UCR Team Pioneers Innovative Detector Technology in Groundbreaking Particle Collider Experiments

Physicists from UC Riverside have recently tested a new type of detector at the Relativistic Heavy Ion Collider (RHIC) in New York. This six-month trial, part of the 2024 RHIC run, is a big step in creating detectors for the upcoming Electron-Ion Collider (EIC).

The EIC is a significant nuclear physics facility being planned at Brookhaven National Laboratory. It aims to uncover the secrets of the “strong force,” the force that holds atomic nuclei together. At the EIC, electrons and ions will collide at nearly the speed of light.

The UCR team tested a prototype detector that uses SiPM-on-tile technology, which combines silicon photomultipliers (SiPM) with special scintillator tiles. This was the first time this technology was put to the test in a particle collider like RHIC.

Miguel Arratia, an assistant professor of physics and astronomy, noted the importance of this work. He said, “This technology will play a crucial role in detectors at the EIC, especially for studying high energies.”

Postdoctoral researcher Weibin Zhang, working at Brookhaven, mentioned that the successful operation of the prototype during the 2024 run is a key validation for the EIC’s detector systems. The prototype performed well through various proton collisions at 200 GeV energy.

“It’s quite rare to run a test like this at a collider,” Zhang added.

Senior graduate student Sean Preins explained that the detector consists of layers with tiles that transform energy from high-energy particles into light, which is then detected by SiPMs. The prototype was built and tested by a team of undergraduates at UCR, who engaged in everything from machining tiles to testing with cosmic rays.

“This has taught us a lot about how to design and build a SiPM-on-tile calorimeter,” said Preins. “We’re already using this knowledge to improve our next prototype that will have twice as many channels and will be tested at Jefferson Lab and Brookhaven Lab.”

As the team gears up for the 2025 RHIC run, they’ll face more complex tests, including gold-gold collisions known to generate higher energy density.

Alongside Arratia, Zhang, and Preins, the research team included undergraduates Peter Carney, Ryan Tsiao, Yousef Abdelkadous, and Miguel Rodriguez; graduate students Jiajun Huang and Ryan Milton; and postdoctoral fellow Sebouh Paul. Notably, Carney is now a graduate student at Caltech.