摘要 |
Electrons moving in a first direction are concentrated (e.g. magnetically) in a beam within a first tube. A converter converts the electrons to x-rays for movement to a particular position (e.g. tumor) in a patient. A fluid (e.g. water) flowing past the converter through a second tube co-axial with the first tube cools the converter. Microwave energy passes in the first direction through a third tube co-axial with the first tube. The third tube is open at the end near the converter so that the microwave energy will pass to the particular position in the patient. A second fluid (e.g. air) passing through a fourth tube coaxial with the first tube cools the tissue in direct contact with the x-ray needle. The second, third and fourth tubes may respectively have diameters of approximately 2, 3 and 4 millimeters. The microwave energy may pass into the third tube from a fifth tube transverse to the third tube. The microwave energy impedance may be approximately 50 OMEGA at the fifth tube input and approximately 5 OMEGA at the third tube input. The fifth tube is constructed to match the 50 OMEGA and 5 OMEGA impedances. A first portion of the microwave energy introduced to the third tube flows in the first direction through the third tube coaxially with the electron beam. A second portion of the microwave energy flows in a direction opposite to the first direction, is reflected by a short circuit and then flows in the first direction in phase with the first energy portion. |