Heavy ions acceleration by the spiral waveguide

The heavy ion accelerator contains two sections 16 and 13 meters long. Ions of uranium with the charge Z=+32 have an energy from 84 keV/nucl. to 8 MeV/nucl. at the end. The generator power is 3 MW (each channel), the frequency is f=150 MHz. The radius of the spiral waveguide r0 changes from r0=2.6 cm at the beginning to r0=1 cm at the length l=7 m and then becomes permanent. The radius of the outside cylinder is R=7.5 cm, the step of the spiral waveguide changes from h=2.1 mm at the beginning to h=4.5 mm at the end. Beam focusing is provided by the solenoid magnetic field B= 6 T. The fields are calculated taking into account the power losses in the copper spiral waveguide covered with silver