William Cassata

Portrait of  William Cassata

  • Title
    Staff Scientist
  • Email
  • Phone
    (925) 423-2812
  • Organization
    Not Available


Bill started his career at LLNL as a postdoc in the Nuclear & Chemical Sciences Division. He is presently the lead scientist of the Livermore Noble Gas Lab, a state-of-the-art facility for noble gas isotope ratio and abundance measurements. The noble gas mass spectrometry group includes two staff scientists, a post-doctoral researcher, and a graduate student from UC Davis. His current research efforts are focused in the Global Security and Physical and Life Sciences directorates at LLNL.

Research Interests

Bill's research seeks to use isotopic variations created by natural and anthropogenic processes to understand historical events or otherwise unobservable phenomena. His research primarily focuses on applications of noble gases to nuclear forensics, nuclear engineering, Earth and planetary science, and atmospheric dynamics. Cassata also specializes in applications of thermal ionization and inductively coupled plasma mass spectrometry to nuclear forensics.

Ph.D., Earth and Planetary Science, University of California, Berkeley, 2012

B.S., Geology and Geophysics, University of Wisconsin, Madison, 2007

  1. Zhang, S., Yu, E., Gates, S.D., Cassata, W.S., Makel, J., Thron, A.M., Bartel, C., Weimer, A.W., Faller, R., Stroeve, P., and Tringe, J.W., 2018, Helium interactions with alumina formed by atomic layer deposition show potential for mitigating problems with excess helium in spent nuclear fuel, Journal of Nuclear Materials 499, 301-311.
  2. Cassata, W.S., 2017, Meteorite constraints on Martian atmospheric loss and paleoclimate, Earth and Planetary Science Letters 479, 322-329.
  3. Cohen, B.E., Mark, D.F., Cassata, W.S., Lee, M.R., Tomkinson, T., and Smith, C.L., 2017, Taking the pulse of Mars via dating of a plume-fed volcano, Nature Communications 8, 640.
  4. Herd, C.D.K., Walton, E.L., … Cassata, W.S., et al., 2017, The Northwest Africa 8159 martian meteorite: Expanding the martian sampl`e suite to the early Amazonian, Geochimica et Cosmochimica Acta 218, 1-26.
  5. Divol, L., Pak., A. Berzak Hopkins, L.F., LePape, S., Meezan, N.B., … Cassata, W.S., et al., 2017, Symmetry control of an indirectly driven high-density-carbon implosion at high convergence and high velocity, Physics of Plasmas 24, 056309.
  6. Borg, L.E., Connelly, J.N., Cassata, W.S., Gaffney, A.M., and Bizzarro, M., 2017, Chronologic implications for slow cooling of troctolite 76535 and temporal relationships between the Mg-suite and the ferroan anorthosite suite, Geochimica et Cosmochimica Acta 201, 377-391.
  7. Wilson, D.C., Cassata, W.S., Sepke, S.M., Velsko, C.A., Huang, H., Yeamans, C.B., Kline, J.L., Yi, A., Simakov, A.N., Haan, S.W., Batha, S.H., Dewald, E.L., Rygg, J.R., Tommasini, R., Xu, H., Kong, C., Bae, J., and Rice, N., 2017, Use of 41Ar production to measure ablator areal density in NIF beryllium implosions, Physics of Plasmas 24, 022701.
  8. Tremblay, M.M., Shuster, D.L., Balco, G., and Cassata, W.S., 2017, Neon diffusion kinetics and implications for cosmogenic neon paleothermometry in feldspars, Geochimica et Cosmochimica Acta 205, 14-30.
