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Compact monochromatic flash x‐ray generator utilizing a disk‐cathode molybdenum tube
Author(s) -
Sato Eiichi,
Tanaka Etsuro,
Mori Hidezo,
Kawai Toshiaki,
Ichimaru Toshio,
Sato Shigehiro,
Takayama Kazuyoshi,
Ido Hideaki
Publication year - 2005
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.1829247
Subject(s) - bremsstrahlung , optics , marx generator , materials science , spark gap , cathode , thyratron , pulse generator , physics , anode , x ray tube , diode , voltage , photon , electrical engineering , optoelectronics , electrode , quantum mechanics , engineering
The high‐voltage condensers in a polarity‐inversion two‐stage Marx surge generator are charged from −50 to −70 kV by a power supply, and the electric charges in the condensers are discharged to an x‐ray tube after closing gap switches in the surge generator with a trigger device. The x‐ray tube is a demountable diode, and the turbo molecular pump evacuates air from the tube with a pressure of approximately 1 mPa. Clean molybdenum K α lines are produced using a 20 μm‐thick zirconium filter, since the tube utilizes a disk cathode and a rod target, and bremsstrahlung rays are not emitted in the opposite direction to that of electron acceleration. At a charging voltage of −70 kV, the instantaneous tube voltage and current were 120 kV and 1.0 kA, respectively. The x‐ray pulse widths were approximately 70 ns, and the generator produced instantaneous number of K α photons was approximately 3 × 10 7photons ∕ cm 2 per pulse at 0.5 m from the source of 3.0 mm in diameter.