Samuel A. Briggs

Profile Information
Name
Dr. Samuel A. Briggs
Institution
Oregon State University
Position
Assistant Professor
h-Index
ORCID
0000-0002-2490-4720
Biography

Assistant Professor in the School of Nuclear Science & Engineering at Oregon State University. Research interests include enabling next-generation nuclear reactor technologies through materials design and development. Expertise in microstructural characterization and microscopy of radiation damage in materials, with a focus on advanced steels and structural metals.

Graduated from the University of Wisconsin-Madison with Ph.D. in Nuclear Engineering & Engineering Physics while studying under Dr. Todd Allen/Kumar Sridharan. Dissertation research emphasizes characterization of precipitates in FeCrAl alloys using correlative microscopy techniques, including atom probe tomography, small-angle neutron scattering, and analytical transmission electron microscopy techniques. Previously worked at the In-situ Ion Irradiation Transmission Electron Microscopy (I3TEM) facility at Sandia National Laboratories studying microstructural evolution of materials exposed to extreme environments.

Graduated from Oregon State University with a B.S. in Nuclear Engineering and minors in Mathematics and Chemistry in 2011.

Expertise
Atom Probe Tomography (ATP), Chromium Precipitates, Ferritic/Martensitic (F/M) Steels
Publications:
"A combined APT and SANS investigation of a' phase precipitation in neutron-irradiated model FeCrAl alloys" Philip Edmondson, Kevin Field, Kumar Sridharan, Kurt Terrani, Samuel A. Briggs, Kenneth Littrell, Yukinori Yamamoto, Richard Howard, Charles Daily, Acta Materialia Vol. 129 2017 217-228 Link
"Complementary Techniques for Quantification of a' Phase Precipitation in Neutron-Irradiated Fe-Cr-Al Model Alloys" Samuel A. Briggs, Philip Edmondson, Kevin Field, Kumar Sridharan, Yukinori Yamamoto, Kenneth Littrell, Charles Daily, Microscopy & Microanalysis Vol. 22 2016 1470-1471 Link
"Correlative Microscopy of Neutron-Irradiated Materials" Samuel A. Briggs, Kevin Field, Kumar Sridharan, Advanced Materials & Processes Vol. 174 2016 16-21 Link
Development of new, radiation-tolerant materials that maintain the structural integrity and safety margins over the course of a nuclear power reactor’s service life requires the ability to predict degradation phenomena.
"Dependencies of a' embrittlement in neutron-irradiated model Fe-Cr-Al alloys" Samuel A. Briggs, Philip Edmondson, Kevin Field, Kumar Sridharan, ANS Transactions Vol. 114 2016 1046-1047 Link
"Dislocation loop evolution during in-situ ion irradiation of model FeCrAl alloys" Philip Edmondson, Kevin Field, Jack Haley, Steve Roberts, Kumar Sridharan, Samuel A. Briggs, Sergio Lozano-Perez, Acta Materialia Vol. 136 2017 390-401 Link
Model FeCrAl alloys of Fe-10%Cr-5%Al, Fe-12%Cr-4.5%Al, Fe-15%Cr-4%Al, and Fe-18%Cr-3%Al (in wt %) were irradiated with 1 MeV Kr++ ions in-situ with transmission electron microscopy to a dose of 2.5 displacements per atom (dpa) at 320 °C. In all cases, the microstructural damage consisted of dislocation loops with ½<111> and <100> Burgers vectors. The proportion of ½<111> dislocation loops varied from ~50% in the Fe-10%Cr-5%Al model alloy and the Fe-18Cr%-3%Al model alloy to a peak of ~80% in the model Fe-15%Cr-4.5%Al alloy. The dislocation loop volume density increased with dose for all alloys and showed signs of approaching an upper limit. The total loop populations at 2.5 dpa had a slight (and possibly insignificant) decline as the chromium content was increased from 10 to 15 wt %, but the Fe-18%Cr-3%Al alloy had a dislocation loop population ~50% smaller than the other model alloys. The largest dislocation loops in each alloy had image sizes of close to 20 nm in the micrographs, and the median diameters for all alloys ranged from 6 to 8 nm. Nature analysis by the inside-outside method indicated most dislocation loops were interstitial type.
"Effect of friction stir welding and self-ion irradiation on dispersoid evolution in oxide dispersion strengthened steel MA956 up to 25 dpa" Elizabeth Getto, Brad Baker, B. Tobie, Samuel A. Briggs, Khalid Hattar, K. Knipling, Journal of Nuclear Materials Vol. 515 2018 407-419 Link
"Irradiation-enhanced a' precipitation in model FeCrAl alloys" Philip Edmondson, Kevin Field, Kumar Sridharan, Samuel A. Briggs, Yukinori Yamamoto, Richard Howard, Kurt Terrani, Scripta Materialia Vol. 116 2016 112-116 Link
