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:
Oct. 01, 2019
Filed:
Nov. 09, 2018
B Dot Medical Inc., Sakura-shi, Chiba, JP;
Kota Mizushima, Chiba, JP;
Takuji Furukawa, Chiba, JP;
Eri Takeshita, Chiba, JP;
Yousuke Hara, Chiba, JP;
Naoya Saotome, Chiba, JP;
Yuichi Saraya, Chiba, JP;
Ryohei Tansho, Chiba, JP;
B DOT MEDICAL INC., Sakura-Shi, JP;
Abstract
An embodiment of the invention is a focusing magnet including a coil pair arranged on both sides of a path of a charged particle beam. The coil pair generates an effective magnetic field region in which a magnetic field is oriented in a direction (z-axis) perpendicular to a traveling direction (x-axis) of a charged particle beam. In an xy-plane, an incident charged particle beam deflected at a deflection angle ϕ with respect to the x-axis at a deflection point Q is deflected by the effective magnetic field region, and irradiates an isocenter at an irradiation angle θ with respect to the x-axis; an arbitrary point P2 on a boundary on an exit side of the effective magnetic field region is at an equal distance rfrom the isocenter; a point P1 on a boundary on an incident side of the effective magnetic field region and the point P2 are on a radius rand an arc of a central angle (θ+ϕ); and when a distance between the deflection point Q and the isocenter is L, a distance R between the deflection point Q and the point P1 satisfies a relational equation (4).