Extraction Simulations for the Iba C70 Cyclotron

Since the end of 2005, IBA has been working on the development of the 70MeV Cyclone, the ARRONAX Cyclotron for the Region des Pays de la Loire in Nantes, France. First of a kind for IBA, the accelerator is equipped with two external ion sources (a multicusp and an ECR) so as to produce 4 types of particles, in particular high intensity, variable energy H -(30 -70MeV, 750µA) and fixed energy 4 He 2+ (70MeV, 35pµA). Moreover, the 4 He 2+ beam can be pulsed. The unique magnet structure is composed of three layers: sector, pole and pole cover. Furthermore, compensation coils are wound around each of the poles in order to obtain the different isochronous fields. The RF system at about 30.4MHz consists of a 100kW RF amplifier coupled to a home made cavity. Extraction is then obtained either by stripping or by electrostatic deflection. Finally, two switching magnets redirect the beam to one or two of the 6 transport lines used for R&D applications or radioisotopes production. The overview ...

We discuss the possibility in principle of stripping extraction in combination with reverse bends in isochronous separate-sector cyclotrons (and/or fixed field alternating gradient accelerators). If one uses reverse bends between the sectors (instead of or in combination with drifts) and places stripper foils at the sector exit edges, the stripped beam has a reduced bending radius and it should be able to leave the cyclotron within the range of the valley—even if the beam is stripped at less than full energy. We are especially interested in stripping of H þ 2 , as it doubles the charge to mass ratio of the ions. However the method could be applied to other ions or ionized molecules as well. For the production of proton beams by stripping extraction of an H þ 2 beam, we discuss possible designs for three types of machines: First, a low-energy cyclotron for the simultaneous production of several beams at multiple energies—for instance 15, 30, and 70 MeV—thus allowing beam delivery on several isotope production targets. In this case it can be an advantage to have a strong energy dependence of the direction of the extracted beam. Second, we consider a fast variable-energy proton machine for cancer therapy that should allow extraction (of the complete beam) at all energies in the range of about 70 MeV to about 250 MeV into the same beam line. Third, we consider a high-intensity high-energy machine, where the main design goals are extraction with low losses, low activation of components, and high reliability. Especially if such a machine is considered for an accelerator driven system (ADS), this extraction mechanism has advantages: Beam trips by the failure of electrostatic elements could be avoided and the turn separation would be less critical, which allows operation at lower main cavity voltages. This would in turn reduce the number of rf trips. The price that has to be paid for these advantages is an increase in size and/or field strength compared to proton machines with standard extraction at the final energy.

2021

At the present time, the activities on creation of the new heavy-ion isochronous cyclotron DC140 are carried out at Joint Institute for Nuclear Research. DC140 facility is intended for SEE testing of microchip, for production of track membranes and for solving of applied physics problems. Cyclotron will produce accelerated beams of ions A/Z= 5 – 5.5 and 7. 5 – 8.25 with a fixed beam energy 4.8 MeV/n and 2.124 MeV/n respectively. The variation of operation modes is provided by changing of magnetic field in the range 1.4T – 1.55T with fixed generator frequency 8.632MHz. In this report, the results of design and simulation of the beam acceleration and extraction are presented.

2017

At IBA, we have designed, constructed, tested and industrialized an innovative isochronous cyclotron for PET isotope production. The design has been optimized for costeffectiveness, compactness, ease of maintenance and high performances, with a particular emphasis on its application and market. Multiple target stations can be placed around the vacuum chamber. An innovative extraction method (patent applications pending) has been designed which allows to obtain the same extracted beam sizes and properties on the target window independent of the target number. This is achieved by proper design and shaping of the magnet poles. This magnetic design is discussed together with beam dynamics simulations and beam extraction tests on the first machine. Figure 1: View on the upper half of the CYCLONE®KIUBE. In grey is shown the magnetic iron including the return yoke and the four poles. The pole-inserts (in blue) are used to shim the isochronous field. Further shown is the main coil (yellow),...

2017

According to the agreement between the Institute of Plasma Physics of the Chinese Academy of Sciences (ASIPP) in Hefei, China, and the Joint Institute for Nuclear Research (JINR), in Dubna, Russia, the project of superconducting isochronous cyclotron for proton therapy SC200 is under development at both sites. The cyclotron will provide acceleration of protons up to 200 MeV with maximum beam current of ~1 μA. Extraction system of the beam consists of electrostatic deflector and two passive magnetic channels. Electric field strength in deflector does not exceed 170 kV/cm, gradients of magnetic field in channels are in a range of 24 kG/cm. Both channels focus the beam in horizontal plane. Axial focusing of the beam is provided by edge magnetic field of the cyclotron. Results of the beam tracking inside extraction system are presented. Efficiency of the beam extraction was estimated for different amplitudes of the betatron oscillations in the accelerated beam. WORKING DIAGRAM OF CYCLOT...

The superconducting cyclotron (C400) is under design at IBA (Belgium) (1, 2). The cyclotron will be able to accelerate 12C+6 and 2H+ ions up to the energy 400 MeV/nucleon and protons with the energy close to 260 MeV. The basic technical design line for the cyclotron extraction system uses passive magnetic correctors. By computer simulation with the 2D (POISSON) and 3D (TOSCA, MERMAID and MAFCOD) codes the principal design parameters of the extraction magnetic elements were estimated and their magnetic field maps were simulated. The field maps obtained are used for dynamic simulation of the extracted beam.

Review of Scientific Instruments, 2010

A set of new ion extraction electrodes have been designed for the permanent magnetic electron cyclotron resonance ion source at Peking University to improve beam quality and transmission. PBGUNS has been used to optimize the extraction electrodes and simulate the beam behavior at the extraction region. The experiments showed that with the new system, the beam half divergence angle can be less than 40 mrad and the normalized rms emittance is about 0.13 mm mrad when the extracted current is 100 mA at 50 keV in pulse mode. The voltage of the suppression electrode has great effect on beam divergence. The effect of the microwave power and gas flow is also studied.

2020

The CYRCé (CYclotron pour la ReCherche et Enseignement) TR24 cyclotron is used at IPHC (Institut Pluridisciplinaire Hubert Curien) for the production of radio-isotopes for diagnostics, medical treatments and fundamental research in radiobiology. The TR24 cyclotron produced and commercialized by ACSI delivers a 16-25 MeV proton beam with intensity from few nA up to 500 µA. The TR24 is a compact isochronous cyclotron with normal-conducting magnet and stripper foil for the beam extraction. The calculation model for OPERA 3D program code is described. The magnetic field map in the working region of the cyclotron is generated. The beam characteristics outside the cyclotron, that will serve as initial conditions for the design of future beam lines are determined.

2007

Presently IBA designs and produces a 70 MeV cyclotron for radiochemistry and nuclear medicine (C70) (1), (2), (3), (4), (5). Main problems and solutions of the magnetic design and calculations are described. Two distinguished isochronous magnetic fields are necessary to accelerate both types of ions with charge to mass ratio q/m =1 /1(H − ) and 1/2(D − , α

2010

A new beam extraction scheme from a synchrotron is put forward. The main difference from other schemes of extraction is the use of a magnetic shields instead of a septum. Magnetic shields are located in the central dipole magnets of a pulsed chicane. The magnetic shield is a multi-layer copper-iron tube. Numerical simulations and experimental results for the magnetic shield are presented. A good accordance between them has shown. The advantages of the new scheme are easy technical implementation and compactness. The area of application is extraction from a synchrotron. The proposed scheme will be used in a new synchrotron radiation source in Novosibirsk.