# US 7,746,192 B2 · Polyhedral contoured microwave cavities > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,746,192 B2 - Document ID: US7746192B2 - Status: Granted - Kind: B2 - Application number: 11/425,297 - Filed: 2006-06-20 - Published: 2007-03-29 - Granted: 2010-06-29 - Earliest claimed: 2005-06-20 - Assignees: The Texas A&M University System - Inventors: Peter M. McIntyre - Web page: https://patentgrep.com/patent/US7746192B2 ## CPC - H05H 7/18: Cavities; Resonators {(travelling-wave tubes H01J23/18; hyperfrequency cavities in general H01P7/04, H01P7/06)} - H05H: PLASMA TECHNIQUE (apparatus or processes specially adapted for producing X-rays H05G2/00); PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS ## Abstract Fabrication methods for contoured polyhedral cavities for particle acceleration are disclosed. The process may include: trimming flat sheets to a conformal shape; bending the sheets to form a contour that is axially curved and azimuthally flat; and joining the sheets to form a circumferentially polyhedral cavity that is configured to support a resonant electromagnetic field at cryogenic temperatures. The resulting cavity may have ductile or even brittle superconducting materials with an axially-oriented grain structure at each point on the circumference of the cavity. As part of the assembly process, the sheets may be bonded to a supporting substrate of thermally conductive material having integrated cooling passages. The supporting substrates may be configured to have electrical contact near the cavity openings while having a small gap near the equators of the cavity. Moreover, mode-coupling channels and waveguides may be provided to extract energy from undesired deflection modes. ## Claims ### Claim 1 A particle accelerator that comprises: a path that transports charged particles from a particle source; and at least one high-frequency electromagnetic wave resonator, said resonator including a cavity that is circumferentially polyhedral having azimuthally flat surfaces. ### Claim 2 (depends on 1) The particle accelerator of claim 1, wherein the resonator comprises a plurality of polyhedral segments. ### Claim 3 (depends on 2) The particle accelerator of claim 2, wherein each of the polyhedral segments comprises a superconducting material bonded to a thermally and electrically conductive supporting base. ### Claim 4 (depends on 3) The particle accelerator of claim 3, wherein each supporting base incorporates at least one unlined passage for cryogenic coolant. ### Claim 5 (depends on 3) The particle accelerator of claim 3, wherein the superconducting material is rounded over at each edge for an adjoining face of the polyhedral segment. ### Claim 6 (depends on 3) The particle accelerator of claim 3, wherein the supporting bases of the polyhedral segments are configured to contact each other around each opening to the cavity while leaving a controlled-width gap between adjacent segments at each equator of the cavity. ### Claim 7 (depends on 6) The particle accelerator of claim 6, wherein the supporting bases of the polyhedral segments are further configured to contact each other at an external surface of the resonator. ### Claim 8 (depends on 3) The particle accelerator of claim 3, wherein adjoining faces of at least two polyhedral segments form a mode-coupling channel configured to extract deflection mode energy from the cavity. ### Claim 9 (depends on 8) The particle accelerator of claim 8, further comprising a waveguide configured to route deflection mode energy from the mode-coupling channel to a resistive load. ### Claim 10 (depends on 9) The particle accelerator of claim 9, wherein the resistive load is maintained at room temperature. ### Claim 11 (depends on 9) The particle accelerator of claim 9, wherein the waveguide is elliptical. ### Claim 12 (depends on 9) The particle accelerator of claim 9, wherein the waveguide contains a dielectric material. ### Claim 13 (depends on 9) The particle accelerator of claim 9, wherein the waveguide contains a central coaxial conductor. ### Claim 14 (depends on 9) The particle accelerator of claim 9, wherein the resistive load is maintained at a temperature that is greater than that of the cavity structure. ### Claim 15 (depends on 3) The particle accelerator of claim 3, wherein the polyhedral segments are joined without chemically affecting any of the superconducting material. ### Claim 16 (depends on 3) The particle accelerator of claim 3, wherein the superconducting material comprises YBCO. ### Claim 17 (depends on 3) The particle accelerator of claim 3, wherein the superconducting material comprises one or more layers of Nb3Sn on an Nb substrate. ### Claim 18 (depends on 3) The particle accelerator of claim 3, wherein the superconducting material is a high temperature superconductor. ### Claim 19 (depends on 3) The particle accelerator of claim 3, wherein the superconducting material comprises one or more layers of a type II superconductor on an Nb substrate. ### Claim 20 (depends on 2) The particle accelerator of claim 2, wherein each of the polyhedral segments comprises a superconductive material having a grain structure that is aligned with a long axis of the resonator. ### Claim 21 (depends on 2) The particle accelerator of claim 2, wherein the segments are joined to substantially enclose the cavity, leaving at least one iris opening on a central axis of the cavity.