Fermilab’s Booster accelerator delivers record-setting proton beam

This plot shows the ramp-up of proton flux in the Proton Source under PIP.

This plot shows the ramp-up of proton flux in the Proton Source under PIP.

On Jan. 29, Fermilab’s Booster accelerator achieved a record proton flux of 2.4×1017 protons per hour. This milestone achievement fulfills one of the most important requirements in the Proton Improvement Plan (PIP), which Fermilab has been implementing over the last five years.

The main goal of the PIP project is to increase the proton beam output to meet Fermilab’s experimental needs, in particular for neutrino and muon experiments such as NOvA, MicroBooNE and Muon g-2. The Booster delivers beam to all of the lab’s experiments, and according to PIP, the Booster’s proton beam output, also known as proton flux, had to meet a certain minimum.

We delivered on that promise in January and have been operating the Booster at the new level since then. The record proton flux is about two-and-a-half times higher than what the accelerator was capable of delivering before the PIP upgrades, a flux of 1.1×1017. Now, with the Booster generating 2.4×1017 protons per hour at 15 hertz, the NuMI beamline, Booster Neutrino Beamline and the Muon Campus can all operate simultaneously. (Prior to this, we could operate only one at a time.)

PIP started in 2012 to upgrade our aging Proton Source accelerators. Not only did we set out to increase the proton flux, we also aimed to provide a reliable source of protons for Fermilab’s scientific program. Reliability translates into “up time” — the fraction of time the accelerator is operating. PIP specified an up time of 85 percent, and we’ve exceeded that: We currently run at 92 percent up time, and we’re working to maintain this high performance level in the years to come.

We could not have reached this milestone accelerator goal without the dedication of numerous people at the lab, who took on challenging engineering and beam physics problems and addressed other issues related to the viability and reliability of Fermilab’s Proton Source.

It is truly remarkable that the Booster and the Linac — the oldest machines at the lab — are performing at record levels almost 50 years after they were first built, well higher than their design called for and beyond what anyone could have hoped for at the birth of the lab.

Now we look to the next steps, working to achieve even higher proton flux levels. We’re also working to make sure PIP’s goal of providing a viable beam source until the successor plan, called PIP-II, is put in place. The PIP-II project will replace the current Linac with a new Superconducting Linac — in time for the operation of our flagship, LBNF/DUNE.

The successful implementation of PIP ensures that the Proton Source can generate the beam needed to carry out Fermilab’s — and the nation’s — high-energy physics program. This was no small effort, and we congratulate and thank everyone involved for delivering world-class accelerators for fundamental science.

Bill Pellico is the head of the Fermilab Accelerator Division Proton Source Department.