公开(公告)号：US20130035905A1

公开(公告)日：2013-02-07

申请号：US13622212

申请日：2012-09-18

申请人： The Board of Trustees of the Leland Stanford Junio

发明人： Dragos E. Constantin ,  Rebecca Fahrig ,  Paul J. Keall

IPC分类号： G06F17/50

CPC分类号： H01J3/027 ,  H01J3/029 ,  H05H7/08 ,  H05H2007/084

摘要： 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.