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 Planetary Chemistry and Astrobiology (3225): People
Christopher M. Heirwegh's Picture
Jet Propulsion Laboratory
M/S 183-301
4800 Oak Grove Drive
Pasadena, CA 91109
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Curriculum Vitae:

Christopher M. Heirwegh

Chris has 10 years of experience in refining x-ray fluorescence (XRF) and particle induced x-ray emission (PIXE) composition analysis techniques. Through his work in PIXE, Chris enhanced the accuracy of the fundamental parameters (FPs) approach to quantifying light element constituents found in silicate rocks and minerals. His recent work involved identifying and correcting for non-linear behavior found in the energy-channel calibration of spectra generated by the Mars Science Laboratory (MSL) Alpha-Particle X-ray Spectrometer (APXS) on the Curiosity Rover. These improvements continue to serve both ongoing APXS data analysis and treatment of linearity issues found in other commercially available x-ray detector systems.

Chris’ current role as a Caltech Postdoctoral Fellow at JPL involves calibrating the Planetary Instrument for X-ray Lithochemistry (PIXL) to perform accurate quantitative composition analysis of the Martian Rock and soil (Mars Rover 2020). Efforts include assisting with the development of the PIQUANT software used to process PIXL data, communicating science-related issues to the PIXL engineering team, developing calibration protocols for the model and flight PIXL systems and carrying out experiments to gain understanding of the science associated with PIXL.

Chris brings to JPL extensive knowledge of the fundamental physics behind X-ray emission techniques and semi-conductor detector operation. His primary interests are in research and technological development within the physical and radiation sciences. Chris also acts as a peer reviewer for several journals in his field including X-ray Spectrometry and Nuclear Instruments and Methods (A and B).

  • Ph.D. Experimental Physics, University of Guelph (2014)
  • M.Sc. Medical Physics, McMaster University (2009)
  • B.Sc. Physical Science (Honours program), McMaster University (2004)

Research Interests
  • X-ray fluorescence techniques and wavelength-dispersive X-ray spectroscopy
  • Instrumentation development
  • Semi-conductor detector physics and signal processing
  • Spectra fitting
  • Science of radiation and radioanalytical techniques

Professional Experience
  • Caltech Postdoctoral Fellow and PIXL Calibration Test Lead, Jet Propulsion Laboratory (2016 – present)
  • Postdoctoral Fellow in Physics, University of Guelph (2014 – 2016)
  • Research Assistant (doctorate), University of Guelph (2009 – 2014)
  • Research Assistant (masters), McMaster University (2006 - 2009)
  • Summer Research Assistant, Juravinski Cancer Centre (2003)

Selected Awards
  • Best Poster Award – 2nd place, 14th PIXE conference, Somerset West, South Africa (2015)
  • Ontario Graduate Scholarship, 3 years, Physics, Guelph (2009 - 2012)
  • Graduate Student Scholarship, 2 years, Medical Physics, McMaster (2006 – 2008)
  • Entrance Scholarship, Medical Physics, McMaster (2006)

Selected Publications
  1. Campbell J L, Ganly B, Maxwell J A and Heirwegh C M (in preparation) “Separation of detector non-linearity issues and multiple ionization satellites in alpha-particle PIXE”
  2. Heirwegh C M, Petric M, Kavčič M, Fazinić S, Schneider J and Campbell J L. (in preparation) “Investigating the impact of H+ and He2+ induced multi-vacancy x-ray satellites of Mg, Al and Si on performing accurate energy-dispersive PIXE analysis”
  3. Flannigan E L, Heirwegh C M and Campbell J L (in press, X-ray Spectrom.) “Role of the mass attenuation coefficient database in standardization of a silicon drift X-ray detector for PIXE analysis”
  4. Campbell J L, Heirwegh C M and Ganly B 2016 “Non-linearity issues and multiple ionization satellites in the PIXE portion of spectra from the Mars alpha particle X-ray spectrometer,” Nucl. Instrum. Meth. B 383, 143-151.
  5. Heirwegh C M, Campbell J L and Czamanske G K 2016 “Refinement of of major- and minor-element PIXE analysis of rocks and minerals,” Nucl. Instrum. Meth. B 336, 40-50.
  6. Heirwegh C M, Pradler I and Campbell J L 2015 “Choice of mass attenuation coefficients for PIXE analysis of silicate minerals and rocks,” X-ray Spectrom. 44(2), 63-68.
  7. Heirwegh C M, Pradler I and Campbell J L 2013 “An accuracy assessment of photo-ionization cross-section databases for 1-2 keV x-rays in light elements using PIXE,” J. Phys. B: At. Mol. Opt. Phys. 46(18), 185602.
  8. Hopman T L, Heirwegh C M, Campbell J L, Krumrey M and Scholze F 2012 “An accurate determination of the K-shell fluorescence yield of silicon,” X-ray Spectrom. 41(3), 164-171.
  9. Heirwegh C M, Chettle D R and Pejović-Milić A 2012 “Ex vivo evaluation of a coherent normalization procedure to quantify in vivo finger strontium XRS measurements,” Med. Phys. 39(2), 832-841.
  10. Heirwegh C M, Chettle D R and Pejović-Milić A 2010 “Evaluation of imaging technologies to correct for photon attenuation in the overlying tissue for in vivo bone strontium measurements,” Phys. Med. Biol. 55(4), 1083-1098.

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