Christopher M. Heirwegh

Address:

4800 Oak Grove Drive
M/S 183-301

Pasadena, CA 91109

Phone:

626-807-5420

Fax:

818-292-4445

Curriculum Vitae:

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Website:

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Member of:

Laboratory Studies

Biography

I am an applied physicist with expertise in X-ray fluorescence (XRF) fundamental physics and the fundamental parameters method used in XRF spectroscopy. My research interests involve refining techniques and analytical methods used in XRF spectroscopy to obtain the highest possible levels of accurate quantitative analysis. More recently as well, I have become involved developing XRF instrument concepts for future in situ planetary science missions.

I began working in planetary sciences while at the University of Guelph in Guelph, Canada where I conducted proton beamline research in the Guelph PIXE Group, to support analysis of data returned from the Curiosity Rover’s Alpha-Particle X-ray Spectrometer (APXS). Arriving at the Jet Propulsion Laboratory, California Institute of Technology of Pasadena, California in 2016, I led the elemental calibration effort for the Planetary Instrument for X-ray Lithochemistry (PIXL) presently installed on NASA’s Mars 2020 Perseverance Rover. I also served as science and engineering liaison during PIXL’s critical integration and testing phase of development. During PIXL’s development I provided extensive guidance on the development of PIXL’s open source XRF Quantification software, PIQUANT, and data visualization software, PIXLISE. Both are used by the PIXL team to process PIXL data returned from Mars.

As a scientist at JPL I am now a Mars 2020 Co-Investigator and serve as the PIXL science team’s operations manager. I continue to research means to refine PIXL’s elemental calibration using JPL’s breadboard prototype instrument locating in JPL’s PIXL Science Lab. Through this work, I hope to place better limits on the accuracy of measuring major and minor concentrations of rock-forming element-oxides such as those found in rocks measured by PIXL on Mars.

I am also leading the development of several instrument concepts. One includes developing a prototype thermal-electrically driven (pyroelectric) X-ray source as a potential cost-effective and robust alternative to the radioactive and X-ray tube source technologies typically integrated in spacecraft XRF spectrometers. My goal is to enhance the technological readiness of the pyroelectric source so that, like APXS, a pyroelectric source spectrometer can detect major and minor element abundances but can also extend the detectable range to higher atomic number.

For the Mars Sample Return (MSR) effort, I am also providing subject-matter expertise in our development of a hybrid PIXL – SHERLOC (XRF and ultraviolet – Raman spectrometer) that can be used to investigate samples cached by Perseverance rover and returned to a future sample return facility.

For exceptional achievements made as both science-engineering liaison and science operations manager for PIXL, I have twice received JPL’s Voyager Award.

Education

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

Annually, I serve as a reviewer for proposals and journals in my field and I periodically chair the Quantitative Analysis of XRF session at the annual Denver X-ray Conference. Through involvement in the Mars 2020 DEIA working group, I helped draft the positive values and behaviors guidelines now utilized by the Mars 2020 team. I also enjoy speaking with the public about my work and experiences in the planetary sciences.

Research Interests

X-ray fluorescence (XRF) instrumentation in planetary science
X- and γ-ray semiconductor detector physics
X-ray fundamental parameters accuracy and effects on analysis
High resolution XRF spectroscopy

Selected Awards

Plenary Speaker –Denver X-ray Conference 2022, Bethesda, Maryland, 2022

Voyager Award – For excellent leadership and growth in a new role managing PIXL science operations, JPL, 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

P. R. Lawson, T. V. Kizovski, M. M. Tice, B. C. Clark, S. J. VanBommel, D. R. Thompson, L. A. Wade, R. W. Denise, C. M. Heirwegh, W. T. Elam, M. E. Schmidt, Y. Liu, A. C. Allwood, M. S. Gilbert, B. J. Bornstein, Adaptive Sampling with PIXL on the Mars Perseverance Rover, Icarus, 429 (2025) 116433. doi:10.1016/j.icarus.2024.116433

S. J. VanBommel, S. Sharma, T. V. Kizovski, C. M. Heirwegh, J. R. Christian, A. L. Knight, B. Ganly, A. C. Allwood, J. A. Hurowitz, M. M. Tice, M. L. Cable, W. T. Elam, M. W. M. Jones, B. C. Clark, A. H. Treiman, M. E. Schmidt, Y. Liu, A. Das, Rare earth element assessment in Jezero crater using the Planetary Instrument for X-ray Lithochemistry on the Mars 2020 rover Perseverance: A case study of cerium, Icarus, 425 (2025) 116355. doi: 10.1016/j.icarus.2024.116355

