Heavy ion acceleration and cooling ring TARN 2

Abstract

After the successful experiments of beam accumulation and stochastic cooling at TARN‐1 ring, it was decided to construct the more powerful heavy ion ring TARN‐2 which has the maximum rigidity of 7 T‐m, corresponding to 1.3 GeV for proton and 0.45 GeV/u for ions of 1/2 charge‐to‐mass ratio. In this ring both the stochastic and the electron beam cooling methods are prepared to obtain the high resolution and small emittance beam. Especially the electron beam cooling has the advantage of low energy heavy ion beam cooling, and then the maximum e‐beam energy 120 keV, corresponding to the 200 MeV/u of ion energy, was selected. At present the injector is the sector focusing cyclotron with K–67 which accelerates ion beams from protons to neon for TARN 2. In parallel with the construction of TARN 2, the heavy ion linac is now being constructed. The first part of the linac is an RFQ with the energy of 800 keV/u which was successfully tested with proton beam acceleration. After boosting up the ion energy to 5 MeV/u by the drift tube linac, this system will take the place of injector for TARN 2. In this case the heavy ions up to Xe will be accelerated and cooled in the ring. In this paper, the status of TARN 2 including the linac system will be presented as well as the possibility of its application to HIF experiments.