June 1, 2007

Inaugural Julian Baumert Ph.D. Thesis Award Goes to Benjamin Hornberger

NSLS user and recent Stony Brook University graduate, Benjamin Hornberger, is the recipient of the 2007 Julian Baumert Ph.D. Thesis Award. This inaugural prize was established in memory of Julian David Baumert, a young Brookhaven physicist who was working on x-ray studies of soft-matter interfaces at the NSLS before he died in June 2006. It is given to a researcher who has recently conducted a thesis project that included measurements at the NSLS.

Benjamin Hornberger receives his award from Ben Ocko (left) and Chi-Chang Kao.

Hornberger received his Ph.D. in physics from Stony Brook University in May, a Master’s degree from Stony Brook in 2003, and completed his undergraduate work at Würzburg University, Germany, in 2000.

Hornberger played a key role in the development of next-generation scanning transmission x-ray microscopes operated at NSLS beamlines X1A1 and X1A2, which were updated to work from a new electronics control system with rewritten software. This work, performed in conjunction with Stony Brook’s Holger Fleckenstein, Mirna Lerotic, and Dan Flickinger, also is part of Hornberger’s thesis. His primary role was to write the user interface software so that technically inexperienced users from other scientific fields can easily operate the microscopes. The result was a single, simple interface.

“I am told by a number of users of the X1A scanning transmission x-ray microscopes that the ease of use of this scan control software is an important reason why they continue to come to the NSLS for soft x-ray spectromicroscopy studies, even though the improved brightness of the Advanced Light Source makes for faster data collection times,” said Hornberger’s Stony Brook advisor, Chris Jacobsen.

Collaborating with Pavel Rehak from BNL’s Instrumentation Division, Hornberger also worked extensively on development of an improved soft x-ray detector as well as new chips and detector electronics that are now extensively used at Argonne National Laboratory’s Advanced Photon Source. Called segmented silicon detectors, these devices obtain both the net transmitted beam signal and information about how the beam is diffracted and refracted by the specimen. While these detectors are of limited use to current NSLS users, they could be very valuable for NSLS-II researchers.

The third part of Hornberger’s thesis involves the development of new image reconstruction methods to analyze the data obtained from these detectors. His technique has been used in studies to determine trace metal concentrations in marine protists and to link ultrastructural components of cells with certain “hot spots” of elements.

“His importance to the team research environment extends well beyond these particular activities,” Jacobsen said. “In group meetings and scientific presentations, he has consistently asked extremely perceptive questions that show great insight into x-ray optical physics. He has generated great informational materials in the form of very intuitive figures to explain points from his research and general background information, so that his Ph.D. dissertation is richly illustrated.”

The Baumert award was presented at the 2007 Joint NSLS and CFN Users’ Meeting on May 22 by NSLS Chair Chi-Chang Kao. Hornberger received a $500 honorarium and travel arrangements to the Users’ Meeting, where he gave a 15-minute presentation on his thesis work.

ARTICLE BY: Kendra Snyder