Sharing silicon know-how with Chinese partners
|Beijing-based physicist Cai Xiao stands with some of the equipment used to test silicon sensors for IHEP's test-beam telescope.
With the quiet, deft manner of a jeweler showing his wares, physicist Cai Xiao opened a black box that, in a James Bond movie, might hold a stash of diamonds. This one held something every bit as precious. Inside lay a small, green circuit board topped with three shining silver strips: a silicon detector.
For Cai (pronounced "sigh"), this was the culmination of an almost year-long collaboration with a team at Fermilab's SiDet. Now that the sensor was finished, it was almost time for him to go home.
Cai is a particle physicist at Beijing's Institute of High Energy Physics (IHEP), where he completed work for his Ph.D. in 2008. He'd been sent halfway across the world all because of that shiny silver stuff in the black box. Silicon has become an essential part of almost every new accelerator experiment under consideration.
"For high-momentum particles, it gives almost the best resolution you can get," said Marcel Demarteau, coordinator of Fermilab's detector R&D.
Demarteau said IHEP had been looking to improve its silicon expertise; Fermilab has lots of silicon experts. A collaboration just made sense. Cai arrived at the laboratory in March of 2009.
His mission was to complete a silicon telescope for a test beam at the Beijing Electron Positron Collider. The telescope doesn't look anything like the kind used for star-gazing; and instead of peering at the largest objects in the universe, Cai's telescope tracks the very smallest.
-- Andrea Mustain