2019/03/06 by Pablo Ducru, Vladimir Sobes, Gerald Hale +3 · 1 citation
Chemistry · Computer Science · Engineering · Mathematics · Physics and Astronomy · #Advanced NMR Techniques and Applications #Chemistry #Combinatorics #Imaging phantom #Mathematics #Matrix (chemical analysis) #Matrix Theory and Algorithms #Nuclear reactor physics and engineering #Optics #Parametrization (atmospheric modeling) #Physics #Quantum mechanics #nucl-th
paper · pdf · doi:10.1103/physrevc.103.064608
published as Phys. Rev. C 103, 064608 (2021)
arxiv created 2019/03/06 · openalex created_date 2019/03/22 · openalex publication_date 2021/06/14 · arxiv updated 2021/06/23 · openalex updated_date 2026/08/05
As a trilogy, this first paper along with the authors' two companion articles introduces alternate approaches to standard R-matrix parametrization of nuclear cross sections. The authors present first evidence of so-called shadow poles in R-matrix theory for 134Xe. The number and location of shadow poles depends upon how one continues the R-matrix operators to complex wave numbers. The authors also establish a new pole parametrization of R-matrix cross sections, called the w\phantom\rule00exi\phantom\rule00exn\phantom\rule00exd\phantom\rule00exo\phantom\rule00exw\phantom\rule00exe\phantom\rule00exd m\phantom\rule00exu\phantom\rule00exl\phantom\rule00ext\phantom\rule00exi\phantom\rule00exp\phantom\rule00exo\phantom\rule00exl\phantom\rule00exe p\phantom\rule00exa\phantom\rule00exr\phantom\rule00exa\phantom\rule00exm\phantom\rule00exe\phantom\rule00ext\phantom\rule00exr\phantom\rule00exi\phantom\rule00exz\phantom\rule00exa\phantom\rule00ext\phantom\rule00exi\phantom\rule00exo\phantom\rule00exn, which can be Doppler-broadened analytically. This averaging of cross sections over the thermal motion of target atoms is crucial as it ensures the stability of many nuclear reactors; yet, computing it is a major bottleneck. Doppler-broadened windowed multipole cross sections and their uncertainty can be stored and computed with breakthrough performance.