Diamond’s B16 validates crucial ATLAS detector component

Using the advanced capabilities of Diamond Light Source’s B16 beamline, a team from Canada’s TRIUMF laboratory has successfully validated a key component for the ATLAS Inner Tracker (ITk) - the next-generation tracking detector for the Large Hadron Collider (LHC).

B16’s highly flexible and precise X-ray setup made it the ideal testing ground for the new detector “petal”, one of the intricately engineered assemblies that will form the circular end-caps of the ITk.

The Inner Tracker (ITk) is the new central tracking detector being built for the ATLAS experiment at the Large Hadron Collider. It’s designed to precisely measure the paths of particles created in high-energy collisions by using layers of silicon sensors arranged around the collision point. The ITk will replace the current tracking system to handle the higher collision rates and radiation expected in the upcoming High-Luminosity LHC era.

Under a focused X-ray beam less than one-tenth the width of a human hair, the TRIUMF petal underwent its first major validation test in a beam. The test confirmed the mechanical alignment and hermetic coverage required to ensure no particle track is missed during future high-energy collisions at the LHC.

While the beamline’s pinpoint precision meant only selected areas could be scanned - a full scan would take over a year - these measurements were crucial. They demonstrated that the complex assembly of silicon sensors and electronics in the petal performs exactly as designed.

Dr. Luise Poley, TRIUMF Project Scientist, said: “It was amazing to see all of our hard work validated in real time. While each petal undergoes multiple quality control procedures, this test at Diamond Light Source was the final confirmation that all the individual parts fit together and function as intended.”

The team from Triumf with B16 staff. L-R: Vishal Dhamgaye, Emily Filmer, Matthew Basso, Bruce Gallop, Dennis Sperlich, Luise Poley and Kawal Sawhney.

The B16 beamline is designed for versatile X-ray imaging and diffraction studies, supporting both academic and industrial users. Its ability to switch between high-resolution microfocus and broad-beam configurations makes it invaluable for testing cutting-edge detector systems like those used in particle physics, space research, and medical imaging.

The TRIUMF test represents a critical milestone in the global ITk project. TRIUMF, alongside partners in Toronto and Spain, will contribute around 100 petals to the ATLAS detector upgrade. Each petal integrates thousands of silicon strip sensors, each strip just 75 microns wide, which trace the paths of charged particles with micrometre precision.

With the successful validation at Diamond, the TRIUMF and Simon Fraser University teams are now scaling up production, aiming for a steady build rate over the next three years.

For the scientists involved, the test at Diamond underscored how world-class synchrotron facilities accelerate innovation far beyond their walls.