X-ray emission from a compact hot plasma: applications to radiology and mammography.
Hot electrons confined in a compact magnetized plasma (in a 1 litre chamber) and heated by electron cyclotron resonance were used to provide an intense reproducible x-ray emission. Since electrons were generated in situ, the use of filaments and high voltages at the base of the x-ray tubes was avoided. The source can be pulsed or operated in a highly stable continuous mode. The spatial and energetic characteristics of the hot electrons were determined via their bremsstrahlung by comparison with theoretical calculations. In this test x-ray source the average energy of the hot electron flux was in the range 10-40 keV, depending on the operating parameters: intermagnet distance (6-9 cm), power of the 2.45 GHz microwave (200-1000 W), chamber pressure (4 x 10(-5)-9 x 10(-5) Torr). The insertion of solid targets into the electron flux leads to various focal spot sizes, enabling application in radiology and mammography. The images of a mammographic phantom were obtained in a few seconds with good contrast (microcalcifications being successfully detected).
X-Technologies, Ecole Polytechnique, Palaiseau, France.
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Gaudin
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Lamoureux
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Rouillé
D000818:Animals; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging; D002645:Chickens; D017357:Cyclotrons; D004583:Electrons; D004867:Equipment Design; D005260:Female; D006614:Hindlimb / Q000000981:diagnostic imaging; D006801:Humans; D008327:Mammography; D009333:Neck; D019047:Phantoms, Imaging; D011784:Quail; D011859:Radiography; D011871:Radiology; D015203:Reproducibility of Results; D014965:X-Rays