Patent ID: 8837679

Claim:
A method for closed-loop supply of liquid metal to an interaction region, in which an electron beam is to impact upon the liquid metal to generate X rays, comprising the steps of: raising a pressure of the liquid metal in a first portion of a closed-loop circulation system to at least 10 bar using a high-pressure pump; conducting the liquid metal at a pressure of at least 10 bar to a nozzle for ejecting the liquid metal, the nozzle having a central axis extending in an ejection direction of the liquid metal; ejecting the liquid metal from the nozzle into a vacuum chamber, in which the interaction region is located, for generating a liquid metal jet propagating through the vacuum chamber at 10 m/s or more; collecting the ejected liquid metal in a collection reservoir; raising a pressure of the collected liquid metal, in a second portion of the closed-loop circulation system located between the collection reservoir and the high-pressure pump in the flow direction of the liquid metal, to an inlet pressure suitable for the high-pressure pump, said inlet pressure being at least 0.1 bar; and repeating the above steps to effect supply of liquid metal to the interaction region in a closed loop, wherein before entering the collection reservoir the liquid metal jet is passed through an opening at a proximal-most edge of an exit pipe between the vacuum chamber and the collection reservoir, the opening facing the nozzle and not exceeding a cross-sectional area of the exit pipe immediately adjacent the opening, and wherein said step of collecting the ejected liquid metal includes using a slanting surface positioned downstream of the narrow aperture and arranged such that the slanting surface intersects the central axis of the nozzle in order to reduce contamination of the vacuum chamber by at least liquid-metal splashes and/or mist from the collection reservoir.