High-frequency coaxial input coupler including a transmission window that couples a waveguide to an acceleration cavity

A high-frequency input coupler installed between a waveguide and an acceleration cavity to input high-frequency waves from the waveguide to the acceleration cavity, the coupler comprising:

• an inner conductor,
• an outer conductor provided around an outer circumference of the inner conductor, and
• a high-frequency transmission window structure including a high-frequency transmission window and a coaxial waveguide conversion unit connected to the waveguide,
• wherein the coaxial waveguide conversion unit includes a high-frequency transmission window structure connection unit that connects the high-frequency transmission window structure and an inner conductor connection unit that connects the inner conductor,
• the inner conductor includes an inner conductor support on a side of the inner conductor connection unit,
• the inner conductor connection unit includes a space in which the inner conductor support is placed,
• the high-frequency input coupler comprises an electrically connectable and deformable buffer between the inner conductor support and the inner conductor connection unit, and
• wherein the buffer has an annular shape formed along an outer circumferential edge of the inner conductor support and includes a bend portion between an inner circumferential edge portion fixed to the inner conductor support and an outer circumferential edge portion fixed to the inner conductor connection unit.