19 research outputs found
The first determination of Generalized Polarizabilities of the proton by a Virtual Compton Scattering experiment
Absolute differential cross sections for the reaction (e+p -> e+p+gamma) have
been measured at a four-momentum transfer with virtuality Q^2=0.33 GeV^2 and
polarization \epsilon = 0.62 in the range 33.6 to 111.5 MeV/c for the momentum
of the outgoing photon in the photon-proton center of mass frame. The
experiment has been performed with the high resolution spectrometers at the
Mainz Microtron MAMI. From the photon angular distributions, two structure
functions which are a linear combination of the generalized polarizabilities
have been determined for the first time.Comment: 4 pages, 3 figure
Ultrafast evolution of electric fields from high-intensity laser-matter interactions
The interaction of high-power ultra-short lasers with materials offers fascinating wealth of
transient phenomena which are in the core of novel scientific research. Deciphering its evolution is
a complicated task that strongly depends on the details of the early phase of the interaction, which
acts as complex initial conditions. The entire process, moreover, is difficult to probe since it develops
close to target on the sub-picosecond timescale and ends after some picoseconds. Here we present
experimental results related to the fields and charges generated by the interaction of an ultra-short
high-intensity laser with metallic targets. The temporal evolution of the interaction is probed with a
novel femtosecond resolution diagnostics that enables the differentiation of the contribution by the
high-energy forerunner electrons and the radiated electromagnetic pulses generated by the currents
of the remaining charges on the target surface. Our results provide a snapshot of huge pulses, up to
0.6 teravolt per meter, emitted with multi-megaelectronvolt electron bunches with sub-picosecond
duration and are able to explore the processes involved in laser-matter interactions at the femtosecond
timescale