TY  - UNPB
M1  - Doctoral
AV  - public
A1  - Jones, N.
Y1  - 2009/03//
PB  - UCL (University College London)
UR  - https://discovery.ucl.ac.uk/id/eprint/15823/
EP  - 221
ID  - discovery15823
TI  - The spectroscopy of bound and predissociating
Rydberg states of NO in external electric fields
N1  - Unpublished
N2  - This thesis reports the application of static and ramped electric fields to the Rydberg
states of NO. Chapter 1 introduces the history of Rydberg states, their exotic
properties, decay mechanisms, and the effect of an applied electric field. Chapter 2
details the experimental set-up used for the experiments presented in this thesis.
Chapter 3 describes the structure of NO and multiphoton excitation scheme utilised
for the work presented in this thesis.
Chapter 4 investigates the effect of applied DC electric fields in the range
0 ? 150 V cm-1 on the predissociating Rydberg states of NO below the ?+ = 0
ionisation limit, with principal quantum numbers n = 25 ? 30. The Stark states are
accessed by two-colour, double-resonance excitation via the ?? = 0,N? = 0, 1, 2, and 4
rovibrational states of the A2?+ state. The N (2D) atoms produced by predissociation
are measured by (2 + 1) resonance-enhanced multiphoton ionization. The zero field
and predissociation spectra are analysed using a matrix diagonalisation method. In
Chapter 5, initial progress on simulating the spectra is presented. The predissociation
spectra are compared with pulsed-field ionization spectra of the bound Rydberg state
population providing an almost complete picture of the Rydberg state dynamics.
In Chapter 6, ramped fields of varying slew rates are applied to the bound Rydberg
states of NO, and the ionisation time profiles are obtained. The development of the
experimental chamber and investigation into sources of electrical noise required to
achieve this is discussed. It is shown that the rotational quantum state composition of
field-ionised molecules can be controlled by varying the slew rate of the applied
electric field.
ER  -