A New Pumping System for a 150-Kilovolt Neutron Generator to Reduce the Present Tritium Hazard,

摘要

A new vacuum package incorporating a titanium bulk sublimator/ion pump combination has been designed,built,and evaluated on a typical 150-kilovolt neutron generator. The sublimator/ion pump system has been in operation for the past 10months and has provided the following operating advantages: (1) over 95percent of the tritium released from the target during deuteron bombardment is permanently buried in the sublimator chamber walls as titanium tritide; (2) a rapid pumpdown time of 30minutes from atmosphere to (10to the power of (-7)) torr is obtained routinely; (3) the new vacuum system is able to handle large active gas loads because of its high pumping capacity; (4) neutron generator operating pressure may be regulated between (10to the power of (-7)) torr and (10to the power of (-5)) torr by adjusting the rate of sublimation;and (5) the intermittent sublimation permits optimum use of available titanium,thus increasing pump life. The system is extremely reliable and requires little maintenance over long periods of time. The total cost of the vacuum package is competitive with existing pumping systems for new machines. (Author)