Active high power RF pulse compression using optically switched resonant delay lines

Sami G. Tantawi, Ronald D. Ruth, Arnold E. Vlieks, Max Zolotorev
1997 The seventh workshop on advanced accelerator concepts  
We present the design and a proof of principle experimental results of an optically controlled high power rf pulse compression system. The design should, in principle, handle few hundreds of Megawatts of power at X-band. The system is based on the switched resonant delay line theory [1] . It employs resonant delay lines as a means of storing rf energy. The coupling to the lines is optimized for maximum energy storage during the charging phase. To discharge the lines, a high power microwave
more » ... h increases the coupling to the lines just before the start of the output pulse. The high power microwave switch, required for this system, is realized using optical excitation of an electron-hole plasma layer on the surface of a pure silicon wafer. The switch is designed to operate in the TE 01 mode in a circular waveguide to avoid the edge effects present at the interface between the silicon wafer and the supporting waveguide; thus, enhancing its power handling capability. NLC [2], require peak rf powers that can not be generated by the current state of the art microwave tubes [3] . The SLED Pulse compression system [4] was implemented to enhance the performance of the two mile accelerator structure at Stanford Linear Accelerator Center (SLAC). One drawback of SLED is that it produces an exponentially decaying pulse. To produce a flat pulse and to improve the efficiency, the Binary Pulse Compression (BPC) system [5] was invented. The BPC system has the advantage of 100% intrinsic efficiency and a flat output pulse. Also, if one accepts some efficiency degradation, it can be driven by a single power source [6] . However, The implementation of the BPC[7] requires a large assembly of overmoded waveguides, making it expensive and extremely large in size. The SLED II pulse compression system is a variation of SLED that gives a flat output pulse [8] . The SLED II intrinsic efficiency is higher than SLED [9], but not as good as BPC. However, from the compactness point of view SLED II is far superior to BPC. In this paper we present a variation on SLED II that will enhance its intrinsic efficiency without increasing its physical size.
doi:10.1063/1.53079 fatcat:dodu6pdtzreczbbudqqi4ubvcu