Electron beam deflecting magnet assembly for a scanning electron beam computed tomography scanner

Patent · Tue Feb 17 04:00:00 EST 1987

OSTI ID:6651298

Rand, R E; Wang, D Y

A magnet coil assembly is described for controllably deflecting an incident electron beam in an electron beam system such as a computed tomography scanner. It comprises a pair of x- and y-coils and a generally cylindrical support form supporting the x-coil and the y-coil at physically different radii a/sub x/ and a/sub y/, the coils being at angular positions ..pi../2 relative to one another and defining a generally cylindrical configuration about the axis. An angle phi defines the plane of deflection relative to a fixed plane containing the magnetic coil axis and polar coordinates (r,theta) define the location in a plane defined by mutually orthogonal coordinate axes (x,y) normal to the magnetic coil axis; each coil comprising a selected number of continuous turns comprising a pair of generally axially-extending sections joined by end connecting sections; the direction and configuration of the coils being selected such that for currents I/sub x/ proportional to - sin phi and I/sub y/ proportional to cos phi producing magnetic fields B/sub x/ equal to - B/sub x/ sin phi and B/sub y/ equal to B/sub o/ cos phi then, to a selected accuracy, the magnitude of the resultant magnetic field approximates B/sub o/=(B/sub x//sup 2/+B/sub y//sup 2/)/sup 1/2/, which is a constant independent of R, theta and phi, and the field direction B/sub x//B/sub y/ approximates B/sub x//B/sub y/=-tan phi, independent of r and theta.

• Assignee: Imatron, Inc., So. San Francisco, CA
• Patent Number(s): US 4644168
• OSTI ID: 6651298
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ACCURACY
BEAM BENDING MAGNETS
BEAMS
COMPUTERIZED TOMOGRAPHY
CONFIGURATION
COORDINATES
CYLINDRICAL CONFIGURATION
DIAGNOSTIC TECHNIQUES
ELECTRIC COILS
ELECTRICAL EQUIPMENT
ELECTROMAGNETS
ELECTRON BEAMS
EQUATIONS
EQUIPMENT
ERRORS
IMAGE SCANNERS
INCIDENCE ANGLE
LEPTON BEAMS
MAGNET COILS
MAGNETIC FIELDS
MAGNETS
MECHANICAL STRUCTURES
PARTICLE BEAMS
SUPPORTS
TOMOGRAPHY