  A proposal for a 10-120 mA proton linac employing superconducting
beta-graded, CERN type, four cell cavities at 352 MHz is presented. The high
energy part (100 MeV-1 GeV) of the machine is split in three beta-graded
sections, and transverse focusing is provided via a periodic doublet array. All
the parameters, like power in the couplers and accelerating fields in the
cavities, are within the state of the art, achieved in operating machines. A
first stage of operation at 30 mA beam current is proposed, while the upgrade
of the machine to 120 mA operation can be obtained increasing the number of
klystrons and couplers per cavity. The additional coupler ports, up to four,
will be integrated in the cavity design. Preliminary calculations indicate that
beam transport is feasible, given the wide aperture of the 352 MHz structures.
A capital cost of less than 100 M$ at 10 mA, reaching up to 280 M$ for the 120
mA extension, has been estimated for the superconducting high energy section
(100 MeV-1 GeV). The high efficiency of the proposed machine, reaching 50% at
15 mA, makes it a good candidate for proposed nuclear waste incineration
facilities and Energy Amplifier studies.
