8 research outputs found
Quantitative shadowgraphy and proton radiography for large intensity modulations
Shadowgraphy is a technique widely used to diagnose objects or systems in
various fields in physics and engineering. In shadowgraphy, an optical beam is
deflected by the object and then the intensity modulation is captured on a
screen placed some distance away. However, retrieving quantitative information
from the shadowgrams themselves is a challenging task because of the non-linear
nature of the process. Here, a novel method to retrieve quantitative
information from shadowgrams, based on computational geometry, is presented for
the first time. This process can be applied to proton radiography for electric
and magnetic field diagnosis in high-energy-density plasmas and has been
benchmarked using a toroidal magnetic field as the object, among others. It is
shown that the method can accurately retrieve quantitative parameters with
error bars less than 10%, even when caustics are present. The method is also
shown to be robust enough to process real experimental results with simple pre-
and post-processing techniques. This adds a powerful new tool for research in
various fields in engineering and physics for both techniques
Plasma lensing of a laser wakefield accelerated electron bunch
We report on the first all-optical demonstration of
plasma lensing using laser wakefield accelerated
elec-trons in a two-stage setup. The LWFA electron
bunch was focused by a second plasma stage without
any ex-ternal fields applied..
Direct observation of the injection dynamics of a laser wakefield accelerator using few-femtosecond shadowgraphy
International audienceWe present few-femtosecond shadowgraphic snapshots taken during the non-linear evolution of the plasma wave in a laser wakefield accelerator with transverse synchronized few-cycle probe pulses. These snapshots can be directly associated with the electron density distribution within the plasma wave and give quantitative information about its size and shape. Our results show that self-injection of electrons into the first plasma wave period is induced by a lengthening of the first plasma period. Three dimensional particle in cell simulations support our observations
[poster] Video7 /
Antwerpen 93. Culturele hoofdstad van Europa.Meer informatie op de achterzijde van de affiche.Bijzondere collectie
Quantitative shadowgraphy and proton radiography for large intensity modulations
Shadowgraphy is a technique widely used to diagnose objects or systems in various fields in physics and engineering. In shadowgraphy, an optical beam is deflected by the object and then the intensity modulation is captured on a screen placed some distance away. However, retrieving quantitative information from the shadowgrams themselves is a challenging task because of the non-linear nature of the process. Here, a novel method to retrieve quantitative information from shadowgrams, based on computational geometry, is presented for the first time. This process can also be applied to proton radiography for electric and magnetic field diagnosis in high-energy-density plasmas and has been benchmarked using a toroidal magnetic field as the object, among others. It is shown that the method can accurately retrieve quantitative parameters with error bars less than 10%, even when caustics are present. The method is also shown to be robust enough to process real experimental results with simple pre- and post-processing techniques. This adds a powerful new tool for research in various fields in engineering and physics for both techniques
Quantitative shadowgraphy and proton radiography for large intensity modulations
Shadowgraphy is a technique widely used to diagnose objects or systems in various fields in physics and engineering. In shadowgraphy, an optical beam is deflected by the object and then the intensity modulation is captured on a screen placed some distance away. However, retrieving quantitative information from the shadowgrams themselves is a challenging task because of the non-linear nature of the process. Here, a novel method to retrieve quantitative information from shadowgrams, based on computational geometry, is presented for the first time. This process can also be applied to proton radiography for electric and magnetic field diagnosis in high-energy-density plasmas and has been benchmarked using a toroidal magnetic field as the object, among others. It is shown that the method can accurately retrieve quantitative parameters with error bars less than 10%, even when caustics are present. The method is also shown to be robust enough to process real experimental results with simple pre- and post-processing techniques. This adds a powerful new tool for research in various fields in engineering and physics for both techniques
Current and planned future experiments with relativistic high harmonic generation using the JETI200 laser
High-order harmonic generation (HHG) through nonlinear interaction of intense laser beams with different systems is a promising source of bright, ultra-short bursts of extreme-ultraviolet radiation. High harmonics arise since the radiation is emitted as a train of attosecond pulses. A key objective is to achieve a single isolated pulse to allow time resolved measurements characterized by these pulses on an attosecond scale. We carried out experiments into JETI200 facility in Jena, Germany in order to characterize the properties of the harmonic radiation generated from a solid surface interaction, with the ultimate goal of employing temporal gating schemes to reduce the attosecond pulse train to a single pulse. The reason this laser is well suited for such experiment is a combination of its high power and the fact it is “quasi”-few-cycle (6.39 cycles) ideal for trying out gating scheme