DEVELOPMENT OF A NOVEL W-PG LAMINATE X-RAY TARGET WITH IMPROVED FOCAL SPOT POWER DENSITY

摘要 在X射线成像中，焦斑功率密度制约着成像分辨率的进一步提高和 成像速度。钨(W)的导热系数限制了最大功率和最小功率 X射线源中允许的焦点尺寸。退火热裂解石墨(PG)具有热稳定性 A-b晶面的电导率约为W的10倍，但不适合用作x射线。 因为它的原子序数很低，所以只有一个源目标。我们将设计和开发一种新型的W-PG层压靶 这利用了这两种材料的优点，显著提高了X射线源焦点功率密度。 据此，我们提出了本研究的两个具体目标：1)研制W-PG层压靶材 化学气相沉积(CVD)；2)W-PG层压靶的评价和优化。穿过 经过两年的研究，将开发出一种新的阳极制造工艺，该工艺可用于生产高 高性能X射线源。

ABSTRACT In x-ray imaging, the focal spot power density constrains further improvement of image resolution and imaging speed. The thermal conductivity of tungsten (W) limits the maximum power and minimum dimension of the focal spot allowed in x-ray sources. Annealed Pyrolytic Graphite (PG) has a thermal conductivity about 10 times higher than W in its a-b crystalline plane, but unsuitable to be used as x-ray source target alone due to its low atomic number. We will design and develop a novel W-PG laminate target that takes advantages of both materials and significantly improve x-ray source focal spot power density. Hereby, we propose two specific aims in this study: 1) Development of W-PG laminate target using chemical vapor deposition (CVD); 2) Evaluation and optimization of W-PG laminate target. Through the two-year study, a new anode fabrication process will be developed, which can be used to produce high performance x-ray sources.