Invention of highly sensitive HARP camera tube and its application

In 1985, I found that when an amorphous selenium (a-Se) photoconductive target for camera tubes is operated in a strong electric field of about 10⁸ V/m, continuous and stable avalanche multiplication takes place, allowing high sensitivity to be obtained with little picture degradation. Based on this discovery, we went on to develop a new kind of camera tube called HARP (high-gain avalanche rushing amorphous photoconductor), which has been studied to this day to achieve further increases in sensitivity and a wider range of applications. HARP camera tubes, which have achieved sensitivities roughly 100 times greater than CCDs, can serve as a powerful tool for reporting breaking news at night and other low-light conditions, the production of scientific programs, and numerous other applications.