PROBLEM TO BE SOLVED: To provide a radiation tube in which occurrence of damage on an insulating member due to heat generation of an electron emission source, or the like, is prevented while driving.SOLUTION: In a discharge tube 1 including a cathode 10 including a planar cathode member 11 having an opening in the center, and an insulating member 12 for closing the opening, an anode 20 including a target 23 for generating radiation by capturing electrons emitted from the cathode 10, and an insulation tube 30 provided between the cathode 10 and anode 20, and insulating the cathode member 11 and an anode member 21, the cathode member 11 has a bending thermal stress relaxation part 11a thinner than other part between the outer peripheral edge and inner peripheral edge of the cathode member 11 or on the inner peripheral edge side of the cathode member 11.COPYRIGHT: (C)2015,JPO&INPIT【課題】駆動時において電子放出源等の発熱による絶縁部材のダメージの発生を防止した放射線管を提供する。【解決手段】中央部に開口を有する板状の陰極部材11と、前記開口を閉塞する絶縁部材12と、を備える陰極10と、陰極10から出射された電子を捕捉し放射線を発生させるターゲット23を備える陽極20と、陰極10と陽極20との間に設けられ、陰極部材11と陽極部材21とを絶縁する絶縁管30と、を備えた放射線管において、陰極部材11が、他の部分の板厚より薄く、かつ屈曲している熱応力緩和部11aを、陰極部材11の外周縁と陰極部材11の内周縁との間又は陰極部材11の内周縁側に有することを特徴とする、放射線管1。【選択図】図1
