Rescattering-enhanced dissociation of a molecular ion

Suresh, M.; Srigengan, B.; Williams, Ian D.; Bryan, William A.; English, E. M. L.; Stebbings, Sarah L.; Newell, W R; Turcu, I. C. E.; Smith, Jonathan M.; Divall, E. J.; Hooker, C. J.; Langley, A. J.; Collier, J.

doi:10.1103/physreva.74.043409

Cited by 15 publications

(19 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…DI has been observed in N 2 and O 2 [108,119,120]. In the case of CO 2 McKenna et alsuggest that RIF is responsible for a significant DE enhancement for linear compared to circular polarisation [16]. The results are displayed in part (b) of fig.…”

Section: Small Moleculessupporting

confidence: 50%

“…DE has so far been observed in CO 2 [16] and N 2 [45] and O 2 [119]. DI has been observed in N 2 and O 2 [108,119,120].…”

Section: Small Moleculesmentioning

confidence: 97%

“…Theoretical calculations of the TI rate lead to I (lin) = 0.65I (cir) , as the intensity relationship for achieving this [44]. This has been verified experimentally for atoms and small molecules [44,45], including CO 2 [16].…”

Section: Ellipticity Dependencementioning

confidence: 97%

“…Secondly, the dissociation of the molecular ion CO + 2 is relatively well understood [15]. Thirdly, the resulting fragmentation channels could be identified and isolated rather easily in the used experimental setup due to their lack of kinetic energy release [16]. Two processes were then investigated: the second ionisation and the dissociation mechanism of the molecular ion CO + 2 .…”

Section: Introductionmentioning

confidence: 99%

“…Firstly, the tunneling ionisation of CO 2 may take place from a low lying orbital, which would leave the parent ion in an excited electronic state. In addition, inelastic recollisions [16] and laser induced photo-excitation may facilitate the population of excited ionic states. The experiments presented in this thesis firstly aim at identifying the contributions from the above channels to the dissociation mechanism by recording the resulting fragmentation yield as a function of different laser parameters such as intensity, ellipticity and polarisation.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Resolving Strong Field Dynamics in Cation States of CO_2 via Optimised Molecular Alignment

Oppermann

2014

Springer Theses

View full text Add to dashboard Cite

In this thesis, the role of the molecular structure in strong field induced processes in CO 2 is resolved by the use of optimised impulsive molecular alignment. Two processes were investigated: recollision induced ionisation and the dissociation of the molecular ion CO + 2 . Both processes are driven by the initial tunneling ionisation of CO 2 . Through the use of molecular alignment, the orbital symmetries of the involved molecular ionic states were resolved, revealing the internal molecular dynamics in the form of ionisation and excitation pathways.A novel data analysis procedure was developed to extract the alignment distribution and rotational temperature of the impulsively aligned molecular ensemble. This facilitated the optimisation of molecular alignment in mixed gas samples and was demonstrated for N 2 , O 2 and CO 2 seeded in Ar.The recollision induced or nonsequential double ionisation (NSDI) of CO 2 was then studied in the molecular frame. The process was fully characterised by measuring the shape of the recolliding electron wavepacket and the angularly resolved inelastic electronion recollision cross section. The results reveal the contribution from both the ionic ground and first excited state of CO + 2 to the NSDI mechanism. This study was extended to the strong field induced dissociation of impulsively aligned CO + 2 . It was found that dissociation is driven by a parallel dipole transition from the second excited ionic state B to the predissociating state C, whilst recollision excitation was shown to not play a role. The strong field induced coupling of the ionic states B and C could thus be controlled by the laser polarisation.The results obtained in this thesis further the understanding of population dynamics of cation states in strong field processes. This is of special interest for extending molecular strong field physics to the study of electronic degrees of freedom and their coupling to the nuclear motion. had hoped for in a research degree and I cannot thank Jon enough for making it such an enriching experience, both professionally and personally.

show abstract