximum, then fell somewhat more slowly than it rose. Characteristically, the maxima of the ionization and absorption cross sections were both between 14 and 18 ev. At 1215A, the ionization efficiency of propylene was found to be 12 of cis-butene 2, 9 of 1,3-butadiene, 13 and of all other hydrocarbons studied, 0. It was deduced that the ionization threshold of a hydrocarbon should probably not be more than 9.7 ev if it is to produce useful quantities of ionization in direct, single photon processes in the upper atmosphere. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE