An analysis of recent free electron laser experiments in combined wiggler and strong axial magnetic fields shows that near resonance, Q,,=kwv,,, the proximity of the cyclotron maser instability precludes an unambiguous identification of the radiation mechanism ( 2,, is the cyclotron frequency in the axial field, kw is the wiggler wavenumber, and v,, the axial electron velocity).

Context. Spectroscopic observations and theoretical models suggest resonant wave-particle interactions, involving high-frequency ion-cyclotron waves, as the principal mechanism for heating and accelerating ions in the open coronal holes. However, the mechanism responsible for the generation of the ion-cyclotron waves remains unclear. One possible scenario is that ion beams originating from smal...

PURPOSE The purpose of this study was to evaluate the impact of a cyclotron on small-animal PET equipment installed directly above the cyclotron. METHODS The cyclotron equipment was HM-12, which has two targets, and the PET/CT equipment was Inveon. The equipment was installed in conformity to Japanese law and regulations. Before installation of the PET/CT equipment, the radiation dose, radio ...

Cyclotrons are used in medical applications mostly for radioisotope production for positron emission tomography (PET) and proton therapy. PET is a diagnostic technique requiring daily production of radiotracers. Most of the PET cyclotron centres produce 18F for the synthesis of fl uorodeoxyglucose (FDG). The cyclotron laboratory in Bern is a part of the SWAN project aiming at the realization of...

The sawtooth control mechanism in plasmas employing off-axis toroidally propagating ion cyclotron resonance waves in tokamaks is reinvestigated. The radial drift excursion of energetic passing ions distributed asymmetrically in the velocity parallel to the magnetic field determines stability when the rational q=1 surface resides within a narrow region centered about the shifted fundamental cycl...

The form of the propagating electrostatic Bernstein mode in a relativistic electron-positron plasma is markedly different from that in the classical plasma, once the momentum-dependent cyclotron frequency is accounted for in full inside the integrations. Given that particles in different parts of momentum space "see" a different cyclotron frequency, there is no simple global singularity which r...

1MRC Cyclotron Unit, Hammersmith Hospital, Correspondence to: Dr M. Samuel, MRC Cyclotron Unit, 2Wellcome Department of Cognitive Neurology, Institute of Hammersmith Hospital, Du Cane Road, London Neurology, London, UK, 3Neurologische Klinik der W12 0NN, UK Technischen Universität, München, Germany, 4Louvain University, Brussels, Belgium and 5National Hospital for Mental, Nervous and Muscular D...