A system for producing a high-speed beam of electrons can include a racetrack microtron (RTM) powered by a magnetron. The RTM can include a linear accelerator (linac) integrated with a racetrack-shaped beam path to accelerate a beam of electrons using continuous wave (CW) radio-frequency (RF) electromagnetic energy provided by the magnetron.

Provided is a superconducting cryo module that can be made more compact. A superconducting cryo module according to the present disclosure comprises: a superconducting accelerating cavity that has a cell part accelerating electrons, a beam pipe part extending from the cell part to an electron incidence side, and an extraction part of the electrons which were accelerated by the cell part; and an electron gun that is located in the interior of the beam pipe part of the superconducting accelerating cavity, is located on the same axis as a beam axis BA of the superconducting accelerating cavity, and emits electrons into the cell part.

A system and method for treating a cavity comprises arranging a niobium structure in a coating chamber, the coating chamber being arranged inside a furnace, coating the niobium structure with tin thereby forming an Nb.sub.3Sn layer on the niobium structure, and doping the Nb.sub.3Sn layer with nitrogen, thereby forming a nitrogen doped Nb.sub.3Sn layer on the niobium structure.

A system and method for treating a cavity comprises arranging a niobium structure in a coating chamber, the coating chamber being arranged inside a furnace, coating the niobium structure with tin thereby forming an Nb.sub.3Sn layer on the niobium structure, and doping the Nb.sub.3Sn layer with nitrogen, thereby forming a nitrogen doped Nb.sub.3Sn layer on the niobium structure.