Oxygen-enriched operation of the PDU was initiated on April 1, 1981. Eleven oxygen enriched gasmaking tests were made during the month. These tests were interrupted upon eight occasions by slag tap pluggage or imminent pluggage. Direction was received from both contract sponsoring agencies (DOE and EPRI) changing the priority of April's testing from shakedown and parametric oxygen-enriched testing to running a 15 to 20 day sustained operations test. This test was begun during the month, but not successfully completed owing to the tap hole pluggage problems. Iron reduced from the slag due to the low oxygen concentration in this region is the most obvious explanation for the tap hole pluggages.

The objectives of this project are two fold: (1) To extract high energy protons from the Main Ring (MR) and target them to produce antiprotons which are subsequently captured in the existing Booster accelerator; and (2) to provide a channel for injecting either protons or antiprotons into the MR from the booster in a direction opposite to that of the normal proton acceleration as colliding beams can be created. The present design, therefore, is in support of two separate larger projects, viz., the collisions of protons in the Tevatron (normal circulation direction) with 'reverse injected' protons in the MR, and the collision of normal direction protons with reverse injected antiprotons either in the MR or in the Tevatron. Figure 1 shows the layout of the project area. It spans the shortest distance between possible injection/ejection points in the existing accelerator structures, hence minimizing costs. The tunnel will lie underground at the level of the MR and booster.