Hi, my name is

Petr Stepanov

I am a PhD graduate in Photochemical Sciences, desktop and frontend developer, web designer.

Petr Stepanov profile picture
+1 (419) 496-8602
Current address:
2270 NW Savier St, Portland, OR 97210, United States
Willing to relocate.


Ph.D. graduate with expertise in gamma spectroscopy, positron annihilation spectroscopy, microscopy, and nuclear physics. Strong background in computational techniques, desktop software development and web applications. More than five years in user interface and user experience design.

Graduated from BGSU in April 2020. Seeking a software development position in the software development industry. Willing to become an effective member of a research group in academia and continue a scientific career.

Authorized to work in the US on Optional Practical Training (OPT) in physics, chemistry and computer science. Will consider visa sponsorship offers.

Computer skills

🛠️ Basics.
Jira, Git, SVN, SSH, HTTP, Terminal usage, BASH and SLURM scripting. MVC/MVP design patterns. IDEs: Eclipse, NetBeans; Atom, VS Code.
🎨 UI/UX design.
Figma, Sketch, InVision Studio, Adobe XD, Adobe Photoshop, Adobe Illustrator, Inkscape, Blender.
🖥️ Desktop development.
Java and Swing, C/C++ and Qt, compiling from source (gcc, GNU makefiles), Fortran 95.
🖲️ Frontend.
HTML, CSS (LESS and SASS), Bootstrap, responsive web design, JavaScript and jQuery, npm, gulp, CommonJS, Google Web Toolkit. Familiar with AngularJS, React.js, and Backbone.js. WordPress themes development.
🕳️ Backend.
EJS, PHP, Java, Node.js.
📱 iOS development.
Fundamental Swift skills. User interface development with UiKit and storyboards.
🧮 Scientific packages.
CERN ROOT, Geant4, Wolfram Mathematica, Maple, MATLAB.
📊 Data visualization.
OriginLab, Gnuplot, QtiPlot, SciDaVis, Grapher.
🖋 Markup.
Markdown, LaTeX, MS Office Suite, Zotero.

Material research skills

Characterization facilities. Positron Lifetime and Doppler Broadening Annihilation Spectroscopy (PALS, DBAR). Atom Probe Tomography (ATP). Scanning Electron Microscopy (SEM). Transmission electron microscopy (TEM). Atomic Force Microscopy (AFM). UV-VIS Spectroscopy. Fourier Transform Infrared Spectroscopy (FTIR).

Materials processing. High-temperature annealing. Wet chemical etching. Electrical Contact Fabrication. Sample polishing.

Work experience

  • Jefferson Lab logo


    Thomas Jefferson National Accelerator Facility Newport News, VA, USA

    • Coded a Geant4-based sumulation for studying the optimal light guide length (range 0-10 cm) for the EM calorimeter used in the Electron-Ion-Collider (EIC) project. Link to GitHub.
    • Used Machine Learning (ML) techniques to perform binary classification of thousands of signals from a data acquisition (DAQ) setup. Link to GitHub].
    • Applied CERN ROOT framework (C++) to perform statistical analysis of a significant amount (over 100 GB) of the raw experimental data of the Kaon LT experiment at JLab. Link to GitHub.
    • Utilized SLURM environment on JLab supercomputer environment to run resourceful particle simulations on multiple computing nodes at the same time. This decreased the wall computation time by more than 10 times.
    • Proposed and implemented RAMDisk functionality in the development environment. This led to an over 60% increase in source code indexing time.
    • Replaced proprietary MS Windows-based data acquisition (DAQ) system with an open-source solution. This eliminated random crashes during continuous acquisition.
    • Active collaborator of the Pion LT project. Committed more than 50 shifts performing Target Operator and Shift Leader duties in the experimental Hall C counting room.
  • Catholic University of America (CUA) logo

    Postdoctoral Researcher

    Catholic University of America Washington, DC, USA

    • Programmed a Geant-4 computer simulation (C++, CMake, Eclipse IDE, gdb) to study performance of a novel scintillation material for EIC, Brookhaven National Lab. Link to GitHub.
    • Visualized energy deposition profiles and calculated energy resolutions for variety of detector assemblies.
    • Teaching experience: mentoring students within a 3-month Research Experiences for Undergraduates (REU) program at the Physics Department at CUA. Giving talks and presentations about Linux Terminal, and supercomputer environment.
    • Enhanced debugging of the core library source code lead to opening more than 10 bug reports on the ROOT (C++) forum.
  • Freelance logo

