James R. Macdonald Laboratory (JRML)
Lew Cocke

This has been a year of major transitions and events.  After leading the James R. Macdonald laboratory as Principal Investigator and/or director for nearly three decades and guiding it through a major upgrade in the late eighties and early nineties, Pat Richard stepped down as director in February.  Do not think of this as a “retirement” however.  Pat remains a very active member of the James R. Macdonald group, doing research on nanotubes using the new Kansas Light Source in the James R. Macdonald Laboratory.  The directorship and PI duties have fallen to yours truly, who has a very hard act to follow.  The Department of Energy three year grant’ “Structure and Dynamics of Atoms, Molecules and Surfaces”, was renewed at $2.5M per year in February of 2004, through February of 2007.

February 13, 2004 - Retirement reception for Dr. Richard.  (Patrick Richard (left) and President Jon Wefeld (right).  See more pictures here.

The evolution of the laboratory from pure accelerator-based dynamics to laser-based work continues.  The target rooms which were served by the Tandem Van de Graaff accelerator have now been entirely converted for laser-related work.  The old “long room” houses the Kansas Light Source (KLS) which is the central Ti:Sapphire laser system of the laboratory.  This facility, built and operated by Zenghu Chang and Bing Shan, delivers up to 4 mJ / 35 fs  pulses of 800 nm radiation at 1 to 2 kHz, and feeds five experimental areas outside the KLS as well as numerous experiments inside.  It runs nearly 24 hours a day and often seven days a week, serving typically two to three users in parallel.  With the recent addition of two fiber installations, it can deliver pulse lengths as short as 8 fs.  Also in the “long room” area is the MOTRIMS (Magneto Optical Trap Recoil Ion Momentum Spectroscopy) setup of Brett DePaola.  Brett is using a MOT (Magneto Optical Trap) as a very cold target for studying both collisions and for using the collisions to follow the time evolution of the MOT.  The old “square room” now houses a COLTRIMS (Cold Target Recoil Ion Momentum Spectroscopy) chamber with which Igor Litvinyuk and I are studying the dynamics of small molecules exposed to intense laser pulses from the KLS.  It also houses the new LUMOS (Lasers for Ultrafast Metrology and Optical Spectroscopy) laboratory of Kristan Corwin.  Kristan is doing laser-metrology, using a laser “clock” to determine frequency references which are of use to, for example, the communications industry.  This effort will be strengthened by the addition in the fall of 2005 of a new faculty member in this area, Brian Washburn.  Brian received his Ph.D. degree from Georgia Tech and has been working as a post doc on fiber lasers at NIST in Boulder, Colorado.

Stand-alone operation of the accelerators continues in the LINAC and EBIS areas.  Steve Lundeen (Colorado State University) continues to use the EBIS regularly, and Theo Zouros (University of Crete) returns often to use the fast ion beams.  The ECR ion source is being used by Itzik Ben-Itzhak to study the ionization of small molecular ions by interaction with the intense laser pulses from the KLS, while Charles Fehrenbach is constructing a MOTRIMS setup on the EBIS whenever he is not taking care of the EBIS and the ECR.  A new project, directed by Kevin Carnes, has just been initiated on the Tandem to use the KLS beams to generate picosecond pulses of energetic ion beams.  This will serve as yet another tool with which to probe the real-time evolution of matter on a picosecond time scale.

The theoretical program has also continued to evolve over the past year, supporting and to a considerable extent driving the changes in the experimental program.  Chii Dong Lin, Uwe Thumm, Brett Esry and Xiao-Min Tong are all working in various areas of intense laser work, often in close collaboration with the experimental programs.  The productivity of the laboratory remains very high.  During the past calendar year we have published about fifty articles in refereed journals, of which eleven were in Physical Review Letters.  Some of these have been selected for special citing in Physics Today (Search and Discovery, September 2003), Physics Focus (http://focus.aps.org/story/v14/st12) the Advanced Light Source Newsletter (http://www.lbl.gov/Science-Articles/Archive/CSD-molecular-movement.html, http://www-als.lbl.gov/als/science/sci_archive/90electron_emission.html).  The study of the dynamics of ions, atoms, molecules and clusters fills the air with both lasers and accelerators humming.  It is an exciting time in the JRM laboratory.