PPM-Focused Klystron for Accelerator Systems

Project X at Fermi National Accelerator Laboratory listed a requirement for 75 - 125 500 kW L-Band solenoid focused klystrons for the main LINAC. CCR proposed a periodic permanent magnet (PPM) focused klystron. Funding was cut substantially for the LINAC, and CCR received a change of scope to address a near term application for an S-Band klystron for the Varian Medical Systems future CLINAC. CCR will continue to address long term DOE requirements. CCR is proposing a 5 MW PPM-focused klystron for commercial applications while still addressing long term technology requirements for DOE. All of the Phase I goals were met for both klystrons. A design was produced for the 500 kW L-Band, including detailed simulation of the diode type electron gun, interaction circuit consisting of 7 individual cavities, and an RF output window. In addition, a design was produced for the 5 MW S-Band PPM focused klystron with an efficiency of 49%. This is higher than that produced by the CLINAC solenoid klystron. Individual designs were realized for all of the critical components. In Phase II we will complete the design of the 5 MW PPM klystron, optimizing critical parameters such as electron gun, electron beam focusing, PPM structure, interaction circuit, collector, and RF output window. A detailed thermal analysis will be performed on the electron gun, circuit, and window. CCR will then perform a detailed mechanical design, fabricate, bake out, and high power test. Testing will be conducted at CPI, CCRs industrial partner. Commercial Applications and Other Benefits: A detailed commercial plan has been submitted with this Phase II proposal. The VARIAN MEDICAL CLINAC application constitutes a large commercial possibility. Establishment of the PPM technology will result in installing klystrons in many systems in lieu of solenoid focused klystrons, increasing overall efficiency while reducing size and weight.