Observation of a non-thermal ortho-to-para ratio of H{sub 3}{sup +} in hydrogen plasmas
- Univ. of Chicago, IL (United States); and others
Although the extremely slow conversion between different nuclear spin modifications of molecules in radiative and collisional processes has been well-established, no observation of non-thermal ratios of spin modifications has been reported except for H{sub 2} and its isotopic species. The authors have studied the V{sub 2} fundamental band of H{sub 3}{sup +} using normal and para-H{sub 2} as the source gases to see if one could detect a different ortho-to-para ratio of H{sub 3}{sup +}. The reaction H{sub 2} + H{sub 2}{sup +} {r_arrow} H{sub 3}{sup +} + H generates only para-H{sub 3}{sup +} if para-H{sub 2} is used, and the subsequent proton hop reaction H{sub 3}{sup +} + H{sub 2} {r_arrow} H{sub 2}H{sup +} + H{sub 2} will retain para-H{sub 3}{sup +} while the hydrogen exchange reaction H{sub 3}{sup +} + H{sub 2} {r_arrow} H{sub 2} H{sup +} + HH is expected to convert para-H{sub 3}{sup +} to ortho-H{sub 3}{sup +}. The authors have used two pairs of transitions, R(4,3){sup -} and R(4,4){sup -} separated by 0.13 cm{sup -1} and R(1,0){sup +} and R(l, 1){sup +} separated by 0.32 cm{sup -1}, for measurements of relative intensities. A clear difference in the intensity ratios of the ortho and para lines was detected depending on whether normal or para-H{sub 2} was used. The ion-neutral chemical kinetics will be discussed to explain the observed results.
- OSTI ID:
- 456852
- Report Number(s):
- CONF-9506113-; TRN: 97:012088
- Resource Relation:
- Conference: 50. symposium on molecular spectroscopy, Columbus, OH (United States), 12-16 Jun 1995; Other Information: PBD: 1995; Related Information: Is Part Of Ohio State University 50th international symposium on molecular spectroscopy; PB: 371 p.
- Country of Publication:
- United States
- Language:
- English
Similar Records
The ortho-to-para ratio of H2Cl+: Quasi-classical trajectory calculations and new simulations in light of new observations
Observation of Ortho-Para {bold H}{sup {bold +}}{sub {bold 3}} Selection Rules in Plasma Chemistry