68 research outputs found
Frustrated Double Ionization of Argon Atoms in Strong Laser Fields
We demonstrate kinematically complete measurements on frustrated double
ionization of argon atoms in strong laser fields with a reaction microscope. We
found that the electron trapping probability after strong field double
ionization is much higher than that after strong field single ionization,
especially in case of high laser intensity. The retrieved electron momentum
distributions of frustrated double ionization show a clear transition from the
nonsequential to the sequential regime, similar to those of strong field double
ionization. The dependence of electron momentum width on the laser intensity
further indicates that the second released electron has a dominant contribution
to frustrated double ionization in the sequential regime
The Governance of Decentralized Autonomous Organizations: A Study of Contributors' Influence, Networks, and Shifts in Voting Power
We present a study analyzing the voting behavior of contributors, or vested
users, in Decentralized Autonomous Organizations (DAOs). We evaluate their
involvement in decision-making processes, discovering that in at least 7.54% of
all DAOs, contributors, on average, held the necessary majority to control
governance decisions. Furthermore, contributors have singularly decided at
least one proposal in 20.41% of DAOs. Notably, contributors tend to be
centrally positioned within the DAO governance ecosystem, suggesting the
presence of inner power circles. Additionally, we observed a tendency for
shifts in governance token ownership shortly before governance polls take place
in 1202 (14.81%) of 8116 evaluated proposals. Our findings highlight the
central role of contributors across a spectrum of DAOs, including Decentralized
Finance protocols. Our research also offers important empirical insights
pertinent to ongoing regulatory activities aimed at increasing transparency to
DAO governance frameworks
Laser-sub-cycle two-dimensional electron momentum mapping using orthogonal two-color fields
The two-dimensional sub-cycle-time to electron momentum mapping provided by
orthogonal two-color laser fields is applied to photoelectron spectroscopy.
Using neon as the example we gain experimental access to the dynamics of
emitted electron wave packets in electron momenta spectra measured by
coincidence momentum imaging. We demonstrate the opportunities provided by this
time-to-momentum mapping by investigating the influence of the parent ion on
the emitted electrons on laser-sub-cycle times. It is found that depending on
their sub-cycle birth time the trajectories of photoelectrons are affected
differently by the ion's Coulomb field
Time-dependent density-functional study of the alignment-dependent ionization of acetylene and ethylene by strong laser pulses
The alignment-dependent ionization of acetylene and ethylene in short laser pulses is investigated in the framework of the time-dependent density-functional theory coupled with Ehrenfest dynamics. The molecular alignment is found to have a substantial effect on the total ionization. Bond stretching is shown to cause an increase of the ionization efficiency, i.e., enhanced ionization, in qualitative agreement with previous theoretical investigations. It is also demonstrated that the enhanced ionization mechanism greatly enhances the ionization from the inner valence orbitals, and the ionization of the inner orbitals is primarily due to their extended weakly bound density tail
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