Spectroscopic HgL2 for Photon-Counting x-ray Detector

描述(由申请人提供)： 我们将开发一种新型的高灵敏度直接转换X射线探测器，它可能会给数字乳房X光照相带来革命性的变化，因为它将首次允许对单个光子进行计数，从而实现“完美的”DQE。到目前为止，所有的商业乳房X光检查系统都使用了集成胶片或探测器。通过将高灵敏度探测器材料--碘化汞(H912)与最新推出的cmos技术光子计数读数相结合，我们预计将在x射线探测器性能方面实现重大突破。这项新技术将通过消除信号中的暗电流和读出电路噪声来提高信噪比。这些因素限制了积分模式探测器的灵敏度，但由于能够检测每个单独的光子，我们可以在不影响图像质量的情况下减少提供的剂量并提高系统吞吐量。这在数字乳房X光检查中很重要，因为患者数量很大。这一进展将通过优化我们的直接x射线转换材料多晶Hg12的特性来实现，多晶Hg12是一种高Z大带隙化合物半导体，以一种用于光子计数的新方式。我们一直致力于优化用于传统集成平板的转换器膜特性。然而，由于它具有出色的电荷收集性能，这种材料作为光子计数探测器的潜力是独一无二的。我们建议开发一种合成光谱级高纯度Hg12的工艺，然后将x射线转换器直接生长到专门设计的光子计数读出设备上。最新开发的CMOS读出技术允许我们在阵列中的每个像素上放置电荷灵敏前置放大器、整形放大器、双鉴别器和数字计数器。我们希望将该设备作为OEM组件广泛销售给乳房X光检查系统制造商。在第一阶段，我们将设计化学工艺来生产所需的光谱Hg12源材料，使用热蒸汽传输生长薄膜，在玻璃衬底上测试薄膜的性能，然后将薄膜沉积在CMOS读出设备上，并测试光子计数和成像性能。在第二阶段，我们将从模块构建面板探测器，根据需要修改Hg12的合成和沉积，完成乳房X光照相面板探测器原型，并在光子成像和加州大学戴维斯分校医学中心进行测试。

DESCRIPTION (provided by applicant): We will develop a novel high-sensitivity direct-conversion x-ray detector that could revolutionize digital mammography because it will for the first time allow counting of individual photons leading to "perfect" DQE. Until now all commercial mammography systems have utilized integrating film or detectors. By combining a high-sensitivity detector material, mercuric iodide (H912), with newly available CMOS technology photon- counting readouts, we expect to achieve a significant breakthrough in x-ray detector performance. The new technology will improve the signal to noise ratio by removing the dark current and readout circuitry noise from the signal. These factors limit the sensitivity of integrating mode detectors, but with the ability to detect each individual photon, we can reduce the dose delivered and improve the system throughput without compromising image quality. This is important in digital mammography screening due to the large patient volume. This advance will be made possible by optimizing the characteristics of our direct x-ray converter material, polycrystalline Hg12, a high-Z large-bandgap compound semiconductor, in a new way for use in photon counting. Our efforts have been directed at optimizing the converter film characteristics for use in conventional integrating flat panels. However, because it has outstanding charge collection properties, the material is unique in its potential as a photon counting detector. We propose to develop a process to synthesize spectroscopic-grade high-purity Hg12 and then grow the x-ray converter directly onto specially designed photon-counting readout devices. Newly-developed CMOS readout technology allows us to place a charge-sensitive preamplifier, shaping amplifier, dual discriminators, and digital counter at each pixel in the array. We expect to widely market the device as an OEM component to mammography system manufacturers. In Phase I we will devise the chemical processes to produce the required spectroscopic Hg12 source material, grow the films using thermal vapor transport, test the film performance on glass substrates, and then deposit the film on the CMOS readout devices and test for photon counting and imaging performance. In Phase II we will build a panel detector from modules, modify the Hg12 synthesis and deposition as required, complete a mammography panel detector prototype, and test it at Photon Imaging and the UC Davis Medical Center.