  Ionization profile monitors (IPMs) are used in the Fermilab Main Injector
(MI) to monitor injection lattice matching by measuring turn-by-turn sigmas at
injection and to measure transverse emittance of the beam during the
acceleration cycle. The IPMs provide a periodic, non-destructive means of
performing turn-by-turn emittance measurements where other techniques are not
applicable. As Fermilab is refocusing its attention on the intensity frontier,
non-intercepting diagnostics such as IPMs are expected to become even more
important. This paper gives an overview of the operational use of IPMs for
emittance measurements and injection lattice matching measurements at Fermilab,
and summarizes the future plans.
