Current Team Members

John Mattingly
John Mattingly

John Mattingly, Associate Professor of Nuclear Engineering: Prof. Mattingly leads the RADIANS research team.  His expertise includes active and passive neutron multiplicity and gamma spectroscopy measurements of Special Nuclear Material (SNM) and inverse methods for inferring SNM properties (mass, enrichment, and multiplication) from neutron and gamma measurements.

You can find Prof. Mattingly’s bio here.

 

Dr. Jonathan Mueller (right)
Jonathan Mueller (right)

Jonathan Mueller, Postdoctoral Scholar: Dr. Mueller has a Ph.D. in Physics from Duke University, where his research uncovered asymmetries in photofission-induced neutron emission that differ between fissile and non-fissile isotopes of uranium and plutonium.  Jonathan’s current research focuses on the analysis of neutron and gamma time-correlation and multiplicity experiments conducted with fast organic scintillators and digital data acquisition systems.  Dr. Mueller is also working with Ph.D. students Rob Weldon and Mudit Mishra to design an experiment to characterize the anisotropy of crystalline organic scintillator sensitivity to neutrons.

 

Michael Boyd
Michael Boyd

Michael Boyd, M.N.E. student: Michael is studying the temporal and spectral resolution of cerium bromide (CeBr3 – a new inorganic scintillator) using digital pulse processing and analysis methods.  His work will enable digital pulse pile-up corrections for gamma spectroscopic measurements acquired at extremely high counting rates.  Michael is working with Ph.D. student Alex Clark to model the dynamics of CeBr3 pulse shape evolution.

 

Pete Chapman
Pete Chapman

Pete Chapman (LTC US Army), Ph.D. student: Pete is developing digital pulse processing and analysis methods to study the dynamics of fission chain-reactions.  His work will exploit the temporal evolution of neutron and gamma time-correlation signatures to differentiate between chemical neutron sources (e.g., AmBe), spontaneous fission sources (e.g. 252Cf), and subcritical masses of fissile material (e.g., weapons-grade plutonium).  Pete is working with Jack Linkous and Dr. Jonathan Mueller to develop his fission chain-reaction dynamics analyses.

Alex Clark
Alex Clark

Alex Clark, Ph.D. student: Alex is developing parameter estimation methods using perturbation theory applied to deterministic models of neutron multiplicity statistics.  Alex’s work will allow fundamental nuclear data (e.g., cross-sections) to be adjusted so that computational simulations of subcritical experiments match measured neutron multiplicity statistics.  Alex is working with Ph.D. student Sean O’Brien to develop his parameter estimation methods.

 

Garrett Dean
Garrett Dean

Garrett Dean, Ph.D. student: Garrett is developing computational models that predict the gamma spectrum emitted by neutron-irradiated special nuclear material (SNM).  He has implemented inverse analysis methods that solve for the pre-irradiation composition and irradiation history of SNM.  His research will enable rapid forensic analysis of irradiated SNM using gamma spectroscopy measurements acquired by field-deployable instruments.

 

Jason Hite
Jason Hite

Jason Hite, M.S. student: Jason is developing a framework to locate radiation sources in urban environments using Markov Chain Monte Carlo parameter estimation applied to radiation sensor networks.  His work will enable emergency responders to design the optimal deployment of radiation sensors to locate a ‘loose source’ in cluttered urban environments.  Jason’s research was chosen as the basis for the Consortium for Nonproliferation Enabling Capabilities (CNEC) Simulation, Analysis, and Modeling (SAM) Challenge Problem.

 

Jack Linkous
Jack Linkous

Jack Linkous: Jack is working with Oak Ridge National Laboratory (ORNL) to implement image reconstruction methods for ORNL’s neutron coded-aperature imager (NCAI) that exploit the dynamics of the temporal evolution of neutron and gamma time-correlation signatures.  Jack’s work will differentiate between images acquired from chemical neutron sources (e.g., AmBe), spontaneous fission sources (e.g. 252Cf), and subcritical masses of fissile material (e.g., weapons-grade plutonium).  Jack is working with Ph.D. student Pete Chapman and Dr. Jonathan Mueller.

 

Gabe and Natalia Lucero
Gabe and Natalia Lucero

Gabe Lucero (CPT US Army), M.S. student: Gabe is developing multivariate analysis of variance (MANOVA) applied to simulations of nuclear fallout formation using the Defense Land Fallout Interpretive Code (DELFIC).  Gabe’s work will enable the forensic analysis of nuclear fallout to infer the pre-detonation device composition (e.g., 235U vs. 239Pu) and the during-detonation neutron spectrum (e.g., fission vs. fusion) from gamma spectroscopic measurements of fallout using field-deployable instruments.

 

Mudit Mishra
Mudit Mishra

Mudit Mishra, Ph.D. student: Mudit is developing a data acquisition system that will employ the tunable, monochromatic neutron beam constructed by Duke University Physics Professor Phil Barbeau to acquire high-resolution measurements of the response function of stilbene, anthracene, and other organic scintillators.  Mudit is working with Ph.D. student Rob Weldon and postdoctoral scholar Dr. Jonathan Mueller.

 

Sean O'Brien (left)
Sean O’Brien (left)

Sean O’Brien, Ph.D. student: Sean is developing mathematical and numerical models to estimate the sensitivity of neutron multiplicity counting statistics to variations in fundamental nuclear data.  The models Sean is developing will enable future evaluations of fundamental nuclear data using subcritical neutron multiplicity measurements.  Sean recently won a J. D. Williams student paper award from the Institute of Nuclear Materials Management.

 

Kelsey Reamer
Kelsey Reamer

Kelsey Reamer, B.S. student: Kelsey has worked with the RADIANS team for several years conducting independent undergraduate research.  Kelsey conducted experiments to quantitatively characterize the linearity, resolution, and efficiency of cerium bromide (CeBr3 – a new inorganic scintillator), which she presented to the Institute of Nuclear Materials Management (INMM) during their 2014 and 2015 annual meetings.  Kelsey is also the Immediate Past President of the NCSU INMM student chapter.  In summer 2015, Kelsey interned at Sandia National Laboratories (SNL), where she analyzed experiments to characterize a new neutron multiplicity counter jointly being developed by SNL, Los Alamos National Laboratory (LANL), and Lawrence Livermore National Laboratory (LLNL).

 

Kyle Weinfurther
Kyle Weinfurther

Kyle Weinfurther, Ph.D. student: Kyle is designing a high-efficiency, single-volume scatter camera (SVSC) with Sandia National Laboratories (SNL).  Kyle’s research is focused on developing an optically-segmented SVSC that has the potential to improve the efficiency of neutron source location by a factor of 10.  His work will enable rapid location of neutron sources for long-standoff, wide-area searches.  His work is supported by SNL’s Laboratory Directed R&D (LDRD) program.

 

Rob Weldon
Rob Weldon

Rob Weldon, Ph.D. student: Rob is designing an experiment to characterize the anisotropy of scintillation photon emission in crystalline organic scintillators (stilbene and anthracene) in conjunction with the Triangle Universities Nuclear Laboratory (TUNL).  Rob will employ the tunable, monochromatic neutron beam constructed by Duke University Physics Professor Phil Barbeau to acquire high-resolution measurements of the response function of stilbene, anthracene, and other organic scintillators.  Rob’s research will produce the most precise evaluations of organic scintillator sensitivity to neutrons ever measured.  Rob is working with Dr. Jonathan Mueller and Ph.D. student Mudit Mishra to design this experiment.