Initial far-field OTR images generated by 120-GeV protons at FNAL

We have successfully imaged for the first time the angular distribution patterns of optical transition radiation (OTR) generated by 120-GeV proton beams passing through an Al metal plane. These experiments were performed at Fermilab (FNAL) with the same chamber, foil, and camera design as with the near-field experiments previously reported. In this case the lens-to-CID-chip separation was remotely adjusted to provide the focus-at- infinity, or far-field optical imaging. Data have been obtained in transport lines both before the antiproton production target and before the NuMI target with particle intensities of about 5 to 22 times 10
¹²
. A two-foil interferometer calculation was also performed. Single-foil experimental and modeling results will be presented.