IH structure

1
IH-structure
The second acceleration stage, the IH-structure
accelerates the ions from 0.3 MeV/u to an
extraction energy between 1.1 and 1.2 MeV/u. The
variation of the final energy of the IH-structure
can be achieved by adjusting the gap voltage
distribution via capacitive plungers.

• Theory
• Inside the resonator tank cylindrical cavity
  drift tubes of varying length (matching the ion
  velocity) are mounted alternating on opposite
  sides. The magnetic field lines are parallel to
  the beam axis and the induced currents flow
  azimuthally on the wall, creating electric fields
  of alternating direction between the drift tubes.
  This field forces the ions forward.

end view
side view

• Matching section
• To match the beam into the acceptances of the
  IH-structure a section consisting of two magnetic
  quadrupole triplet lenses and a rebuncher is
  required. The rebuncher is a two gap spiral
  resonator.

• IH-structure data
• Energy Ein 300 keV/u, Eout 1.1-1.2 MeV/u
• Electrode voltage Veff 4.05 MV
• Tank length L 1.5 m
• Number of gaps 20
• Peak power consumption Wpeak 36 kW