Thermal characteristics of repetitively operated high-current beam collector

For a traditional collector of an S-band backward-wave oscillator, the affected area due to bombardment by energetic electrons was experimentally measured, and the power per unit area as thermal loading for a 700 keV and 7 kA beam with 50 ns duration was calculated. By using an ANSYS-APDL package, the 10 to 100 Hz repetitive operation results of temperature history and distribution of the collector were typically presented at convective coefficient of 7 000 W/(m2·℃) and water temperature of 20℃. The relationship between the equilibrium temperature and convective coefficient for different pulse repetition rate was also obtained. In addition, the cooling flow rate corresponding to different convective coefficient was given.