Characterization of an electron beam

A liquid metal jet X-ray source, comprising:

• an electron source arranged for providing an electron beam and directing said electron beam to an interaction region;
• an electron beam dump connected to ground potential, said electron beam dump being arranged for receiving the electron beam after it has traversed said interaction region;
• a scanning arrangement capable of scanning said electron beam over at least part of said interaction region;
• an X-ray sensor positioned and arranged to detect X-ray radiation generated by interaction between said electron beam and said electron beam dump;
• and
• circuitry operatively connected to said scanning arrangement and to said X-ray sensor, said circuitry being configured to determine an X-ray profile during scanning of said electron beam.