Particle detectors are essential tools for studying the fundamental components of the universe. They help scientists analyze the behavior and properties of particles created in high-energy collisions. In these experiments, particles are accelerated to nearly the speed of light and then smashed into targets or other particles. Detectors capture and measure the results, revealing valuable insights. However, traditional detectors often lack the sensitivity and precision needed for certain types of research.

Recently, researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory achieved a major breakthrough in high-energy particle detection. Their experiments, conducted at the Test Beam Facility at DOE’s Fermi National Accelerator Laboratory (Fermilab), have opened new possibilities for more precise and effective particle detection.

"This was a first-of-its-kind use of the technology. This step was critical to demonstrate that the technology works the way we want it to because it is typically geared toward photons. It was a key demonstration for future high-impact applications." — Whitney Armstrong, Argonne physicist

Revolutionizing Photon Sensors for Particle Detection

The team found a new use for superconducting nanowire single-photon detectors (SNSPDs), already employed for detecting photons, the fundamental particles of light. These highly sensitive and precise detectors work by absorbing individual photons, generating small electrical changes in superconducting nanowires at very low temperatures. Such devices are crucial for quantum cryptography (securing information), advanced optical sensing (precision measurement using light), and quantum computing.

From Photons to Protons: A Surprising Discovery

In this study, the researchers discovered that these photon sensors could also function as highly accurate particle detectors, specifically for high-energy protons used as projectiles in particle accelerators. Protons, which carry a positive charge, are found in the atomic nucleus of every element.

The breakthrough opens exciting opportunities in nuclear and particle physics.

"This was a first-of-its-kind use of the technology," said Argonne physicist Whitney Armstrong. "This step was critical to demonstrate that the technology works the way we want it to because it is typically geared toward photons. It was a key demonstration for future high-impact applications."

Testing the Limits: High-Energy Protons at Fermilab

The team fabricated SNSPDs with different wire sizes and tested them with a beam of 120 GeV protons at Fermilab, the nearest facility equipped for such experiments. These high-energy protons help simulate conditions relevant to high-energy physics experiments, providing valuable insights into the detectors’ capabilities and limitations.

They found that wire widths smaller than 400 nanometers—whereas a human hair is approximately 100,000 nanometers wide—demonstrated the high detection efficiency needed for high-energy proton sensing. The study also revealed an optimal wire size of approximately 250 nanometers for this application.

Expanding the Possibilities for Particle Accelerators

Beyond their sensitivity and precision, SNSPDs perform well under high magnetic fields, making them ideal for use in the superconducting magnets of particle accelerators. The ability to detect high-energy protons with SNSPDs had never been reported before, broadening the scope of particle detection applications.

"This was a successful technology transfer between quantum sciences, for photon detection, into experimental nuclear physics," said Argonne physicist Tomas Polakovic. "We took the photon-sensing device and made slight changes to make it work better in magnetic fields and for particles. And behold, we saw the particles exactly as we expected."

Shaping the Future of the Electron-Ion Collider

This research also demonstrates the feasibility of using SNSPD technology in the Electron-Ion Collider (EIC), a next-generation particle accelerator under construction at DOE’s Brookhaven National Laboratory. The EIC will collide electrons with protons and atomic nuclei (ions) to reveal the internal structure of these particles, including quarks and gluons.

The EIC requires highly sensitive and precise detectors, and SNSPDs will be valuable for capturing and analyzing collision byproducts.

"The proton energy range that we tested at Fermilab is right in the middle of the span of the ion’s energy range that we will detect at EIC, so these tests were well-suited," said Sangbaek Lee, a physics postdoctoral appointee at Argonne.

Research and Funding

Reference: "Beam tests of SNSPDs with 120 GeV protons" by Sangbaek Lee, Tomas Polakovic, Whitney Armstrong, Alan Dibos, Timothy Draher, Nathaniel Pastika, Zein-Eddine Meziani, and Valentine Novosad, 9 October 2024, Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment.
DOI: 10.1016/j.nima.2024.169956

The research team utilized the Reactive Ion Etching tool at the Center for Nanoscale Materials, a DOE Office of Science user facility at Argonne.

Other contributors to this work include Alan Dibos, Timothy Draher, Nathaniel Pastika, Zein-Eddine Meziani, and Valentine Novosad. The study was funded by the DOE Office of Science, Office of Nuclear Physics.

Source: SciTech Daily

Image: Scientists at Argonne National Laboratory have made a major breakthrough in high-energy particle detection, repurposing superconducting nanowire photon detectors (SNSPDs) for detecting high-energy protons. Credit: SciTechDaily.com