Charge state distribution analysis of Al and Pb ions from the laser ion source at IMP

A prototype laser ion source that could demonstrate the possibility of producing intense pulsed high charge state ion beams has been established with a commercial Nd：YAG laser （E =3 J, 1064 rim, ~ 10 ns） to produce laser plasma for the research of Laser Ion Source （LIS）. At the laser ion source test bench, high purity （99.998%） aluminum and lead targets have been tested for laser plasma experiment. An Electrostatic Ion Analyzer （EIA） and Electron Multiply Tube （EMT） detector were used to analyze the charge state and energy distribution of the ions produced by the laser ion source. The maximum charge states of A112＋ and Pb7＋ were achieved. The results will be presented and discussed in this paper.

Conceptional design of the laser ion source based hadrontherapy facility

A laser ion source （LIS）, which can provide a carbon beam with highly stripped state （C^6＋） and high intensity （several tens mA）, would significantly change the overall design of the hadrontherapy facility. The proposed LIS based hadrontherapy facility has the advantages of short linac length, simple injection scheme, and small synchrotron size. With the experience from the DPIS and HITFiL projects that have been conducted in IMP, a conceptional design of the LIS based hadrontherapy facility will be presented, with special attention given to APF type IH DTL design and simulation.

Progress in particle-beam-driven inertial fusion research: Activities in Japan

Research activities in Japan relevant to particle beam inertial fusion are briefly reviewed.These activities can be ascended to the 1980s.During the past three decades,significant progress in particle beam fusion,pulsed power systems,accelerator schemes for intense beams,target physics,and high-energy-density physics research has been made by a number of research groups at universities and accelerator facilities in Japan.High-flux ions have been extracted from laser ablation plasmas.Controllability of the ion velocity distribution in the plasma by an axial magnetic and/or electric field has realized a stable high-flux low-emittance beam injector.Beam dynamics have been studied both theoretically and experimentally.The efforts have been concentrated on the beam behavior during the final compression stage of intense beam accelerators.A novel accelerator scheme based on a repetitive induction modulator has been proposed as a cost-effective particle-beam driver scheme.Beam-plasma interaction and pulse-powered plasma experiments have been investigated as relevant studies of particle beam inertial fusion.An irradiation method to mitigate the instability in imploding target has been proposed using oscillating heavy-ion beams.The new irradiation method has reopened the exploration of direct drive scheme of particle beam fusion.

High power acceleration of an HSC type injector for cancer therapy

A hybrid single cavity （HSC） linac, which is formed by combining a radio frequency quadrupole （RFQ） and a drift tube （DT） structure into one interdigital-H （IH） cavity, is fabricated and assembled as a proof of principle injector for cancer therapy synchrotron, based on the culmination of several years of research. The HSC linac adopts a direct plasma injection scheme （DPIS）, which can inject a high intensity heavy ion beam produced by a laser ion source （LIS）. The input beam current of the HSC is designed to be 20 mAC6＋ ions. According to numerical simulations, the HSC linac can accelerate a 6-mA C6＋beam, which meets the requirement of the needed particle number for cancer therapy （10s-9 ions/pulse）. The HSC injector with the DPIS method makes the existing multi- turn injection system and stripping system unnecessary, and can also bring down the size of the beam pipe in existing synchrotron magnets, which could reduce the whole cost of synchrotron. The radio frequency （rf） measurements show excellent rf properties for the resonator, with a measured Q equal to 91% of the simulated value. A C6＋ ion beam extracted from the LIS was used for the HSC commissioning. In beam testing, we found the measured beam parameters agreed with simulations. More details of the measurements and the results of the high power test are reported in this paper.