News from the James R. Macdonald Lab
Lew Cocke
 

The past year has been a highly productive one in the J.R. Macdonald Laboratory (see http://jrm.phys.ksu.edu/).  The change of emphasis from ion-atom collisions to AMO (atomic, molecular and optical) ultrafast physics has become quite mature.  Lasers, including both the KLS (Kansas Light Source) and MOT (magneto-optical trap) projects, have become central to the work of all six of the experimental principle investigators.  In addition, theoretical work on the interaction of high intensity fields with atoms and clusters is an important part of the work of all three theoretical principle investigators.  The ion-beam facilities continue to be used in conjunction with the KLS for both laser-ion and “picopulse” projects.  A MOT target is being set up on the EBIS for doing Q value measurements with multiply charged ions.  The ion beam facilities also continue to serve visiting users of the facility from Colorado State University (Steve Lundeen), the University of Crete (Theo Zouros), and Augustana College (Eric Wells) as well as in-house users in High Energy Physics (Tim Bolton).  We continue to collaborate with users at the ALS at LBNL and the Weizmann Institute of Science.  

The physics department has welcomed Brian Washburn as a new Assistant Professor in the area of nonlinear optics and ultrafast fiber lasers.  As I write he is moving into his new laboratory space in the JRML, next to the LUMOS laboratory of Kristan Corwin.  He and Kristan will form a formidable team.  The construction of Brian’s laboratory nearly completes the transformation of the “square room,” which once housed beamlines from the Tandem Van de Graaff to a laser laboratory.  Several new research associates have joined the JRML in the past months.  Dr. Goga Veshapidze has joined Brett DePaola’s MOTRIMS group, and Dr. Chengquan Li has joined Zenghu Chang’s group to work on the KLS. Dr. Zuoliang Duan is also a visitor in Dr. Chang’s laboratory from the Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Science.  Dr. Ahmer Naweed is a new research associate with Kristan Corwin in the LUMOS laboratory.  As we welcome these new research associates, we are sorry to announce the departure of two important Research Assistant Professors.  Dr. Bing Shan took a position as Laser Scientist with Quantronix Corporation and Dr. Xiao-Min Tong took a faculty position in the Graduate School of Pure and Applied Sciences at the University of Tsukuba.  

During the past year we have published 53 papers in refereed journals, including five in Physical Review Letters.  The research findings in these are many: we summarize a few here.  Richard and colleagues reported the first experimental evidence for the existence of image-potential states in carbon nanotubes.  A theoretical analysis of image-potential states of single- and multi-walled carbon nanotubes was carried out by a collaboration between the groups of Richard and Thumm.  Chang and colleagues have demonstrated the production of the “supercontinuum,” implying the production of a single attosecond pulse in argon. Ben-Itzhak and colleagues reported a comprehensive study of the dissociation and ionization by short laser pulses of the simplest of all molecules, the H2+ ion.  Lin and Tong have developed a quantum theory for analysis of the decay of an autoionizing state created by an attosecond xuv pump pulse and probed by an intense infrared pulse.  Cocke, Litvinyuk and colleagues have found that a very simple COLTRIMS experimental approach can be used to map out the spatial profiles of the outermost orbitals in small molecules.  DePaola and colleagues have used their MOTRIMS approach to follow the temporal evolution of state populations in Rb during coherent excitation.  Esry and colleagues reported a theoretical study of the dissociation of HD+ and H2+ by ultrashort laser pulses.