  9. Gates, S.D., and Cassata, W.S., 2016, Application of the uranium–helium chronometer to the analysis of nuclear forensic materials, Analytical Chemistry 88, 12310-12315.
  10. Cassata, W.S., and Borg, L.E., 2016, A new approach to cosmogenic corrections in 40Ar/39Ar chronometry: Implications for the ages of Martian meteorites, Geochimica et Cosmochimica Acta 187, 279-293.
  11. Kristo, M.J., Gaffney, A., Marks, N., Knight, K.B., Cassata, W.S., and Hutcheon, I.D., 2016, Analysis of nuclear material out of regulatory control, Annual Reviews in Earth and Planetary Science 44, 555-579.
  12. Bleuel, D.L., Bernstein, L.A., Brand, C.A., Cassata, W.S., Daub, B.H., Dauffy, L.S., Goldblum, B.L., Hall, J.M., Hagmann, C.A., Hopkins, L.B., Khater, H.Y., Kritcher, A.L., Siem, S., Velsko, C.A., and Wiedeking, M., 2016, Method for Detection of Nuclear-Plasma Interactions in a 134Xe-Doped Exploding Pusher at the National Ignition Facility, Plasma Fusion Research 11, 3401075.
  13. Cassata, W.S., Velsko, C.A., Stoeffl, W., Jedlovec, D.R., Golod, A.B., Shaughnessy, D.A., Yeamans, C.B., Edwards, E.R., and Schneider, D.H.G, 2016, Determination of gaseous fission product yields from 14 MeV neutron induced fission of 238U at the National Ignition Facility, Journal of Radioanalytical and Nuclear Chemistry, doi:10.1007/s10967-015-4662-8.
  14. Shuster, D.L., and Cassata, W.S., 2015, Paleotemperatures at the lunar surfaces from open system behavior of cosmogenic 38Ar and radiogenic 40Ar, Geochimica et Cosmochimica Acta 155, 154-171.
  15. Cassata, W.S., and Renne, P.R., 2015, Reply to the comment of Lovera et al. (2015) on "Systematic variations of argon diffusion in feldspars and implications for thermochronometry" by Cassata and Renne, Geochimica et Cosmochimica Acta 157, 228-232.
  16. Cassata, W.S., Prussin, S., Knight, K.B., Isselhardt, B., Hutcheon, I.D., and Renne, P.R., 2014, When the dust settles: Applications of stable xenon isotopes to the formation of nuclear fallout, Journal of Environmental Radioactivity 137, 88-95.
  17. Tikoo, S.M., Weiss, B.P., Cassata, W.S., Shuster, D.L., Gattacceca, J., Lima, E.A., Suavet, C., Nimmo, F., and Fuller, M.D., 2014, Decline of the lunar core dynamo, Earth and Planetary Science Letters 404, 89-97.
  18. Cassata, W.S., 2014, In situ dating on Mars: A new approach to the K-Ar method utilizing cosmogenic argon, Acta Astronautica 94, 222-233.
  19. Iorio, M., Liddicoat, J., Budillon, F., Incoronato, A., Coe, R.S., Insinga, D.D., Cassata, W.S., Lubritto, C., Angelino, A., Tamburrino, S., 2014, Combined paleomagnetic secular variation and petrophysical records to time-constrain geological and hazardous events: An example from the eastern Tyrrehian Sea over the last 120 ka, Global and Planetary Change 113, 91-109.
  20. Negrini, R.M., McCuan, D., Horton, R., Lopez, J., Cassata, W.S., Channell, J.E., Verosub, K.L., Knott, J.R., Coe, R.S., Liddicoat, J.C., Lund, S., Benson, L.V., and Sarna-Wojcicki, A., 2014, Nongeocentric axial dipole field behavior during the Mono Lake Excursion, Journal of Geophysical Research - Solid Earth 119, doi: 10.1002/2013JB010846.
  21. Cassata, W.S., and Renne, P.R., 2013, Systematic variations of argon diffusion in feldspars and implications for thermochronometry, Geochimica et Cosmochimica Acta 112, 251-287.
