The actual situation with respect to the use of an RF linac driver
for heavy ion inertial fusion (HIF) is discussed. At present, there is
no high current heavy ion linac under construction. However, in the
course of linac projects for e−, p, d, or highly
charged ions several developments were made, which may have some impact
on the design of a HIF driver. Medium- and low-β superconducting
structures suited for pulsed high current beam operation are actually
designed and investigated at several laboratories. A superconducting 40
MeV, 125 mA cw linac for deuteron acceleration is designed for the
Inertial Fusion Material Irradiation Facility (IFMIF). The Institute
for Applied Physics (IAP) is developing a superconducting 350-MHz,
19-cell prototype CH-cavity for β = 0.1. The prototype cavity will
be ready for tests in 2004. A superconducting main HIF driver linac
would considerably reduce the power losses. Moreover, it would allow
for an efficient linac operation at a higher duty factor.
The
1.4-AMeV room-temperature High Current Injector HSI at Gesellschaft
für Schwerionenforschung (GSI) has been in routine operation for
more than 2 years now. With a mass-to-charge ratio of up to 65, a
current limit of 15 mA for U4+, and an energy range from 2.2
AkeV up to 1.4 AMeV, this linac is suited to gain useful experience on
the way toward the design of a HIF RF driver. The status and technical
improvements of that A/q ≤ 65, 91-MV linac are reported. Beam
dynamics calculations for Bi1+-beams show that powerful
focusing elements at the linac front end are the bottleneck with
respect to a further increase in beam current. Besides superconducting
and pulsed wire quadrupoles, the potential of the Gabor-plasma lenses
is investigated.