Method and apparatus for radiation detection

Abstract

A detection system is provided. In one embodiment a silicon Compton recoil electron detector uses the Compton double scatter technique with recoil electron tracking to detect medium energy gamma rays from 0.3 to 30 MeV. Two detector layers are required; a silicon microstrip hodoscope and a calorimeter. The incoming photon Compton scatters in the hodoscope. The second scatter layer is the calorimeter where the scattered gamma ray is totally absorbed. The recoil electron in the hodoscope is tracked through several detector planes until it stops. The x and y position signals from the first two planes of the electron track determine the direction of the recoil electron while the energy loss from all planes determines the energy of the recoil electron. In another embodiment of the invention, the Compton double scatter technique with recoil electron tracking is used to detect x-rays from 300 to 2,000 keV. This embodiment is useful for nondestructive, real time inspection of munition items. In another embodiment of the invention, the invention is used to provide a high sensitivity, high spatial resolution and electronically collimated single photon emission computed tomography system which is sensitive from 81 keV to 511 keV gamma ray photons. In another embodiment, a high sensitivity three-dimensional scintimammography system is provided which utilizes gamma ray imaging. In another embodiment, a Compton scatter positron emission tomography system is provided.