Model FeCrAl alloys with varying compositions (Fe(10–18)Cr(10–6)Al at.%) have been neutron irradiated at ~ 320 to damage levels of ~ 7 displacements per atom (dpa) to investigate the compositional influence on the formation of irradiation-induced Cr-rich a' precipitates using atom probe tomography. In all alloys, significant number densities of these precipitates were observed. Cluster compositions were investigated and it was found that the average cluster Cr content ranged between 51.1 and 62.5 at.% dependent on initial compositions. This is significantly lower than the Cr-content of a' in binary FeCr alloys. Significant partitioning of the Al from the a' precipitates was also observed.
"Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys" Samuel A. Briggs, Journal of Nuclear Materials Vol. 479 2016 48-58
Two binary Ni-Cr model alloys with 5 wt% Cr and 18 wt% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni4+ ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy.
"Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys" Samuel A. Briggs, Khalid Hattar, Janne Pakarinen, Kumar Sridharan, Mitra Taheri, Christopher Barr, Mahmood Mamivand, Dane Morgan, Journal of Nuclear Materials Vol. Volume 479 2016 48-58 Link
Two binary Ni-Cr model alloys with 5 wt% Cr and 18 wt% Cr were irradiated using 2 MeV protons at 400 and 500 °C and 20 MeV Ni4+ ions at 500 °C to investigate microstructural evolution as a function of composition, irradiation temperature, and irradiating ion species. Transmission electron microscopy (TEM) was applied to study irradiation-induced void and faulted Frank loops microstructures. Irradiations at 500 °C were shown to generate decreased densities of larger defects, likely due to increased barriers to defect nucleation as compared to 400 °C irradiations. Heavy ion irradiation resulted in a larger density of smaller voids when compared to proton irradiations, indicating in-cascade clustering of point defects. Cluster dynamics simulations were in good agreement with the experimental findings, suggesting that increases in Cr content lead to an increase in interstitial binding energy, leading to higher densities of smaller dislocation loops in the Ni-18Cr alloy as compared to the Ni-5Cr alloy.
Presentations:
"Effect of Friction Stir Welding on Microstructure Evolution on in situ and ex situ Self-Ion Irradiated MA956" Elizabeth Getto, Samuel A. Briggs, Khalid Hattar, Brad Baker, TMS 2018 March 11-15, (2018)
NSUF Articles:
U.S. DOE Nuclear Science User Facilities Awards 30 Rapid Turnaround Experiment Research Proposals - Awards total nearly $1.2 million The U.S. Department of Energy (DOE) Nuclear Science User Facilities (NSUF) has selected 30 new Rapid Turnaround Experiment (RTE) projects, totaling up to approximately $1.2 million. These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Wednesday, April 26, 2017 - Calls and Awards
DOE Awards 31 RTE Proposals, Opens FY-20 1st Call - Projects total $1.1 million; Next proposals due 10/31 Awards will go to 22 principal investigators from universities, six from national laboratories, and three from foreign universities. Tuesday, September 17, 2019 - Calls and Awards, Announcement
Additional Publications:
"Influence of welding and neutron irradiation on dislocation loop formation and α′ precipitation in a FeCrAl alloy" Samuel A. Briggs, Philip D. Edmondson, Maxim N. Gussev, Richard H. Howard, Kevin G. Field, Dalong Zhang, [2019] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2019.151784 · ISSN: 0022-3115
"Investigations of irradiation effects in crystalline and amorphous SiC" Mohamed S. El-Genk, Khalid Hattar, Samuel A. Briggs, Benjamin J. Cowen, [2019] Journal of Applied Physics · DOI: 10.1063/1.5085216 · ISSN: 0021-8979

The effects of irradiation on 3C-silicon carbide (SiC) and amorphous SiC (a-SiC) are investigated using both in situ transmission electron microscopy (TEM) and complementary molecular dynamics (MD) simulations. The single ion strikes identified in the in situ TEM irradiation experiments, utilizing a 1.7 MeV Au3+ ion beam with nanosecond resolution, are contrasted to MD simulation results of the defect cascades produced by 10–100 keV Si primary knock-on atoms (PKAs). The MD simulations also investigated defect structures that could possibly be responsible for the observed strain fields produced by single ion strikes in the TEM ion beam irradiation experiments. Both MD simulations and in situ TEM experiments show evidence of radiation damage in 3C-SiC but none in a-SiC. Selected area electron diffraction patterns, based on the results of MD simulations and in situ TEM irradiation experiments, show no evidence of structural changes in either 3C-SiC or a-SiC.

