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Old 05-30-2013, 10:45 PM
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jr_tech jr_tech is offline
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As I understand it, there are 2 distinct processes: "Breakdown" is done on the pump station and is achieved by ramping up the heater voltage to remove the binder used when the Barium Carbonate material is sprayed onto the Nickel cathode surface, as well as Carbon Monoxide from the Carbonate. Both heater voltage *and* RF induction heating are involved in this process. "Activation" , the second process is done after the tube is sealed off and the getter is flashed, and involves ramping up the heater voltage *and* drawing current from the cathode, to create stable emission sites on the very surface of the cathode. After current is drawn for some length of time, the heater voltage is brought down to "normal" voltage, and operated there for a while, a "slump test" may be performed to determine the stability of the cathode emission.
jr
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