Photodissociation of polyatomic molecules by vacuum-uv light often results in the formation of electronically excited diatomic molecular fragments. Based on this, instruments that measure mixing ratios or densities of selected polyatomic species in the stratosphere and higher troposphere can be constructed. This is demonstrated by an instrument to detect and measure stratospheric water mixing ratios utilizing H(2)O photodissociation by Ly alpha (1216 A) light and detecting OH(A(2)J(+)X(2)Pi) emission. Also, detectors for H(2)O(2), HNO(3), and NO(2) are discussed.

The Space k s e a x h Coordination Center, established in my. 1963, has the following functions: (1) it administers predmtoral and postdoctoral fellowships in space-related science and engheesing programs; (2) it makes available, on a p p l i c a t i o n and after review, allmatiom to assist new faculty members in the Division of the N a tu r a 1 Sciences and the Schcrol of Engineering to initiate m a r c h programs or to permit established faculty members to do preliminary; work rn reseazch ideas of a novel character; (3) in the Division of the Natural Sciences it makes an annual allocation of funds to a e interdisciplinary Laboratory h r Atmapkric and Space Sciences; (4) in the School of Engineering i t makes a simila allocation of funds to the Department of Metallurgical and Materials Engineering and to the program in Engineering System Managerraeet of the Department of Indmial Engineering; and (5) in concert with the University's Knowledge Availability Systems Center, it seeks to assist in the orderly transfer of new space-generated knowledge in industrial application, The Center also issum periodic reports of space-oriented research and a comprehensive annual report. hands were used to determine the dependence of Re on the r-centroid, which i s Re = 1,9(1,0 . 0.6 iVpv,,). Absolute transition probabilities were computed usinq t h i s functional form f o r Re and normalizing the total transition probability of the v ' = 2 level to published experimental r e s u l t s ,The total f-value f o r t h i s transition i s then 0.15, Absolute excitation cross sections f o r the f i r s t f i v e vibrational levels (v" 0 -+ 4) of the A1n s t a t e were determined f o r each parent gas usinq the measured cross sections of specific bands and the absolute transition probabilities, When CO was the parent gas, the r e l a t i v e populations of these vibrational 1 eve1 s were proportional t o the Franck-Condon factors, q v b 0 , The sum of the cross sections f o r these levels i s 1.87 x lowP7 cm2 -+ 15% a t 300 eV, This represents 87.4% of the total excitation cross section f o r the A1n s t a t e . The r e l a t i v e populations of the f i r s t f i v e vibrational levels were also determined f o r dissociative excitation of C02 and they differed from the relative populations which resulted from d i r e c t excitation of CO, The sum of the cross sections f o r these f i v e levels i s 1 , 4 x 10-" cm2 -+ 17% a t 300 eV,The importance o f carbon monoxide and carbon d i o x i d e i n planetary atmospheres has r e c e n t l y been emphasized by t h e Mariner space probe i nv e s t i q a t i o n s of Mars and Venus, En p a r t i c u l a r , t h e recent Mariner VII probe toward Mars detected a strong emission spectrum i n t h e vacuum 0 u l t r a v i o l e t , dominated below 2000 A by t h e Lyman alpha r a d i a t i o n from atsmTc hydrogen and t h e Fourth P o s i t i v e band system o f carbon monoxide, cO(A1n = X1c+],% Absolute e l e c t r o n e x c i t a t i o n cross sections a r e needed t o determine the r e l a t i ...

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