Cornell scientists have received a major grant for developing a portable X-ray detector to serve as a novel set of "eyes" for observing dynamic matter.

The four-year, $2.19 million grant from the W.M. Keck Foundation will help develop a cutting-edge pixel array detector, which will allow Cornell physicists to perform studies that are currently beyond the limits of today's X-ray detectors.

Sol Gruner, the John L. Wetherill Professor of Physics and the project's principal investigator, explained that the world is full of important objects whose structures change on microsecond time scales. Examples include engine fuel injectors, ink jets, spray coatings, colloids, biological cells, cavitation phenomena (such as bubbles in a liquid), enzymes and phase transitions in alloys, liquid crystals and suspensions.

"The standard X-ray methods used to track structure are limited by the absence of X-ray detectors that can record rapidly changing X-ray images," Gruner said. "The Keck detector will be able to make short movies of processes changing on submicrosecond time scales."

The possibilities of future applications are seemingly endless. For example, in common gasoline fuel injectors, little is actually known about the critical gap of microseconds after injection and the spatial distribution of the fuel particles. But that initial distribution determines energy efficiency and even pollution generation. X-ray methods such as the ones being proposed are the only way to analyze the fundamental structure of these materials.

The instrument -- about the size of a breadbox -- will be named the W.M. Keck Pixel Array Detector and will provide the missing link in new studies of dynamic matter. Development of the detector at Cornell is a perfect fit, Gruner said, with the ongoing development at Cornell of the Energy Recovery Linac, which, when completed, will be the world's most powerful X-ray source.

The Keck detector will be a two-dimensional imager, consisting of an array of pixelated integrated circuits that capture X-rays using hundreds of thousands of miniature X-ray detectors all operating at the same time. It will be capable of storing time-lapsed frames of moving matter in less than 0.5 microseconds. It will be used for time-resolved experiments where speed is a critical factor.

"What we are proposing is something that ultimately takes advantage of advances in the semiconductor industry," Gruner explained. "The heart of the detector consists of a set of custom integrated circuits that detect the X-rays and process the resultant signals."

No other institution or research group has successfully built the type of detector that Cornell will be undertaking. Gruner's research group has created a prototype detector, which has proved that the technology is viable.

The total budget for the detector is estimated at $4.06 million, with $2.19 million covered by the Keck grant and additional funding from Cornell and other sources.