    Freelance UI/UX Designer and Frontend Developer

    • Built an online e-commerce store Sticker Store LLC with static website generator (Hexo, Snipcart, Bootstrap, SASS, EJS, Node.js).
      • Improved the Google PageSpeed Insights metrics (CLS, LCP) up to 97%.
      • Created a recursive script to export over 300 products from the YAML file to Google Merchant.
      • Optimized SEO. The project reached over 1400 organic monthly users.
    • Made iOS application (Swift, UIkit, storyboards) for the We.Team messenger (more than 3k monthly downloads in AppStore). Participated in cloud-based messenger development with enhanced file sharing capabilities (HTML, React JS, SASS).
    • Migrated the landing page for Sweetbridge company from WordPress to Jekyll static site generator (Ruby, CSS). This resulted in a 70% improvement in the page load time.
    • Developed the front-end part (Angular.js, HTML, LESS) for Lili Social network.
      • Assisted with the front-end styling and animations for the iOS mobile application (Ionic).
      • Enabled SEO crawling of over 1000 Angular.js pages with Google bot.
    • Web design.
      • Designed logos, UI/UX prototypes (Figma, Sketch, Illustrator) and branding identity for over 10 different companies.
      • Converted numerous design assets and mockups into responsive HTML and CSS (Bootstrap).
      • Mocked up and integrated dozens of cross-browser responsive email templates.
  • BGSU Center for Photochemical Sciences logo

    Research Assistant, Software Developer

    Center for Photochemical Sciences Bowling Green, OH, USA

    • Applied ROOT C++ libraries to write four GUI open-source software for scientific data interpretation.
    • Wrote a GUI application LuminApp (Java, Swing) to parse and merge time-stamped data from optical spectrometer and thermometer. This increased data processing time by two orders of magnitude.
    • Developed static website (Hexo, Gulp, Bootstrap) and visual identity for the SelimLab research group. The website has a 99% Google performance rank and features 700 ms time to interactive metrics.
    • Maintained local Apache HTTP server physics.bgsu.edu hosting over 10 websites at the BGSU.
    • Created website for the ICPA-18 international conference with registration (over 150 users) and payment system workflow (WordPress, PHP, Recurly.js), and landing pages for events.
  • Gridnine Systems logo

    Web Designer, Frontend Web Developer

    Gridnine Systems Moscow, Russia

    • Responsible for the front-end development of the ATH American Express – the largest travel management company in Russia (JavaScript, Backbone.js, and RequireJS). Increased the front-end load time by over 30%.
    • Utilized Google Web Toolkit (GWT) Model-View-Presenter (MVP) framework to develop frontend for Otixo cloud file integrator (JavaScript, CSS, responsive design).
    • Implemented image processing servlets on the backend to generate banners for five different social networks (PHP, ImageMagic).
    • Prototyping conceptual wireframes and UI/UX mockups for numerous web applications (Adobe Creative Suite).
  • Yunium logo

    Computer Science Teacher

    Yunium Educational Center at MIPT Moscow, Russia


    Provided instruction and guidance to middle school students on the following computer courses: advanced C++ programming, the markup on the web, Photoshop, and 3D Studio Max.

  • ITEP logo

    Research Scientist

    Institute for Theoretical and Experimental Physics (ITEP) Moscow, Russia


    Application of positron lifetime spectroscopy for studying the radioactive-induced defects in steels. Monte-Carlo particle simulations with Fortran 95. Maintaining software for CAMECA tomographic atom probe (MSVC). Application of CERN ROOT libraries for fitting and analysis of experimental spectra.


  • BGSU logo

    Bowling Green State University


    Bowling Green, OH, USA

    Ph.D. Doctor of Philosophy in photochemical sciences. Occupation: materials science, interaction of ionizing radiation with matter, radiation defects in solids, radiation chemistry, gamma-spectroscopy, positron annihilation spectroscopy.

    Dissertation topic: New developments in positron annihilation spectroscopy techniques: from experimental setups to advanced processing software. Download manuscript with corrections.

