Our Staff

Dan T. Abell

Senior 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.

Krista Beck

Executive Assistant

Krista Beck is RadiaSoft’s executive assistant. She received her BS in Ecology and her MS in Conservation Biology from the University of Minnesota. Krista has worked in the field of physics research support for 20 years.

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.

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.

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.

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.

Derrell Durrett

Senior Software Developer

Senior Software Developer Derrell Durrett (B.S., Physics, Texas Tech, 1986; Ph.D., Physics, U. of Colorado, 1993) worked on two experiments while pursuing his Ph.D.: SLD and MARK-II, helping to assemble, model, and write data-taking software for the former (specifically the Endcap Drift Chambers), and maintaining/improving, operating, and debugging the latter (specifically the Vertex Drift Chamber). He wrote his thesis on data from the PEP runs of MARK-II, searching for evidence of charmed strange mesons in events with high-momentum leptons.

When he found that the only remunerable skill he’d thus acquired was writing software, he took to that, writing code for a large variety of purposes, both professional (including twelve years working on the build systems for the EDA software of a large semiconductor company) and personal (a March Madness pool management app for his wife, because she insists on a specific and unusual scoring system).

Otherwise, he’s pursued a variety of external interests, currently serving as a coach of Boulder High Ultimate, playing disc golf, cooking, and scuba diving.

Jonathan Edelen

Associate Research Scientist

Associate 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 his undergraduate degree from Rensselaer Polytechnic Institute. Following his undergraduate education Jonathan worked at the Naval Surface Warfare Center Carderock Division conducting electromagnetic modeling of submarines and submarine systems. He then earned his PhD in accelerator physics from Colorado State University, where he focused on the design and simulation of a 6 MeV photoinjector and beamline for a THz FEL, as well as contributing to the theory of beam dynamics in thermionic cathode RF guns. 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, electron gun design for nonlinear optics in IOTA, beam dynamics and RF transient effects in the proposed PIP-II accelerator, and thermionic cathode RF guns at the Advanced Photon Source. 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.

Nick Goldring

Assistant Research Scientist

Assistant 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

Associate Research Scientist

Associate 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.


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.


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.

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.”

Paula Messamer

Marketing and Design Consultant

Marketing and Design Consultant 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.