PNNL

Dr. Aalseth is a nuclear physicist at Pacific Northwest National Laboratory (PNNL) specializing in fundamental nuclear and particle physics research and its applications in national security. At PNNL, Dr. Aalseth advances research by developing and connecting PNNL’s unique capabilities in ultra-sensitive nuclear measurements to address new and evolving challenges in national security, environmental science, and fundamental physics.

Dr. Aalseth’s work directly enhances the U.S. government's ability to effectively respond to security threats, study environmental processes using radioisotopes, and further the understanding of fundamental physics by measuring the mass and character of neutrinos and observing dark matter. Currently, Dr. Aalseth leads the Ultra-Sensitive Nuclear Measurements program, which includes PNNL’s Shallow Underground Laboratory—a unique national resource that combines cosmic-ray shielding, cleanroom operations, and ultra-pure materials to enable the development of new ultra-sensitive measurements and capabilities. 

Over his two-decade career at PNNL, Dr. Aalseth has served as chief scientist for the Ultra-Sensitive Nuclear Measurements Initiative, a laboratory directed research and development project which has fostered new research efforts even after its completion in 2016. He also leads the strategic vision for national security applications of underground laboratory measurements, which has been adopted by both internal and external stakeholders and is a driving force for new application areas and research priorities. 

Dr. Aalseth has played a leading role in the Majorana Collaboration, an international group proposing and executing next-generation neutrino mass experiments. Through this and other fundamental physics collaborations, such as the International Germanium Experiment, Coherent Germanium Neutrino Technology, and, most recently, the DarkSide-50 liquid-argon-based dark-matter search, he maintains connection to the international neutrino mass, dark matter, and ultra-low-background research communities.

His international engagements include representing PNNL to the International Committee on Radionuclide Metrology and participating in international workshops, such as Tracer Applications of Noble Gas Radionuclides in the Geosciences. Dr. Aalseth has also been an invited participant in working groups as a technical expert in low-level measurements of 37Ar for nuclear treaty verification by the Comprehensive Nuclear-Test-Ban Treaty Organization.

• Nuclear Physics 
• Particle Physics 
• Ultra-sensitive Nuclear Measurements 
• Radioisotope Techniques 
• Dark Matter Research

• PhD in nuclear and astroparticle physics, University of South Carolina, 2000
• BS in physics, South Dakota School of Mines and Technology, 1991

• Member, American Physical Society
• Member, IEEE
• Institutional Representative for PNNL, International Committee on Radionuclide Metrology 

• IEEE Nuclear and Plasma Science Society Early Achievement Award, 2006
• Laboratory Director’s Award for Early Career Achievement, PNNL, 2005

2022

Reduction of detection limit and quantification uncertainty due to interferent by neural classification with abstention. Hagen A.R., K.D. Jarman, J.D. Ward, G.C. Eiden, C.J. Barinaga, E.K. Mace, and C.E. Aalseth, et al. 2022. Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 1040. 

2021

Groundwater Residence Time Estimates Obscured by Anthropogenic Carbonate Seltzer A.M., D.V. Bekaert, P.H. Barry, K.E. Durkin, E.K. Mace, C.E. Aalseth, and J.C. Zappala, et al. 2021. Science Advances Vol. 7, no. No. 17:eabf3503

2020 

High Throughput Argon-37 Field System. Hayes J.C., C.E. Aalseth, T.R. Alexander, H.O. Back, E.D. Church, M.P. Foxe, and T.W. Hossbach, et al. 2020. Pure and Applied Geophysics.    

2018 

Prediction of sub-surface 37Ar concentrations at locations in the Northwestern United States. Fritz B.G., C.E. Aalseth, H.O. Back, J.C. Hayes, P.H. Humble, P. Ivanusa, and E.K. Mace. 2018. Journal of Environmental Radioactivity 181. 

Search for Neutrinoless Double-ß Decay in 76Ge with the Majorana Demonstrator. Aalseth C.E., N. Abgrall, E. Aguayo, S.I. Alvis, M. Amman, I.J. Arnquist, and F.T. Avignone, et al. 2018. Physical Review Letters 120, no. 13:Article No. 132502.

DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS. Aalseth C.E., F. Acerbi, P. Agnes, I. Albuquerque, T.R. Alexander, A. Alici, and A. Alton, et al. 2018. European Physical Journal Plus 133, no. 3:Article No. 131. 

Direct Low-Energy Measurement of 37Ar and 127Xe in a Radiotracer Gas using Low-Background Proportional Counters. Mace E.K., C.E. Aalseth, A.R. Day, E.W. Hoppe, J.I. McIntyre, A. Seifert, and R.M. Williams. 2018. Journal of Radioanalytical and Nuclear Chemistry 318, no. 1:125-129.

2017 

Simultaneous Measurement of Tritium and Radiocarbon by Ultra-Low-Background Proportional Counting. Mace E.K., C.E. Aalseth, T.R. Alexander, H.O. Back, A.R. Day, E.W. Hoppe, and M.E. Keillor, et al. 2017. "Simultaneous Measurement of Tritium and Radiocarbon by Ultra-Low-Background Proportional Counting." Applied Radiation and Isotopes 126. 

Methods for Using Argon-39 to Age-Date Groundwater using Ultra-Low-Background Proportional Counting. Mace E.K., C.E. Aalseth, J.M. Brandenberger, A.R. Day, E.W. Hoppe, P.H. Humble, and M.E. Keillor, et al. 2017. "Methods for Using Argon-39 to Age-Date Groundwater using Ultra-Low-Background Proportional Counting." Applied Radiation and Isotopes 126. 

Development of a Low-Level 39Ar Calibration Standard – Analysis by Absolute Gas Counting Measurements Augmented with Simulation. Williams R.M., C.E. Aalseth, J.M. Brandenberger, A.R. Day, E.C. Finn, E.S. Fuller, and E.W. Hoppe, et al. 2017. Applied Radiation and Isotopes 126.

2016

Development of a Low-Level Ar-37 Calibration Standard  . Williams R.M., C.E. Aalseth, T.W. Bowyer, A.R. Day, E.S. Fuller, D.A. Haas, and J.C. Hayes, et al. 2016. Applied Radiation and Isotopes 109. doi:10.1016/j.apradiso.2015.12.027

First results of a simultaneous measurement of tritium and 14C in an ultra-low-background proportional counter for environmental sources of methane. Mace E.K., C.E. Aalseth, A.R. Day, E.W. Hoppe, M.E. Keillor, J.J. Moran, and M.E. Panisko, et al. 2016. Journal of Environmental Radioactivity 155-156. 

Assay Methods for 238U, 232Th, and 210Pb in Lead and Calibration of 210Bi Bremsstrahlung Emission from Lead. Orrell J.L., C.E. Aalseth, I.J. Arnquist, T.A. Eggemeyer, B.D. Glasgow, E.W. Hoppe, and M.E. Keillor, et al. 2016. Journal of Radioanalytical and Nuclear Chemistry 309, no. 3:1271-1281. 

Measurement Background and the Sediment Age-Dating Reach of 32Si. Keillor M.E., C.E. Aalseth, L.M. Arrigo, J.M. Brandenberger, J.M. Cloutier, G.C. Eiden, and J.E. Fast, et al. 2016. Journal of Radioanalytical and Nuclear Chemistry 307, no. 3:2313-2319. 

2015

The DarkSide Multiton Detector for the Direct Dark Matter Search. Aalseth C.E., P. Agnes, A. Alton, K. Arisaka, D.M. Asner, H.O. Back, and B. Baldin, et al. 2015. Advances in High Energy Physics Volume 2015. 

2013

CoGeNT: A Search for Low-Mass Dark Matter Using Type Point Contact Germanium Detectors. Aalseth C.E., P.S. Barbeau, J. Colaresi, J. Colaresi, J.I. Collar, J. Diaz Leon, and J.E. Fast, et al. 2013. Physical Review D 88, no. 1:Article No. 012002. 

2012

A shallow Underground Laboratory for Low-Background Radiation Measurments and Materials Development. Aalseth C.E., R. Bonicalzi, M.G. Cantaloub, A.R. Day, L.E. Erikson, J.E. Fast, and J.B. Forrester, et al. 2012. Review of Scientific Instruments 83, no. 11:Article No. 113503.