X-Ray generator for fast dose rate control
AssigneeU.S. Philips Corporation
InventorHeinz Mester
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Abstract
An X-ray generator comprising two high voltage generators which supply a positive and a negative potential to the anode and cathode, respectively, of an X-ray tube. The high voltage generator connected to the cathode is connected in series with a grid-controlled electron tube. The X-ray tube has a grounded electrode between its anode and cathode. If the grid voltage of the electron tube is changed so that the anode potential decreases, then there is an increase in the X-ray tube voltage and an increase in the voltage between the anode and electrode of the X-ray tube, thus increasing the tube current. Tube current and voltage are thus varied in the same sense by modifying the grid voltage, thus producing a fast dose rate control.
Claims9
An X-ray generator comprising an X-ray tube including an anode, a cathode and an electrode between the anode and cathode, first and second high voltage generators each of which comprises a high voltage transformer winding and rectifying means, means connecting the first high voltage generator to the anode of the X-ray tube to supply thereto a positive high voltage, means connecting the second high voltage generator to the cathode of the X-ray tube to supply thereto a negative high voltage, means connecting said electrode of the X-ray tube to a source of reference voltage which is intermediate in value the anode and cathode voltages of the X-ray tube, and a grid-controlled electron tube connected in series with the second high voltage generator and with its cathode connected to the source of reference voltage whereby a change in the grid voltage of the electron tube produces a simultaneous change in the X-ray tube voltage and current and in the same sense.
An X-ray generator comprising, an X-ray tube including an anode, a cathode and a control electrode, first and second high voltage generators each of which comprises a high voltage transformer winding and rectifying means, a grid-controlled electron tube, means connecting the first high voltage generator, the X-ray tube, the second high voltage generator and the electron tube in series circuit so that the first high voltage generator supplies a high positive voltage to the X-ray tube anode and the second high voltage generator supplies a high negative voltage to the X-ray tube cathode, means connecting the control electrode of the X-ray tube to a source of fixed reference voltage, and means coupling the grid of the electron tube to a source of control voltage and a cathode of the electron tube to a source of reference voltage so that a change in the grid voltage of the electron tube produces a change in the X-ray tube voltage and current in the same sense.
Dependencies are inferred from the claim text.