    Under the guidance of Dr. Selim I have successfully assembled and maintained Doppler and lifetime positron spectrometers from ORTEC and Canberra fast-timing units. My research was aimed at the application of Doppler and lifetime positron spectroscopy techniques to study the following effects in materials:

    • Defects and grain sizes in solids.
    • Kinetics of positrons and positronium atoms in nano-powders.
    • Oxidation and ortho-para conversion of positronium atoms in liquids.

    My research required a good understanding of single-photon counting techniques with HPGe and scintillation-based detector systems. I manufactured sources of positron radiation and was responsible for inventorying the radioactive materials.

    I have developed several open-source desktop GUI software solutions for fitting and interpreting the raw positron experimental spectra. Software is written in C++, it extensively utilizes the CERN ROOT and RooFit frameworks.

    Additionally, I created was responsible for creating websites for the research groups and international conferences.

  • MEPhI logo

    National Research Nuclear University


    Moscow, Russia

    B.S. M.S. Bachelor and Master of Science in solid state physics. Monte-Carlo particle simulations with Fortran 95. Maintaining software for CAMECA tomographic atom probe (MSVC). Application of CERN ROOT libraries for fitting and analysis of experimental data.

    Thesis topic: Radiation defect studies of nuclear power plant vessel steels by means of positron lifetime annihilation spectroscopy.

Relevant courses

  • OSC logo

    Ohio Supercomputer Workshop

    Bowling Green, OH, USA

    Hands-on sessions on supercomputer operation. Got familiar with the newest developments in the supercomputer services: network use with SSH, job control with SLURM scripts, RedHat and CentOS operating systems, CMake compiling platform, parallel environments and more.

  • BHSAD logo

    British Higher School of Art and Design


    Moscow, Russia

    Three-month intensive: graphical design and visual communications.

    Introduction to the major tricks and instruments of visual communication; learning fundamental rules of illustrations, typography, fonts, and lettering. Intensives on brand identity, graphical language, and advertising campaigns.

Web Projects

Bimmer Sticker Store
Sticker Store LLC

Website that features a collection of vinyl stickers for cars.


Otixo Cloud Messenger

A messenger with enhanced cloud file sharing capabilities.

Sketch HTML SCSS React Swift

Otixo Cloud Messenger

Social network focused on sharing lists of things.

Photoshop HTML LESS Angular

Bimmer Sticker Store

Wordpress theme for a research group website.

Sketch HTML SCSS Wordpress JS

Bimmer Sticker Store

A homepage and identity for anonymous iOS messenger app.

Photoshop HTML LESS JS

Petr Stepanov monogram

Feel free to check out more of my user interface designs, logos and creative artwork on Dribbble.

View more shots  -

Scientific software

During my post-doctorate researcher role at the CUA I was responsible for carrying out Monte Carlo particle simulations in High Energy Physics (HEP). The gold standard simulation toolkit in physics is Geant4. I utilized Geant4 framework to collaborate on the Electron-Ion Detector (EIC) project. Additionally, I developed a Geant4-based simulation for studying the performance of scintillation materials. The program reconstructs energy deposition, light yield, and detector response.

Geant4 simulation of the particle escape locations
Studies of the energy conservation of a Geant4 simulation. Ensuring the incident particle energy equals to the deposited energy and cumulative kinetic energy of the particles that escaped the simulation.
Geant4 visualization of the energy deposition
Visualizing the energy deposition in a 3x3 assembly of scintillation crystals with the help of Geant4 scoring meshes.
Glass Prototype Simulation

A Geant4-based simulation that studies the performance of a novel scintillation material "SciGlass". Simulation reconstructs detector response from the interaction of the scintillation crystals with high energy ionizing particles.

Contributions of the scintillation and Cherenkov-produced light are individually detected. Two types of visible light detectors are supported: Photo-Multiplier tubes (PMT) and Multi-Pixel Photon Counters (MPPC/SiPM). Energy deposition studies in the sensitive part of the detector are carried out.

C++, CMake, Geant4, CERN ROOT framework

View on GitHub

My PhD research in physics at BGSU was interdisciplinary with computer science. I developed several desktop software products for data analysis and experimental spectra interpretation. I utilized and contributed to the development of the CERN ROOT framework. ROOT ecosystem offers a variety of tools for histogram manipulation, plotting, fitting, and data storage. The framework allows for building standalone graphical user interface (GUI) software.

