Southeastern Univ. Research Assn., Inc.

Southeastern Universities Research Association, Inc.

Chen Yan

Randolph Frank Wojcik

Cornelis Apeldoorn

Nikolai I Sinkine

William Gunning

Jeffrey Glenn Dail

An improved raster magnet driver for a linear particle beam is based on an H-bridge technique. Four branches of power HEXFETs form a two-by-two switch. Switching the HEXFETs in a predetermined order and at the right frequency produces a triangular current waveform. An H-bridge controller controls switching sequence and timing. The magnetic field of the coil follows the shape of the waveform and thus steers the beam using a triangular rather than a sinusoidal waveform. The system produces a raster pattern having a highly uniform raster density distribution, eliminates target heating from non-uniform raster density distributions, and produces higher levels of beam current.

Linear beam raster magnet driver based on H-bridge technique

A conventional particle generation and magnet configuration are used in combination with a relatively low-power power amplifier, a resonant loop magnet driver system, an amplitude modulator that induces a homogeneous amplitude function proportional to (t) and, when individual X and Y magnets are used, a precision phase shifter that induces a 90&deg; phase shift in the applied power to one of the magnets to produce a circular raster pattern of virtually uniform density.

Uniform raster pattern generating system

Growing community of inventors

Yorktown, VA, United States of America

Chen Yan