Dr. Gerald Gabrielse

Harvard University

 

Photo Dr. Gabrielse

Title forthcoming

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Biography: Professor Gerald Gabrielse became Professor of Physics at Harvard University in 1987, and was named the George Vasmer Leverett Professor of Physics at Harvard University in 2003. His physics research activities are currently focused upon antihydrogen experiments, upon measuring the electron magnetic moment and the fine structure constant, and upon precise laser spectroscopy of helium. Currently Prof. Gabrielse leads the international ATRAP Collaboration whose goal is accurate laser spectroscopy with trapped antihydrogen atoms. The group's nested Penning trap, invented and demonstrated at Harvard as a method for getting cold antiprotons and cold positrons to interact, was the crucial device that first permitted the observation of cold antihydrogen. ATRAP's first demonstration of positron cooling in a nested Penning trap established the crucial technique needed to first produce cold antihydrogen; ATRAP and others then used this device and method to observe cold antihydrogen. ATRAP's field ionization detection technique allowed a background-free observation and the first measurement of states of antihydrogen being produced, and their method to drive the production of antihydrogen substantially increased the production rate. ATRAP also demonstrated a second method to produce slow antihydrogen, for the first time using lasers to control the production via a charge exchange method. Recently ATRAP demonstrated the first production of antihydrogen atoms within the fields of a Penning-Ioffe trap. The ATRAP Collaboration grew out of the earlier TRAP collaboration, also led by Prof. Gabrielse. The international TRAP team developed the techniques to accumulate antiprotons at 4 K - an energy 1010 times lower than realized before -- techniques which now are being used in all efforts to produce and study cold antihydrogen. These techniques led to the most stringent CPT test with baryons when the charge-to-mass ratio of a single antiproton and proton were compared to 9 parts in 1011, an accuracy improved by nearly a factor of a million. Technological spin-offs include a patented solenoid design being used for nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI) and ion cyclotron resonance (ICR), along with improved cell designs for ICR. A variety of atomic, optical, elementary particle, plasma and low temperature physics experiments are carried out by Gabrielse and his students at Harvard. The most accurate measurement of the electron magnetic moment has been realized by probing the quantum structure of an electron bound into a trap – the first improved measurement since 1987. This first "quantum cyclotron", with a single electron isolated and suspended for months while cooled below 100 mK, allows an electron to be cleanly prepared in the ground state of its cyclotron motion. Quantum jumps to the first excited state (in response to a resonant driving force) can be counted for quantum jump spectroscopy, making use of the one-particle self-excited oscillator. The new measurement, along with accurate QED theory, determines the fundamental fine structure constant about tens times more accurately than does any independent method. Extremely accurate laser spectroscopy of helium tests two-electron QED theory. Gerald Gabrielse graduated with honors from Calvin College in 1973. He received a faculty research scholarship and served as a teaching assistant working under the supervision of Professor Vernon Ehlers (currently a member of the US House of Representatives). He also built an apparatus to measure the density and Fermi levels of high reactive liquid alkaline earth metals, working under the supervision of Prof. John Van Zytveld (later of the Murdock Charitable Trust). This physics research led to his first physics publication. Gabrielse was awarded M.S. and Ph.D. degrees from the University of Chicago where he was supported by both a Danforth Graduate Fellowship and an Argonne Graduate Fellowship. He received his M.S. degree in 1975 and his Ph.D. in 1980. The experimental portion of his thesis, supervised by Prof. Berry, focused upon the production of hydrogen as fast protons traversed thin targets. The theoretical portion of 3 Gabrielse Resume his thesis, supervised by Prof. Fano, focused upon the use of time reversal symmetry to classify hydrogenic observables. While a graduate student he was an author of many experimental and theoretical publications. On the side he taught a physics course at a small liberal arts college. Gerald Gabrielse became a postdoctoral research fellow at the University of Washington, and subsequently was awarded a Chaim Weizmann Postdoctoral Fellowship. He worked under the supervision of Prof. Hans Dehmelt, who later shared the Nobel Prize in physics. He built an apparatus in which he confined a single electron for more than 10 months, observed the hysteresis and bistability in its cyclotron motion, and used a cavity to inhibit its spontaneous emission of synchrotron radiation. He used his theoretical studies of the anharmonicity compensation that is possible within Penning traps to suggest new and improved geometries for Penning traps that are now widely used. He and particle theorist Prof. Lowell Brown published a number of theoretical papers, including a major review that still serves as a standard reference work on particle trapping. Gabrielse became Assistant Professor of Physics at the University of Washington in 1985, and Associate Professor of Physics in 1986. A year later, Professor Gabrielse accepted a tenured position as Professor of Physics at Harvard University. He later chaired the Physics Department and was named the George Vasmer Leverett Professor of Physics. He has given nearly 345 invited talks at scientific conferences and university colloquia, and is the author of more than 135 scientific publications. Twenty three students have been awarded Ph.D. degrees under his supervision, working alongside many postdocs and undergraduates. Professor Gabrielse has taught a physics course and served as the Scientist in Residence at a local high school, and continues to visit schools to talk about science. Harvard University has presented him its awards for both exceptional teaching and exceptional research. He was awarded Harvard's Levenson Teaching Award for exceptional undergraduate teaching by a senior faculty for his "Reality Physics" course for non-science students. He was awarded Harvard's George Ledlie Prize for his scientific accomplishment of creating and observing antimatter atoms – a prize awarded every two years to someone affiliated with the University who "has by research, discovery or otherwise made the most valuable contribution to science, or in any way for the benefit of mankind." Professor Gabrielse is a member of the U.S. National Academy of Sciences. He has served on the executive committees of both the Division of Atomic, Molecular and Optical Physics and the Topical Group on Precision Measurement of the American Physical Society (APS). He was awarded the Davisson-Germer Prize by the American Physical Society "for pioneering work in trapping, cooling, and precision measurements of the properties of matter and antimatter in ion traps." Both Trinity College and Calvin College have selected him for a distinguished alumnus award. He received the Alexander von Humboldt Research Award from the Humboldt Foundation of Germany and the Italian "Premio Caterina Tomassoni and Felice Pietro Chisesi Prize "for the measurement of the g-factor of the electron", for "low energy antimatter physics" and for "pioneering methods [that] opened the way to antihydrogen production and future spectroscopy." The University of Chicago honored him as their Zachariasen lecturer, "for developing innovative trapping and cooling methods and using them to perform high precision measurements of ... fundamental particles and anti-particles." He was a Källén Lecturer in Sweden and a Poincaré Lecturer in France..