Ion Linac accelerates electric charged particles in the high frequency electric field provided between drift tubes placed along with the center line of the accelerating cavity.
ALVAREZ type Linac
ALVAREZ type Linac is often used for an injector of Ion Synchrotron.The picture shows ALVAREZ type Linac installed for an injector arranged after RFQ type Linac at the heavy ion beam cancer treatment facility ("HIMAC") in the National Institute of Radiology Science ("NIRS") in Japan. The ALVAREZ type Linac accelerates He through Ar up to 6 MeV/n..
RFQ type Linac
If low energy ion is accelerated, Radio-Frequency Quadrupole (RFQ) type Linac is utilized. The picture shows 4-vane type RFQ Linac supplied to NIRS.