Cross-Sectional Imaging of Tree Stem Density Distribution using Gamma-Ray Tomography Technique

Cavities in the tree stem increase the potential of the tree to collapse and threaten the safety of people. The stem needs to be checked to determine whether the tree is safe or not. The option of tree stem inspection techniques without destructing it is still very limited. Gamma-ray tomography techniques was used to image tree stem density distributions. A collimated 2.96 GBq ¹³⁷Cs emits gamma photons through the wood phantom as the object and received by the NaI(Tl) scintillation detector on the other side. The object was scanned with the parallel beam method. The data was built into the image using filtered back projection (FBP) algorithm. The results show the cross-sectional of the wood phantom include the cavities (holes) inside it. Density patterns of wood phantom can be observed. Finally, the use of gamma-ray tomography provided a non-destructive and accurate method for investigation of tree stem density distribution. The results in images form make it easier to be interpreted.