title: Performance of an electron gun for a high-brightness X-ray generator.
abstract: A prototype thermionic electron gun for a high-brightness X-ray generator has been developed. Its extraction voltage and design current are 60 kV and 100 mA (DC), respectively. The X-ray generator aims towards a maximum brilliance of 60 kW mm(-2). The beam sizes at the rotating anticathode must therefore be within 1.0 mm x 0.1 mm and a small beam emittance is required. The fabricated electron gun optimizes an aperture grid and a Whenelt electrode. The performance of the prototype electron gun measured using pulsed-beam tests is as follows: maximum beam current, 85.7 mA; beam focus size at the rotating anticathode, 0.79 mm x 0.13 mm. In DC beam tests, FWHM beam sizes were measured to be 0.65 mm x 0.08 mm at the rotating anticathode with a beam current of 45 mA. The beam current recently reached approximately 60 mA with some thermal problems.
authors.affiliation: Accelerator Laboratory, High Energy Accelerator Research Organization (KEK), Japan. takashi.sugimura@kek.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugimura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ohsawa
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Ikeda