Quasi-Optical 34-GHz Radio Frequency (RF) Pulse Compressor

72041-The quest for an ever-increasing acceleration gradient for a high-energy linear collider leads naturally to considerations of producing energy at millimeter wavelengths. As at centimeter wavelengths, radio frequency pulse compression is needed to produce the required high peak power pulses. Therefore, this project will develop quasi-optical passive and active pulse compression structures. A 34-GHz 40-MW magnicon will be made available to test components and determine breakdown and surface fatigue limits in millimeter-wave accelerator-relevant structures. In Phase I, designs of three- and four-mirror quasi-optical resonators, along with passive and active diffraction gratings, were refined and successfully cold tested with low-power 34-GHz radiation. A preliminary design of a high-power, high-vacuum version of a four-mirror millimeter-wave pulse compressor was carried out. Phase II will refine the design of the four-mirror quasi-optical resonator, and high-vacuum tests will be carried out at input power levels up to 10 MW at 34 GHz, with both passive and active diffraction gratings, and using chirp frequency modulation during the input pulse. Successful results would allow tests up to 40 MW, using combined outputs from all four arms of the 34-GHz magnicon. Commercial Applications and Other Benefits as described by awardee: The 34-GHz, high-power accelerator-relevant technology should allow for the implementation of an alternative upgrade for the Next Linear Collider to a center-of-mass energy of 1.5 TeV or higher. This upgrade would create a market for several thousand quasi-optical millimeter-wave pulse compressors, with a potential sales volume of several million dollars. Other applications include millimeter-wave radars for military and civilian uses.