超軟X線写真による木材内部構造の研究 (第1報)針葉樹材の年輪構成について

X-ray can penetrate opaque materials such as wood, however the degree to which X-ray radiation penetrates depends upon density and thickness of cellwalls or specimens of wood and timbers. Penetration of the large order of wave length of X-ray is weaker than that of the short order of wave length. This work is one of the studies on the inner structure of wood and timbers by the ultra-soft X-ray(the longest wave length), and in this paper the constitution of annual rings of some coniferous wood is showed and examined by the ultra-soft X-ray photographs. The photographic conditions are as follows: Insturument; SOFTEX-EMB. Secondary voltage; 14 KVP. Secondary electric current; 5 mA. Distance of specimens and X-ray tube; 40 cm. Thickness of specimens(crossection to the longitudinal) ; 0.7 cm. Radiation time of X-ray; 10 sec. Developing time of photographic film; 10 min. at 20℃. The experimental results are showed in photos. 1-6, and a clear contrast on X-ray films was brought out between the tissues of annual rings, spring arid summer woods, false rings and coloured bands, compression wood, branches and nots. This seems to be on available method for studies of the inner construction of woods and timbers.