Award Date

5-1-2012

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Physics and Astronomy

First Committee Member

Victor H. Kwong

Second Committee Member

Stephen Lepp

Third Committee Member

Michael Pravica

Fourth Committee Member

Peter Shiue

Number of Pages

77

Abstract

Experimental determination of the rate coefficient values of deuterium abstraction in water ions and deuterium substitution in hydronium ions can improve the understanding of D/H in water at planetary atmospheres, cometary atmospheres, and interstellar medium. Using a cylindrical ion trap, (CIT) and time of flight (TOF) mass spectrometry, a number of measurements at energies below 1 eV have been performed. The deuterium abstraction rate coefficient in water ions, H2O+, and an upper limit for the hydrogen-deuterium substitution rate coefficient in monodeuterated hydronium ion, H2DO+, have been measured. Both the abstraction and substitution rates were obtained by monitoring the population of H2DO+. He2+ is present in solar winds and cosmic radiation. It is also the ash of nuclear fusion in fusion reactors. Its charge transfer rate coefficients with various neutrals can help explain observations in astronomy as well as aid in better understanding the cooling via charge transfer of a plasma confinement type fusion reactor. Using the same experimental facility, the charge transfer rate coefficient of α-particles with a number of neutrals in various reactions was also measured. For the first time at an energy as low, the resonant charge transfer (RCT) of α-particles, He2+, with helium has been measured. Also the rate coefficient of the sum of single and double charge transfer of He2+with Ne, Ar, Kr, Xe, H2, D2, CH4, N2 and CO were measured. The rate coefficients for charge transfer were measured by recording the loss rate of He2+.

Keywords

Charge; Charge transfer; Deuterium; Ion exchange; Ions; Oxonium ions; Transfer; Water

Disciplines

Atomic, Molecular and Optical Physics | Physics

Language

English


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