Electron optical apparatus, x-ray emitting device and method of producing an electron beam

It is described an electron optical arrangement, a X-ray emitting device and a method of creating an electron beam. An electron optical apparatus (1) comprises the following components along an optical axis (25): a cathode with an emitter (3) having a substantially planar surface (9) for emitting electrons; an anode (11) for accelerating the emitted electrons in a direction essentially along the optical axis (25); a first magnetic quadrupole lens (19) for deflecting the accelerated electrons and having a first yoke(41); a second magnetic quadrupole lens (21) for further deflecting the accelerated electrons and having a second yoke(51); and a magnetic dipole lens (23) for further deflecting the accelerated electrons.