State specific relaxation of neutral molecules at low temperatures

Persistent Link:
http://hdl.handle.net/10150/282859
Title:
State specific relaxation of neutral molecules at low temperatures
Author:
Ahern, Michael Mark
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
This dissertation presents the results of several investigations into vibrational and rotational relaxation of neutral molecules at low temperatures. The use of the free jet flow reactor technique for production of very low local temperatures and the determination of relaxation data and derivation of rate coefficients are discussed. Four different molecules, HBr, CO, OH and OD, are examined in the free jet with various buffer gases to determine their vibrational and rotational relaxation properties. For HBr and CO, terminal rotational temperatures are measured in various buffer gases with the resonance enhanced multiphoton ionization (REMPI) technique, and results are analyzed and compared with translational temperatures. For OH and OD, discussion includes experimental production of radicals and relaxation within the X²Π and A²Σ states is made. With the use of laser induced fluorescence (LIF) and a novel method for production of radicals in the free jet, radical relaxation rates are determined for the first time at extremely low collision energies. We have measured the low temperature (T(trans) near 1 K) rate coefficients for: OH(A²Σ,vᵢ,Nᵢ)+Ar →(k) OH(A²Σv(f)N(f)) +Ar where v and N refer to the quantum numbers for vibration and pure rotational angular momentum, while the subscripts i and f refer to the initial and final states, respectively. The experiments reported in this dissertation help lead to a better understanding of collisions on a molecular level at very low collision energies.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Chemistry, Physical.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Chemistry
Degree Grantor:
University of Arizona
Advisor:
Smith, Mark A.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleState specific relaxation of neutral molecules at low temperaturesen_US
dc.creatorAhern, Michael Marken_US
dc.contributor.authorAhern, Michael Marken_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThis dissertation presents the results of several investigations into vibrational and rotational relaxation of neutral molecules at low temperatures. The use of the free jet flow reactor technique for production of very low local temperatures and the determination of relaxation data and derivation of rate coefficients are discussed. Four different molecules, HBr, CO, OH and OD, are examined in the free jet with various buffer gases to determine their vibrational and rotational relaxation properties. For HBr and CO, terminal rotational temperatures are measured in various buffer gases with the resonance enhanced multiphoton ionization (REMPI) technique, and results are analyzed and compared with translational temperatures. For OH and OD, discussion includes experimental production of radicals and relaxation within the X²Π and A²Σ states is made. With the use of laser induced fluorescence (LIF) and a novel method for production of radicals in the free jet, radical relaxation rates are determined for the first time at extremely low collision energies. We have measured the low temperature (T(trans) near 1 K) rate coefficients for: OH(A²Σ,vᵢ,Nᵢ)+Ar →(k) OH(A²Σv(f)N(f)) +Ar where v and N refer to the quantum numbers for vibration and pure rotational angular momentum, while the subscripts i and f refer to the initial and final states, respectively. The experiments reported in this dissertation help lead to a better understanding of collisions on a molecular level at very low collision energies.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectChemistry, Physical.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineChemistryen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorSmith, Mark A.en_US
dc.identifier.proquest9923152en_US
dc.identifier.bibrecord.b39470775en_US
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