arXiv subjects

Pawel Ambrozewicz

Publications and source records attributed to Pawel Ambrozewicz.

5 recordsLinked to original sources

arXiv2026

Measurement of the neutron shielding efficacy of magnetite for Proton Therapy Facilities and other applications

The neutron shielding properties of high-density concrete and magnetite aggregates were evaluated using both experimental measurements and Monte Carlo simulations. Because these materials are commonly used in medical accelerator facilities, it is essential to characterize their behavior under neutron radiation to ensure adequate shielding performance. Our experimental results show good agreement with the Monte Carlo calculations, confirming the reliability of the simulation approach. The attenuated neutron doses for various shielding thicknesses were determined for each aggregate type based on simulation and then compared as dose ratios. The findings indicate that magnetite provides superior neutron shielding, exhibiting a shorter attenuation length than conventional concrete for the same barrier thickness. The neutron attenuation characteristics of both concrete and magnetite were studied for typical neutron spectra encountered in clinical proton-therapy accelerators, including treatment rooms, primary, secondary barriers, and mazes. These results can support the optimization of radiation-shielding designs in medical and research facilities.

physics.med-ph↗

arXiv2025

A Beamdump Facility at Jefferson Lab

This White Paper is exploring the potential of intense secondary muon, neutrino, and (hypothetical) light dark matter beams produced in interactions of high-intensity electron beams with beam dumps. Light dark matter searches with the approved Beam Dump eXperiment (BDX) are driving the realization of a new underground vault at Jefferson Lab that could be extended to a Beamdump Facility with minimal additional installations. The paper summarizes contributions and discussions from the International Workshop on Secondary Beams at Jefferson Lab (BDX & Beyond). Several possible muon physics applications and neutrino detector technologies for Jefferson Lab are highlighted. The potential of a secondary neutron beam will be addressed in a future edition.

physics.acc-ph↗

arXiv2021

A survey of machine learning-based physics event generation

Event generators in high-energy nuclear and particle physics play an important role in facilitating studies of particle reactions. We survey the state-of-the-art of machine learning (ML) efforts at building physics event generators. We review ML generative models used in ML-based event generators and their specific challenges, and discuss various approaches of incorporating physics into the ML model designs to overcome these challenges. Finally, we explore some open questions related to super-resolution, fidelity, and extrapolation for physics event generation based on ML technology.

hep-ph↗

arXiv2021

Simulation of electron-proton scattering events by a Feature-Augmented and Transformed Generative Adversarial Network (FAT-GAN)

We apply generative adversarial network (GAN) technology to build an event generator that simulates particle production in electron-proton scattering that is free of theoretical assumptions about underlying particle dynamics. The difficulty of efficiently training a GAN event simulator lies in learning the complicated patterns of the distributions of the particles physical properties. We develop a GAN that selects a set of transformed features from particle momenta that can be generated easily by the generator, and uses these to produce a set of augmented features that improve the sensitivity of the discriminator. The new Feature-Augmented and Transformed GAN (FAT-GAN) is able to faithfully reproduce the distribution of final state electron momenta in inclusive electron scattering, without the need for input derived from domain-based theoretical assumptions. The developed technology can play a significant role in boosting the science of existing and future accelerator facilities, such as the Electron-Ion Collider.

hep-ph↗

arXiv2008

Polarized Structure Function $σ_{LT'}$ for $p({\vec e},e'K^+)Λ$ in the Nucleon Resonance Region

The first measurements of the polarized structure function $σ_{LT'}$ for the reaction $p(\vec e,e'K^+)Λ$ in the nucleon resonance region are reported. Measurements are included from threshold up to $W$=2.05 GeV for central values of $Q^2$ of 0.65 and 1.00 GeV$^2$, and nearly the entire kaon center-of-mass angular range. $σ_{LT'}$ is the imaginary part of the longitudinal-transverse response and is expected to be sensitive to interferences between competing intermediate s-channel resonances, as well as resonant and non-resonant processes. The results for $σ_{LT'}$ are comparable in magnitude to previously reported results from CLAS for $σ_{LT}$, the real part of the same response. An intriguing sign change in $σ_{LT'}$ is observed in the high $Q^2$ data at $W\approx 1.9$ GeV. Comparisons to several existing model predictions are shown.

nucl-ex↗