Monte Carlo analysis of energy deposition and X-ray fluence in cylindrical anode systems

IF 2.2 4区医学 Q3 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Journal of Applied Clinical Medical Physics Pub Date : 2025-09-30 DOI:10.1002/acm2.70262

M. K. M. Alharbi, Abel Zhou, Rob Davidson, Mark Naunton, Chandra Makanjee

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引用次数: 0

Abstract

Background

Cylindrical anode X-ray systems are increasingly used in multisource imaging; however, electron beam interactions with the curved anodes cause geometric distortions that alter energy deposition and X-ray emission. Understanding these effects is key to optimizing system performance.

Purpose

This study uses Monte Carlo (MC) simulations to examine how electron beam size, anode radius, and polar angle influence energy deposition and X-ray fluence in cylindrical anode setups, and to quantify the distortions and energy redistribution for improved X-ray generation efficiency and beam stability.

Methods

MC simulations were performed with electron beams (0.5 × 0.5 mm and 2 × 2 mm, 120 keV) on cylindrical tungsten anodes with radii from 1 to 5 cm and polar angles from 20.5° to 71.8°. Energy deposition profiles, dimensions, and photon fluence distributions were analyzed using the FLUKA MC package, with mapping in cylindrical coordinates (r-ϕ-z).

Results

Energy deposition profiles varied with beam position and anode curvature. The axial full width at half maximum (FWHM) increased by up to 650% at larger polar angles, while the azimuthal FWHM decreased up to 50%. Larger anode radii reduced the azimuthal FWHM by up to 78%, with minimal changes in axial and radial components. Narrower beams (0.5 × 0.5 mm²) produced smaller, more symmetric energy deposition profiles on anode surface. Overshoot occurred at small radii and large polar angles, leading to incomplete energy deposition.

Conclusions

Larger anode radii and moderate polar angles minimized energy deposition profiles distortion and improved X-ray fluence uniformity and production efficiency. Overshooting at small radii and large angles caused deformation, emphasizing the need for precise beam positioning to balance distortion, uniformity, and efficiency. These results define the geometric limits for effective energy deposition profile formation in cylindrical anode systems.

Abstract Image

查看原文本刊更多论文

圆柱形阳极体系中能量沉积和x射线通量的蒙特卡罗分析。

背景：圆柱阳极x射线系统越来越多地用于多源成像；然而，电子束与弯曲阳极的相互作用会引起几何畸变，从而改变能量沉积和x射线发射。理解这些影响是优化系统性能的关键。目的：本研究使用蒙特卡罗（MC）模拟来研究电子束尺寸、阳极半径和极性角度如何影响圆柱形阳极装置中的能量沉积和x射线通量，并量化扭曲和能量再分配，以提高x射线产生效率和光束稳定性。方法：采用电子束（0.5 × 0.5 mm和2 × 2mm， 120 keV）对半径为1 ~ 5 cm、极角为20.5°~ 71.8°的圆柱形钨阳极进行MC模拟。使用FLUKA MC包分析能量沉积剖面、尺寸和光子通量分布，并在柱坐标（r-ϕ-z）中进行映射。结果：能量沉积曲线随光束位置和阳极曲率的变化而变化。极角增大时，轴向半最宽增大650%，而方位半最宽减小50%。更大的阳极半径使方向频宽降低了78%，而轴向和径向分量的变化最小。较窄的光束（0.5 × 0.5 mm2）在阳极表面产生更小，更对称的能量沉积剖面。超调发生在小半径和大极角，导致能量沉积不完全。结论：较大的阳极半径和适中的极角可减小能量沉积剖面畸变，提高x射线通量均匀性和生产效率。在小半径和大角度的过冲引起变形，强调需要精确的光束定位，以平衡畸变，均匀性和效率。这些结果确定了圆柱阳极体系中有效能量沉积剖面形成的几何极限。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Applied Clinical Medical Physics 医学-核医学

CiteScore

3.60

自引率

19.00%

发文量

331

审稿时长

3 months

期刊介绍： Journal of Applied Clinical Medical Physics is an international Open Access publication dedicated to clinical medical physics. JACMP welcomes original contributions dealing with all aspects of medical physics from scientists working in the clinical medical physics around the world. JACMP accepts only online submission. JACMP will publish: -Original Contributions: Peer-reviewed, investigations that represent new and significant contributions to the field. Recommended word count: up to 7500. -Review Articles: Reviews of major areas or sub-areas in the field of clinical medical physics. These articles may be of any length and are peer reviewed. -Technical Notes: These should be no longer than 3000 words, including key references. -Letters to the Editor: Comments on papers published in JACMP or on any other matters of interest to clinical medical physics. These should not be more than 1250 (including the literature) and their publication is only based on the decision of the editor, who occasionally asks experts on the merit of the contents. -Book Reviews: The editorial office solicits Book Reviews. -Announcements of Forthcoming Meetings: The Editor may provide notice of forthcoming meetings, course offerings, and other events relevant to clinical medical physics. -Parallel Opposed Editorial: We welcome topics relevant to clinical practice and medical physics profession. The contents can be controversial debate or opposed aspects of an issue. One author argues for the position and the other against. Each side of the debate contains an opening statement up to 800 words, followed by a rebuttal up to 500 words. Readers interested in participating in this series should contact the moderator with a proposed title and a short description of the topic