Large Area Detector for X-Ray Diffraction Studies

用于 X 射线衍射研究的大面积探测器

• 批准号: 9261557
• 负责人: Michael Squillante
• 金额: $ 5万
• 依托单位: Radiation Monitoring Devices Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-01-01 至 1993-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9261557&HistoricalAwards=false
• 关键词: Large; Area; Detector; Ray; Diffraction

New techniques for digital X-ray imaging have been under investigation for decades. Some of the most promising techniques incorporate solid-state X-ray detectors, which are attractive because of their compactness. High-Z semiconductor X-ray detectors have further advantages due to their high stopping power. One of the drawbacks of high-Z semiconductor detectors was the cost of producing large-area arrays. The usual approach was to assemble an array of isolated, individually-fabricated detector elements. A competing technology is to enhance large area arrays of amorphous silicon (a-Si) photodiodes by coating them with a film of high-Z scintillating material (e.g. CsI) by evaporation. While this technique is more effective in stopping X-rays than using "naked" silicon photodiodes, the poor conversion efficiency of scintillators limits the signal amplitude. We propose producing sublimed films of a new, high-Z semiconductor (thallium bromide), and to characterize their utility as pixilated detectors for X-ray image detection. We have made measurements of sublimed TlBr films produced in our laboratories and have noted that these detectors maintain surprisingly good charge carrier transport properties in spite of their poor crystallinity. We propose that these films will be read out by depositing them on an amorphous silicon thin-film transistor array. These detectors would yield a larger signal than the scintillator-enhanced detectors, due to their high conversion efficiency while maintaining high X-ray stopping power.

几十年来，人们一直在研究数字X射线成像的新技术。一些最有希望的技术包括固态X射线探测器，这是因为它们的紧凑性而吸引人。高Z半导体X射线探测器由于其高阻挡能力而具有进一步的优势。高Z半导体探测器的缺点之一是制造大面积阵列的成本。通常的方法是组装一组孤立的、单独制造的探测器元件。一种竞争的技术是通过蒸发在非晶硅(a-Si)光电二极管的大面积阵列上涂覆一层高Z闪烁材料(例如CSI)来增强它们。虽然这种技术在阻止X射线方面比使用“裸露”的硅光电二极管更有效，但闪烁体较差的转换效率限制了信号的幅度。我们建议生产一种新的高Z半导体(溴化铊)的升华薄膜，并表征它们作为像素化探测器用于X射线图像检测的用途。我们已经对我们实验室生产的升华TlBr膜进行了测量，并注意到这些探测器尽管结晶度较差，但仍保持着令人惊讶的良好的载流子传输性能。我们提出，这些薄膜将通过将它们沉积在非晶硅薄膜晶体管阵列上来读出。这些探测器将产生比闪烁体增强型探测器更大的信号，因为它们在保持高X射线阻止能力的同时具有高转换效率。