P1–12: Analysis of quick start-up test on an S-band high average power klystron

A measurement about 4 minutes quick start-up is done on a kind of S-band high average power klystron. The test requires that the filament warms up only 4 minutes, and then the klystron starts up immediately. The results show that the klystron can work steadily, but in the 5
^th
minute the output power is about 93 % of the full power and the beam average current is about 97 % of the full current. Then the power and beam current are gradually increased, until the 15
^th
minute the klystron produces the full power and full beam average current. In conclusion, the 4mins quick start-up of the klystron will decrease the lifetime of the cathode, therefore the measurement isn't used often, but when meeting an emergency.