Principle Investigator Dr. Steven J. Smith
For the period 1989-91 I carried out research at the Jet Propulsion Laboratory (JPL) as a NASA-NRC Resident Research Associate. In 1992 I became member of Technical Staff, Earth and Space Sciences Division, JPL. Until July, 2007 I was engaged in a variety of experiments in electron-collisions with highly-charged ions (HCI), including excitation, measurement of lifetimes of metastable HCI states, and charge-exchange of HCIs with atoms and molecules, including measurement of X-ray emission spectra. I was also involved through JPL’s Technology Affiliates Program (TAP) with Beckman Coulter, Inc. in the development and patent of my own Rotating Field Mass Spectrometer, for analysis of large organic (protein) compounds. I have been an active member of the C. S. Lewis Society of Southern California. Until July, 2007 I was engaged in a variety of experiments in electron-collisions with highly-charged ions (HCI), including excitation, measurement of lifetimes of metastable HCI states, and charge-exchange of HCIs with atoms and molecules, including measurement of X-ray emission spectra.
Two separate sections will be considered. I am considered an atomic physicist as well as an experimental laboratory astrophysicist. My Ph.D. from Wayne State was in positron differential scattering. This dissertation work led directly upon graduation to a two-year post doctoral position with the National Research Council’s Resident Research Fellowship. My assignment was to work at JPL with an important atomic collisions research team. Two years latter Smith was invited to join the JPL technical staff to continue this work. This effort involves operating a world class multiply charged ion source called an ECR (electron-cyclotron resonance ion source). Multiple-charged ions in ground and metastable states are introduced into three separate beam lines. My CV lists the publications that have come from these efforts.
I was Principal Investigator on a Nasa code S Astrophysics program dealing with measuring metastable lifetimes of highly charged ions. Ions produced by the ECR are trapped in an electrostatic Kingdon trap operating at ultrahigh vacuum We have published results for C+, O+2 ,and another publications for Fe+9,Fe+10 and Fe+13.
a. Electron–Multiply-Charged Ion (MCI) excitation cross sections for transitions from ground state to the first several spin allowed and spin forbidden states of the excited ion. We have recently published O+3, and Fe+9, please see publication list for more details.
b. Electron-MCI charge exchange cross section measurements. These are also coupled to x-ray measurements of charge exchange and fluorescence excitation reactions from comet like gas targets and meteor-like crystal targets such as olivine and augite.
Atomic Physics References
26. “Absolute cross sections for single and double charge-exchange in Fe
impact on He”, I. Cadez, J.B. Greenwood, A. Chutjian, S.J. Smith, J. Phys.B: Atomic, Molecular & Optical Physics<363003 (2003).
28. “Photon Emission Resulting From Collisions of O<5+ with CO”, Ehrenreich T., Miller K., Gee P., Kessel Q., Pollack E., Smith W.W., Djuric N., Lozano J., Smith S.J. and Chutjian, A., Nucl. Instr. Methods B 241 (2005) 125-128.
29. “Measurements of Metastable Lifetimes for Fe X, Fe XI and Fe IVX”, Smith S.J., Chutjian, A, Lozano, J, Phys. Rev. A, 72, 062504 (2005)
32. “Absolute single and multiple charge exchange cross sections for highly-charged C,O, and Ne ions on H2
33. “Measurement and Calculation of Absolute Cross Sections for Excitation of the 2
<1/2o Fine-Structure Transition in Fe<13+”, S. Hossain, S.S. Tayal, S.J. Smith, J. C. Raymond and A. Chutjian. Phys. Rev. A 75<022709 (2007).
36. “Absolute cross sections for single and single and multiple charge exchange in Feq<+< impacting on CO, CO2 and H2O”, R.J. Mawhorter, J. Sim, H. Aliabadi, I. Cadež, A. Chutjian, J.B. Greenwood, J.A. MacAskill and S.J. Smith, J. Phys.: Conf. Ser194, 102008, (2009).
5. “Atomic Processes with the JPL ECR” Invited colloquium presented at the Cal State Fullerton Physics Department Colloquium, September, 2002.