Recent advances have led to the demonstration of trains of attosecond
pulses and isolated attosecond pulses in the vacuum ultraviolet (VUV)
and extreme ultraviolet (XUV) regions of the electromagnetic spectrum
in a number of laboratories. This has raised the possibility of direct
time resolved measurements of correlation driven electron dynamics within
molecules, with a long term aim of unprecedented control over the dynamics
of matter at atomic and molecular length scales. Particular interest
has arisen towards the possibility of a charge migration mechanism within
molecules, in which purely electron driven processes result in the movement
of charge around an excited molecule in the absence of any nuclear
dynamics.
However, even once these sources have been established, using them in
time resolved experiments is challenging. This is due to extremely short
time-scales involved, the complexity of the processes under study, and the
limitations of currently available attosecond sources.
In this thesis I describe the development of novel instrumentation and
methods for attosecond pump – probe experiments on electron dynamics
in molecules. Strategies for the experimental study of charge migration are
reviewed in detail which motivates the design and implementation of a purpose
built instrument combining an electron velocity map imaging (VMI)
spectrometer and an ion time of flight (iTOF) spectrometer. This instrument
is designed in tandem with the development and characterisation of
an isolated pulse at the new photon energy of 20eV. This 20eV pulse is intrinsically
synchronized with another attosecond pulse at 90eV. Together,
the new instrument and light source represent a unique capability for the
investigation of electron dynamics in molecules.
Finally, the first experimental results are presented and perspectives
for future studies using the new developments are discussed.