Patent Number: 
Section: claims

1. A beam head comprising:a vacuum housing, in which an electron source is arranged;a beam finger that is connected to the vacuum housing, the beam finger comprising an outlet window at a distal end; anda high voltage transformer housing, in which a high voltage transformer connected to the electron source is arranged via a high voltage transformer connection,wherein the high voltage transformer housing is arranged directly on a side of the vacuum housing such that the high voltage transformer housing and the vacuum housing share a common dividing wall and form a common beam head housing, and the high-voltage transformer connection to the electron source is entirely inside the common beam head housing. 2. The beam head as claimed in claim 1, wherein the high voltage transformer housing is arranged at a side of the vacuum housing remote from the beam finger. 3. The beam head as claimed in claim 1, wherein the high voltage transformer housing is evacuated. 4. The beam head as claimed in claim 1, wherein the high voltage transformer housing is filled with oil. 5. The beam head as claimed in claim 1, wherein the high voltage transformer housing is filled with a casting compound. 6. The beam head as claimed in claim 1, wherein the beam finger has a cross-section that is smaller than a cross-section of the vacuum housing. 7. The beam head as claimed in claim 1, wherein the vacuum housing and the beam finger are made from stainless steel. 8. The beam head as claimed in claim 1, wherein the electron source is configured as a flat emitter. 9. The beam head as claimed in claim 1, wherein the electron source is configured as an incandescent filament. 10. The beam head as claimed in claim 1, wherein the outlet window has a layer thickness of between 10 μm and 20 μm. 11. The beam head as claimed in claim 1, wherein the outlet window is made from titanium. 12. The beam head as claimed in claim 1, wherein the high voltage transformer housing is arranged at a side of the vacuum housing furthest from the beam finger. 13. The beam head as claimed in claim 1, wherein the high voltage transformer housing is arranged directly on a side of the vacuum housing opposite the beam finger such that the high voltage transformer housing, the vacuum housing, and the beam finger share a common axis,wherein the common beam head housing has a height measured along the common axis and a width measured perpendicular to the common axis, andwherein a maximum width of the high voltage transformer housing is the same as (1) a maximum width of the vacuum housing and (2) a maximum width of the beam head.