  22. Suavet, C., Weiss, B.P., Cassata, W.S., Shuster, D.L., Gattacceca, J., Chan, L., Garrick-Bethell, I., Head, J.W., Grove, T.L., and Fuller, M.D., 2013, Persistence and origin of the lunar core dynamo, Proceedings of the National Academy of Sciences 110, 8453-8458.
  23. Cassata, W.S., and Renne, P.R., 2013, Kinetics of argon diffusion in calcite, Chemie der Erde 73, 113-115.
  24. Cassata, W.S., Shuster, D.L., Renne, P.R., and Weiss, B.P., 2012, Trapped Ar isotopes in meteorite ALH 84001 indicate Mars did not have a thick ancient atmosphere, Icarus 221, 461-465.
  25. Cassata, W.S., and Renne, P.R., 2012, Fossil raindrops and ancient air, "News and Views" article, Nature 484, 322-324.
  26. Shea, E.K., Weiss, B.P., Cassata, W.S., Shuster, D.L., Tikoo, S.M., Gattacceca, J., Grove, T.L., and Fuller, M., 2012, A long-lived lunar core dynamo, Science 335, 453-456.
  27. Gourbet, L., Shuster, D.L., Balco, G., Cassata, W.S., Rood, D., and Renne, P.R., 2012, Neon diffusion kinetics in olivine, pyroxene, and feldspar: Retentivity of cosmogenic and nucleogenic neon, Geochimica et Cosmochimica Acta 86, 21-36.
  28. Renne, P.R., Mulcahy, S.R., Cassata, W.S., Morgan, L.E., Kelley, S.P., Hlusko, L., and Njau, J., 2012, Retention of inherited argon by alkali feldspar xenocrysts in a magma: Kinetic constraints from Ba zoning profiles, Geochimica et Cosmochimica Acta 93, 129-142.
  29. Cassata, W.S., 2011, An isochron approach to 21Ne cosmic ray exposure dating by activation with deuteron-deuteron fusion neutrons, Chemical Geology 284, 21-25.
  30. Cassata, W.S., Renne, P.R., and Shuster, D.L., 2011, Argon diffusion in pyroxenes: Implications for thermochronometry and mantle degassing, Earth and Planetary Science Letters 304, 407-416.
  31. Huber, C., Cassata, W.S., and Renne, P.R., 2011, A lattice Boltzmann model for noble gas diffusion in solids: The importance of domain shape and diffusive anisotropy and implications for thermochronometry, Geochimica et Cosmochimica Acta 75, 2170-2186.
  32. Cassata, W.S., Shuster, D.L., Renne, P.R., and Weiss, B.P., 2010, Evidence for shock heating and constraints on Martian surface temperatures revealed by 40Ar/39Ar thermochronometry of Martian meteorites, Geochimica et Cosmochimica Acta 74, 6900-6920.
  33. Cassata, W.S., Singer, B.S., Liddicoat, J., and Coe, R., 2010, Reconciling discrepant chronologies for the geomagnetic excursion at Mono Lake: Insights from new 40Ar/39Ar dating experiments and a revised paleointensity correlation, Quaternary Geochronology 5, 533-543.
  34. Shuster, D.L., Balco, G., Cassata, W.S., Fernandes, V.A., Garrick-Bethell, I., and Weiss, B.P., 2010, A record of impacts preserved in the lunar regolith, Earth & Planetary Science Letters 290, 155-165.
  35. Cassata, W.S., Renne, P.R., and Shuster, D.L., 2009, Argon diffusion in plagioclase and implications for thermochronometry: A case study from the Bushveld Complex, South Africa, Geochimica et Cosmochimica Acta 73, 6600-6612.
  36. Renne, P.R., Cassata, W.S., and Morgan, L., 2009, The isotopic composition of atmospheric argon and 40Ar/39Ar geochronology: Time for a change?, Quaternary Geochronology 4, 288-298.
  37. Cassata, W.S., Singer, B.S., and Cassidy, J., 2008, Laschamp and Mono Lake geomagnetic excursions recorded in New Zealand, Earth and Planetary Science Letters 268, 76-88.