Manufacturing Bits: Feb. 10

Accelerating and cooling muons
Using a novel particle accelerator, a group for the first time have observed a phenomenon called muon ionization cooling–an event that could give researchers a better understanding of matter and the universe.

Muons are obscure sub-atomic particles. This experiment could pave the way towards the development of new and powerful muon particle accelerators. These accelerators in turn could provide more insights in the atomic structures of materials. They could also propel the development of catalysts for nuclear fusion and other applications.

The muon experiment was conducted by MICE or the international Muon Ionization and Cooling Experiment collaboration. The group made the discovery using the muon beam-line at the Science and Technology Facilities Council (STFC) ISIS Neutron and Muon Beam facility on the Harwell Campus in the United Kingdom.

The ISIS Neutron and Muon Source produces beams of neutrons and muons. This in turn allows scientists to study materials at the atomic level using a suite of instruments.

Nonetheless, all matter is made up of atoms. Atoms have a nucleus, which has protons and neutrons. These are surrounded by electrons. Protons and neutrons are made of sub-atomic particles called quarks. Protons and neutrons each consist of three quarks. Gluons glue quarks together.

A muon is also a sub-atomic particle. A muon doesn’t consist of any other particles, but rather it comprises of its own elementary particle, according to Vanderbilt University. A muon is identical to an electron, but the mass of a muon is 207 times the mass of an electron, according to Vanderbilt University.

The goal of the MICE collaboration is to generate a cold beam of muons. To accomplish this feat, researchers use a proton accelerator at the ISIS Neutron and Muon Beam facility.

At the heart of ISIS is an 800MeV proton accelerator, which produces intense pulses of protons 50 times a second. Muons are produced by colliding the proton beam into a target of dense material. The collisions produce pions, which decay with a mean lifetime of 26ns into muons.

The muons are then directed through a series of magnetic lenses. The muons form a diffuse cloud. Then, researchers use a process called beam cooling, which brings the muons closer together. They are also moving in the same direction.

The problem is that muons only live for two millionths of a second, making it difficult to cool them.

Researchers at the MICE collaboration developed a new way to cool the muons. This was done by putting the muons through energy-absorbing materials, such as lithium hydride or liquid hydrogen cooled to minus 250 degrees Celsius.

“After cooling the beam, the muons can be accelerated by a normal particle accelerator in a precise direction, making it much more likely for the muons to collide,” according to the STFC. “Alternatively, the cold muons can be slowed down so that their decay products can be studied.”

All told, researchers have demonstrated that ionization cooling works and can be used to channel muons into a tiny volume. “This was an extremely difficult achievement, and crucial to the dream of a muon collider,” said Derun Li, a researcher at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab), which is part of the MICE effort. “Muons combine many of the best advantages of electrons and protons for collider-based particle physics, but also introduce technical challenges.”

Ion colliders
The U.S. Department of Energy has named Brookhaven National Laboratory as the site for building the new Electron-Ion Collider (EIC).

The design for an EIC at Brookhaven includes building a new electron storage ring and electron accelerator components. The electron ring will allow electrons to interact with protons and large nuclei to probe and produce snapshots of the building blocks of these nuclear particles.

The EIC will also allow nuclear physicists to track the arrangement of sub-atomic particles called quarks and gluons.

Source: Brookhaven National Lab

The EIC will be funded by the federal government through the DOE Office of Science. Brookhaven Lab and the Thomas Jefferson National Accelerator Facility will participate in the project.

“The EIectron-Ion Collider will open up a new frontier in nuclear physics that will expand our knowledge of the fundamental constituents of the atoms that make up all visible matter in the universe today and the force that holds it all together,” said Brookhaven Lab Director Doon Gibbs. “We look forward to working with Jefferson Lab, other DOE labs, universities and the worldwide EIC user community—about 1000 scientists from 30 nations—to deliver the EIC and advance this important field of science.”

R&D Lab
The National Nuclear Security Administration (NNSA) and Lawrence Livermore National Laboratory (LLNL) recently held an event to dedicate the Advanced Manufacturing Laboratory (AML).

The lab is a new collaborative hub intended to spur public-private partnerships. The $10 million, 14,000-square-foot facility is located at the Livermore Valley Open Campus.

The facility includes a 5,000-square-foot wet lab with various 3D-printing machines and other equipment. Laboratory Director Bill Goldstein said: “At the AML, we will work side-by-side with innovators from industry and academia to transfer cutting-edge capability to our programs, as well as to spin out some of the unique discoveries in materials and manufacturing that we make here to our partners.”