New paper published in the Journal of Instrumentation led by Jesse Liu solves major problem of sensor fracturing for the ATLAS Inner Tracker detector upgrade.
Construction of the Inner Tracker (ITk) for the ATLAS Phase II upgrade is among the highest priorities for particle physics today.
Planned to be operational in 2030, this new all-silicon detector will open countless extraordinary new discoveries with 10 times higher definition taking particle collisions 100 times faster at the High-Luminosity Large Hadron Collider (HL-LHC).
The new paper documents an innovative study led by Jesse Liu that he started with Cavendish Laboratory collaborators as a Junior Research Fellow in Cambridge, UK. The paper solves a major problem preventing the project entering mass production.
Overlooked in the original design, the sensors fracture in the near-final "pre-production" modules when cooled to -35 Celcius. A high-school student can tell us a fractured sensor is no use for detecting particles!
The new paper details engineering ingenuity constructing the world's first prototype with a modified design that uses a soft rubbery material made of silicone called an "interposer".
The paper performs tour-de-force thermal cycles on the modified modules to extract decisive evidence that the thermal stress is reduced so that the sensors no longer fracture when cold.
The final design adopts this modified design, saving the day and reopening the project to production!
This summer, graduate student research assistant Amelia Stevens started testing these interposer modules at Brookhaven National Laboratory to verify the design change is production worthy!