| 摘要 |
FIELD: flaw inspections, customs examination equipment, medicine, and roentgen diagnosing spectroscopic installations. ^ SUBSTANCE: proposed X-ray tube has vacuum envelope accommodating anode, X-ray output aperture, cathode assembly incorporating field-radiating cathode in the form of bundle of carbon fibers placed in conducting or semiconducting shell, contact assembly of field-radiating cathode, and cap that functions as control electrode. In order to prevent stray surface electric conductance caused by sputtering of field-radiating cathode material on structural components of X-ray tube, dielectric washer is inserted in this tube wherein during X-ray tube assembly annular cavity is formed between inner hole of washer, field-radiating cathode shell, and upper end of field-radiating cathode contact assembly. Cavity provided in dielectric washer and also its slots prevent formation of solid conducting and semiconducting films which enhances stability of electrical and radiating characteristics of tube. For raising electric strength of tube and excluding breakdown of its envelope cap is installed on dielectric washer that functions as control electrode. Cap is installed so that axis of carbon fiber bundle is aligned with that of optoelectronic system of X-ray tube and symmetry axis of cap. ^ EFFECT: enhanced operating stability, electric strength, reliability, and service life of X-ray tubes with field-radiating cathode. ^ 1 cl, 3 dwg |