TLIST Processor
Fitting and subtracting the two-dimensional background from a coincidence Doppler broadening spectrum of aluminum.
TLIST Processor

Software is designed to process two-dimensional energy spectra and output one-dimensional coincidence broadened Doppler spectrum.

A background fitting and subtraction technique is developed and implemented.

C++, CERN ROOT framework, GNU Automake

View on GitHub

SW Calculator
Decomposition of a 1D Doppler spectrum into contributions from Fermi electrons, core and valence electrons.
SW Calculator

Program calculates S and W parameters of the 511 keV peak of the annihilation radiation. Software estimates values of the binding electron energies by fitting the CDB spectrum with contributions from e+ annihilation on electrons with different wave functions.

Electrons from the conduction band contribute to the spectrum as an inverted parabola. Upon the shape of the parabola, we calculate Fermi energy.

C++, CERN ROOT framework, GNU Automake

View on GitHub

SW Calculator
Simultaneous fitting of three positron lifetime specrtra (PALS) with a fitting model that supports shared fitting parameters.

A flexible terminal-based positron lifetime fitting software. A graphical user interface is in progress.

Software supports deconvolution of lifetime spectra into the conventional multiexponential model as well as trapping model. Supports integration of models with custom fitting parameters.

C++, CERN ROOT framework, GNU Automake

View on GitHub

Recent publications

  • Revealing the Structure of Light Pseudoscalar Mesons at the Electron-Ion Collider.

    Arrington, J.; Gayoso, C. A.; Barry, P. C.; Berdnikov, V.; Binosi, D.; Chang, L.; Diefenthaler, M.; Ding, M.; Ent, R.; Frederico, T.; Furletova, Y.; Hobbs, T. J.; Horn, T.; Huber, G. M.; Kay, S. J. D.; Keppel, C.; Lin, H.-W.; Mezrag, C.; Montgomery, R.; Pegg, I. L.; Raya, K.; Reimer, P.; Richards, D. G.; Roberts, C. D.; Rodríguez-Quintero, J.; Romanov, D.; Salmè, G.; Sato, N.; Segovia, J.; Stepanov, P.; Tadepalli, A. S.; Trotta, R. L. J. Phys. G: Nucl. Part. Phys. 2021, 48 (7), 075106. DOI: 10.1088/1361-6471/abf5c3.

  • Interaction of positronium with dissolved oxygen in liquids.

    Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Bokov, A. V.; Ilyukhina, O. V.; Duplâtre, G.; Byakov, V. M. Physical Chemistry Chemical Physics 2020, DOI: 10.1039/C9CP06105C

  • A Model for Joint Processing of LT and CDB Spectra of Dielectric Nano-sized Powders.

    Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Byakov, V. M. AIP Conference Proceedings 2019, 2182 (1), 040004. DOI: 10.1063/1.5135836

  • Positron and positronium in Al2O nanopowders.

    Stepanov, P. S.; Selim, F. A.; Stepanov, S. V.; Byakov, V. M. AIP Conference Proceedings 2019, 2182 (1), 050008. DOI: 10.1063/1.5135851

  • Defects and solarization in YAG transparent ceramics.

    Zhang, L.; Wu, J.; Stepanov, P.; Haseman, M.; Zhou, T.; Winarski, D.; Saadatkia, P.; Agarwal, S.; Selim, F. A.; Yang, H.; et al. Photonics Research 2019, 7 (5), 549-557 DOI: 10.1364/prj.7.000549

  • Photoconductivity of bulk SrTiO3 single crystals at room temperature.

    Saadatkia, P.; Stepanov, P.; Selim, F. A. Materials Research Express 2018, 5 (1), 016202 DOI: 10.1088/2053-1591/aaa094

  • Track Effects in Positronium Formation.

    Stepanov, S.; Byakov, V.; Duplâtre, G.; Stepanov, P.; Bokov, A. Acta Physica Polonica A 2017, 132 (5), 1461-1466 DOI: 10.12693/APhysPolA.132.1461

  • Developing new routine for processing two-dimensional coincidence doppler energy spectra and evaluation of electron subsystem properties in metals.

    Stepanov, P.; Stepanov, S.; Byakov, V.; Selim, F. Acta Physica Polonica A 2017, 132 (5), 1628-1633 DOI: 10.12693/APhysPolA.132.1628

  • ZnO Luminescence and scintillation studied via photoexcitation, X-ray excitation, and gamma-induced positron spectroscopy.

