A bundled electron beam (BEB) (14) is controlled regarding its excursion in its direction by two pairs of plate electrodes (17.1,17.2;18.1,18.2) that operate vertically to each other. The BEB can use appropriate control of these plate electrodes to scan an anode (16) like scanning a TV picture line by line with a desirable gap and, as a result, can generate desired X-rays. Independent claims are also included for the following: (1) An X-ray system for generating projective phase-contrast exposures; (2) A method for generating projective or tomographic X-ray phase-contrast exposures of an object under examination with the help of a focus-detector system.