2001 Volume 57 Issue 10 Pages 1209-1217
This paper presents a high-speed pulse fluoroscopic x-ray generation system with high-voltage semiconductor hybrid switching modules to obtain a short fall time on the tube-voltage. The high-voltage semiconductor hybrid switching module consists of a super-cascade MOSFET switching circuit with a subordinate driving mechanism that has a mis-operation prevention strategy and voltage-dividing elements. The most significant features of the high-voltage semiconductor switch-type high-speed fluoroscopic system are its long life, freedom from maintenance, and compact size compared with conventional vacuum-tube systems. In this paper, tube-voltage fall waveforms are also discussed and evaluated based on two x-ray load models, a constant-current load model and an equivalent-resistance load model. Finally, tube voltage and fluorescence intensity, surface, transit, and scattered dose rates are examined to demonstrate the feasibility of using high-voltage semiconductor switching modules in a fluoroscopic x-ray generation system.