Neutron Sciences Directorate

The Basics

Once the Linear Accelerator accelerates the ion beam, the ions pass through a diamond foil to strip off their electrons, which leaves only protons in the beam. To create a more intense proton beam, powerful magnets bend the beam and inject the protons into the accumulator ring. There the protons are bunched together while traveling about 1,000 times around the 271-yard-long ring—in less than one-millionth of a second. The bunches of protons are then steered by extraction magnets toward a liquid mercury Target System 60-times per second.

PPU Upgrades

In the beam injection area of the ring, two new chicane magnets and two new injection dump magnets were installed, while the power supplies for the existing injection magnets were upgraded. The thickness of the stripping foil was increased to maintain stripping efficiency at increased beam energies.

The extraction magnet power supplies were upgraded to provide a stronger magnetic field for extracting the higher-energy beam from the accumulator ring.

Due to the higher operating power for all the ring magnets, the water-cooling system for their power supply was upgraded by adding a cooling loop, pumping station, and heat exchanger.

One of two existing extraction magnet tanks that contain seven magnets.