"Electrostatic subframing and compressive-sensing video in transmission electron microscopy" A. A. Moghadam, R. S. Bloom, S. T. Park, A. M. Monterrosa, P. M. Price, C. M. Barr, S. A. Briggs, K. Hattar, J. T. McKeown, D. J. Masiel, B. W. Reed, [2019] Structural Dynamics · DOI: 10.1063/1.5115162 · ISSN: 2329-7778

We present kilohertz-scale video capture rates in a transmission electron microscope, using a camera normally limited to hertz-scale acquisition. An electrostatic deflector rasters a discrete array of images over a large camera, decoupling the acquisition time per subframe from the camera readout time. Total-variation regularization allows features in overlapping subframes to be correctly placed in each frame. Moreover, the system can be operated in a compressive-sensing video mode, whereby the deflections are performed in a known pseudorandom sequence. Compressive sensing in effect performs data compression before the readout, such that the video resulting from the reconstruction can have substantially more total pixels than that were read from the camera. This allows, for example, 100 frames of video to be encoded and reconstructed using only 15 captured subframes in a single camera exposure. We demonstrate experimental tests including laser-driven melting/dewetting, sintering, and grain coarsening of nanostructured gold, with reconstructed video rates up to 10 kHz. The results exemplify the power of the technique by showing that it can be used to study the fundamentally different temporal behavior for the three different physical processes. Both sintering and coarsening exhibited self-limiting behavior, whereby the process essentially stopped even while the heating laser continued to strike the material. We attribute this to changes in laser absorption and to processes inherent to thin-film coarsening. In contrast, the dewetting proceeded at a relatively uniform rate after an initial incubation time consistent with the establishment of a steady-state temperature profile.

"Investigating Helium Bubble Nucleation and Growth through Simultaneous In-Situ Cryogenic, Ion Implantation, and Environmental Transmission Electron Microscopy" Samuel Briggs, Graeme Greaves, Anthony Monterrosa, Emily Aradi, Joshua D. Sugar, David B. Robinson, Khalid Hattar, Jonathan A. Hinks, Caitlin A. Taylor, [2019] Materials · DOI: 10.3390/ma12162618 · ISSN: 1996-1944

Palladium can readily dissociate molecular hydrogen at its surface, and rapidly accept it onto the octahedral sites of its face-centered cubic crystal structure. This can include radioactive tritium. As tritium β-decays with a half-life of 12.3 years, He-3 is generated in the metal lattice, causing significant degradation of the material. Helium bubble evolution at high concentrations can result in blister formation or exfoliation and must therefore be well understood to predict the longevity of materials that absorb tritium. A hydrogen over-pressure must be applied to palladium hydride to prevent hydrogen from desorbing from the metal, making it difficult to study tritium in palladium by methods that involve vacuum, such as electron microscopy. Recent improvements in in-situ ion implantation Transmission Electron Microscopy (TEM) allow for the direct observation of He bubble nucleation and growth in materials. In this work, we present results from preliminary experiments using the new ion implantation Environmental TEM (ETEM) at the University of Huddersfield to observe He bubble nucleation and growth, in-situ, in palladium at cryogenic temperatures in a hydrogen environment. After the initial nucleation phase, bubble diameter remained constant throughout the implantation, but bubble density increased with implantation time. β-phase palladium hydride was not observed to form during the experiments, likely indicating that the cryogenic implantation temperature played a dominating role in the bubble nucleation and growth behavior.

"Using high energy electrons for Elastic Recoil Detection of hydrogen" S.B. Van Deusen, S. Briggs, B.L. Doyle, [2019] Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms · DOI: 10.1016/j.nimb.2018.10.016 · ISSN: 0168-583X
"Effect of friction stir welding and self-ion irradiation on dispersoid evolution in oxide dispersion strengthened steel MA956 up to 25 dpa" B. Baker, B. Tobie, S. Briggs, K. Hattar, K. Knipling, E. Getto, [2019] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2018.12.040 · ISSN: 0022-3115
"A study of irradiation effects in TiO2 using molecular dynamics simulation and complementary in situ transmission electron microscopy" Mohamed S. El-Genk, Khalid Hattar, Samuel A. Briggs, Benjamin J. Cowen, [2018] Journal of Applied Physics · DOI: 10.1063/1.5045491 · ISSN: 0021-8979

