Communications Physics,
Journal Year:
2021,
Volume and Issue:
4(1)
Published: Nov. 26, 2021
Abstract
The
high
brilliance
of
ultrashort
X-ray
pulses
recently
generated
in
free
electron
lasers
will
soon
open
the
way
to
investigation
non-linear
processes
that
still
remain
inaccessible
due
smallness
corresponding
cross
sections.
One
them
is
stimulated
Compton
scattering
from
molecules.
In
this
work,
we
investigate
fixed-in-space
H
2
molecules
few-hundred
eV
photon
energy
range,
where
both
dipole
and
non-dipole
transitions
are
important.
We
show
interference
between
leads
pronounced
asymmetries
angular
distributions.
These
strongly
depend
on
molecular
orientation,
point
they
can
lead
emission
either
forward
or
backward
directions
with
respect
propagation
axis,
directions,
even
orthogonal
direction.
This
contrast
electrons
atomic
targets.
Reviews of Modern Physics,
Journal Year:
2021,
Volume and Issue:
93(3)
Published: July 8, 2021
With
high
brightness
and
tunable
resolution,
x-ray
synchrotron
light
sources
have
enhanced
the
ability
to
characterize
materials.
This
experimental
theoretical
overview
of
elastic
inelastic
resonant
Auger
element-specific
scattering
processes
enabled
by
these
tools
provides
an
updated
comprehensive
perspective
on
electron-nuclear
dynamics
together
with
structural
aspects
a
broad
variety
Materials
characterized
using
techniques
include
liquids,
gases,
molecules,
solids
correlated
excitations,
Mott
insulators,
semiconductors.
Communications Physics,
Journal Year:
2024,
Volume and Issue:
7(1)
Published: Jan. 2, 2024
Abstract
Time-resolved
X-ray
photoelectron
spectroscopy
(TXPS)
is
a
well-established
technique
to
probe
coherent
nuclear
wavepacket
dynamics
using
both
table-top
and
free-electron-based
ultrafast
lasers.
Energy
resolution,
however,
becomes
compromised
for
very
short
pulse
duration
in
the
sub-femtosecond
range.
By
resonantly
tuning
core-excited
states
undergoing
Auger
decay,
this
drawback
of
TXPS
can
be
mitigated.
While
resonant
Auger-electron
(RAS)
recover
vibrational
structures
not
hidden
by
broadband
excitation,
full
reconstruction
standing
challenge.
Here,
we
theoretically
demonstrate
how
complete
information
wavepacket,
i.e.,
populations
relative
phases
constituting
retrieved
from
time-resolved
RAS
(TRAS)
measurements.
Thus,
TRAS
offers
key
insights
into
coupled
electronic
complex
systems
on
ultrashort
timescales,
providing
an
alternative
leverage
femtosecond
attosecond
pulses.
Ultrafast Science,
Journal Year:
2024,
Volume and Issue:
4
Published: Jan. 1, 2024
Advancements
in
light
engineering
have
led
to
the
creation
of
pulsed
laser
sources
capable
delivering
high-repetition-rate,
high-power
few-cycle
pulses
across
a
wide
spectral
range,
enabling
exploration
many
fascinating
nonlinear
processes
occurring
all
states
matter.
High-harmonic
generation,
one
such
process,
which
converts
low-frequency
photons
driver
field
into
soft
x-rays,
has
revolutionized
atomic,
molecular,
and
optical
physics,
leading
progress
attosecond
science
ultrafast
optoelectronics.
The
Extreme
Light
Infrastructure,
Attosecond
Pulse
Source
(ELI
ALPS)
facility
pioneers
state-of-the-art
tools
for
research
these
areas.
This
paper
outlines
design
rationale,
capabilities,
applications
plasma-
gas-based
high-repetition-rate
(1
kHz
100
kHz)
extreme
ultraviolet
(XUV)
beamlines
developed
at
ELI
ALPS,
highlighting
their
potential
advancing
various
fields.
Advances in Physics X,
Journal Year:
2022,
Volume and Issue:
8(1)
Published: Oct. 13, 2022
Over
the
last
20
years,
XUV
and
X-ray
free-electron
lasers
have
enabled
a
wide
variety
of
time-resolved
experiments
that
dramatically
advanced
our
understanding
ultrafast
molecular
dynamics
on
atomic
length
scales
femtosecond
time
scales.
This
review
focuses
experimental
studies
atoms
molecules
in
gas
phase,
tracing
development
field
from
early
proof-of-principle
to
recent
pump-probe
elucidate
coupled
electronic
nuclear
during
photochemical
reactions
with
temporal
resolution
is
now
extending
into
attosecond
domain.
Photonics,
Journal Year:
2025,
Volume and Issue:
12(3), P. 211 - 211
Published: Feb. 28, 2025
The
calibration
activities
of
the
COmpact
SPectrometer—COSP
for
FERMI
Free-Electron
Laser
(FEL)
facility
at
Elettra
Synchrotron
(Italy)
are
presented.
COSP
is
an
in-house
built
grating
spectrometer
designed
to
be
used
during
optimization
parameters
and
control
relative
stability
between
different
FEL
harmonics
in
multi-harmonic
emission
mode.
work
single-shot
mode
a
repetition
rate
50
Hz
providing
medium
resolution
wide
spectral
range
order
either
measure
separate
intensities
being
mixed
multi-color
experiment
or
quantify
amount
possible
spurious
harmonics.
These
key
importance
new
class
experiments
based
on
wave
mixing
paradigm
tested
seeded
FERMI.
Physical review. A/Physical review, A,
Journal Year:
2025,
Volume and Issue:
111(3)
Published: March 10, 2025
The
reconstruction
of
attosecond
beating
by
interference
two-photon
transitions
(RABBITT)
setup
is
theoretically
studied
for
various
combinations
extreme
ultraviolet
and
infrared
(IR)
field
components
polarization:
``$\mathrm{linear}+\mathrm{linear}$,''
``$\mathrm{linear}+\mathrm{circular}$''
with
crossed
propagation
directions,
``$\mathrm{circular}+\mathrm{circular}$''
parallel
directions.
We
examine
the
general
properties
photoelectron
angular
distributions
their
response
to
variation
IR
pulse
delay.
Numerical
simulations
are
performed
neon
valence
shell
ionization
into
structureless
continuum
using
two
approaches:
time-dependent
perturbation
theory
solution
amplitude
rate
equations.
To
distinguish
between
``geometrical''
governed
fields
polarization
spectroscopic
features,
we
provide
an
additional
analysis
case
$s$-shell
ionization.
