Dan T. Abell

Principal Research Scientist

 Dan T. Abell received his B.A. in physics from Swarthmore College in 1982 and his PhD from the University of Maryland at College Park in 1995. Dan is an expert on Hamiltonian methods and symplectic maps, especially with application to beam dynamics in particle accelerators. Early in his career, he developed the codes CREMONA and CTRACK to perform map symplectification and fast symplectic tracking. These codes were later used for tracking studies of the Large Hadron Collider (LHC). Dan helped to design the Spallation Neutron Source, considering the effect of magnet fringe fields on tune spread, the use of octupole magnets to shape the tune footprint, and particle tracking through the injection magnet to explore dumping of stripped electrons. Dan developed a technique for computing generalized gradients for rf cavity fields, used to compute high-order maps. He has worked extensively with the Polymorphic Tracking Code (PTC) and with GPUSPINTRACK, a GPU-accelerated code for fast and accurate tracking and analysis of spin-orbit motion in particle accelerators. Dan is now working on the development and implementation of symplectic algorithms for the efficient simulation of rf cavity beam loading in the presence of multiple high-order modes.

David Bruhwiler

President and CEO

David Bruhwiler has devoted over 25 years to the simulation of experiments and physical systems, including beam and laser-driven plasma accelerators, electron cooling of relativistic heavy ion beams, electron and ion sources, particle tracking and accelerator design and nonlinear dynamical systems. In addition to codeveloping both free and commercial software, and coauthoring more than 30 refereed journal articles, David has managed more than $10M in contracts and grants, and successfully mentored teams of more than 10 scientists, mathematicians and software developers. David is a Fellow of the American Physical Society.

Evan Carlin

Software Developer

Software Developer Evan Carlin received a BS in Computer Science from the University of Puget Sound. After graduation he worked as a consultant on a variety of software projects ranging from a cloud migration for a Fortune 500 bank to building a web app for a streaming TV Service. He then went to work for Google where he focused on customer support data analysis and new tool development.

Johan Carlsson

Principal Research Scientist

Principal Research Scientist Johan Carlsson has more than 20 years experience of computational plasma physics. He has an MSc in Engineering Physics from Lund University in Sweden, and a PhD in Fusion Plasma Physics from the Alfven Laboratory, Royal Institute of Technology in Stockholm. Dr. Carlsson has published more than 30 papers in peer-reviewed journals, and has been the PI for DOE FES and ASCR SBIR projects with funding totaling over $2M. In 2007 he received a Green Card as an Outstanding Professor or Researcher. His most recent publications are on Particle-In-Cell simulation of low-temperature plasmas for thruster and power-electronics applications, as well as of relativistic ion beams in background plasma.

Stephen Coleman

Research Scientist

 Stephen Coleman is a research scientist with experience in neutrino physics at Fermilab and J-PARC in Tokai, Japan. He studied physics at the University of Colorado, and received his Ph.D. from the College of William and Mary, working on muon neutrino oscillations in a muon neutrino beam. He also worked for several years in a biology laboratory on a DARPA-funded research project, studying the dynamics of proteins responding to chemical stimulus.

Nathan Cook

Research Scientist

Research Scientist Nathan Cook is an accelerator physicist who has a strong interest in laser driven ion acceleration and related applications in radiation therapy, medical imaging, and accelerator driven systems. He has published papers in peer reviewed journals on the subjects of laser driven ion acceleration, RF acceleration, and ion beam imaging diagnostics, and was an editor of the Pre-Conceptual Design Report for the Ion Rapid Cycling Medical Synchrotron project at Brookhaven National Laboratory. Nathan received his BA in Physics and Mathematics from Williams College and his PhD in Physics from Stony Brook University. His thesis work comprised novel approaches to RF acceleration of carbon ions for a rapid cycling medical synchrotron and laser driven shock acceleration of helium ions from a gas target.

Beck Cotter

Research Administrator

Rebecca “Beck” Cotter is our Research Administrator. She brings over 10 years of experience in pre-award management and proposal development from both a small business and government program perspective. She has worked extensively with the DOE, NASA, and the USAF to secure funding for earth science and climate related projects. Beck holds a bachelor’s degree in Kinesiology from the University of Houston.

Joan Danver

Operations Manager

Operations Manager Joan Danver comes to Radiasoft LLC with a background in project management in a small business setting. She has experience managing government contracted projects requiring extensive filings and oversight. Joan received her BA in Biology from Williams College and her MS in Biochemistry and Cell Biology from Stony Brook University, where she investigated the role of microglia in the brain.

Jonathan Edelen

Research Scientist

Research Scientist Jonathan Edelen is an accelerator physicist with a broad range of experience across the field. He specializes in thermionic cathode guns and space-charge effects in low energy electron beams. Jonathan earned a PhD in accelerator physics from Colorado State University. After completing his PhD Jonathan was selected for the prestigious Bardeen Fellowship at Fermilab. While at Fermilab he worked on RF systems for the PIP-II Injector Test, beam dynamics and RF transient effects in the proposed PIP-II accelerator, and thermionic cathode RF guns at the Advanced Photon Source. Currently, Jonathan is focused on building advanced control algorithms for particle accelerators including solutions involving machine learning. He is also developing improved simulation tools for studying field enhanced thermionic emission in thermionic energy converters. Jonathan has published papers and presented at international conferences on a variety of topics in accelerators.

