Drift Tube Linac

RF linear accelerator: alternating voltage timed so the particle always sees a push

--
Final E (MeV)
--
Final v/c
--
Linac length (m)
--
Last tube L (cm)
Drift Tube Linac (Alvarez type): A proton enters a series of cylindrical drift tubes. Inside each tube, the proton is shielded from the RF field. The gaps are timed so the RF field is always accelerating when the proton crosses a gap. Since the proton speeds up, each successive drift tube must be longer (L_n = v_n/2f) to keep the timing. At low energies L ∝ √(n·V₀·e/m). Used at the front end of large accelerators like Fermilab and CERN Linac4.