Awardee Interviews | Biography: Howard A. Padmore

Howard A. Padmore

Howard A. PadmoreHoward A. Padmore, received a BSc (1977) and a PhD (1983) in Physics from the University of Leicester, UK. His doctoral research work was on measurement and interpretation of the x-ray emission spectra of the heavy rare earth metals and this led to his lifelong interest in x-ray science. Following postdoctoral research working on photoemission from low dimensional systems with the group of Colin Norris, he joined the staff at the UK synchrotron radiation facility at Daresbury in the UK at the time the new SRS was being commissioned. In 1993 he left the UK to take up a position at the Advanced Light Source  (ALS) at Lawrence Berkeley National Laboratory, the first 3rd generation x-ray facility optimized for the production of soft x-rays, where he leads the Experimental Systems Group.

His main contributions to synchrotron radiation research are in the development of new methodologies and techniques that enhance or allow new types of methods to be applied to a broad range of materials science. His early work at Daresbury showed that the development of new x-ray optical design methods could lead to systems with vastly improved performance in terms of through-put and resolution, enabling new generations of complex experiments. Several of these designs have become standards used at many facilities around the world. This line of research continues up to today, where his focus is now on grating optical systems that offer ultra-high resolution soft x-ray spectroscopy by combining high line density blazed gratings with multilayer reflection in such a way that efficient diffraction can be achieved in high spectral order. His other contributions to x-ray optics have been mainly in the area of mirror micro-focusing of hard x-rays for Laue x-ray micro-diffraction, and in the development of brightness-preserving optical systems for protein crystallography. He has also worked in the area of x-ray microscopy and made contributions to the design and implementation of high resolution photo-emission electron microscopes, including new aberration corrected microscopes. These systems have been applied to a wide range of thin film problems, but have been particularly successful in the study of magnetic systems using linear and circularly polarized x-ray spectroscopy. His work has also involved the development of new techniques for ultra-fast experiments, mainly in the area of ultrafast detection, using streak cameras. These methods have achieved psec resolution combined with x-ray spectroscopy, and have been applied to a range of problems from phonon dynamics in semiconductors to magnetization dynamics. His other work in the area of detectors ranges from multi-channel detectors for photoemission to pixelated counting detectors and CCDs for x-ray detection. He is now involved in the development of photocathodes for the next generation of synchrotron radiation sources, based on the Free Electron Laser (FEL). Photocathodes are one of the most critical elements of FELs, and his work has concentrated on two areas, the production of highly efficient visible light sensitive cathodes based on alkali antimonides, and on the development of ultrafast metal cathodes. This latter work has led to a completely new class of cathodes based on plasmonic light trapping in metal surfaces.

Dr Padmore leads the Experimental Systems Group at the ALS in LBNL. The group is responsible for the operation of 11 synchrotron x-ray beamlines, as well as a wide range of instrumentation found at the facility. Many of the group members have made large contributions to the wide range of advanced instrumentation found at the facility and described above.

Dr Padmore has been an Editorial Board Member of Measurement Science and Technology and of the Journal of Synchrotron Radiation. He has served on the Scientific Advisory Committees of many synchrotron radiation facilities around the world, including the UK (Diamond), US (SSRL, CAMD), Taiwan (SRRC), Korea (PLS), and Italy (Elettra). He is a fellow of the Optical Society of America, and the American Physical Society. He has published more than 200 journal papers with over 4400 citations, and has an h-index of 35.