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The project "Dubna Electron Synchrotron" (DELSY) is aimed to construct a synchrotron radiation source of the 3d generation at the Joint Institute for Nuclear Research. The DELSY synchrotron radiation source will be constructed on the base of the accelerator facility of the Institute for Nuclear Physics and High Energy Physics (NIKHEF), Amsterdam, the Netherlands. This accelerator facility consists of a linear electron accelerator MEA (Medium Energy Accelerator) for the electron energy of 700 MeV and the electron storage ring AmPS (Amsterdam Pulse Stretcher) for the maximum electron energy of 900 MeV at the circulating beam current of 200 mA. The DELSY storage ring is supposed to be constructed with the use of the "Amsterdam Pulse Stretcher" (AmPS) [1] storage ring the focusing system of which will be essentially modified: the ring circumference will be approximately 1.5 times smaller, the electron energy will be increased up to 1.2 GeV and the focusing strength will be enhanced. These measures will allow obtaining the beam emittance at least ten times smaller which subsequently increases the synchrotron radiation brilliance by several orders of magnitude. The rigging of the DELSY ring with the insertion devices — the superconducting wiggler with the magnetic field of 10 T and the so-called "vacuum hybrid miniundulator" is the principle feature of the new synchrotron radiation source. Both devices developed by Budker INP, Novosibirsk, will allow to enrich the DELSY characteristics as the synchrotron radiation source expanding its radiation spectrum in the region of the hard X-rays and increasing its brilliance up to 3 ⋅10 18

This paper reports a lattice design of a dedicated proton synchrotron for hadron therapy. This synchrotron, named as a Prague Medical Synchrotron (PRAMES), will be used as a kernel of an accelerator complex of a Prague Oncological Hospital (Czech Republic). The synchrotron will be able to accelerate high-intensity proton beams of 625/spl middot/10/sup 10/ protons per pulse till the energy of 60-220 MeV with 1 Hz repetition rate. The active scanning of tumours is assumed. To satisfy this requirement, the slow (third-order) extraction scheme is analysed. The single turn injection of the proton beam is utilised to get the trapped proton beam with small transverse emittance on the injection energy of 12 MeV.

The ring design of the synchrotron for cancer treatment, based on the third-order resonant extraction, was been performed to meet the special medical requirements. The uniformity of the slow extracted beam from the proton synchrotron is the main requirement on the beam quality determined by the medical application. The smooth extraction during at least 400 msec should be realized for the `raster' scanning of tumours. Control of the slow extraction over the whole spill time is discussed in this report. To keep all lattice functions of the ring constant during the extraction a slow movement of the accelerated particles into the resonance can be used. To reduce degradation of the uniformity of the extracted beam by ripples from the power converters of the magnetic elements, the RF empty-bucket channeling method should be utilized. This method allows reduce the ripple influence during slow extraction. Both methods are analyzed to control the slow extraction for the dedicated proton synchrotron. The main parameters of the betatron core for this machine are determined. To realize the `empty-bucket' technique, the RF system of the synchrotron can be used with the maximum voltage at least 1.5 kV. The influence of the high-frequency ripple on the multiplying factor and the duty factor of the spill is studied. (4 refs).