This is a preliminary document meant to outline the general approach we will take towards reverse injection. Many of the details still need to be worked out.

The basic strategy

The basic strategy for the Tevatron Reverse Injection is to inject a single proton buch (or single batch if uncoalesced beam is used) on MI $2B cycle and the eject the proton bunch on the following MI $2A cycle.

The MI $2B cycle will be a standard 150 Gev proton cycle that has a short front porch for proton injection and a flattop long enough for coalescing and cogging. The entire $2B lasts ~3.5 second long. The MI $2A cycle will be longer than the $2B because of the time it will take to switch the loads from the P150 line to the A150 line. The time to complete the switching is still unkown, but will be on the order of several seconds provided that the current in the P150 line can be driven to zero amps (as opposed to just letting the current decay.) The $2A will take on the order of 6 seconds.  The extra length of the $2A should give us enough time in the Tevatron to ramp up the separators to put the protons on the antiproton helix after before they are ejected from the Tevatron. This method of reverse injection should make it easier to tune up (or commission) the A150 line using protons. Because we will continually inject and eject we can perform reverse injection indefinitely.

Sequence of Events

The sequence of events would be

• Load timeline with $2B-$2A combinations.
• Inject protons into the Tevatron on the $2B with the separators at zero voltage.
• In parallel
• Ramp up the Tevatron separators in "reverse polarity" to put the protons on the injection helix.
• Start the $2A cycle
• Eject the protons when the $2A cycle is at flattop.
• Ramp down the Tevatron separators to zero volts to prepare for the next proton injection

The following figure shows the timeline for the MI->Tevatron->MI reverse injection sequence.