INFN/LNS, Catania
The EXCYT project has successfully come to conclusion at the end of 2006. As a consequence a new facility for production and acceleration of radioactive ion beams is now available at Laboratori Nazionali del Sud, Catania. This facility is based on the ISOL method: in particular the primary beam is delivered by a Superconducting Cyclotron, while the secondary beam is post-accelerated by a Tandem. A low energy radioactive beam is also available at the exit of the pre-injector. The main features of the commissioning of the facility will be described. Details will be given on the characteristics of the diagnostic devices. Future development activities are related both to the operative features of the new facility and to the improvements and upgrading that are planned to be introduced in the near future. All of these subjects will be extensively discussed.
RIKEN, Wako, Saitama
The Radioactive Isotope Beam Factory at RIKEN Nishina Center is a next generation facility which is capable of providing the world’s most intense RI beams over the whole range of atomic masses. Three new ring cyclotrons have been constructed as post-accelerators for the existing facility in order to provide the intense heavy ion beam for the RI beam production by using a in-flight separation method. The beam commissioning of RIBF was started at July 2006 and we succeeded in the first beam extraction from the final booster cyclotron, SRC, by using 345 MeV/nucleon aluminum beam on December 28th 2006. The first uranium beam with energy of 345 MeV/nucleon was extracted from the SRC on March 23rd 2007. Various modifications for equipments and many beam studies were performed in order to improve the transmission efficiency and to gain up the beam intensity. Consequently, the world’s most intense 0.4 pnA 238U beam with energy of 345 MeV/nucleon and 170 pnA 48Ca beam with energy of 345 MeV/nucleon have been provided for experiments.
Osaka University/RCNP, Osaka
The Research Center for Nuclear Physics (RCNP) cyclotron cascade system has been operated to provide high quality beams for various experiments. In order to increase the physics opportunities, the Azimuthally Varying Field (AVF) cyclotron facility was upgraded recently. A flat-topping system and an 18-GHz superconducting Electron Cyclotron Resonance (ECR) ion source were introduced to improve the beam’s quality and intensity. A new beam line was installed to diagnose the characteristics of the beam to be injected into the ring cyclotron and to bypass the ring cyclotron and directly transport low energy beams from the AVF cyclotron to experimental halls. A separator is equipped to provide RI beams produced by fusion reactions at low energy and by projectile fragmentations at high energy. Development has continued to realize the designed performance of these systems.
RIKEN, Wako
At RIKEN RIB-factory (RIBF) an accelerator complex as an energy booster which consists of superconducting ring cyclotron (SRC), intermediate-stage ring cyclotron (IRC) and fixed-frequency ring cyclotron (FRC) provides very heavy ion beams like uranium with an energy of 345 MeV/u. The total beam power obtained up to now at the SRC is as high as 3 kW in the case of 48Ca with an intensity of 170 pnA. Recently we have succeeded in achieving stable and reliable operation of rf system for new cyclotrons. In this paper the present performance of the rf system and a recent development is reported.
MPI-K, Heidelberg
Several experiments at the heavy ion storage ring TSR have shown the feasibility of wide range, efficient acceleration and deceleration. The newly developed method of mass selective acceleration enables an effective separation of ion species with relative mass differences of ∆m/m = 3.7 · 10-4. Parabola shaped short bunch lengths were measured for an electron cooled 50 MeV 12C6+ ion beam in the space charge limit. To overcome the space charge limit the TSR was operated at a momentum compaction of α = 1.57.
TIFR, Mumbai
BARC, Mumbai
The superconducting LINAC booster, indigenously developed to boost the energy of the heavy ion beams from the 14 MV Pelletron accelerator at TIFR, Mumbai, has been fully operational since July 2007. The LINAC consists of seven modular cryostats, each housing four lead plated quarter wave resonators, designed for an optimum velocity β0=0.1 at an operating frequency of 150 MHz. In order to maintain a stable phase and amplitude of the electric field in the cavity, the RF controller cards based on a self-excited loop (SEL) with phase and amplitude feedback have been developed indigenously. The cryogenic system for the LINAC has been designed for a typical power dissipation of 6 W in each resonator. Initial beam trials have yielded average energy gain of 0.4 MV/q per cavity corresponding to 80% of the design value. Operational experience of the LINAC, namely, empirically devised procedures for the acceleration of different beams and RF settings, and associated developments are presented.
GSI, Darmstadt
TU Darmstadt, Darmstadt
Funding: Work supported by EURATOM (IFE KiT Program).
The recent development in laser acceleration of protons and ions has stimulated ideas for using this concept as innovative and compact therapy accelerator. While currently achieved parameters do not allow a realistic conceptual study yet we find that our simulation studies on ion collimation and transport, based on output data from the PHELIX experiment, already give a useful guidance. Of particular importance are the chromatic and geometric aberrations of the first collimator as interface between the production target and a conventional accelerator structure. We show that the resulting 6D phase space matches well with the requirements for synchrotron injection.
JINR/FLNR, Dubna
At the present time, the activities on creation of the new multi-purpose isochronous cyclotron U400R are carried out at the FLNR, JINR. The isochronous cyclotron U400R is intended for obtaining the beams of the accelerated ions from 4He1+ (A/Z=4, W=27MeV/u) up to 132Xe11+ (A/Z=12, W=3.5MeV/u). The cyclotron magnetic field can be changed from 0.8T to 1.8T and allow the smoothly variation of the ion beam energy at the range ±35% from nominal. The cyclotron RF system keeps up 2 - 6 harmonic modes. The aim of the present work is to investigate the optimal geometry of U400R cyclotron center for the wide range of acceleration regimes. The computation of the beams acceleration is carried out by means of the computer code CENTR.