Subject: Reminder & Info: RF Meeting for Proton Driver Tuesday 3:00 Penthouse From: "G. William Foster" Date: Mon, 08 Mar 2004 14:28:24 -0600 To: Ralph Pasquinelli , Iouri Terechkine , Nikolay Solyak , Brian Chase , Markus Huening , Bob Kephart , "C. Shekhar Mishra" , Al Moretti , Dave Wildman , Ding Sun , Vladimir Kashikhin , Steve Hays , Pierre Bauer , Roger Dixon , steve holmes , Eric Prebys , Weiren Chou , Ioanis Kourbanis , Milorad Popovic , Howard Pfeffer Hi RF gang, Here are some agenda items for tomorrow's Proton Driver RF meeting: I won't be there, so you can interpret these things as items to be accomplished before, during, or after next Tuesday's meeting. I'm asking Pierre Bauer to take minutes. - Bauer/Wildman: progress report on getting the Ferrite ordered (& expedited?) - Vladimir/Steve Hays first cut at the bias coil & power supply requirements for pulsing the coax tuner at 10 Hz with a 1.5 msec (programmable) flat top. - Moretti/Solyak/Terechkine: next iteration of bid spec for 805 MHZ IQ modulator - All RF Simulation wonks: how are we set for RF simulation tools: A) for simulating the circularly polarized waved in the biased ferrite in the "waveguide" designs, and B) if we restrict ourselves to metal waveguide structures plus coaxial ferrite tuners - All: any bright ideas for simplifying the E-H tuner topology given the limited requirement for range of phase and attentuation? Also enclosed: 1) a concept drawing from Gennady on a possible simplification of the phase shifter for the 1207MHz electron-proton switchover. It seems like a good idea which could reduce the amount of ferrite needed. However somne of the shifters will see 5MW of Klystron power...? 2) Some preliminary parameters for the waveguide and coax shifters from Ding, as well as some ideas on how we might proceed. 3) There are also some related ideas embedded into last week's meeting notes. From: Ding Sun After few weeks of simulation and other paper researches, the following are the basic parameters we can use as a base line for "slow" 360 degree phase shifter. 1. Two slab in waveguide. We should use differential phase shift which gives much better phase shift/unit length (it can produce 180 degree for 6" ferrite with 0.5" thick alumina loading, at 1200 MHz, HFSS simulation, needs experiment verify). For the same configuration, the experimental results of ANL shows the non-differential phase shift is 40 degree/6 inches (at 805 MHz). However, the quality of magnetic field may be a problem because the ferrite slabs are too close to each other (0.5" apart). To solve this problem, we can take out the alumina. (actually we do not need it for slow switching). Without alumina loading, I got 190 degree/6 inches (HFSS simulation) ( I feel this is the way we should go). Internal bias field for all the above phase shift is 19000 A/m. Relatively modest. The engineering problem would be: how to conduct heat out? Magnet design (need Vladimir to decide which way is better for magnet economy). 2. Ferrite filled Coax Line in transmission mode. For this configuration, I have successfully simulated the Bell Lab¡¯s experimental results (7/8" coax line). It needs longitudinal bias field varies between 71600 A/m (900 Oe) to 111408 kA/m (1400 Oe) to get phase change 108 degree/6 inches. I believe we have to increase coax line to at least 1 5/8¡" or above. The engineering problem should be the same: how to conduct heat out? Work Plan: 1. R/D on both options since the second option cost very little (this can be incorporated into Dave/Al's program. 2. Start building the half height waveguide (including launcher) test setup. (1 month) 3. Start buying YIG ferrite (8 week delivery) 4. Do more simulation for detail of the configuration (best matching etc.) (2 weeks). 5. Start design and building magnet for waveguide option. (????) An addition R&D is can we change two slabs of ferrite into toroid and use a DC wire to replace the magnet at our power level? Ding gennady_concept.doc Content-Type: application/msword Content-Encoding: BASE64 Ding_Parameters_Concepts.txt Content-Type: text/plain Content-Encoding: QUOTED-PRINTABLE RF_Minutes_March_2.doc Content-Type: application/msword Content-Encoding: BASE64