QUASI-MONOCHROMATIC X-RAY SOURCE FOR MAMMOGRAPHY

本研究的目的是利用一种新型的、高效的混合辐射体，由中等能量和电流的相对论电子束驱动，构建一个用于医学成像的窄带宽x射线源原型。源的高x射线产率（光子/电子）允许使用适度的电子束电流，防止散热器本身的热损伤。由于光源本身是准准单色的，它将产生更高质量的放射图像，同时降低对患者的剂量。一个初步的实验已经证明了强烈的准单色x射线在乳房x线摄影的最佳范围。x射线产率的初步计算将扩大到包括各种参数范围，其中不同的x射线产生机制占主导地位。研究将继续优化混合辐射体的设计，并通过实验证明其可行性，使用紧凑型电子加速器，其中电子通过辐射体多次循环。后者将使整个系统的效率提高许多倍。原型成像系统成功开发的潜力非常高，因为我们的初步实验已经证明了在乳房x光检查的最佳区域有效的窄带宽x射线产生。我们将展示这些结果表明高质量的乳房x光片可以在不到3秒的时间内生成。建议的商业应用：具有与同步加速器相似特性的高效x射线源的优点是在不损坏辐射体的情况下更容易获得高x射线通量。这项工作直接适用于乳房x线摄影，因为定向、准单色光源允许减少散射，而窄带宽和频率选择优化对比度并降低剂量。

The objective of the proposed research is to construct a prototype narrow- bandwidth x-ray source for medical imaging using a new, efficient hybrid radiator driven by a relativistic electron beam of moderate energy and current. The high x-ray yield (photons/electron) of the source permits the use of modest electron-beam currents preventing thermal damage to the radiator itself. Since the source is inherently collimated and quasi- monochromatic it will produce higher quality radiographic images while lowering the dose to the patient. A preliminary experiment has demonstrated intense quasi-monochromatic x-rays in the range optimum for mammography. A preliminary calculation of the x-ray yield will be expanded to include various parameter ranges where different x-ray generation mechanisms dominate. The research will proceed by optimizing the design of the hybrid radiator and experimentally demonstrate its feasibility by use of a compact betatroN wherein the electrons are recycled through the radiator many times. The later will increase the overall system efficiency many times. The potential for successful development of the prototype imaging system is very high because our preliminary experiment has demonstrated efficient narrow-bandwidth x-ray generation in the region optimal for mammography. We will show that these results indicate that a high quality mammogram can be generated in less than 3 seconds. PROPOSED COMMERCIAL APPLICATIONS: An efficient x-ray source with characteristics similar to the synchrotron has benefits of making high x-ray fluxes more accessible without radiator damage. This work is directly applicable to mammography since the directional-, quasi-monochromatic-source permits reduced scattering while the narrow bandwidth and frequency selection optimizes contrast and reduces dose.