High current ion beam RF acceleration and perspectives for an inertial fusion driver

Abstract

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 Ϫ , 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-b 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 b ϭ 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 U 4ϩ , 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 A0q Յ 65, 91-MV linac are reported. Beam dynamics calculations for Bi 1ϩ -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.

Frontiers of dense plasma physics with intense ion and laser beams and accelerator technology

“…Investigation of interaction processes of heavy ion beams with ionized matter had originally been motivated by inertial fusion physics, where intense heavy ion beams were proposed to ignite a fusion target [34][35][36]. Inertial fusion energy today is an area of active basic research while some aspects of the fusion scenario are already technically feasible.…”

Development of room temperature crossbar-H-mode cavities for proton and ion acceleration in the low to medium beta range

“…29, as the radius of the coupling cell is increased, the field in the adjacent cells close to the intertank section becomes stronger increasing the strength of the coupling. This phenomenon should be taken into account since higher voltage levels in this area could increase the risk of sparking between the lens and the adjacent stems of the CH structures, as happened between the lens housing and an adjacent drift tube inside an earlier IH cavity [43].…”

Gamma radiation measurements as a diagnostic tool of beam-induced dense plasmas

“…Experimental work on ion beam induced high energy density matter was initiated by the quest for inertial fusion energy driven by intense ion beams~Hora, 2004; Ratzinger et al, 2003!. In this scenario, a heavy ion beam deposits its energy in the volume of a converter target and generates plasma at or close to solid state density. As an experimental challenge and for this reason especially, the diagnostics of solid-state density plasmas was an important topical question for a long time~Renner et al, 2002!.…”