34 h. Innovative Magnetron Power Sources for Superconducting RF (SRF) Accelerators

The construction, replacement, and operating costs for klystron power sources now used for superconducting RF (SRF) accelerators are high. In their most cost-effective configuration, one high-power klystron drives several SRF cavities that have separate requirements for phase and amplitude control, requiring additional phase and amplitude control devices for each cavity. Magnetron RF power sources for single cavities can cost much less and operate at much higher efficiency than klystrons, but they do not have the phase and amplitude control or lifetime needed to drive SRF cavities for NP particle accelerators. Existing magnetrons that are typically used to study methods of control or lifetime improvements for SRF accelerators are built for much different applications such kitchen microwave ovens (1kW, 2.45 GHz) or industrial heating (100 kW, 915 MHz). In this project, Muons, Inc. will work with an industrial partner to develop fast and flexible manufacturing techniques to allow many ideas to be tested for construction variations that enable new phase and amplitude injection locking control methods, longer lifetime, and inexpensive refurbishing resulting in the lowest possible life-cycle costs. In Phase II magnetron sources will be tested on SRF cavities to accelerate an electron beam at JLab. A magnetron suitable for 1497 MHz klystron replacements at Jefferson Lab will be constructed and tested with our novel patented subcritical voltage operation methods to drive an SRF cavity. The critical areas of magnetron manufacturing and design affecting life-cycle costs that will be modeled for improvement include: Qext, filaments, magnetic field, vane design, and novel control of outgassing. The most immediate benefit of this project is to make SRF accelerator projects more affordable for NP and other users of SRF Linacs. One of the most attractive commercial applications for SRF accelerators is to drive subcritical nuclear reactors to burn Light Water Reactor Spent Nuclear Fuel (LWR SNF). A 1 GeV proton beam hitting an internal uranium spallation neutron target can produce over 30 neutrons for each incident proton to allow the reactor to operate far below criticality to generate electricity or process heat while reducing high-level waste disposal costs. This commercial application has the additional attribute of addressing climate change.