Status of the hadrontherapy projects in Europe

International audienceRobert R. Wilson, an accelerator pioneer working with E.O. Lawrence at Berkeley, made the first proposal to treat cancer using proton beams more than 60 year ago (1946). In a first period, many accelerators built for nuclear and particle physics research have been progressively used to treat patients all over the word. It was the time of the hadrontherapy “first generation”. As it has been the case for the evolution of the synchrotron radiation sources, starting with Loma Linda in 1990, a “second generation” of dedicated facilities has then been built to treat cancer without the constraints imposed to “parasitic users”. The total number of patients treated with protons was about 10.000 in 1993 and 50.000 in 2006, the progression looks to be exponential. Hadrontherapy is today part of the medical business landscape, several companies sell turnkey protontherapy centres and the fight is started for carbon centres. The status of some hadrontherapy projects in Europe (existing facilities and future projects) as well as the industrial aspects will be presented in this framework

On the Choice of Linac Parameters for Minimal Beam Losses

TUPWA034In high intensity linear accelerators, the tune spreads induced by the space-charge forces in the radial and longitudinal planes are key parameters for halo formation and beam losses. For matched beams they are the parameters governing the number of resonances (including coupling resonances) which affect the beam and determine the respective sizes of the stable and halo areas in phase space. The number and strength of the resonances excited in mismatched beams leading to even higher amplitude halos are also directly linked to the tune spreads. In this paper, the equations making the link between the basic linac parameters (rf frequency, zero-current phase advances, beam intensity and emittances) and the tune spreads are given. A first analysis of the way these linac parameters can be chosen to minimize the tune spreads is presented. The parameters of ESS linac are used for this study

Space-charge transport limits of ion beams in periodic quadrupole focusing channels

It has been empirically observed in both experiments and particle-in-cell simulations that space-charge-dominated beams suffer strong growth in statistical phase-space area (degraded quality) and particle losses in alternating gradient quadrupole transport channels when the undepressed phase advance sigma_0 increases beyond about 85 degrees per lattice period. Although this criterion has been used extensively in practical designs of strong focusing intense beam transport lattices, the origin of the limit has not been understood. We propose a mechanism for the transport limit resulting from classes of halo particle resonances near the core of the beam that allow near-edge particles to rapidly increase in oscillation amplitude when the space-charge intensity and the flutter of the matched beam envelope are both sufficiently large. When coupled with a diffuse beam edge and/or perturbations internal to the beam core that can drive particles outside the edge, this mechanism can result in large and rapid halo-driven increases in the statistical phase-space area of the beam, lost particles, and degraded transport. A core-particle model is applied to parametrically analyze this process. Extensive self-consistent particle in cell simulations are employed to better quantify space-charge limit and verify core-particle model predictions.Comment: 17 pages, 5 figures. Submitted to Nuclear Instruments and Methods A. Includes a long version of a conference talk (trans_limits_talk.pdf) presented on the topic at the "Coulomb'05 -- High Intensity Beam Dynamics" workshop (Senigallia, Italy, 12-16 September 2005). This talk presents further supporting information/plots not included in the abbreviated, draft-format manuscrip

Spiral2 Project: Integration of the Accelerator Processes, Construction of the Buildings and Process Connections

TUA2C01International audienceThe GANIL SPIRAL 2 Project is based on the construction of a superconducting ion CW LINAC (up to 5 mA - 40 MeV deuteron and 33 MeV proton beams, up to 1 mA - 14.5 MeV/u heavy ion beams) with two experimental areas named S3 ('Super Separator Spectrometer' for very heavy and super heavy element production) and NFS ('Neutron For Science'), The building studies as well as the accelerator and experimental equipment integration started in 2009. The ground breaking started at the end of 2010. The integration task of the different equipments into the buildings is managed by a trade-oriented integration unit gathering the accelerator integration team, the building prime contractor and a dedicated contracting assistant. All work packages are synthesized at the same time using 3D models. 3D tools are used to carry out integration, synthesis, process connections and the preparation of the future assembly. Since 2014, the buildings and process connections are received and the accelerator installation is well advanced. This contribution will describe these 3D tools, the building construction, the process connection status and our experience feedback

Chaos and Noise in a Truncated Toda Potential

Results are reported from a numerical investigation of orbits in a truncated Toda potential which is perturbed by weak friction and noise. Two significant conclusions are shown to emerge: (1) Despite other nontrivial behaviour, configuration, velocity, and energy space moments associated with these perturbations exhibit a simple scaling in the amplitude of the friction and noise. (2) Even very weak friction and noise can induce an extrinsic diffusion through cantori on a time scale much shorter than that associated with intrinsic diffusion in the unperturbed system.Comment: 10 pages uuencoded PostScript (figures included), (A trivial mathematical error leading to an erroneous conclusion is corrected