Yury Eidelman

Senior Research Scientist

Senior Research Scientist Yury Eidelman is a leading scientist in particle accelerator technology and high energy physics, as well as an expert in the software and hardware of control systems. The Budker Institute of Nuclear Physics awarded Dr. Eidelman his PhD in 1968 and the title of Full Professor in 1996. Since 1999, Dr. Eidelman has worked on a wide variety of projects for Argonne National Laboratory, Brookhaven National Laboratory, Oak Ridge National Laboratory, Fermi National Accelerator Laboratory and Euclid Techlabs LLC. His professional interests include the design and simulation of shielding in high-power accelerator and detector facilities, longitudinal beam dynamics in linear accelerators, database and user interface design for scientific softare, polarized electron beams for colliders, beam dynamics in rings, diagnostics, medical physics, control systems and teaching. He has published over 90 articles on these and other topics.

Callie Federer

Associate Research Scientist

Associate Research Scientist Callie Federer received her BS cum laude in Computer Science from Truman State University and her PhD in Computational Bioscience from the University of Colorado Anschutz Medical Campus. Her thesis work, Putting More ‘Neural’ in Artificial Neural Networks, focused on the intersection of neuroscience and artificial intelligence – how we can use the brain to build better machine learning algorithms, and how can we use machine learning algorithms to better understand the brain? She was awarded the National Science Foundation (NSF) Graduate Research Fellowship in 2017 which is awarded to 16% of applications who have demonstrated the potential to be high achieving scientist and engineers early in careers.

Nick Goldring

Associate Research Scientist

Associate Research Scientist Nick Goldring is a practicing physicist with active research interests in x-ray science and accelerator physics. Before joining Radiasoft, Nicholas was a member of the multi-disciplinary team at Argonne National Laboratory tasked with upgrading the Advanced Photon Source (APS) Synchrotron Facility. During his time at ANL, he did significant work on the design and optimization of high heat load beamline optics. Nicholas has 4 years experience in modeling a variety of physical phenomena via finite element analysis (FEA) using software COMSOL as the primary tool. His familiarity with particle accelerator codes and FEA expertise allows him to continue research and development in the field of modern accelerator design. His current work includes the simulation of complex vacuum chamber systems and the development of user-friendly GUIs for the benefit of next generation particle accelerators. Nicholas received his BS in Chemistry from Oregon State University and his MS in Physics from the Illinois Institute of Technology in 2017.


Chris Hall

Research Scientist

Research Scientist Chris Hall is an expert in the simulation and analysis of collective beam effects in energy recovery linac (ERL) driven free-electron lasers (FEL), with an emphasis on coherent synchrotron radiation (CSR) effects. He developed techniques to mitigate the negative impact of CSR on the electron beam, based on analysis of experimental data from the Jefferson Laboratory ERL driven FEL. Chris received a BS in Physics and Mathematics from Hope College, his MS in Physics from Michigan State University, and his PhD in Electrical Engineering from Colorado State University in 2016.


Yuan Hu

Associate Research Scientist

Associate Research Scientist Yuan Hu is an expert in high performance scientific computing, and rarefied plasmas and gases. He received an MS in Computer Science and his PhD in Astronautical Engineering from the University of Southern California in 2018. He has been developing and using different particle simulation tools, including direct simulation Monte Carlo (DSMC), particle-in-cell (PIC), and molecular dynamics (MD), to study various nonequilibrium physical phenomena in space engineering, such as hypersonic rarefied aerodynamics, low temperature plasmas in electric propulsion, and dielectric materials’ athermal heating in microwave propulsion. He has coauthored more than 20 peer-reviewed journal articles and conference proceedings in these fields.


Mike Keilman

Senior Software Developer

Senior Software Developer Mike Keilman received his BS cum laude in Physics from Oberlin College and his PhD in Nuclear Physics at the University of Colorado. His thesis experiment, measurement of pion single charge exchange on Deuterium, ran at the Los Alamos Meson Physics Facility using the Neutral Meson Spectrometer. He analyzed the data with tools ranging from Fortran to shell scripting to an obscure language called “HTML”. Thus armed, he shifted to software development in the far-flung realms of herbal medicine and telecommunications, most recently hand-crafting a variety of iOS apps. At Radiasoft he builds and maintains web UIs based on the Sirepo framework, supporting back-end software for X-ray optics, particle accelerators, and other applications.


Paula Messamer

Product Manager

Product Manager Paula Messamer is an experienced research and design professional with extensive industry experience in new product development. Paula holds a PhD in Speech, Language, and Hearing Sciences from the University of Colorado and is on the Board of Directors of “Brain Buddy”- a local non-profit serving people with aphasia.

