Development and testing of improved high power thermionic emitters for magnetron injection gun applications

Summary form only given. At the University of Maryland, we have been engaged in the development of high power gyroklystrons amplifiers for Advanced Collider applications. The facility utilizes a Magnetron Injection Gun that contains an annular thermionic emitter, which is in excess of 150 mm in diameter and requires a heater power greater than 2 kW. Historically, the performance of these emitters has constrained the overall system performance. There are inherent difficulties in the design and fabrication of emitters of this size and we typically see substantial out-gassing, and azimuthal temperature variations greater than 30 degrees Celsius. We have engaged in an effort to systematically improve the performance of this class of emitters. We present and discuss information on emitter design, modeling, processing and testing.