Automated High-Power RF Microwave Tube Test Stand

This paper describes an automated test stand used for testing the high-power klystron amplifiers for the Ground Test Accelerator (GTA). To verify klystron performance, we have developed an automated test system using data-acquisition and control programs based on LabVIEW™, a program that readily interfaces with both the high-power transmitter’s programmable logic controller and the GPIB interface test equipment. The automated test system also provides extensive analysis, improved data storage and processing, and documentation of the test conditions. This approach allows one to develop and operate a complex test system using an iconic-programming system. Three automated tests were developed and performed on the high-power klystron: swept-frequency, power-transfer, and voltage standing wave ration (VSWR) at several operating conditions. This paper describes the hardware used to test the klystrons, presents an example of the test data, provides block diagrams of the software used in the test stand, and characterizes all the capabilities for the automated test system. This test facility is being used by the GTA program to fully characterize the klystron amplifiers before they are placed into accelerator service, verify the factory acceptance tests, and determine optimal operating conditions for power levels below saturation. Currently, we are moving the test stand to the Los Alamos Meson Physics Facility (LAMPF) where we will test many klystrons used in their accelerator. These klystrons have been in operation for twenty years. Some of the amplifiers have been rebuilt and other amplifiers are in process of being retuned or decommissioned.