Tribute to Prof. Ulrich Bonse

Prof. Bonse was an absolute reference in X-ray physics and pioneered many modern X-ray techniques among which X-ray interferometry and micro-tomography.

Professor at the University of Dortmund, he was a strong supporter of synchrotron science and of the ESRF programme. A long-time DESY user on the Doris ring, he was among the three first ESRF users, pioneering on ID06, in 1992, the first attempts in X-ray tomography thanks to the novel undulator X-ray radiation. With the unprecedented X-ray brightness and material penetration, in collaboration with the ESRF Optics Group, headed at the time by Andreas Freund, and training a large number of PhD students among them M. Krisch, Head of the Instrumentation Services and Development Division of the ESRF from 2015 to 2019, he broke the ice of a technique which have been doing steadily impressive steps in X-ray imaging, a technique that is allowing scientists, with ESRF-Extremely Brilliant source, to continue to push the frontiers of science in areas such as medical imaging, paleontology and material science studies.

With his deep knowledge of X-ray dynamical theory, he proposed and realised many technical developments based on the use of “perfect” silicon crystals creating the field of X-ray interferometry, ultra-high energy resolution X-ray monochromators, and manipulation of X-ray phase space,  which are still at the heart of the most demanding  exploitation and use of hard X-ray synchrotron sources, including the most advanced ones as the ESRF-EBS.

We are going to deeply missing him, and we thank him for his dedication to the advancement of science and to have inspired and continue to inspire generations of X-ray scientists.

Our thoughts go to his family in these difficult moments marked by the loss of such an exceptional scientist.

On behalf of present and past ESRF management and staff,

Francesco Sette,

ESRF Director GEneral