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Christopher M. Heirwegh

Photo of Christopher Heirwegh


4800 Oak Grove Drive
M/S 183-301

Pasadena, CA 91109





Curriculum Vitae:

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Member of:

Laboratory Studies


Chris is an applied physicist with expertise in the physics fundamentals of X-ray spectroscopy and its application to geo-chemical in situ planetary exploration. As a Scientist employed at the Jet Propulsion Laboratory in Pasadena, California, Chris serves as an X-ray spectroscopy subject matter expert and Science Operations Manager for the Planetary Instrument of X-ray Lithochemistry (PIXL) team.

Chris has contributed to two NASA missions that have sent rovers to Mars. On the first, Chris provided analytical expertise for analyzing data returned from the Curiosity Rover’s alpha-particle X-ray Spectrometer (APXS). For the latter, Chris lent support to the integration and testing phase of the Planetary Instrument for X-ray Lithochemistry (PIXL) as a subject matter expert. Chris is also a co-developer of the PIQUANT XRF Quantification software used by the PIXL team to analyze data returned from Mars and the Earth-bound flight equivalent instruments.

Chris’ scientific research focuses on developing analytical techniques and methods that improve the accuracy of using X-ray fluorescence spectroscopy to analyze the composition materials. Chris also conducts research toward developing XRF instrumentation that might be utilized on future in situ planetary exploration missions. On a recent project Chris assessed the feasibility of using pyroelectric X-ray sources as an alternative to radioactive and electrically-driven tube X-ray sources.


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

Professional Experience

  • PIXL Science Operations Manager, JPL (2021 – present)
  • Scientist, Jet Propulsion Laboratory (2018 – present)
  • Sessional Lecturer, University of Guelph (2015, 2021)
  • JPL Postdoctoral Scholar, Jet Propulsion Laboratory (2018)
  • Caltech Postdoctoral Fellow, Jet Propulsion Laboratory (2016 – 2018)
  • Postdoctoral Fellow in Physics, University of Guelph (2014 – 2016)
  • Research Assistant (doctorate), University of Guelph (2009 – 2014)
  • Research Assistant (masters), McMaster University (2006 – 2008)

Community Service

Chris serves as an academic reviewer for articles written within the field of X-ray spectroscopy from journals: Icarus, the Journal of Synchrotron Radiation, Advances in X-ray Analysis, Nuclear Instruments and Methods A and B and X-ray Spectrometry.

In the wake of the Perseverance Rover landing, Chris has participated in multiple interviews and has delivered several public talks to share his experience on the Mars 2020 mission.

Chris also lends his expertise in radiation and radiation detection as a reviewer for NASA proposals for technology and instrument development.

Research Interests

  • Development of X-ray instrument concepts for use on spacecraft
  • Application of spectroscopic analysis techniques to planetary science research
  • Semiconductor detector physics and spectral line-shapes peak fitting
  • X-ray fundamental parameter accuracy refinement
  • Energy- and wavelength-dispersive X-ray analysis methods
  • Charge-induced multiple-shell vacancy effects on X-ray emission
  • Radiation and radioactivity
  • Medical physics applications of radiation

Selected Awards

  • Session Chair & Plenary Speaker – 71st Denver X-ray Conference, Bethesda, Maryland, 2022
  • Team Award – PIXL ops development and testing leading to successful commissioning, JPL 2021
  • Voyager Award – For exceptional achievement as Science-Engineering Liaison, JPL, 2021
  • Invited Speaker – European X-ray Spec. Assoc. Virtual Meeting, Budapest, Hungary, 2021
  • Invited Speaker – 70th Denver X-ray Conference (virtual), Westminster, Colorado, 2021
  • Certificate of Recognition - Dedication to completion of PXL Flight Sensor Assembly, JPL, 2020
  • Invited Speaker – Physics Dept. Colloquium, University of Guelph, Guelph, Canada, 2020

Selected Publications

  • C. M. Heirwegh, W. T. Elam, L. P. O’Neil, K. P. Sinclair, The Focused Beam X-ray Fluorescence Elemental Quantification Software Package PIQUANT, Spectrochim. Acta B, 2021 (Accepted, pending revision).
  • B. J. Orenstein, D. T. Flannery, L. W. Casey, W. T. Elam, C. M. Heirwegh, M. W. M. Jones, A noise dependent method of diffraction removal from X-ray fluorescence spectra. Analytica Chimica Acta. Submitted 03/15/2022.
  • Y. Liu, M. M. Tice, M. E. Schmidt, A. H. Treiman, T. V. Kizovski, J. A. Hurowitz, J. Henneke, D. A. K. Pedersen, S. J. VanBommel, M. W. M. Jones, et al. An olivine cumulate outcrop on the floor of Jezero crater, Mars, Science, in press, 2022.
  • E. C. Fayolle, A. C. Noell, P. V. Johnson, R. P. Hodyss, C. Heirwegh, M. Braun, J. Hein, Viability of Bacterial Spores Under Icy World Surface Conditions. 53rd LPSC (2022) Abstract 1785.
  • C. M. Heirwegh, Y. Liu, B. C. Clark, W. T. Elam, L. P. O’Neil, K. P. Sinclair, M. Tice, J. A. Hurowitz, A. C. Allwood, Calibrating the PIXL Instrument for Elemental Analysis of Mars, 52nd LPSC (2021) Abstract 1260.
  • J. L. Campbell, D. J. T. Cureatz, E. L. Flannigan, C. M. Heirwegh, J. A. Maxwell, J. L. Russell, S. M. Taylor, The Guelph PIXE Software Package V. Nucl. Instrum. Meth. B., 499 (2021) 77 – 88.
  • S. J. VanBommel, J. A. Berger, E. B. Rampe, C. M. Heirwegh, In-Situ X-ray Spectrometers in Space Exploration, in Advances in Portable X-ray Fluorescence Spectrometry - Instrumentation, Application and Interpretation, publisher: The Royal Society of Chemistry, 2021.
  • A. C. Allwood, L. A. Wade, M. C. Foote, et al., PIXL: Planetary Instrument for X-ray Lithochemistry (vol 216, 134, 2020), Space Sci. Rev. 217 (2021) 28.
  • A. C. Allwood, L. A. Wade, M. C. Foote, et al., PIXL: Planetary Instrument for X-ray Lithochemistry, Space Sci. Rev. 216 (2020) 134.
  • A. C. Allwood, M. T. Rosing, D. T. Flannery, J. A. Hurowitz, C. M. Heirwegh, “Reassessing Evidence of Life in 3,700 million year old rocks of Greenland,” Nature 563 (2018) 241 – 244.
  • C. M. Heirwegh, W. T. Elam, D. T. Flannery, A. C. Allwood, An empirical derivation of the x-ray optic transmission profile used in calibrating the Planetary Instrument for X-ray Lithochemistry (PIXL) for Mars 2020, Powder Diffraction Journal 33 (2018) 162 – 165.
  • C. M. Heirwegh, M. Petric, S. Fazinić, M. Kavčič, I. Božičević Mihalić, J. Schneider, I. Zamboni, J. L. Campbell, Multiple ionization X-ray satellites of Mg, Al and Si in alpha particle PIXE, Nucl. Instrum. Meth. B. 428 (2018) 9 – 16.