Book Review
Imaging in Molecular Dynamics: Technology and Applications
Benjamin Whitaker, ed.
Cambridge University Press, New York, 2003
249 pp.
ISBN 0-521-81059-0
Reviewed by Andrew Resnick
see all book reviews
 The experimental technique of charged-particle imaging as applied
to the study of molecular reaction dynamics is the subject of Imaging
in Molecular Dynamics, edited by Benjamin Whitaker. The book—consisting
of 11 chapters, each written by various contributors—is organized
into two parts: Technology and Applications. Chapters 2 and 3, “Velocity
Map Imaging” and “Reconstruction Methods,” constitute
about a third of the book. These two chapters lay out the background
theory and practice of obtaining product data from molecular reactions
by directly imaging the “Newton sphere” produced by
a molecular reaction. The rest of the first part describes different
experimental variations of the basic technique and includes chapters
on time-resolved measurements, obtaining three-dimensional velocity
information, and the use of femtosecond lasers to probe subpicosecond
reaction dynamics.
The second part of the book, Applications, contains three chapters
covering specific research applications and a fourth on a new approach
to velocity map imaging. The three specific examples were chosen
to display the breadth of applications available: coincidence imaging
and the study of bimolecular collisions. The final chapter of the
book presents a version of velocity map imaging, which resembles
confocal imaging.
When studying a molecular reaction, and specifically the dynamics
of the reaction, both the initial and final states of the reactants
must be specified. Most of the work relevant to this book, performed
to date, is in the area of photodissociation reactions, but bimolecular
reactions are discussed as well. In a typical experiment, a probe
laser is used to selectively ionize a subset of the photofragments
at some given time after the primary photolysis event. It has become
possible to prepare an atomic or molecular beam in a well-defined
state, for example by using laser excitation. Until recently, however,
it has been difficult to measure the final state; typical methods
have included mass spectroscopy and time-of-flight spectroscopy.
This book presents a novel method, developed recently by the contributors
to this book, termed velocity map imaging. This technique directly
images the reaction product fragments onto a microchannel plate
in such a way as to reproduce their (directional) velocity and
kinetic energy distributions.
The tone of the book is one of excitement, as expected from a
book covering an emerging field and written by the major contributors
(for example, Benjamin Whitaker, Department of Chemistry, University
of Leeds; and Andre T. J. B. Eppink and David H. Parker, both of
the department of molecular and laser physics, University of Nijmegen,
The Netherlands). This lively tone provides a pleasant coloring
to the content. Enough experimental details are presented so that
one could, in principle, build his or her own apparatus and begin
a research program.
Imaging in Molecular Dynamics serves as an excellent introductory
tutorial to a developing experimental technique in the field of
molecular reaction dynamics. It is nominally geared toward graduate
students interested in pursuing this line of research but could
appeal to anyone who wishes to learn more about this emerging field,
especially those involved in molecular dynamics or charged-particle
optics.
Biography
Andrew Resnick is staff scientist at the National Center for Microgravity
Research, NASA Glenn Research Center, Cleveland, Ohio.
He has been involved with imaging for approximately five years,
although not specifically charged-particle imaging, and his current
research focuses on colloidal systems, capillary-driven fluid flow,
and how cells sense their fluid environment using a primary cilium.
|
