On the Overestimation of Efficiency in Relativistic Electron Scattering
Bibliographic record
Abstract
With the rapid global advancement of relativistic ultrafast electron diffraction systems, the impact of relativistic effects on electron scattering efficiency has attracted renewed attention. Recent reviews emphasize the γ 2 scaling of the differential elastic-scattering cross-section with increasing electron energy. Although such observations are not formally incorrect, they can lead to a misperception of the relative scattering efficiency of relativistic electrons compared to that of their nonrelativistic counterparts. The γ 2 scaling originates from analyses conducted in the angular domain, where the compression of the scattering angle θ (or solid angle Ω ) with increasing energy creates an enhancement of the differential elastic-scattering cross-section, dσ / dΩ . In this work, we recast the problem in momentum-transfer space q , where scattering is accurately accounted for. This transformation eliminates the angular compression artifact and reveals that high-energy scaling follows a simple β − 2 dependence, with no intrinsic relativistic gain. We demonstrate this by directly integrating relativistic differential elastic-scattering cross-sections from ELSEPA and by applying a straightforward transformation of the well-known Mott–Massey formalism into q -space. The results are general, with calculations performed for elements from carbon to gold and for energies between 50 and 5,000 keV. They reproduce the long-established trend in total elastic-scattering cross-sections, in which scattering strength decreases with increasing electron kinetic energy. Practically, at energies above roughly 50 keV, scattering is already dominated by the forward direction, and most of the scattered intensity falls within the acceptance range of typical ultrafast electron diffraction detectors.
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 machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.013 | 0.023 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.005 |
| Scholarly communication | 0.004 | 0.007 |
| Open science | 0.003 | 0.003 |
| Research integrity | 0.002 | 0.003 |
| Insufficient payload (model declined to judge) | 0.004 | 0.003 |
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 source (direct Gemma or distilled Codex), 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".