Chris is a scientist with expertise in fundamental physics of X-ray fluorescence (XRF) spectroscopy and ion-beam analytical techniques.His earlier work at the University of Guelph, in Canada, supported analysis of data returned from the alpha-particle X-ray spectrometers (APXS) on Opportunity (Mars Exploration Rover – MER) and Curiosity (Mars Science Laboratory - MSL) rovers.

At JPL, Chris serves as the science-engineering liaison for the integration and testing phase of the Planetary Instrument for X-ray Lithochemistry (PIXL), selected for Mars 2020. He also formulates test plans used in the verification and validation of PIXL instrument fidelity and has a key role in supporting analysis and interpretation of test results. Chris’ current research focuses on developing quantification techniques that planetary scientists could use to extract elemental abundances from micro-focus XRF measurements made of the Martian rock and soil. His efforts are in support the 2020 mission goals to learn about Mars’ early geological history and search for signs of past life.

Also at JPL, Chris is leading a JPL-funded project to develop a newer form of XRF technology that utilizes thermally cycled pyro-electric crystals to produce a primary X-ray flux. In this project, the Pyroelectric Instrument for Rock Analysis (PIRANA) Chris is directing efforts to optimize the balance of increasing X-ray yield while minimizing consumption of operational resources, such as power. His group is planning to develop software that can perform elemental analysis using PIRANA as an X-ray source.

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

• Fundamental physics of X-ray fluorescence (XRF) spectroscopy and instrument development
• Quantitative elemental geo-chemistry
• Semi-conductor detector physics and signal processing
• Wavelength dispersive X-ray spectroscopy techniques
• Particle induced X-ray emission (PIXE) studies and techniques

• Scientist, Jet Propulsion Laboratory (2018 – present)
• JPL Postdoctoral Scholar, Jet Propulsion Laboratory (2018)
• Caltech Postdoctoral Fellow, Jet Propulsion Laboratory (2016 – 2018)
• Course Instructor, University of Guelph (2015)
• Postdoctoral Fellow in Physics, University of Guelph (2014 – 2016)
• Research Assistant (doctorate), University of Guelph (2009 – 2014)
• Research Assistant (masters), McMaster University (2006 – 2009)
• Teaching assistant (McMaster and U of Guelph (2004 – 2012)
• Summer Research Assistant, Juravinski Cancer Centre (2003)

Over the past several years, I have served as a reviewer for the Journal of Synchrotron Radiation, Nuclear Instruments and Methods A and X-ray Spectrometry.

• Invited Talk – 67^th Denver X-ray Conference, Colorado, Aug. 2018
• Best Poster Award – 2nd place, 14th PIXE conference, Somerset West, South Africa (2015)

• Allwood A C, Rosing M T, Flannery D T, Hurowitz J A and Heirwegh C M, “Reassessing Evidence of Life in 3,700 million year old rocks of Greenland,” Nature 563 (2018) 241 – 244.
• Heirwegh C M, Elam W T, Flannery D T and Allwood A C, “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.
• Heirwegh C M, Petric M, Fazinić S, Kavčič M, Božičević Mihalić I, Schneider J, Zamboni I, and Campbell J L, “Multiple ionization X-ray satellites of Mg, Al and Si in alpha particle PIXE,” Instrum. Meth. B 428 (2018) 9 – 16.
• Campbell J L, Ganly B, Heirwegh C M and Maxwell J A, “Separation of detector non-linearity issues and multiple ionization satellites in alpha-particle PIXE,” Nucl. Instrum. Meth. B 414 (2018) 38 – 44.
• Flannigan E L, Heirwegh C M and Campbell J L, “Role of the mass attenuation coefficient database in standardization of a silicon drift X-ray detector for PIXE analysis,” X-Ray Spectrom. 47 (2018) 63 - 71.
• Campbell J L, Heirwegh C M and Ganly B, “Non-linearity issues and multiple ionization satellites in the PIXE portion of spectra from the Mars alpha particle X-ray spectrometer,” Instrum. Meth. B 383 (2016) 143 – 151.
• Heirwegh C M, Campbell J L and Czamanske G K, “Refinement of of major- and minor-element PIXE analysis of rocks and minerals,” Instrum. Meth. B 336 (2016) 40 - 50.
• 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 (2013) 185602.