Conceptual Design of Rapid Circular Particle Accelerator Using High-Gradient Resonant Cavities with Fixed Frequency

A new high-energy particle accelerator with static combined type of magnetic field and high-gradient resonant cavities is introduced for muon acceleration up to 300 MeV and proton acceleration up to 400 MeV. The accelerator concept is expected to realize Mpps-class rapid cycling high-energy particle acceleration in circular particle accelerators. Conceptual designs of the circular accelerator are discussed with an emphasis on short lifetime particles. The fundamental concept of particle acceleration and the related practical issues, which should be discussed when designing the accelerators, are described as well

Cool-stacking injection and damping of a transverse

SPring-8ビーム物理研究会200

BEAM DYNAMICS WITH ELECTRON COOLING

XIX RUSSIAN PARTICLE ACCELERATOR CONFERENC

Dynamics of a High Density Ion-Beam with Electron Cooling

High density circulating-ion beam was obtained with electron-cooling and cool-stacking injection in HIMAC synchrotron. The ion density was saturated at 1.0e9/cm^2. Coherent transverse instability was observed when ion- and electron-beam density was high. The dynamics of the cooled ion-beam are described in this report.Particle Accelerator Conference 2005 (PAC05)

Electron Cooling of Coasting and Bunched Beams in HIMAC Synchrotron

Experiments of electron cooling have been done with the HIMAC synchrotron in NIRS. Limitation on cooled beam-sizes in longitudianl and transverse spaces were measured.COOL0

ELECTRON BEAM COOLING AND BEAM INSTABILITY ISSUES ON HIMAC

Experiments of electron cooling have been done with the HIMAC synchrotron in NIRS. Coherent transverse instability was observed when ion- and electron-beam density was high. Limitation on cooled beam-sizes in longitudianl and transverse spaces were measured.NANOBEAM200

Experimental study of a half-integer resonance with space-charge effects in a synchrotron

Beam losses due to half-integer resonance have been observed in the Heavy Ion Medical Accelerator in Chiba synchrotron, along with exciting the harmonic component of gradient field errors. During operation, while varying the defocusing quadrupole to cross a half-integer tune in the vertical space, the region of bare tunes which causes the half-integer resonance was evaluated. When the initial beam intensity was high, the bare tune where the beam loss occurred became higher. The beam loss occurred rapidly when the half-integer tune was crossed upward, but gradually when it was crossed downward. Those results mean that the half-integer resonance is affected by space-charge-induced tune shifts. This fact was verified experimentally for the first time. The results from a one-dimensional multiparticle simulation agreed with those characteristics. Finally, the beam-size growth and the change in distribution were studied by a simulation

Particle-core analysis of dispersion effects on beam halo formation

A simple particle-core model for circular accelerators has been constructed assuming that dispersion effects are relatively weak. This model is applicable to a large class of high-intensity rings designed for modest density applications such as spallation neutron sources. Applying this model to isotropic beams in a smooth ring, halo formation processes in the presence of dispersion are investigated. In the analysis, it is found that dispersion matching is essential to suppress horizontal beam widening in injection if momentum spread is larger than a certain threshold. Even if the beam widening due to dispersion mismatch is suppressed, a halo can be formed in the same mechanism as in a linac, namely, parametric resonance between oscillating core and single particles. The width of halos formed by the particle-core resonance in modest-density rings is found to be a little narrower than that in a straight channel, and typically 1.6 to 1.8 times the maximum core width