Abstract: A stationary anode X-ray tube is provided with an X-ray transmitting window which does not face an inclined electron-impact surface of an anode target and is deflected from the vertical center plane of such electron-impact surface. The deflection angle of the X-ray transmitting window to the vertical center plane of the electron-impact surface, that is, the anode target twist angle to the vertical center plane should preferably be within a range from 30.degree. to 60.degree..

Abstract: An X-ray tube for analytic use comprises a bottomed cylindrical nozzle which is formed at the bottom with a slit having substantially the same shape and size as that of a focus formed on an electron-impact surface of an anode target. A pair of recesses are formed out in the backside surface of the anode. The nozzle is provided on its outer periphery with a pair of engaging members fitted into the recess, respectively, to prevent the rotation of the nozzle relative to the anode target. Consequently, the nozzle is detachably fitted to the anode and rotated substantially together with the anode thus resulting in a sure alignment of the slit of nozzle with the focus of target.