MEASURING CERENKOV RADIATION PRODUCED BY CHARGED PARTICLES PASSING THROUGH A GAS AS INDICATIVE OF THE ENERGY OF THE CHARGED PARTICLES

摘要

A device for determining the energy of electrically charged particles emanating from a particle accelerator such as a Betatron used for radiation therapy includes a gas interval traversed by the accelerated particles for producing a Cerenkov radiation whose optical index of refraction is variable. First and second adjacently located detectors are disposed in the path of Cerenkov radiation, both of these detectors being exposed to the same dispersed and secondary particle radiation but one detector being shielded from the direct Cerenkov radiation. The respective outputs from the detectors are led through amplifiers whose amplification factors are adjustable into a difference meter, and the output of the difference meter is applied to a measuring instrument.