Patent ID: 8107591

Claim:
An x-ray tube comprising: an evacuated housing; a cathode and an anode in said evacuated housing, said cathode emitting electrons that are accelerated in a propagation path to said anode and strike said anode, causing emission of x-rays from said anode as well as backscattered electrons; a catching device in said housing in said propagation path between said cathode and said anode, said catching device capturing said backscattered electrons from said anode, and being electrically insulated with respect to the anode and with respect to the cathode; and a voltage source arrangement that establishes electrical potentials at said anode, said cathode and said catching device, said voltage source arrangement placing said catching device at an electrical potential having a value between a value of electrical potential at said anode and a value of electrical potential at said cathode, with a magnitude of a difference between the electrical potential of the catching device and the electrical potential of the anode being in a range between 1% and 40% of a magnitude of a difference between the electrical potential of a cathode and the electrical potential of the anode.