Abstract: A rapidly tunable RF cavity includes a cavity body, and at least one ferroelectric element disposed within a hollow interior region of the cavity body. A biasing system provides a nominal DC electric field bias across the ferroelectric element so as to induce a rapid change in dielectric permittivity of the ferroelectric element, and a corresponding change in resonant frequency of the RF cavity. A change in dielectric permittivity of up to about 20% can be induced within a response time of less than 10 nanoseconds, with a biasing field strength of less than 50 kV. In some embodiments, the ferroelectric element is made of BST (barium-strontium titanate). The ferroelectric element may be cylindrically shaped, and coaxial with the cavity body. The biasing system may include one or more copper cylinders supported by supporting rods.

Abstract: A pair of cavities defined within a hollow elongate accelerator body include a first resonant cavity having a first resonant slot through an outer wall thereof, and a second resonant cavity having a second resonant slot through an outer wall thereof. The first resonant slot and the second resonant slot are separated by a void region that extends between the outer wall of the first cavity and the outer wall of the second cavity and is bounded in part by an inner surface of the hollow elongate member. The first and second cavities are coupled to each other through a dual slot coupling structure that includes the first resonant slot, the void region, and the second resonant slot.

Abstract: A slot resonance coupled, linear standing wave particle accelerator. The accelerator includes a series of resonant accelerator cavities positioned along a beam line, which are connected by resonant azimuthal slots formed in interior walls separating adjacent cavities. At least some of the slots are resonant at a frequency comparable to the resonant frequency of the cavities. The resonant slots are offset from the axis of the accelerator and have a major dimension extending in a direction transverse to the radial direction with respect to the accelerator axis. The off-axis resonant slots function to magnetically couple adjacent cavities of the accelerator while also advancing the phase difference between the standing wave in adjacent cavities by 180 degrees in addition to the 180 degree phase difference resulting from coupling of the standing wave in each cavity with the adjacent slot, such that the signals in each cavity are in phase with one another and each cavity functions as a live accelerating cavity.

Abstract: A slot resonance coupled, linear standing wave particle accelerator. The accelerator includes a series of resonant accelerator cavities positioned along a beam line, which are connected by resonant azimuthal slots formed in interior walls separating adjacent cavities. At least some of the slots are resonant at a frequency comparable to the resonant frequency of the cavities. The resonant slots are offset from the axis of the accelerator and have a major dimension extending in a direction transverse to the radial direction with respect to the accelerator axis. The off-axis resonant slots function to magnetically couple adjacent cavities of the accelerator while also advancing the phase difference between the standing wave in adjacent cavities by 180 degrees in addition to the 180 degree phase difference resulting from coupling of the standing wave in each cavity with the adjacent slot, such that the signals in each cavity are in phase with one another and each cavity functions as a live accelerating cavity.

Abstract: Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.

Abstract: Disclosed is a diagnostic resonant cavity for determining characteristics of a charged particle beam, such as an electron beam, produced in a charged particle accelerator. The cavity is based on resonant quadrupole-mode and higher order cavities. Enhanced shunt impedance in such cavities is obtained by the incorporation of a set of four or more electrically conductive rods extending inwardly from either one or both of the end walls of the cavity, so as to form capacitive gaps near the outer radius of the beam tube. For typical diagnostic cavity applications, a five-fold increase in shunt impedance can be obtained. In alternative embodiments the cavity may include either four or more opposing pairs of rods which extend coaxially toward one another from the opposite end walls of the cavity and are spaced from one another to form capacitative gaps; or the cavity may include a single set of individual rods that extend from one end wall to a point adjacent the opposing end wall.