Method and system for operating electron guns in magnetic fields

Patent metadata

Field	Value
Publication number	US-9099271-B2
Application number	US-201213622212-A
Country	US
Kind code	B2
Filing date	Sep 18, 2012
Priority date	Aug 2, 2011
Publication date	Aug 4, 2015
Grant date	Aug 4, 2015

Abstract

A method of configuring an electron gun for generating and injecting an electron beam into a linac accelerating waveguide operating in magnetic fringe fields of an MRI scanner in the absence of a magnetic shield is provided using an appropriately programmed computer to determining an anode drift tube diameter at an injection point of a linac according to a magnetic field value from an MRI scanner and to a predetermined current density, where the magnetic field has an isocenter, determining a transverse diameter of a Type M cathode in an electron gun, according to the anode drift tube diameter and the current density, and minimizing an emittance value in an electron beam of the electron gun at an entry point of the anode drift tube by optimizing the distance between the cathode and the anode, where the electron beam is along an axis of symmetry of the magnetic field.

First claim

What is claimed:

1. A method of configuring an electron gun for generating and injecting an electron beam into a linac accelerating waveguide operating in magnetic fringe fields of an MRI scanner in the absence of a magnetic shield, comprising:
a) providing an in-line MRI-linac configuration with no magnetic shielding;
b) determining an anode drift tube diameter at an injection point of a linac of said in-line MRI-linac configuration, using an appropriately programmed computer,…

Assignees

• Univ Leland Stanford Junior

Inventors

• Constantin Dragos E
• Fahrig Rebecca
• Keall Paul J

Classifications

• H05H2007/084

  Electricity · mapped topic

• H05H7/08

  Electricity · mapped topic

• H01J3/029

  Electricity · mapped topic

• H01J3/027 Primary

  Electricity · mapped topic