  We have performed a series of experiments at Fermilab to explore the electron
cloud phenomenon. The Main Injector will have its beam intensity increased
four-fold in the Project X upgrade, and would be subject to instabilities from
the electron cloud. We present measurements of the cloud formation in the Main
Injector and experiments with materials for the mitigation of the Cloud. An
experimental installation of Titanium-Nitride (TiN) coated beam pipes has been
under study in the Main Injector since 2009; this material was directly
compared to an adjacent stainless chamber through electron cloud measurement
with Retarding Field Analyzers (RFAs). Over the long period of running we were
able to observe the secondary electron yield (SEY) change and correlate it with
electron fluence, establishing a conditioning history. Additionally, the
installation has allowed measurement of the electron energy spectrum,
comparison of instrumentation techniques, and energy-dependent behavior of the
electron cloud. Finally, a new installation, developed in conjunction with
Cornell and SLAC, will allow direct SEY measurement of material samples
irradiated in the accelerator.