    Ji, J.; Colosimo, A. M.; Anwand, W.; Boatner, L. A.; Wagner, A.; Stepanov, P. S.; Trinh, T. T.; Liedke, M. O.; Krause-Rehberg, R.; Cowan, T. E.; et al. Scientific reports 2016, 6 (1), 31238 DOI: 10.1038/srep31238

  • Premelting as studied by positron annihilation and emission Mössbauer spectroscopies.

    Stepanov, S. V.; Byakov, V. M.; Zvezhinskiy, D. S.; Duplâtre, G.; Dubov, L. Y.; Stepanov, P. S.; Perfiliev, Y. D.; Kulikov, L. A. Journal of Physics: Conference Series 2016, 674, 012018 DOI: 10.1088/1742-6596/674/1/012018

  • Scintillation of Un-doped ZnO Single Crystals.

    Colosimo, A. M.; Ji, J.; Stepanov, P. S.; Boatner, L. A.; Selim, F. A MRS Advances 2016, 1 (2), 121-126 DOI: 10.1557/adv.2015.60

  • Early processes in positron and positronium chemistry: possible scavenging of epithermal e by nitrate ion in aqueous solutions.

    Stepanov, S. V.; Byakov, V. M.; Duplâtre, G.; Zvezhinskiy, D. S.; Stepanov, P. S.; Zaluzhnyi, A. G. Journal of Physics: Conference Series 2015, 618, 012003 DOI: 10.1088/1742-6596/618/1/012003

  • The use of positron spectroscopy for revealing the nanosized structures in liquid mixtures. Identification of n-propanol nanoagglomerates in aqueous solutions.

    Stepanov, P. S.; Byakov, V. M.; Zaluzhnyi, A. G. Russian Journal of Physical Chemistry A 2014, 88 (4), 685-690 DOI: 10.1134/s003602441404027x

View more publications


  • 18th International Conference on Positron Annihilation (ICPA-18)

    @Orlando, FL, USA

    Oral talk “Positions and Ps in Al2O3 Nanopowders”.

  • International Workshop on Physics with Positrons (JPos17)

    @Jefferson Lab, Newport News, VA, USA

    Poster “A routine of background subtraction from two-dimensional Doppler broadened spectra”.

  • 12th International Workshop on Positron and Positronium Chemistry (PPC12)

    @Maria Curie-Sklodowska University, Lublin, Poland

    Poster “Developing new routine for processing two-dimensional coincidence Doppler energy spectra”.

  • Ohio Photochemical Society Meeting (Oops)

    @Maumee Bay Lodge & Conference Center, Maumee, OH, USA

    Poster “Developing new routine for background subtraction in two-dimensional coincidence Doppler broadening spectroscopy”.

  • 58th Electronic Materials Conference (EMC)

    @University of Delaware, Newark, DE, USA

    Oral talk “High-Sensitivity Measurements of Defects in ZnO by Means of Digital Coincidence Doppler Broadening of Positron Annihilation Spectroscopy”.

  • Annual Spring Meeting of the APS Ohio-Region

    @University of Delaware, Newark, DE, USA

    Oral talk “Identification of chemical environment of defects in ZnO by means of digital coincidence Doppler broadening of positron annihilation radiation”.

  • Ohio Inorganic Weekend

    @Bowling Green State University, OH, USA

    Poster “Approaching Structural Defect Characterization and their Chemical Identification by Means of Coincidence Doppler Broadening of Annihilation Radiation”.

  • 41st Polish Seminar on Positron Annihilation (PSPA-13)

    @Maria Curie-Sklodowska University, Lublin, Poland

    Oral talk “Application of positron spectroscopy for detection of nanostructures in alcohol―aqueous mixtures”.

Professional networks


  • 💻 Linux and open-source software.
  • 🛠 Working on cars and bicycles.
  • 🎞 Shooting and developing film.
  • Rollerblading and snowboarding.
  • Hiking and kayaking.

What's next?

I am looking for new full-time job opportunities. I am eligible to work in United States under OPT. OPT expires in February 2023. Will consider visa sponsorship offers.

Get in touch

My inbox is always open. Whether for a potential project or just to say hi, I'll try my best to answer your email!