Goethe Universität Frankfurt/IAP, Frankfurt
MSU/NSCL, East Lansing
ECR and EBIS have become well-known ion sources for most heavy ion accelerator projects. The basic difference arises from the method, how energy is provided to create dense energetic electrons: An ECR uses microwave heating of a magnetically confined plasma, while in an EBIS the energy comes from a power supply to accelerate an electron beam and focus it to high density in a strong solenoidal magnetic field. Basically ECR sources are dc sources of heavy ions but the afterglow extraction also provides intense mA pulses in ms. In contrast to this EBIS sources provide an intense ion pulse in 1-100 μs and therefore find application in feeding synchrotrons. This determines most of the accelerator applications: ECR sources have very successfully extended the range (and life) of cyclotrons, while EBIS has found application at high energy facilities. For radioactive beam facilities, both kind of sources are in use. ECR sources in the trapping mode (ECRIT) perform the ionization (charge breeding) of high intensity primary beams, while EBIS can reach higher charge states at lower emittance, which provides an improved signal to noise ratio for rare isotopes.
INFN/LNL, Legnaro
GSI, Darmstadt
CNAO, Milan
INFN/LNF, Frascati
INFN/LNS, Catania
The CNAO (Centro Nazionale di Adroterapia Oncologica), located in Pavia (Italy), is a dedicated clinical synchrotron facility for cancer therapy using high energy proton and Carbon beams. The 400 MeV/u synchrotron is injected by a 216.8 MHz 7 MeV/u linac composed by a low energy beam transport (fed by two ion sources), a 400 keV/u 4-rod type RFQ and a 20 MV IHDTL. The commissioning of the two ECRIS ion sources and the low-energy line was successfully completed at the end of January 2009 reaching the proper beam conditions for injection into the RFQ. After installation and conditioning, the RFQ was commissioned with beam by the GSI-CNAO-INFN team in March 2009. The beam tests results are presented and compared to the design parameters.
GSI, Darmstadt
The GSI linear accelerator UNILAC and the synchrotron SIS18 will feed the future accelerator facility FAIR (Facility for Antiproton and Ion Research) with heavy ion beams. Several hardware measures at the UNILAC are necessary to meet the FAIR requirement, implicating a beam intensity of 3.2·1011 of U28+-particles within an UNILAC macro pulse of 100μs length and defined emittance space at SIS18 injection. The stripper gas jet density was strongly increased to get the equilibrium charge state even for the heaviest ions. A procedure matching the 6-D-phase space for proper A lvarez DTL injection and increase of the transverse phase advance in the Alvarez accelerators reduces emittance growth. In front of SIS18 injection a new separator provides an immediate selection of the desired charge state after stripping and therefore reduces space charge induced emittance growth. The front-end of the high current injector includes several bottle necks. A compact solenoid channel is planned providing straight line injection into the 4-rod- RFQ. The RFQ will be equipped with new designed electrodes for increased acceptance and reduced emittance growth. The contribution gives an overview of end-to-end simulations, the different upgrade measures, the particular beam investigations, and the status of beam development satisfying FAIR requirements.
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.
KIRAMS, Seoul
Design of conventional 4-vane/rod type of RFQ (Radio Frequency Quadrupole) for the heavy ion medical facility has been studied. The RFQ is capable of accelerating C4+ ions from an initial energy of 10 keV/u to 300 keV/u. In this work, all the design parameters have been optimized to achieve stable structure and compactness. The 3D electromagnetic field distribution and RF analysis were obtained by CST Microwave Studio and the field was used in TOUTATIS for beam simulation. This paper shows the determined physical and mechanical design parameters of RFQ.
CNAO, Milano
GSI, Darmstadt
INFN/LNF, Frascati
INFN/LNL, Legnaro
INFN/LNS, Catania
University of Pavia, Pavia
Politecnico di Milano, Milano
The Centro Nazionale di Adroterapia Oncologica (CNAO) is the Italian centre for deep hadrontherapy, namely an innovative type of radiotherapy using hadrons. The wide range of beam parameters (i.e., energy and intensity) at patient level together with the advantages of hadron-therapy with respect to traditional radio-therapy nourishes the hopes for more effective patient recovery. After the LEBT and the RFQ commissioning, the IH commissioning is now in progress. First patients are expected to be treated in 2010. The present paper summarizes and evaluates the Low Energy Beam Transfer (LEBT) line commissioning, which has been carried out between July 2008 and January 2009.
TRIUMF, Vancouver
At the ISAC facility in TRIUMF radioactive ion beams (RIB) are produced using the ISOL method and post accelerated. The post accelerator chain consists of a radio frequency quadrupole (RFQ) injector followed by a drift tube linac (DTL) that accelerates the ions from 150 keV/u up to 1.8 MeV/u. A further stage of acceleration is achieved using a superconducting linac where the beam is injected using the DTL and the energy boosted with 20 MV of acceleration voltage (increased to 40MV by the end of 2009). The possibility of decelerating the beam maintaining good beam quality using the DTL is investigated based on experimenters request to reach energies lower than 150 keV/u. The beam dynamics simulation using the LANA code are compared with on line measurements. In this paper we will report the results of the investigation that aims to establish the lowest energy we can deliver in the post accelerator section of the ISAC facility.
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.
INFN/LNL, Legnaro
ITEP, Moscow
The positive ion injector for the PIAVE-ALPI complex consists of an ECR ion source placed on a high voltage platform. A 14.4 GHz ECRIS named Alice, designed and constructed at LNL in the early &##8216;90, reliably delivered gaseous beams to the Superconducting RFQ PIAVE for nuclear physics experiments until 2008. The requests for heavy ion beams of increased current and energy, needed to perform the experiments planned for the next years with the AGATA demonstrator, prompted us to upgrade our injector with a new ECR source capable of higher output beam currents and higher charge states. This activity started in 2008 and was completed at the beginning of 2009. A 14.5 GHz, SUPERNANOGAN type ECRIS built by Pantechnik, was installed in our refurbished high voltage platform in July 2008. The space available for maintenance in the platform was increased and a new lead shielding for X-rays has been set up. The water cooling circuits have been redesigned to deliver different fluxes and inlet pressures to the equipment mounted on the platform (plasma chamber, extraction electrodes, bending dipole and power supply). A new safety system has been implemented in order to cope with new and more demanding safety rules. A lot of attention has been paid to the optimisation of the injection line with new diagnostic devices for beam characterisation (movable slits, emittance measurement tools). Commissioning of the new source and injector with beams has started and first results will be reported.
INFN/LNL, Legnaro
ITEP, Moscow
Singly charged ion sources can easily surpass the 1 kW beam power, as in TRIPS (H+, 60 mA, 80 kV, now installed at LNL) or in NIO1 (H-, 130 mA distributed into 9 beamlets, 60 kV, a project of RFX and INFN-LNL). Beam diagnostic constitutes an important instrument in the high current source development. Even if calorimetric and optical beam profile monitors become possible, still a phase space plot of the beam will be the most useful tool for validation of extraction simulation and for input of subsequent beam transport optimization. Improvements in extraction beam simulations are briefly reported, and effect of space charge neutralization is discussed. Since preliminary design of the traditional two moving slit beam emittance meter show problems with slit deformations and tolerances and with secondary emission, an Allison scanner was chosen with the advantages: only one movement is needed; data acquisition is serial and signal can have an adequate suppression of secondary electrons. The design of a compact Allison scanner head is discussed in detail, showing: 1) the parameter optimization; 2) the segmented construction of electrodes. Experimental commissioning at lower power seems advisable.