PROBLEM TO BE SOLVED: To adjust the position of the focus of an X-ray tube with a high degree of freedom and a high resolution.SOLUTION: The electron beam of the X-ray tube is deflected in two-dimensional directions and the focus of the X-ray tube is made movable in an optional direction. For instance, two electrodes 114a and 114b in a rod shape parallel to an x direction are provided so as to hold the electron beam (e) in a z direction emitted from an electron gun 113 to a rotating anode 112 therebetween in a y direction. Also, two electrodes 114c and 114d in the rod shape parallel to the y direction are provided so as to hold the electron beam (e) therebetween in the x direction. A voltage is applied between the electrodes 114a and 114b to form an electric field E1 in the y direction, and a voltage is applied between the electrodes 114c and 114d to form an electric field E2 in the x direction. The electron beam e is deflected in the y direction by the electric field E1 and is deflected in the x direction by the electric field E2.COPYRIGHT: (C)2010,JPO&INPIT【課題】X線管の焦点の位置を高い自由度で高分解能に調整する。【解決手段】X線管の電子線を2次元方向で偏向して、X線管の焦点を任意の方向へ移動可能にする。例えば、電子銃113から回転陽極112へ射出されるz方向の電子線eをy方向で挟むように、x方向に平行な2本のロッド形状の電極114a,114bを設ける。また、この電子線eをx方向で挟むように、y方向に平行な2本のロッド形状の電極114c,114dとを設ける。電極114a,114b間に電圧を印加してy方向の電場E1を形成し、電極114c,114d間に電圧を印加してx方向の電場E2を形成する。電子線eは、電場E1によりy方向に偏向し、電場E2によりx方向に偏向する。【選択図】図3
