470 likes | 490 Views
Diagnostics for FFAG-accelerator. Takahisa ITAHASHI Department of Physics, Osaka Univ. Toyonaka, Osaka, 560-0043,Japan. Contents. Performances of beam quality for various Accelerators Diagnostic instruments for a qualified beam Diagnostic instruments proposed for PRISM-FFAG Conclusion.
E N D
Diagnostics for FFAG-accelerator Takahisa ITAHASHI Department of Physics, Osaka Univ. Toyonaka, Osaka, 560-0043,Japan FFAG-Workshop Dec. 2005 Kumatori Japan
Contents • Performances of beam quality for various Accelerators • Diagnostic instruments for a qualified beam • Diagnostic instruments proposed for PRISM-FFAG • Conclusion FFAG-Workshop Dec. 2005 Kumatori Japan
Performances of up-dated accelerators(the state of the art) such as static acc., cyclotron, linac and synchrotron • 10-4 energy resolution (Osaka RCNP ring) • High beam power around 1 M-watt (PSI) • Precise positioning less than 1-micron (static acc.) • High Luminosity achieved for B-Physics (KEK, SLAC) • Synchrotron orbit radiation ( SPRING-8) FFAG-Workshop Dec. 2005 Kumatori Japan
Tail or skirt part of beam profile or beam distribution • The measurement is crucial for high current accelerators such as PSI cyclotron • Achieved extraction efficiency is about 99.99% at 1mA operation • In design of ADS a few hundreds MeV ~ 1 GeV, 100 microA~1mA Precise knowledge of beam distribution is needed FFAG-Workshop Dec. 2005 Kumatori Japan
6-Dimensional beam behavior should be discussed in FFAG design • Recent study of high current beam dynamics concerns with non-linear physics issues, which includes • Space-charge dominated beams • Several resonance effects in FFAG accelerators FFAG-Workshop Dec. 2005 Kumatori Japan
Beam loss due to deterioration beam quality • Beam envelope in 6-D phase space, in particular • Transverse-planes • Characteristic X-rays which are measured in a wide dynanic range of intensity lower to 10-6 of the peak are very helpful for getting the ideas FFAG-Workshop Dec. 2005 Kumatori Japan
Beam loss due to deterioration beam quality • Longitudinal-plane???microscopic time bunch of FFAG beam • Rf-gamma • Particle-particle • For measurement of longitudinal distribution • Comparison for measurement with FFT FFAG-Workshop Dec. 2005 Kumatori Japan
Diagnostic devices • Beam transformer x(non destructive) • Wall current monitor x(non destructive) • Pick-ups x(non destructive) • Faraday cup D(destructive) • Secondary emission monitor - + • Wire scanner - • Wire chamber - + • Ionization chamber - + • Beam loss monitor x(non destructive) • Gas curtain/jet - • Residual gas monitors x(non destructive) • Scintillator screens - + D • Scrapers, target D • Schottoky scan x(non destructive) • Synchrotron radiation x(non destructive) • Laser-Compton scattering x(non destructive) • Q-measurement x(non destructive) - • Emittance measurement - + D • Measurement of energy x(non destructive) - + D • Polarimeter x(non destructive) Based on H. Koziol ( CAS at Univ. of Jyvaskyla) FFAG-Workshop Dec. 2005 Kumatori Japan
Requirements fordiagnostics in PRISM-FFAG • Comparison with anti-proton production Similar facilities as PRISM was ? at CERN and will be AD-project at J-PARC(ref. E.Widman). AD : 200 pi mm mrad and dp/p = 6 % : stable : proton beam of capture momentum is very helpful for tuning : various cooling techniques are helpful for storage • Comparison with radio-active ion beam at RIBF MUSES : +/- 10 mrad and dp/p = 2.5 % : lifetimes of order of 1 microsec. : cooling and high luminosity are considered for collision FFAG-Workshop Dec. 2005 Kumatori Japan
Measurement of beam profile at POP-FFAG with BPM( non-destructive) • Measurement of beam profile • Measurement of beam oscillation • Measurement of synchrotron freq. • Measurement of betatron tune FFAG-Workshop Dec. 2005 Kumatori Japan
Injected muon beam • Dispersion matched at injection • Central momentum : 68 MeV/c • Requi = 6.5 m • Momentum spread : +/- 20 % • Beam intensity 1011 ~ 1012 / sec • Aperture : 30 cm (v) x 100 cm (h) FFAG-Workshop Dec. 2005 Kumatori Japan
Scrapers and measurement targetsDifferential type beam probe head (for transversal) • Differential current measurement in horizontal and vertical planes • Probe head has a slightly separated(~5mm) tips • Horizontal stroke is +/- 50 cm • Vertiacal stroke is +/- 15 cm or rotated • Measurable current is about 10pA~100nA with log amplifier FFAG-Workshop Dec. 2005 Kumatori Japan
Position sensitive solid state counter (energy and TOF) • 50 mm x 50 mm silicon strip solid state counter for energy measurement • rf-particle TOF measurement • Two dimensional measurement between position and energy will be avairable FFAG-Workshop Dec. 2005 Kumatori Japan
Sci-Fiber • Sci-Fiber could be applied for beam diagnostics in PRISM-FFAG • Dr. M. Yoshida-san would have a short comment for this issue • Mr. Takayanagi-san would like to develop the device next year. FFAG-Workshop Dec. 2005 Kumatori Japan
Parameters for PRISM-FFAG Accelerator N = 10 K = 4.6 F/D = 6.2 r0 = 6.5 m for 68 MeV/c Half gap = 17 cm mag. Size 110 cm at F center Tune h : 2.73 and v : 1.58 FFAG-Workshop Dec. 2005 Kumatori Japan
Conclusion • Feasible and actual design of beam diagnostic devices in PRISM-FFAG is needed • Space problem for devices should be solved • Data taking and display would be needed for easy operation of PRISM-FFAG • Precise measurement in 6-D beam optics would be helpful for study of non-linear beam dynamics FFAG-Workshop Dec. 2005 Kumatori Japan