STATUS OF THE HIIF RF LINAC STUDY BASED ON H-MODE CAVITIES

The H-mode structure family was extended recently to gain access to ve locity profiles ranging from beta similar to 0.002 to 0.6. This means that the (Heavy-Ion Inertial Fusion) (HIIF) relevant energy range is w ell included (beta less than or equal to 0.3). RF power tests show the capability of IH-cavities to withstand about 10 MV/m effective voltag e gain. A linac lattice at 30 MeV/u and based on the (Kombinierte Null Grad Struktur) (KONUS) beam dynamics is investigated at beam intensit ies of up to 1 A. The use of multibeam cavities along the low energy l inac sections is suggested. As the RF frequency along the H-type linac is changed from around 10 MHz up to around 400 MHz, typically 32 chan nels could be funneled into the single aperture high-energy linac sect ion. This principle should open the possibility to get linac beam inte nsities as high as 2 A within norm, transverse emittances around 1 pi mm mrad and a final energy spread Delta W/W similar to +/- 2 x 10(-4). At the low-energy end beam intensities around 500 mA along each multi aperture cavity are feasible. Higher linac beam intensities give shor t RF pulse lengths. This will allow to develop RF power sources with s ignificantly higher peak power levels. Additionally, the whole system will benefit from the time-averaged wall loss reduction. (C) 1998 Else vier Science B.V. All rights reserved.