April 15, 2021

Günter W. Lugmair passed away on March 31 after a short illness.  A Fellow of the Meteoritical Society since 1980 when he also served as an organizer of the Annual Meeting in La Jolla, and winner of the society’s Leonard Medal, Günter’s mastery of the mass spectrometer pushed the precision of isotopic measurements to new levels.  He pioneered the applications of new radiometric systems and measurements of nucleosynthetic anomalies to fundamentally advance our understanding of the processes operating in the early Solar System.

 

After obtaining a PhD in Physics from the University of Vienna in 1968, where he worked with the International Atomic Energy Agency group in Seibersdorf on the neutron capture cross sections of the isotopes of Gd, he moved to a postdoctoral appointment at the Max Planck Institute in Mainz, Germany.  In Mainz, as a member of the Hintenberger group, he rebuilt existing mass spectrometers to improve the atomic mass determinations for Gd to the point needed for nuclear physics applications.  While at Mainz, Heinrich Wänke introduced Günter to Harold Urey who offered him a position at the University of California, San Diego.  He started in 1968 as a research chemist in the UCSD chemistry department with colleagues that then included Urey, Hans Suess, James Arnold, and Kurt Marti.  Günter told the story that he was looking forward to coming to UCSD as he would not have to once again rebuild old mass spectrometers.  That turned out not to be the case, but his wizardry with the instrument led him to set new standards for isotope ratio precision even with this aged equipment.  His advice to mass spectrometer companies resulted in the advanced instruments we have today that no longer require a user to have a background in building mass spectrometers to produce good data.

 

At UCSD, his PhD background was quickly put to use in the determination of the cosmic ray irradiation history of the lunar surface through Gd isotopic analysis of the then recently returned lunar samples.  His experience with the chemistry and mass spectrometry of the rare earth elements then led to a focus on the Sm-Nd radioactive decay system where he produced the first Nd isotopic data of sufficient precision to begin to fully explore its potential for dating and petrogenetic tracing of meteoritic, lunar, and terrestrial samples.  His first applications of this method to lunar samples provided strong evidence in support of the model for initial differentiation of the Moon through crystallization of a magma ocean.  The isotopic ratio precision he obtained for his early Sm-Nd work allowed him to document the evidence for live 146Sm in the early Solar system.  The techniques he developed were also used for the near simultaneous discovery with Gerald Wasserburg’s group at Caltech of the first CAIs that contained large isotopic anomalies of nucleosynthetic origin in elements other than the noble gases.  The fact that these advances were made using an old, highly self-modified, single-collector thermal ionization mass spectrometer is testimony to Günter’s mass spectrometry skills.  He had a deep understanding not only of the basic physics of the instrument, but also of the electronics and computer control needed to push isotope ratio precisions forward by one to two orders of magnitude.  After expanding and moving his laboratory operation at UCSD to Scripps Institution of Oceanography in collaboration with J.D. Macdougall, Günter would go on to conduct the foundational work to document the existence of the extinct radionuclide 60Fe and to use another extinct radionuclide, 53Mn, for wide ranging applications towards the chronology of planetesimal differentiation and the detection of the contribution of extraterrestrial bodies to terrestrial impact craters.

 

Günter W. Lugmair was born in Wels, Austria in 1940.  He would occasionally recount vivid descriptions of the depravations experienced as a child in post-WWII Europe that often focused on the food available during the Marshall Plan.  One wonders if this experience drove his great appreciation for culinary delights and good wine later in life.  Günter continued his association with Scripps and UCSD throughout his career reaching the position of Distinguished Research Scientist in 2005 and Emeritus Professor in 2007.  In 1996, he was appointed Director of the Cosmochemistry Department at the Max Planck Institute for Chemistry, a position he maintained through the time of his retirement in 2005.  In addition to his recognition by the Meteoritical Society, he received the George P. Merrill Award of the U.S. National Academy of Sciences in 1987, the Goldschmidt Medal of the Geochemical Society in 2007, and was a member or Fellow of the Max-Planck Society, The Geochemical Society and European Association of Geochemistry, Academia Europaea, and the American Geophysical Union.  Though never in an official professorial role, Günter was a marvelous mentor for early career isotope geochemists, including the authors of this obituary.  He loved to share his fascination with the intricacies of the chemistry lab, the inner workings of the mass spectrometer, and the big questions of the origin and evolution of the Solar system, usually while puffing on his pipe.   His advice to colleagues was generous, patient, and clear.  Beyond the laboratory, along with his wife Rosemarie, he hosted many scientists of all ages in their homes both in La Jolla and Mainz, the latter overlooking the region’s vineyards.  Günter was a competitive skier and sailor in college, and played jazz trumpet, reportedly at a level where he once got to jam with Miles Davis.  He continued his interest in sailing when he returned to Austria during retirement by coaching the local sailing club.  He is survived by his wife Rosemarie and their children Claus and Claudia.

 

Richard W. Carlson, Carnegie Institution of Science, Washington DC, USA

Stephen Galer, Max Planck Institute, Mainz, Germany

Mark Thiemens, University of California San Diego, San Diego, USA

Meenakshi Wadhwa, Arizona State University, Tempe, USA

 

Categories: In Memoriam

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