Biography
Dr. Velissaris received his PhD in Particle Physics from University of Rochester in 1995. He was in Military Service. Corps of Engineers (1995-1997). He worked as a Post-doctoral Associate in New Mexico State University Stationed at Brookhaven National Lab (1997-2000). He joined University of Wisconsin-Madison as a Assistant Scientist in 2000. and Monmouth College as a Visiting Assistant Professor in 2005. He is a Lecturer at Department of Physics, UCF since 2006.
Research Areas
Dr. Christos Velissaris is an Experimental Particle Physicist and has worked in electron positron collider experiments at KEK accelerator in Japan as well as in neutrino experiments at Fermi National laboratory. His Research areas concentration were Statistical massive data analysis and gaseous detector operation and development (drift chambers). In his research he tested the “Standard model” of Fundamental Interactions in electron positron collisions by measuring the production of dileptons (muon and tau particles) and. He also studied the “neutrino” particles at Fermi National Laboratory.
Currently Dr. Velissaris with the UCF Physics Department is doing Research with undergraduate students in the areas of Medical Physics (Medica Imaging) as well as in Artificially Intelligence and Neural Network applications in Science and Engineering.
Research Opportunities for Students
Dr. Christos Velissaris, currently at UCF offers Undergraduate Research Opportunities in the following areas:
- Interaction of Radiation with Matter and Radiation detector operation and simulations.
- Medical Physics with emphasis in Radiation Oncology and Medical Imaging (computed tomography and gamma camera) simulations.
- Artificial Intelligence and Deep Learning with applications in Science and Engineering. Training of Neural Networks to solve partial Differential equations of Interest in Science
- Accelerator and beam dynamics physics in Linear accelerators and Rings.
Past undergraduate research projects are:
- Optimizing the collimator shape of a Gamma Camera.
- Studying the Gamma camera Resolution as a function of the distance from the light source to the Camera.
- Solving the Helmholtz equation and studying the Mie and Rutherford light scattering from small dielectric particles using a PINN (Physics Informed neural Network).
- Studying the beam focusing in a circular accelerator (FODO lattice).
- Studying the feasibility of using the Lunar Regolith as a Radiation Shield in future Lunar dwellings.
- Studying and comparing the performance of electron, proton and Carbon Ion beams in Oncology for Malignant Tumor Irradiation.
- Studying and simulating the Radon Transform and its application in Computed Tomography.
Publications
• “Studying Electromagnetic Wave Scattering from Small Dielectric Particles Using Neural Networks”. Bryan Taylan, Patrick Corzo, Chris Velissaris, Theodoros Panagiotakopoulos. STARS, Faculty Scholarship and Creative Works, UCF. https://stars.library.ucf.edu/cgi/viewcontent.cgi?article=1013&context=undergradscholar
• “Physics Informed Neural Network Solution of the 2D Helmholtz equation with a Gaussian Source”. Theodoros Panagiotakopoulos, Chris Velissaris, Aristotelis Nikolaos Rapsomanikis. STARS, Faculty Scholarship and Creative Works, UCF. https://stars.library.ucf.edu/ucfscholar/1345/
• Cassidy Bryan. “Computed Tomography. Theory and Simulations”. Summer 2026.
• Fady Nabih. “Gamma Camera Resolution Studies”. University of Central Florida, Spring 2026.
• Adaliz Montoya. A comparison of Electron, Proton and ion Carbon beams performance for cancerous tumor irradiation: SURF Scholarship Summer 2026.
• Study and optimization of a Gamma Camera Collimator. Bishoy Mikhail, C. Velissaris. A-N Rapsomanikis SURF Scholarship Summer 2024.
• Simulation of Galactic Cosmic Rays and Solar Flare Particles Penetration Through Lunar Regolith. Bishoy Mikhail, C. Velissaris. A-N Rapsomanikis Summer 2024.
• A time dependent solution for the operation of ion chambers in a high ionisation background. C. Velissaris. Nucl. Instrum. Meth A547(2-3) 511-516, 2005
Courses Taught
1) Introductory Physics I and II
2) Modern Physics
3) Quantum Mechanics
4) Statistical Physics
5) General Relativity
6) Introductory Cosmology (Newtonian and introductory General Relativity based)
7) Analog Electronics (Laboratory and Theory)
8) Digital Electronics (Laboratory and Theory)
9) Intermediate labs
10) Statistical Data Analysis for Scientists
11) Interaction of Radiation with matter and Detection
