Accelerator and NuMI upgrade shutdown status

Cons Gattuso

Cons Gattuso, Accelerator and NuMI upgrade shutdown coordinator, wrote this column.

The accelerator complex shutdown started April 30, 2012, and is slated to last roughly one year. Approximately 60 technicians and trades personnel from AD, PPD and TD have been working full time for the last 10 months in the Main Injector tunnel and NuMI beamline. They have done an outstanding job.

As part of the NOvA project, the accelerator complex infrastructure and the NuMI beamline are being upgraded to provide higher neutrino intensities than are possible in the current configuration. These upgrades focus mainly on converting the Recycler Ring from an antiproton storage machine to a pre-injector for the Main Injector.

By using the Recycler Ring as a pre-injector, we can reduce the Main Injector cycle time from 2.2 seconds to 1.33 seconds. This, along with other improvements, will yield an 80 percent increase in beam power, even though we increase the number of protons per bunch by only 10 percent. These upgrades require the construction of new transfer lines and additional radio-frequency power stations in the Recycler and Main Injector. In addition, the NuMI line must be upgraded to handle the higher proton beam powers. This involves construction of a new target, upgrades to the cooling systems and improvements to the primary proton line.

In the Main Injector, we have removed all of the antiproton equipment, which comes to over 1,400 feet of beamline components. Keeping true the Recycler name, we are reusing 60 percent of the instrumentation and 90 percent of the vacuum components. We have installed a new transfer line into the Recycler and are in the process of installing a new transfer line from the Recycler to the Main Injector. Counting all material moved, including magnets, stands and beam pipe, the crews have moved approximately 340 tons of material. More than 950,000 feet of cable have been pulled to support the new transfer lines and instrumentation.

In the NuMI target hall we have relocated Horn 2 and are currently installing an upgraded Horn 1 and target. Utilities have also been upgraded to handle the increased power load from both the shorter cycle time and the increased beam power.

The PPD alignment group has provided support to align 500-plus tunnel components and roughly 3,500 feet of beam pipe.

Most importantly, there have been zero DART injury cases in more than 100,000 hours of tunnel work.

The work will be wrapping up in the near term and the Accelerator Division will start providing protons to the experimental programs.