Patent ID: 8164064

Claim:
A sensor for directionally locating an ionizing radiation source, the sensor comprising at least one functional component comprising at least one first radiation detector and at least one second radiation detector, said at least one first radiation detector capable of receiving radiation from the ionizing radiation source and producing a first output signal, and said at least one second radiation detector capable of receiving radiation from the ionizing radiation source and producing a second output signal; a displacement mechanism which imparts angular sensitivity to the sensor by moving said at least one functional component, wherein said displacement mechanism is capable of rotating said at least one first radiation detector and said at least one second radiation detector through a rotation angle so that said first output signal varies with said rotation angle and so that said second output signal varies with said rotation angle; and at least one radiation shield installed at a fixed angle with respect to said at least one first radiation detector and said at least one second radiation detector so that a magnitude of said first output signal from said at least one first radiation detector and a magnitude of said second output signal from said second radiation detector vary with said rotation angle.