The beam dynamics design of the low energy DTL section of a
fusion driver linac based on the IH-structure is presented.
The acceleration of a 209Bi1+ beam by
an IH-DTL operated at 27 MHz (54 MHz) is investigated for two
specific injection energies at 60 A keV and at 200 A keV, respectively.
Both cases are optimized separately, with the goal to find out the
maximum achievable acceleration gradient, beam current, as well as the
most attractive field strength range of the quadrupole lenses.
Calculations are performed on one beamlet, but the results can
be applied to build up multibeam cavities. H-mode cavities are
very well suited for this purpose and provide high acceleration
efficiency, especially at low particle velocity. In addition,
the “Combined 0° structure” (“Kombinierte
Null Grad Struktur–KONUS”) beam dynamics concept
allows grouping into modular units consisting of short, simple
rf cavities and of multiaperture quadrupole triplet lenses located
in the intertank sections.