Paul Moeller

Principal Software Developer

Principal Software Developer Paul Moeller has developed real-world solutions in a variety of problem domains including finance, graphics, medical billing, and generic user interfaces. Paul holds a BS in Computer Science from Clarke University and an MS in Computer Science from Loyola University.

Rob Nagler


CTO Rob Nagler has designed and deployed leading-edge distributed systems for over 30 years. Rob has written extensively about software, including his book on agile development methods, Extreme Perl. Rob started his career in the Distributed Systems Group at Stanford working with Dr. David Cheriton. At Sun Microsystems, he worked with Eric Schmidt in the telecommunications group. He led OLAP development at Olsen & Associates, a pioneer in financial research and analysis. At Tandem Computers(tm) High Performance Research Center, Rob implemented a multi-platform, distributed architecture based on CORBA and used for internet traffic routing for mobile phone networks. Rob holds a BS in Computer Engineering from the University of California, San Diego and an MS in Computer Engineering from Stanford University.

Boaz Nash

Research Scientist

Research Scientist Boaz Nash is an accelerator physicist with an expertise in synchrotron light sources. Boaz studied math and physics at Reed college, and received his PhD from Stanford University in Physics, studying beam dynamics of electron storage rings. He did his first postdoc at Brookhaven National Lab, working on dynamic aperture and Touschek lifetime calculation and optimization for NSLS-II. Starting in 2009, he worked at the European Synchrotron Radiation Facility in Grenoble, France on existing ESRF, and design for the upgrade EBS machine. He is particularly interested in bridging the gap between the electron beam dynamics and experiments in the synchrotron light sources worldwide.

Ilya Pogorelov

Senior Research Scientist

Senior Research Scientist Ilya Pogorelov is a computational accelerator physicist with over 15 years of experience in the development of scientific software and high-fidelity simulation. He has worked on a number of projects in the areas of relativistic electron cooling, polarized beam transport, free-electron lasers, collective effects in beams, high-order modes in RF structures, non-equilibrium statistical physics, and nonlinear dynamical systems. Ilya’s work has been published in peer-reviewed journals and numerous conference proceedings, and he has been the PI for several DOE SBIR and internal R&D projects.

Leslie W. Rosczyk

Accounting and HR

Leslie W. Rosczyk is RadiaSoft’s Accounting and HR Specialist. Leslie has extensive experience with Government accounting, contract negotiations and closeouts as well as proposal submissions and human resource administration. Leslie holds a bachelor’s degree from the University of Wisconsin, Madison.

Xi Tan

Associate Research Scientist

Associate Research Scientist Xi Tan is an Associate Research Scientist at RadiaSoft LLC, and her research interests are computational plasma physics, plasm-boundary interactions, vacuum nanoelectronics, etc. Now she is working on high-performance PIC simulation for designing energy-efficient TECs (thermionic emission converters). Xi received her Ph.D. in Mechanical Engineering from the University of Notre Dame, and her thesis work focuses on field emission-driven microdischarges. Before that, she has a BS and multiple MS degrees in the field of energy engineering.

Stephen Webb

Senior Research Scientist

Senior Research Scientist Stephen Webb is an expert in scientific computing and theoretical plasma and beam physics, with an eye towards the theoretical underpinnings of computational algorithms. He has co-authored over twenty conference proceedings and peer-reviewed journal articles covering the fields of intense ion beams, free-electron lasers, and computational plasma and beam physics. Stephen holds a BS in Physics from Georgia Tech and a PhD in Accelerator Physics from Stony Brook University. The Air Force Office of Scientific Research (AFOSR) has awarded Stephen one of its prestigious 2015 Young Investigator Research Program awards. His project “High average power electron beams from a novel compact plasma wakefield accelerator” will develop fundamentally new algorithms and computational tools to enable the accurate simulation of novel ultra-bright electron beams for a wide variety of scientific, industrial and military applications.


Rami A. Kishek


Consultant Rami A. Kishek is also Research Professor at the University of Maryland (UMD), where he leads the UMER facility. He has 20 years experience in charged particle dynamics and is an expert on space charge effects, computation, and multipactor, where he made groundbreaking contributions to its theoretical modeling. He has published over 190 scientific papers, delivered 50 invited talks, and has over 1000 citations to his work. Rami has chaired several workshops, most recently the 4th Workshop on the Microbunching Instability in FELs (April, 2012). He has advised or co-advised 11 graduate students and guided the research of dozens more graduate, undergraduate and high school students. Rami teaches regularly at UMD and at the US Particle Accelerator School (USPAS). Rami is a Fellow of the American Physical Society and a Senior Member of IEEE. He was awarded the 2015 USPAS Prize for Achievement in Accelerator Science and Technology: For “groundbreaking work on the theory of multipactor discharge, his contributions to the understanding of physics of space-charge-dominated beams and his excellent mentorship of young scientists.”