Fermilab honored to host SOI pixel workshop

KEK's Yasuo Arai, Fermilab's Grzegorz Deptuch, and OKI Semiconductor's Masao Okihara and Ikuo Kurachi look over design ideas during the recent SOI collaboration meeting.

From its inception, particle physics has confronted a Catch-22: how do you measure something without somehow altering it? A fresh-faced young German named Heisenberg published a paper on this conundrum in 1927, and the question has bedeviled scientists ever since.

SOI (silicon on insulator) pixel detectors, a new technology in which Japan leads the world, may offer a dramatic solution to this problem by combining several functions in one slice of silicon, greatly reducing the mass interfering with a particle's path.

Minuscule chips only a few hundred micrometers thick, the SOI chips contain both electronic readout and sensors, demand little power, and provide two-dimensional readings of a particle's location. Although currently far from perfected, the chips offer several advantages over conventional (CMOS) pixel detectors; and if continuing R&D is successful, the technology could be used across myriad applications--especially large future undertakings like the ILC.

Recently, KEK's Yasuo Arai, the man behind SOI pixel technology for high-energy physics, asked Fermilab to host a two-day workshop so that all the key players could meet. In the past, most workshops were held in Japan, and collaborators attended via video conference. Because of Fermilab's continuous contributions to developing the SOI pixel process, this year KEK brought the annual meeting to Illinois.

Lead by Grzegorz (Gregory) Deptuch, Fermilab electrical engineers and scientists talked with groups from KEK and Lawrence Berkeley National Laboratory, among others, along with leaders from Japan's OKI Semiconductor, the only foundry that makes the chips.

"It was good to meet here and exchange information," Arai said. "Fermilab proposed some modifications, so we wanted to discuss the best way to improve the design and production process."

Ray Yarema, head of the Fermilab microelectronics group, said the workshop was invaluable. "It's the first time we've had direct communication with the foundry," he said. "It resulted in great interactions between OKI and our people, and I hope it will lead to a closer working relationship with KEK."

OKI is planning to make new wafers this summer, which will incorporate design ideas from the meeting.

-- Andrea Mustain

Fermilab's Tingjun Yang wins APS dissertation award

Tingjun Yang

Fermilab postdoc Tingjun Yang was recently named the recipient of the Mitsuyoshi Tanaka Dissertation Award in Experimental Particle Physics.

"I feel very lucky that I got this prestigious award," Yang said.

The award, given annually by the American Physical Society, recognizes an exceptional young scientist's outstanding doctoral thesis work in particle physics. Yang received the award for his doctoral research on "A study of muon neutrino to electron neutrino oscillations in the MINOS experiment."

Yang received his Ph.D. in physics in 2009 from Stanford University. He worked for seven years on the MINOS experiment and contributed to muon-to-electron neutrino oscillation analyses. Since the MINOS experiment wasn't really designed to search for electrons from electron neutrinos, Yang and colleagues created an event selection algorithm to pick out the electrons from similar backgrounds in the detector.

"Tingjun was involved at every level of analysis," said MINOS co-spokesperson Rob Plunkett. "He was an outstanding graduate student in every way."

Stan Wojcicki, MINOS co-spokesperson at the time and Yang's advisor at Stanford University, nominated Yang for the award because of the graduate student's excellent thesis and quality of work.

"His contributions were crucial to the experiment," Wojcicki said. "I expect Tingjun has a great career ahead of him."

In October 2009, Yang was hired as a post doc research associate on the CDF experiment. He also works on research and development of liquid argon detectors for future experiments.

"He's a very impressive physicist. Tingjun does very good work and he catches on to things quickly," said Brian Rebel, a Fermilab scientist who worked with Yang on MINOS and now works with him in liquid argon R&D.

"I decided to work on CDF because I wanted exposure to something that was new for me," Yang said. "But I also wanted to get involved at the Intensity Frontier."

-- Rhianna Wisniewski

Hunt for the sterile neutrino heats up

From Nature News, March 17, 2010

The elusive particles, if they exist, could help solve some of the most pressing problems in astrophysics.

Neutrinos like to keep to themselves. These ghostly particles are so reluctant to interact with ordinary matter that billions zip harmlessly through each person every day, and it takes giant, specialized detectors to capture even a handful of them. Now astronomers are finding hints of an even more elusive type of neutrino, one so shy that it could never be detected directly: the sterile neutrino.

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