利用钴60CT成像技术重建木构文物的实验研究

Experimental Research on the Use of Cobalt-60 Computed Tomography for Heritage Timber Buildings

摘要:

CT 成像技术（computed tomography）具备无损、 直观反映被检测物内部信息的优点，已经在工业、医学等领域得到了广泛的应用。现有成熟的 X 射线 CT（X-Ray computed tomography，XCT）技术也逐渐被运用在了文化遗产保护领域。但由于 X 射线能量的限制，XCT 只适用于体量较小的可移动文物。除了 X 射线外，放射性同位素钴 60 衰变所产生的 γ 射线可以作为 CT 技术检测的放射源来使用，其射线能量更高，穿透力更强，具备运用在不可移动文物，如木构建筑上的潜力。本文采用钴 60CT 技术， 针对一个体量超过一般可移动文物的木构斗栱模型以及一个古建筑散斗构件进行了分析重建，通过成果数据探讨钴 60CT 分析技术在木构建筑中运用的可能。

Abstract:

Computed tomography (CT) is a non-destructive testing method that produces images of the inside of an object and extracts arbitrary cross-section imaging. CT is widely used in the industrial and medical field. Additionally, mature X-Ray CT instruments (XCT) were introduced to cultural heritage studies, and are now used by the world’s leading museums. Because of the special energy level of X-rays, XCT can only show images of small and movable objects. However, the radioisotope of cobalt-60 emits high-energy γ-rays. If it is used for CT, it has the potential for utilization at immovable cultural heritage such as timber-framed buildings. This paper documents the experiment of using cobalt-60 to scan larger objects: firstly, a wooden model of a dougong; and secondly, one of the load-bearing blocks in a dougong (precisely sandou) taken from an actual building. The results will contribute to the discussion of feasibility of CT technology.