Toward highly accurate multigroup coupled photon-electron-positron cross-sections for the Boltzmann Fokker-Planck equation
Bibliographic record
Abstract
For many contemporary applications, ionizing radiation transport plays a pivotal role, requiring an accurate assessment of its impact on the exposed environment. While Monte Carlo simulations are widely considered the gold standard for accurate general-purpose coupled transport of photons, electrons and positrons in matter, discrete ordinates algorithms provide a viable alternative. This work consolidates cross-section models for coupled photon-electron-positron transport and provides the methodology to generate the data required by the multigroup Boltzmann Fokker-Planck transport equation and by energy and charge deposition formulas. It includes elastic, collisional and radiative inelastic interactions of leptons, annihilation of positrons, Compton scattering, Rayleigh scattering, photoelectric effect, pair production as well as fluorescence and Auger electron production from relaxation cascades following ionization. Comparative analyses of energy deposition in water, aluminum, and gold are conducted for incident beams of 1 MeV, 10 MeV, and 100 MeV electrons and photons, and juxtaposed against Monte Carlo reference calculations. While disparities of a few percent are typical, higher deviation can be observed due to discretization or physical model limitations. Energy spectrums per particle type at varying depths in the medium are also contrasted with Monte Carlo calculations to discern limitations in the current implementation and to propose potential avenues for enhancing the presented models. Energy and charge deposition calculations are also compared to experimental measurements. The cross-section production and transport algorithms are implemented in an open-source Julia package, Radiant.jl . • A determinist solver for coupled particle transport is implemented. • Coupled multigroup photon-electron-positron cross-sections are developed. • Energy deposition and energy spectrum profiles are compared with Monte-Carlo ones.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".