The principle

structure

adjustment of the gap voltage

beam dynamic

RF system and the bunchers of the post-accelerator with Interdigital-H type structure

which was developed by the author and Technical University Munich in four years

is described. The energy of ions with mass of three was increased from 340keV to 1.74MeV

when resonant frequency of 84.2MHz and input RF power of 3kW. The effective shunt impedance reached to 408MΩ/m. The commissioning was succeeded with H + 3 ion beams. The output energy of H + 3 ion beams reached the design value. The two harmonic double drift buncher used by the IH structure bunches the beam to the bunches with the width of 360ps. Then the acceptance of the IH structure is increased to 240°. Its shunt impedance is three times higher than former single gap bunchers used by TUM and the length of the buncher system is one fifth of former one only because the use of λ/4 coaxial cavities with double gaps.