FFAG-Workshop Dec Kumatori Japan Diagnostics for FFAG- accelerator Takahisa ITAHASHI Department of Physics, Osaka Univ. Toyonaka, Osaka, ,Japan

FFAG-Workshop Dec 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 Kumatori Japan Performances of up-dated accelerators (the state of the art) such as static acc., cyclotron, linac and synchrotron 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 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 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 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 of the peak are very helpful for getting the ideas

FFAG-Workshop Dec Kumatori Japan

Beam loss due to deterioration beam quality Longitudinal-plane???microscopic time bunch of FFAG beam Rf-gammaParticle-particle For measurement of longitudinal distribution Comparison for measurement with FFT

FFAG-Workshop Dec 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 Kumatori Japan

Requirements for diagnostics 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 : stable : proton beam of capture momentum is : proton beam of capture momentum is very helpful for tuning very helpful for tuning : various cooling techniques are helpful for storage : 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. : lifetimes of order of 1 microsec. : cooling and high luminosity are considered for collision : cooling and high luminosity are considered for collision

FFAG-Workshop Dec 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 Kumatori Japan Injected muon beam Dispersion matched at injection Central momentum : 68 MeV/c R equi = 6.5 m Momentum spread : +/- 20 % Beam intensity ~ / sec Aperture : 30 cm (v) x 100 cm (h)

FFAG-Workshop Dec Kumatori Japan Scrapers and measurement targets Differential 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 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 position and energy will be avairable

FFAG-Workshop Dec 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 Kumatori Japan

Parameters for PRISM-FFAG Accelerator N = 10 K = 4.6 F/D = 6.2 r 0 = 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 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