Measurement of Yield and Energy Spectrum of Secondary Electrons Emitted by Fission from Uranium-Oxide Cathode for Neutron Streak Tube

• Published in: Journal of nuclear science and technology Vol. 25; no. 10; pp. 780 - 788
• Main Authors: IIDA, Toshiyuki, ARAKI, Tatsuya, MIYAKE, Chie, SUMITA, Kenji, YAMANAKA, Tatsuhiko, YAMANAKA, Masanobu, MIYANAGA, Noriaki, YAMAMOTO, Takayoshi
• Format: Journal Article
• Language: English
• Published: Tokyo Taylor & Francis Group 01.10.1988; Taylor & Francis Ltd
• Subjects: D-T neutrons; energy spectra; laser fusion diagnostics; microchannel plate; neutron streak tube; secondary electron yield; secondary electrons; suppression grid; uranium-oxide cathode
• ISSN: 0022-3131; 1881-1248
• DOI: 10.1080/18811248.1988.9735925

We describe a method for measuring the yield and energy spectrum of secondary electrons emitted by fission from a uranium-oxide cathode for a neutron streak tube. In a compact vacuum chamber about 1-μm thick uranium-oxide cathodes made by an evaporation process were irradiated by D-T neutrons. The secondary electrons emitted from the cathode were detected with a microchannel plate for which gain and efficiency were determined. The yield of the secondary electrons was determined from the average output charge of the microchannel plate and was found to be about 400 electrons per fission. The energy spectrum of the secondary electrons was also obtained by using a suppression grid technique. It was found from the spectrum that the average energy of the secondary electrons was about 5 eV and about 30% of them had an energy higher than 5 eV. These results are good guides to design of the electrode structure of the neutron streak tube. Also the present method can be efficiently used for optimizing the uranium-oxide cathode.