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Ultrafast Nanodosimetry - the role of the nanoscale in radiation interactions in matter.

超快纳米剂量测定法 - 纳米尺度在物质辐射相互作用中的作用。

基本信息

批准号：
EP/W017245/1
负责人：
Brendan Hugh Dromey
金额：
$ 140.33万
依托单位：
Queen's University Belfast
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FW017245%2F1
关键词：
Ultrafast Nanodosimetry role nanoscale radiation

项目摘要

As radiation-based technologies continue to target tighter controls over processes and applications, limits in our understanding of how materials respond to irradiation on the very smallest scales is becoming a barrier to progress. With the commissioning of the Extreme Photonics Applications Centre at the Central Laser Facility due in 2024, there is now a growing need to develop the methodologies required for interrogating and understanding these interactions on the nanoscale to accelerate the next wave of innovation that will be unlocked by this new national capability. In 'Ultrafast Nanodosimetry' we will address this challenge by investigating the interplay between ultrafast processes and the nanoscopic structure of matter for ionising radiation interactions. Currently, in models for applications that operate over extended length scales it is standard practice to assume that matter is evenly, or uniformly, distributed on the nanoscale. This is because including the disorder typical in extended volumes would be computationally very expensive. Also, the uniform approximation accurately predicts the range over which the incident radiation loses energy in the medium, making this a versatile and efficient approach. However, while range is certainly important for applications, the radiation chemistry and permanent damage caused by the passage of ionising species is equally important. For instance, as manufacturing demands greater precision e.g. ion-induced defects for quantum dot light emitting diodes, it is clear that a limit will be reached where an understanding of nanostructure-dependent processes will be crucial to match these ambitions. Furthermore, even macroscopic applications such as radiotherapy will increasingly rely on understanding nanoscopic radiation chemistry pathways to open, for example, routes towards patient-specific modalities using gold nanoparticle dose-enhanced treatments. Therefore, it is essential that we begin to build a comprehensive picture of how energy is deposited and transported on the nanoscale in irradiated matter. We propose that there are processes that persist on the nanoscale that are highly sensitive to nanoscopic heterogeneity and, as such, are crucial for fully understanding these interactions in a predictive framework. This hypothesis is based on recent experiments examining ultrafast proton interactions in matter that have called into question the assumption of a static, uniform density distribution. Testing this will be achieved by harnessing the unique capability of laser-driven accelerators to provide ultrafast pulses of both X-rays and protons from a single source. Both of these species have fundamentally different interactions in matter that we will exploit to interrogate both 'local' and 'non-local' processes in irradiated systems. This can be understood as follows. If the primary ionised electrons have high energy (i.e. those excited by X-rays), they will, on average, travel far from the point of ionisation before their first collision. In this case they do not 'see' the local nanostructure of the material and the initial dose becomes rapidly homogenous (non-local). Conversely, if the primary electrons have low energy (i.e. those excited by protons), they will not travel far before their first collision. In this case they will interact with the material near the point of initial ionisation (local), becoming a probe of nanostructure. Together with our partners in Germany, China and the US we will develop new methods to track these processes. In particular, we aim to show how heterogeneity can influence dynamics in matter far from equilibrium by tuning the structure of matter on the nanoscale. This will provide a hard limit for which current 'homogenous' models break down. Our overarching goal is to reveal how nanoscopic processes can influence macroscopic phenomenology and energy transport in complex systems.

随着基于辐射的技术继续以更严格的工艺和应用控制为目标，我们对材料如何在最小尺度上对辐射作出反应的理解的局限性正在成为进步的障碍。随着中央激光设施极端光子学应用中心的投入使用，现在越来越需要开发询问和理解纳米尺度上这些相互作用所需的方法，以加速将由这种新的国家能力解锁的下一波创新。在“超快纳米剂量学”中，我们将通过研究超快过程和电离辐射相互作用的物质纳米结构之间的相互作用来解决这一挑战。目前，在扩展长度尺度的应用模型中，标准做法是假设物质均匀或均匀地分布在纳米尺度上。这是因为包括扩展体积中典型的无序将在计算上非常昂贵。此外，均匀近似准确地预测了入射辐射在介质中损失能量的范围，使其成为通用且有效的方法。然而，虽然射程对应用来说当然很重要，但辐射化学和电离物质通过造成的永久性损伤也同样重要。例如，随着制造要求更高的精度，例如量子点发光二极管的离子诱导缺陷，很明显，将达到一个极限，其中对纳米结构相关工艺的理解对于匹配这些目标至关重要。此外，即使是宏观的应用，如放射治疗将越来越依赖于理解纳米级辐射化学途径，以打开，例如，使用金纳米粒子剂量增强治疗的患者特异性方式的路线。因此，我们必须开始建立一个全面的图片，能量是如何沉积和传输在纳米级的辐射物质。我们建议，有坚持在纳米尺度上的过程是高度敏感的纳米异质性，因此，在预测框架中充分理解这些相互作用是至关重要的。这一假设是基于最近的实验研究超快质子相互作用的问题，提出了问题的假设，一个静态的，均匀的密度分布。测试这一点将通过利用激光驱动加速器的独特能力来实现，以提供来自单一来源的X射线和质子的超快脉冲。这两个物种有根本不同的相互作用的问题，我们将利用询问“本地”和“非本地”的过程中照射系统。这一点可以理解为：如果初级电离电子具有高能量（即被X射线激发的电子），它们在第一次碰撞之前平均会远离电离点。在这种情况下，它们不会“看到”材料的局部纳米结构，并且初始剂量迅速变得均匀（非局部）。相反，如果初级电子具有低能量（即被质子激发的电子），它们在第一次碰撞之前不会走得很远。在这种情况下，它们将与初始电离点（局部）附近的材料相互作用，成为纳米结构的探针。我们将与德国、中国和美国的合作伙伴一起开发新的方法来跟踪这些过程。特别是，我们的目标是展示异质性如何影响远离平衡的物质的动力学，通过调整纳米尺度上的物质结构。这将为当前的“同质”模型提供一个硬性限制。我们的首要目标是揭示纳米过程如何影响复杂系统中的宏观现象和能量传输。