Beam dynamics simulation in high-power high-energy accelerator-driver of the proton beam

Abstract

The design of linear accelerator-driver of the MW and 1-1.5 GeV proton beam is the main problem in accelerating driven systems (ADS) design. The results of beam dynamics simulation in such linac will present. Linac will consist of RFQ, RF focusing section and SC modular configuration sections.The success of conventional nuclear energetic satisfy all needs of commercial and defense aims long times. But the alternative technologies as fast reactors and accelerating driven systems (ADS) are necessary to solve a number of problems as U-238 or thorium fuel reactor ant nuclear wastes transmutation. ADS consist of megawatt-power proton accelerator, neutron producing target and breeder. A number of ADS projects are under development in EU, Japan, USA, PRC, S.Korea at present [1-10]. The review of main projects was done in [11]. The superconducting linac or their complexes with high energy storage synchrotron are under design in main projects.The design of linear accelerator-driver of the MW and 1-1.5 GeV proton beam is the main problem in accelerating driven systems design. Accelerator-driver design was done in 1999 last time at Russian Federation. The collaboration of MEPhI, ITEP, Kurchatov Institute researchers do the project directed to the preliminary design of such linac in 2013. This project was supported by the Ministry of Science and Education of Russian Federation under contract No. 14.516.11.0084.Linac will consist of RFQ, RF focusing section and SC modular configuration sections. The linac general layout is presented in fig. 1. It is proposed to use the electron cyclotron resonance proton source. CW mode RFQ linac section was developed as the bunching section and for low energy acceleration. Three different types of RF focusing linacs were discussed for the medium energies. There are RF crossed lenses [12], modified electrode profile RFQ [13], axi-symmetrical RF focusing (ARF) [14] and the shot SC cavities system was also discussed. The conventional modular scheme linac [15] based on spoke-cavities and 5-cell elliptical cavities was designed for higher energies. The linac layout have three intermediate energy beam lines which can be used by step-by-step linac construction to different experiments with neutron production targets or for radiation testing of reactor construction materials.Let we briefly discuss results of beam dynamics simulation in the proposed linac.First RFQ section operates on 162 MHz and accelerate Figure 1. The linac general layoutbeam to the 2 MeV. The section length is 2/4 m and the low accelerating potential between electrodes equal to 120 kV was used. It is caused by needs to limit the surface field by 1.2-1.5 of Kilpatrick criterion value for CW mode. The injection velocity is 0.01c. The current transmission coefficient is equal to 96 % for zero current beam and slowly decrease to 94 % for 20 mA.The modified electrode form RFQ [13] can be used as the second section to accelerate the beam in 2-15 MeV energy range. Beam loses are absent, the averaged rate of the energy gain is equal to ...