Professor and Associate Director
Scientific Interests and Work
Studying matter at extreme conditions, with an emphasis on the response of low-Z materials at conditions relevant to planetary interiors.
Dr. Knudson’s research activities have emphasized experimental studies using dynamic compression to explore problems of interest to high-energy-density physics. Of particular interest is the development of novel experimental techniques to access a wide range of the equation of state surface, including: magnetic ramp compression to access states near the room temperature isotherm; magnetically accelerated flyer plates to access the Principal Hugoniot at TPa pressures; combined shock and ramp compression to access states between the room temperature isotherm and the Hugoniot; and high-pressure shock and deep release to access states near the vapor dome. Much of Dr. Knudson’s work is related to the emerging field of warm dense matter (WDM).
Dr. Knudson’s background in shock wave physics began as a graduate student, where his research focused on the use of picosecond time-resolved electronic spectroscopy to investigate a shock-induced phase transition. After earning his Ph.D., Dr. Knudson joined Sandia National Laboratories as a staff scientist in the Pulsed Power Science center. There he was part of a team that developed the Sandia Z Machine into a magnetic compression platform for performing multi-Mbar dynamic compression experiments (both shock and ramp compression) with unprecedented accuracy. Using this platform Dr. Knudson has addressed a number of topics of interest in high-energy-density physics, including resolving a controversy in the shock response of liquid deuterium in the Mbar regime, experimentally observing a diamond-bc8-liquid triple point along the melt boundary of carbon, and identifying a large discrepancy in the compressibility of water at planetary conditions. More recently, Dr. Knudson pioneered a capability to perform shock-ramp experiments on liquids and used this technique to directly observe an abrupt liquid-liquid, insulator-to-metal transition in dense liquid deuterium. Dr. Knudson began a Joint Appointment between Sandia National Laboratories and the Institute for Shock Physics in August 2015. In August 2017 Dr. Knudson joined the Institute for Shock Physics full time as a Professor and Associate Director.
Ph.D. (Physics), 1998, Washington State University, Pullman, WA
B.A. (Physics and Mathematics), 1993, St. John’s University, Collegeville, MN
Honors and Recognition
- Recipient, George E. Duvall Shock Compression Science Scholarship, 1998
- Principal Member of Technical Staff, Sandia National Laboratories, 2000
- Chairman, American Physical Society Topical Group on Shock Compression of Condensed Matter, 2009
- Distinguished Member of Technical Staff, Sandia National Laboratories, 2010
- Fellow, American Physical Society, 2013
- M.D. Knudson, M.P. Desjarlais, A. Becker, R.W. Lemke, K.R. Cochrane, M.E. Savage, D.E. Bliss, T.R. Mattsson, and R. Redmer, “Direct observation of an abrupt insulator-to-metal transition in dense liquid deuterium,” Science, 348, 1455 (2015).
- M.D. Knudson and M.P. Desjarlais, “Adiabatic release measurements in a-quartz between 300 and 1200 GPa: Characterization of a-quartz as a shock standard in the multi-megabar regime,” Phys. Rev. B 88, 184107 (2013).
- M.D. Knudson, M.P. Desjarlais, R.W. Lemke, T.R. Mattsson, M. French, N. Nettelmann, and R. Redmer, “Probing the interiors of the ice giants: Shock compression of water to 700 GPa and 3.8 g/cc,” Phys. Rev. Lett. 108, 091102 (2012).
- M.D. Knudson and M.P. Desjarlais, “Shock compression of quartz to 1.6 TPa: Redefining a pressure standard,” Phys. Rev. Lett. 103, 225501 (2009).
- M.D. Knudson, M.P. Desjarlais, and D.H. Dolan, “Shock-wave exploration of the high- pressure phases of carbon,” Science 322, 1822 (2008).
- D.H. Dolan, M.D. Knudson, C.A. Hall, and C. Deeney, “A metastable limit for compressed liquid water,” Nature Physics 3, 339 (2007).
- M.D. Knudson, D.L. Hanson, J.E. Bailey, C.A. Hall, J.R. Asay, and C. Deeney, “Principal Hugoniot, reverberating wave, and mechanical reshock measurements of liquid deuterium to 400 GPa using plate impact techniques,” Phys. Rev. B 69, 144209 (2004).