The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 17, 2026
Filed:
Jul. 25, 2022
Hitachi High-tech Corporation, Tokyo, JP;
Futaro Ebina, Tokyo, JP;
Kenji Miyata, Tokyo, JP;
HITACHI HIGH-TECH CORPORATION, Tokyo, JP;
Abstract
There is provide a circular accelerator and a particle beam therapy system that can improve the beam extraction efficiency. A circular accelerator that accelerates and extracts charged particle beams circulating in a magnetic field includes a first magnetic field region in which closed trajectories of the beams with different energies are eccentric and which has a magnetic field gradient decreasing in the magnetic field toward an outer peripheral side and a second magnetic field region having a magnetic field gradient increasing in the magnetic field toward the outer peripheral side. A border between the first magnetic field region and the second magnetic field region is located on a downstream side in a traveling direction of the beam with respect to a predetermined region in which an interval between the closed trajectories of the beams with the different energies is narrowest.