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RF Construction for PRISM-FFAG -Ultra High Field Gradient RF for Bunch Rotation@5MHz-. C. Ohmori KEK. Techniques to obtain a beam with low momentum spread. Several ideas Cooling in synchrotron Barrier de-bunch in a synchrotron Linac Option Solution :.
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RF Construction for PRISM-FFAG-Ultra High Field Gradient RF for Bunch Rotation@5MHz- C. Ohmori KEK NUFACT04, RCNP, OSAKA
Techniques to obtain a beam with low momentum spread • Several ideas • Cooling in synchrotron • Barrier de-bunch in a synchrotron • Linac Option • Solution : • These techniques require 100ms-1s. • Short lifetime of m beam More R&D Bunch rotation in a FFAG ! NUFACT04, RCNP, OSAKA
Bunch Rotation in Longitudinal Phase Space Momentum Apply RF Voltage @ 5MHz Direction of Beam Saw Tooth RF is considered for smaller Dp/p After several turns in FFAG Small Dp/p Injection to FFAG Large Dp/p Low Frequency for Large Bucket vs. Difficulty to get High Voltage at Low Frequency NUFACT04, RCNP, OSAKA
Possible Scenarios to obtain High Voltage at 5 MHz • Magnetic Alloy • High Field Gradient ( -200kV/m) might be possible by an optimum design. • Ferrite with High Q • Degradation of characteristics ? • Need R&D • Ceramic Cavity • Very high field gradient might be possible. • Need R&D NUFACT04, RCNP, OSAKA
Magnetic Cores for Cavity Ferrites Magnetic Alloys Requirements for PRISM B=V/wS=400Gauss NUFACT04, RCNP, OSAKA
MA Cavities Himac Cavity: 50cm, 20kV, water cooling driven by 150kW tubes 5kV, CW, driven by 30kW tubes. Barrier Bucket Cavity: 2.6m, 40kV, 6% duty, air cooling, driven by 30kW tubes installed in BNL AGS. J-PARC RF Cavity: 1.7m, 60kV, Cut Core Water cooling, driven by 600kW tubes PoP FFAG Cavity in KEK NUFACT04, RCNP, OSAKA
RF CavitiesField Gradient of Cavities for Proton Synchrotrons JKJ RF Cavities KEK-PS MA Cavity Ferrite Cavities High Gap Voltage (X 3) & Short Cavity (X 2) Very High Gradient for very short moment (10ms) ! NUFACT04, RCNP, OSAKA
MA core for PRISM 1.7 m NUFACT04, RCNP, OSAKA
Parameters of MA Cavity NUFACT04, RCNP, OSAKA
PRISM RF R&D AMP • FY2003: • Production of AMP, PS etc. • FY2004: • AMP Commissioning by a test cavity @ RCNP, Osaka-U. • Design & production of 33 cm Cavity Test Cavity NUFACT04, RCNP, OSAKA
RF system R&D • 43 kVp/gap using 700 W test cavity • Design goal (60 A RF current) of AMP was achieved. • 33 cm cavity will be >900 W: • Very compact design for AMP and APS. RF voltage at the gap (red line) NUFACT04, RCNP, OSAKA
PRISM Cavity Design AMP • 1 Gap will be produced in this FY04. Cavity APS Beam Pipe 33cm Side View By C. Ohmori, Y. Kuriyama NUFACT04, RCNP, OSAKA
Summary • R&D for PRISM RF has been started here, (in M-Exp. Area, RCNP, Osaka-U). • AMP, PS, D-AMP and MA Cores have been produced. • AMP has been tested using a test cavity and achieved 43 kV at 5MHz. • Ultra High Field Gradient Cavity will be • produced in FY2004. • Test of Ultra High Field Gradient in FY2005 NUFACT04, RCNP, OSAKA