A. Das, C. M. Heirwegh, N. Gao, B. C. Clark III, W. T. Elam, L. A. Wade A. C. Allwood, J. A. Hurowitz, Energy Dependence of X-ray Beam size Produced by Polycapillary X-Ray Optics, X-ray Spectrom., online (2024). doi:10.1002/xrs.3450

E. L. Scheller, T. Bosak, F. M. McCubbin, K. Williford, S. Siljeström, R. S. Jakubek, S. A. Eckley, R. V. Morris, S. V. Bykov, T. Kizovski, S. Asher, E. Berger, D. M. Bower, E. L. Cardarelli, B. L. Ehlmann, T. Fornaro, A. Fox, N. Haney, K. Hand, R. Roppel, S. Sharma, A. Steele, K. Uckert, A. G. Yanchilina, O. Beyssac, K. A. Farley, J. Henneke, C. M. Heirwegh, D. A. Klevang, Y. Liu, M. E. Schmidt, M. Sephton, D. Shuster, B. P. Weiss, Inorganic Interpretation of Luminescent Materials Encountered by the Perseverance Rover on Mars, Science Advances, 10 (2024) 39, eadm8241 doi:10.1126/sciadv.adm8241

C. M. Heirwegh, W. T. Elam, Y. Liu, C. Hummel, A. Das, A. C. Allwood, L. G. Armstrong, N. Bacop, K. P. Sinclair, L. P. O’Neil, L. A. Wade, M. C. Foote, M. E. Sondheim, R. W. Denise, P. R. Lawson, J. H. Kawamura, M. H. Au, A. Kitiyakara, R. A. Romero, J. A. Hurowitz, B. C. Clark III, G. R. Rossman, M. S. Anderson, Pre-Flight Calibration of PIXL for X-ray Fluorescence Elemental Quantification (2024) arXiv:2402.01544 [physics.app-ph].

C. Heirwegh, Methods and Reference Materials used to Calibrate PIXL, The Mars 2020 In Situ XRF Spectrometer, Microscopy and Microanalysis, 29 (2023) Suppl 1, 235 – 236. doi:10.1093/micmic/ozad067.105

J. R. Christian, S. J. VanBommel, W. T. Elam, B. Ganly, J. A. Hurowitz, C. M. Heirwegh, A. C. Allwood, B. C. Clark III, T. V. Kizovski, A. L. Knight, Statistical characterization of PIXL trace element detection limits, Acta Astronautica, 212 (2023) 534 – 540. doi:10.1016/j.actaastro.2023.08.032

D. A. Klevang, C. C. Liebe, J. Henneke, J. L. Jørgensen, R. Sharrow, T. Setterfield, L. Wade, M. Sondheim, M. Foote, W. T. Elam, C. M. Heirwegh, J. Hurowitz, A. Allwood, Pre-flight Geometric and Optical Calibration of the Planetary Instrument for X-ray Lithochemistry (PIXL), Space Sci. Rev. 219 (2023) 11. doi:10.1007/s11214-023-00955-1

B. J. Orenstein, D. T. Flannery, L. W. Casey, W. T. Elam, C. M. Heirwegh, M. W. M. Jones, A statistical approach to removing diffraction from X-ray fluorescence spectra. Spectrochimica Acta B, 200 (2023) 106603. doi:10.1016/j.sab.2022.106603

C. M. Heirwegh, W. T. Elam, L. P. O’Neil, K. P. Sinclair, A. Das, The Focused Beam X-ray Fluorescence Elemental Quantification Software Package PIQUANT, Spectrochim. Acta B, 196 (2022) 106520. doi:10.1016/j.sab.2022.106520.

W.T. Elam, C.M. Heirwegh, PIQUANT (Version 3.2.11) [Open source computer software] Zenodo. (2022) doi:10.5281/zenodo.6959225

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…, C. M. Heirwegh… et al., An olivine cumulate outcrop on the floor of Jezero crater, Mars, Science, 377 (2022) 1515 – 1519. doi:10.1126/science.abo2756

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. https://doi.org/10.1016/j.nimb.2021.05.004

A. C. Allwood, L. A. Wade, M. C. Foote,… C. M. Heirwegh,… et al., PIXL: Planetary Instrument for X-ray Lithochemistry, Space Sci. Rev. 216 (2020) 134. https://doi.org/10.1007/s11214-020-00767-7

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.

https://doi.org/10.1017/S0885715618000416