Bright and Fast Sensor for Time Resolved X-Ray Diffraction Studies

描述（由申请人提供）：最近同步辐射源的非凡发展使得强大的研究技术得以发展，例如时间分辨x射线衍射研究，这对于理解动态生物现象和恢复x射线晶体学中的相位信息至关重要。然而，为了最有效地利用这些先进的同步加速器源进行重要的蛋白质研究，需要新的、高效的、高通量的检测器。这种探测器将提高分子模型的质量，这些模型是大分子晶体学过程的最终产品。为了实现这一目标，基于新设计的电荷耦合器件已经开发了几种新颖的读出器。然而，目前的x光转换器提供低光转换效率，低x射线吸收，以及空间分辨率和效率之间的权衡，并大大限制了这些强大的新型CCD设备的性能。为了解决这些问题，我们建议开发一种新型半导体闪烁体，该闪烁体承诺比已知最亮的闪烁体产生多达三倍的光产量，由于其高密度和高有效原子序数，高x射线吸收，无任何余辉的快速衰减，在波长范围内发射最适合ccd类型的器件，并且比当前的闪烁体具有更高的抗辐射能力。这种新型先进的闪烁体除了具有优异的闪烁性能外，还将以微柱状形式制造，这将提供非常高的空间分辨率。当与合适的读出器相结合时，该闪烁体将能够实现重要的时间分辨x射线衍射和其他研究所需的高速，大面积，高分辨率探测器。在第一阶段，我们成功地完成了我们的每一个既定目标，并证明了我们的新闪烁体技术的可行性。在此基础上，第二阶段研究的目标是进一步发展微柱状薄膜的技术，以提供迄今为止尚未实现的非常明亮的信号、可忽略的余辉、高空间分辨率（超过20 lp/mm）和出色的时间分辨率的组合，所有这些都是时间分辨x射线衍射研究、高速x射线成像和数字射线照相所必需的。我们的第二阶段闪烁体预计面积为25 x 25 cm2或更大，通常用于时间分辨研究的x射线能量效率超过98%，与目前最先进的闪烁体屏幕相比，抗辐射能力至少提高3个数量级。制备完成后，将对薄膜的形貌、闪烁特性、光学特性和在RMD下的成像性能进行详细表征。然后将薄膜集成到RMD专门开发的高速读出器中，并在ANL先进光子源（APS）的BioCAT光束线上进行评估，以证明与当前最先进的闪烁体屏幕相比，它们的性能优势。具有上述特殊性能的闪烁体的应用范围很广——从大分子晶体学到医学成像，从无损检测到聚合物研究。因此，这种传感器的商业潜力特别高。我们和我们在APS的合作者以及我们潜在的商业合作伙伴相信，由于其非凡的特性，这种闪烁体将广泛应用于许多重要的基于同步加速器的应用。在拟议的二期研究期间，我们将努力通过我们自己的资源并与我们的商业伙伴合作，成功地开发和销售这些屏幕。公共卫生相关性：拟议的研究将开发和评估一种独特的闪烁体，它将提供比最亮的商业闪烁体高三倍的光，在光谱的红色区域发射，高密度和高有效原子序数，快速衰减时间没有余辉，与目前最好的闪烁体相比，具有更高的抗辐射性数量级。这种传感器的可用性将使许多至关重要的生物学研究所需的高速x射线成像探测器技术取得进步，例如大分子的静态和时间分辨散射。反过来，这将有助于解决重要的“蛋白质折叠问题”和模型膜系统相变的研究，理解这对许多生物技术应用至关重要，例如设计各种药物输送系统。

DESCRIPTION (provided by applicant): Recent extraordinary developments in synchrotron radiation sources have enabled the growth of powerful research techniques such as time-resolved X-ray diffraction studies, essential for understanding dynamic biological phenomena and recovering phase information in X-ray crystallography. To make the most effective use of these advanced synchrotron sources for important protein studies, however, new, efficient, high-throughput detectors are needed. Such detectors will enhance the quality of the molecular models that are the end product of the macromolecular crystallography process. Toward achieving this goal, several novel readouts based on new designs of charge-coupled devices have been developed. However, current X-ray-to- light converters provide low light conversion efficiency, low X-ray absorption, and a tradeoff between spatial resolution and efficiency, and significantly limit the performance of these powerful new CCD devices. To address these issues, we propose to develop a novel semiconductor scintillator that promises to produce as much as a three-fold increase in light yield over the known brightest scintillators, high X-ray absorption due to its high density and high effective atomic number, a fast decay without any afterglow, emission in the wavelength range that is most suitable for CCD-type devices, and orders of magnitude higher radiation resistance than current scintillators. Beyond the excellent scintillation properties of this new and advanced scintillator, it will be fabricated in a microcolumnar form, which will provide very high spatial resolution. When combined with a suitable readout, this scintillator will enable realization of the high speed, large area, high resolution detectors needed for important time-resolved X-ray diffraction and other studies. During Phase I we successfully accomplished each of our stated goals and demonstrated the feasibility of our new scintillator technology. Building upon this foundation, the goal of the Phase II research is to further develop the technology to grow microcolumnar films capable of providing an as-yet unattained combination of very bright signal, negligible afterglow, high spatial resolution (in excess of 20 lp/mm), and excellent temporal resolution, all of which are necessary for time-resolved X-ray diffraction studies in particular, and for high speed X-ray imaging and digital radiography in general. Our Phase II scintillators are expected to measure 25 x 25 cm2 or larger in area, with efficiency in excess of 98% for X-ray energies typically used in time-resolved studies, and at least 3 orders of magnitude higher radiation resistance compared to current state-of-the-art scintillator screens. After fabrication, the films will be characterized in detail in terms of their morphology, scintillation properties, optical properties and imaging performance at RMD. Films will then be integrated into a specially developed high-speed readout by RMD and evaluated at the BioCAT beam line at the Advanced Photon Source (APS) at ANL, to demonstrate their performance superiority compared to current state-of-the- art scintillator screens. Applications of a scintillator with the exceptional properties described range widely - from macromolecular crystallography to medical imaging, and from nondestructive testing to polymer research. As such, the commercial potential for this sensor is particularly high. We and our collaborators at the APS and our potential commercial partners believe that due to its extraordinary properties, this scintillator will have widespread use in many important synchrotron-based applications. During the proposed Phase II research, we will undertake efforts to successfully develop and market these screens through our own resources and in collaboration with our commercial partners. PUBLIC HEALTH RELEVANCE: The proposed research will develop and evaluate a unique scintillator that will provide a factor of three higher light than the brightest commercial scintillators, emission in the red region of the spectrum, high density and high effective atomic number, fast decay time with no afterglow, and orders of magnitude higher radiation resistance compared to the best current scintillators. The availability of such a sensor will enable advancements in the high speed X-ray imaging detector technology needed for many critically important biological studies, such as static and time-resolved scattering from macromolecules. In turn, this will facilitate addressing the important "protein folding problem" and the study of phase transitions in model membrane systems, the understanding of which is vital for many biotechnological applications, such as the design of various drug delivery systems.