Understanding radiation damage in crystalline systems at the atomic scale is essential for the development of multi-scale predictive models for advancing nuclear science and engineering applications. State-of-the-art techniques used for investigating irradiation effects include molecular dynamics (MD) simulations, which can provide attosecond resolution of damage cascades over picosecond time scales, and in situ transmission electron microscopy (TEM), which can provide millisecond resolution in real-time. In this work, MD simulations and in situ TEM ion beam irradiation of crystalline TiO2 with 46 keV Ti1− ions are performed and results are compared. The MD results show that the ratio of the titanium to oxygen defects evolves during the radiation cascade. The vacancies are produced mostly in the core, while self-interstitials are concentrated at the periphery of the cascade. Cluster analysis of the MD results confirms the formation of a void (or a cluster of vacancies) that contains as much as ≈10 000 vacancies in the ballistic phase, compared to &lt;1000 after annealing. The radial distribution functions and the simulated selected area electron diffraction patterns at the peak of the ballistic phase confirm the existence of a short-range order and medium-range order throughout the simulation. However, the long-range order reemerges after annealing of the cascade event in agreement with the in situ TEM ion beam irradiation experiments. The MD simulations and the experiments show no indication of amorphization.

"Role of refractory inclusions in the radiation-induced microstructure of APMT" Samuel A. Briggs, Kevin G. Field, Dalong Zhang, [2018] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2018.04.017 · EID: 2-s2.0-85045771819
"Precipitation of α′ in neutron irradiated commercial FeCrAl alloys" Kenneth C. Littrell, Samuel A. Briggs, Kevin G. Field, [2018] Scripta Materialia · DOI: 10.1016/j.scriptamat.2017.08.022 · EID: 2-s2.0-85027520077
"Precipitation of ?? in neutron irradiated commercial FeCrAl alloys" Kenneth C. Littrell, Samuel A. Briggs, Kevin G. Field, [2018] Scripta Materialia · DOI: 10.1016/j.scriptamat.2017.08.022 · EID: 2-s2.0-85027520077
"Dislocation loop formation in model FeCrAl alloys after neutron irradiation below 1 dpa" Samuel A. Briggs, Kumar Sridharan, Yukinori Yamamoto, Richard H. Howard, Kevin G. Field, [2017] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2017.07.061 · EID: 2-s2.0-85026742014
"Dislocation loop evolution during in-situ ion irradiation of model FeCrAl alloys" Samuel A. Briggs, Philip D. Edmondson, Kumar Sridharan, Steve G. Roberts, Sergio Lozano-Perez, Kevin G. Field, Jack C. Haley, [2017] Acta Materialia · DOI: 10.1016/j.actamat.2017.07.011 · EID: 2-s2.0-85024478265
"Mechanical properties of neutron-irradiated model and commercial FeCrAl alloys" Samuel A. Briggs, Kumar Sridharan, Richard H. Howard, Yukinori Yamamoto, Kevin G. Field, [2017] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2017.03.038 · EID: 2-s2.0-85017105464
"A combined APT and SANS investigation of α′ phase precipitation in neutron-irradiated model FeCrAl alloys" Philip D. Edmondson, Kenneth C. Littrell, Yukinori Yamamoto, Richard H. Howard, Charles R. Daily, Kurt A. Terrani, Kumar Sridharan, Kevin G. Field, Samuel A. Briggs, [2017] Acta Materialia · DOI: 10.1016/j.actamat.2017.02.077 · EID: 2-s2.0-85014720298
"A combined APT and SANS investigation of ?? phase precipitation in neutron-irradiated model FeCrAl alloys" Philip D. Edmondson, Kenneth C. Littrell, Yukinori Yamamoto, Richard H. Howard, Charles R. Daily, Kurt A. Terrani, Kumar Sridharan, Kevin G. Field, Samuel A. Briggs, [2017] Acta Materialia · DOI: 10.1016/j.actamat.2017.02.077 · EID: 2-s2.0-85014720298
"Heterogeneous dislocation loop formation near grain boundaries in a neutron-irradiated commercial FeCrAl alloy" Samuel A. Briggs, Xunxiang Hu, Yukinori Yamamoto, Richard H. Howard, Kumar Sridharan, Kevin G. Field, [2017] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2016.10.050 · EID: 2-s2.0-84996590378
"Correlative microscopy of neutron-irradiated materials" [2016] Advanced Materials and Processes · EID: 2-s2.0-85009401619
"Observations of defect structure evolution in proton and Ni ion irradiated Ni-Cr binary alloys" Christopher M. Barr, Janne Pakarinen, Mahmood Mamivand, Khalid Hattar, Dane D. Morgan, Mitra Taheri, Kumar Sridharan, Samuel A. Briggs, [2016] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2016.06.046 · EID: 2-s2.0-84978064532
"Irradiation-enhanced α′ precipitation in model FeCrAl alloys" S.A. Briggs, Y.Yamamoto, R.H. Howard, K. Sridharan, K.A. Terrani, K.G. Field, P.D. Edmondson, [2016] Scripta Materialia · DOI: 10.1016/j.scriptamat.2016.02.002 · EID: 2-s2.0-84959269326
Source: ORCID/CrossRef using DOI