[en] Short communication

[en] Summary only

[en] The LNS Superconducting Cyclotron (CS) has successfully worked for more than 20 years, with an extracted beam power limited to 100W. Its peculiarity is to provide a broad range of ion species from hydrogen to lead in the energy range between 10 and 80AMeV. Recently, the demand for higher beam intensities came from the experiment NUMEN, which investigates the nuclear matrix element of the neutrinoless double beta decay through double exchange reactions. Also, the in-flight radioactive beams produced at FRIBs@LNS are interested in the high intensity primary beams. Both activities deal with low cross section reactions and require an increase in beam intensities for light ions up to a factor 100. Nevertheless, other experiments will take advantage of the upgrade and there will be even the possibility to produce medical radioisotopes. The solution proposed in this study makes use of extraction by stripping to provide high-intensity beams up to 1014 pps. Major machine modifications, including the cryostat and the superconducting coils, are mandatory to guarantee these new performance. However, heavier ions acceleration will be guaranteed, maintaining the extraction by electrostatic deflectors. An overview of the studies carried out is here presented.

[en] The principles of the Chalk River tandem accelerator superconducting cyclotron are explained at a popular level. The new device has been made by linking the old tandem accelerator up to a new semiconducting cyclotron. By accelerating ions to 10⁸ m/s and allowing them to collide with heavy nuclei, a whole range of unstable exotic nuclei will be made available for study

[en] The accelerator research facility at RIKEN has three major accelerators : variable frequency linear accelerator, K70 AVF cyclotron, and K540 ring cyclotron (RRC). Recently a variable frequency RFQ was added as an injector to the linac to improve the beam intensity along with 18GHz ECR ion source. To continue to serve the users from the various fields, RIKEN proposed the Radio Isotope (RI) Beam Factory project, and it was approved last year. Two new superconducting ring cyclotrons (SRC-4 and SRC-6) will boost the energy of heavy ion beams from the RRC for the RI beam production on the entire periodic table. The RI beam produced is mass-separated and can be injected into accumulator, collider, and booster rings. An overview of the present and proposed facility will be given. And some details will be discussed on the SRC-6 whose model sector magnet is under construction. (author)

[en] This paper discusses the control system of the Tandem Accelerator Superconducting Cyclotron (TASCC) of AECL Research at its Chalk River Laboratories which is presently based on a PDP-11 computer and the IAS operating system. The estimated expense of a custom conversion of the system to a current, equivalent operating system is prohibitive. The authors have evaluated a commercial control package from VISTA Control Systems based on VAX microcomputers and the VMS operating system. Vsystem offers a modern, graphical operator interface, an extensive software toolkit for configuration of the system and a multi-feature data-logging capability, all of which far surpass the functionality of the present control system. However, the implementation of some familiar, practical features that TASCC operators find to be essential has proven to be challenging. The assessment of Vsystem, which is described in terms of presently perceived strengths and weaknesses, is, on balance, very positive

[en] The RF-frequency of AGOR being rather high, neutron TOF measurements have a limited dynamic range and low resolution. This can be improved by injecting beam at a sub-harmonic of the RF-frequency. By injecting beam only once per orbital period the repetition rate of the extracted beam is divided by the harmonic number (h= 2; 3 or 4), even in case of multi-turn extraction. A single gap sawtooth buncher operating up to 15 MHz with a duty cycle of 80%, under development for this purpose, is described and first measurements using the regular buncher are discussed. (authors)

[en] This letter notes that the closing of the TASCC in Chalk River will result in the loss of scientific capability in Canada. (AIP) copyright 1997 American Institute of Physics

[en] The extraction system of the superconducting cyclotrons is normally making a large use of electric extractors followed by magnetostatic elements. The electric field limit initially hoped for (14 MV/m) has been shown to be too optimistic. A more realistic value is around 10 MV/m in the concerned geometries. The first element of the AGOR extraction system is an electrostatic channel where the maximum electric field is limited to 10.5 MV/m. The smaller separation between the internal beam and the extracted beam at the entrance of the first magnetic element is compensated by the replacement of the usual magnetostatic channels with high power electromagnetic channels placed in the reduced space close to the internal beam and where the horizontal position can be adjusted according to the kind of ion accelerated and its energy. The fringing field very close to the channels is controlled with the help of correction coils reducing the perturbations of the internal beam trajectories to an acceptable level

[en] At the LNS the K800 Superconducting Cyclotron has been in operation since 1994 as a booster of a 15 MV Tandem. Several years ago it was decided to provide the machine with an axial injection system so as to operate in stand-alone mode. By a proper choice of the source (a superconducting ECR one), it was also intended to improve the performance of the cyclotron as far as the intensity of all ion beams and the energy of ions with mass higher than 100 a.m.u. are concerned. Several studies have been done in the past to design the axial injection system of the cyclotron, i.e. the inflector and the central region. In the meantime, a new idea has come up, namely to use the cyclotron as a primary machine to produce radioactive ion beams. The new design takes account of the 'high intensity' request, and at the same time allows the acceleration of ion beams in the whole mass range, in 2. harmonic mode (energy range 8±100 MeV/a.m.u.). Beam dynamics features of the designed system are presented. A phase selection system will also be installed to reduce activation of the electrostatic deflectors. (authors)