scholarly journals Pair production by Schwinger and Breit–Wheeler processes in bi-frequent fields

2016 ◽  
Vol 82 (3) ◽  
Author(s):  
A. Otto ◽  
T. Nousch ◽  
D. Seipt ◽  
B. Kämpfer ◽  
D. Blaschke ◽  
...  

Counter-propagating and suitably polarized light (laser) beams can provide conditions for pair production. Here, we consider in more detail the following two situations: (i) in the homogeneity regions of anti-nodes of linearly polarized ultra-high intensity laser beams, the Schwinger process is dynamically assisted by a second high-frequency field, e.g. by an XFEL beam; and (ii) a high-energy probe photon beam colliding with a superposition of co-propagating intense laser and XFEL beams gives rise to the laser-assisted Breit–Wheeler process. The prospects of such bi-frequent field constellations with respect to the feasibility of conversion of light into matter are discussed.

2015 ◽  
Vol 81 (5) ◽  
Author(s):  
D. R. Rusby ◽  
L. A. Wilson ◽  
R. J. Gray ◽  
R. J. Dance ◽  
N. M. H. Butler ◽  
...  

High-intensity laser–solid interactions generate relativistic electrons, as well as high-energy (multi-MeV) ions and x-rays. The directionality, spectra and total number of electrons that escape a target-foil is dependent on the absorption, transport and rear-side sheath conditions. Measuring the electrons escaping the target will aid in improving our understanding of these absorption processes and the rear-surface sheath fields that retard the escaping electrons and accelerate ions via the target normal sheath acceleration (TNSA) mechanism. A comprehensive Geant4 study was performed to help analyse measurements made with a wrap-around diagnostic that surrounds the target and uses differential filtering with a FUJI-film image plate detector. The contribution of secondary sources such as x-rays and protons to the measured signal have been taken into account to aid in the retrieval of the electron signal. Angular and spectral data from a high-intensity laser–solid interaction are presented and accompanied by simulations. The total number of emitted electrons has been measured as $2.6\times 10^{13}$ with an estimated total energy of $12\pm 1~\text{J}$ from a $100~{\rm\mu}\text{m}$ Cu target with 140 J of incident laser energy during a $4\times 10^{20}~\text{W}~\text{cm}^{-2}$ interaction.


Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Marcel Ruijter ◽  
Vittoria Petrillo ◽  
Thomas C. Teter ◽  
Maksim Valialshchikov ◽  
Sergey Rykovanov

High-energy radiation can be generated by colliding a relativistic electron bunch with a high-intensity laser pulse—a process known as Thomson scattering. In the nonlinear regime the emitted radiation contains harmonics. For a laser pulse whose length is comparable to its wavelength, the carrier envelope phase changes the behavior of the motion of the electron and therefore the radiation spectrum. Here we show theoretically and numerically the dependency of the spectrum on the intensity of the laser and the carrier envelope phase. Additionally, we also discuss what experimental parameters are required to measure the effects for a beamed pulse.


2018 ◽  
Vol 167 ◽  
pp. 02001 ◽  
Author(s):  
Dean Rusby ◽  
Ross Gray ◽  
Nick Butler ◽  
Rachel Dance ◽  
Graeme Scott ◽  
...  

The interaction of a high-intensity laser with a solid target produces an energetic distribution of electrons that pass into the target. These electrons reach the rear surface of the target creating strong electric potentials that act to restrict the further escape of additional electrons. The measurement of the angle, flux and spectra of the electrons that do escape gives insights to the initial interaction. Here, the escaping electrons have been measured using a differentially filtered image plate stack, from interactions with intensities from mid 1020-1017 W/cm2, where the intensity has been reduced by defocussing to increase the size of the focal spot. An increase in electron flux is initially observed as the intensity is reduced from 4x1020 to 6x1018 W/cm2. The temperature of the electron distribution is also measured and found to be relatively constant. 2D particle-in-cell modelling is used to demonstrate the importance of pre-plasma conditions in understanding these observations.


2012 ◽  
Vol 19 (2) ◽  
pp. 023110 ◽  
Author(s):  
M. E. Povarnitsyn ◽  
N. E. Andreev ◽  
P. R. Levashov ◽  
K. V. Khishchenko ◽  
O. N. Rosmej

2021 ◽  
Author(s):  
Eng Boon Ng ◽  
C. H. Raymond Ooi

Abstract In this article, we consider an extremely intense laser, enclosed by an atom interferometer. The gravitational potential generated from the high-intensity laser is solved from the Einstein field equation under the Newtonian limit. We compute the strength of the gravitational force and study the feasibility of measuring the force by the atom interferometer. The intense laser field from the laser pulse can induce a phase change in the interferometer with Bose-Einstein condensates. We push up the sensitivity limit of the interferometer with Bose-Einstein condensates by spin-squeezing effect and determine the sensitivity gap for measuring the gravitational effect from intense laser by atom interferometer.


Author(s):  
F. Bisesto ◽  
M. Galletti ◽  
M. P. Anania ◽  
M. Ferrario ◽  
R. Pompili ◽  
...  

Laser–plasma interactions have been studied in detail over the past twenty years, as they show great potential for the next generation of particle accelerators. The interaction between an ultra-intense laser and a solid-state target produces a huge amount of particles: electrons and photons (X-rays and $\unicode[STIX]{x03B3}$ -rays) at early stages of the process, with protons and ions following them. At SPARC_LAB Test Facility we have set up two diagnostic lines to perform simultaneous temporally resolved measurements on both electrons and protons.


1996 ◽  
Vol 74 (6) ◽  
pp. 1236-1247 ◽  
Author(s):  
T.-T. Nguyen-Dang ◽  
F. Châteauneuf ◽  
S. Manoli

The separability of a dressed molecule, a composite molecule + quantized radiation field system, at high field intensities is examined. Various forms of the Hamiltonian describing the dressed molecule are reviewed and are used to assess the zeroth-order separability of the dressed system. A new high-order adiabatic separation between the strongly coupled quantized field and molecular subsystems is derived. Qualitative manifestations of laser-induced molecular structures are discussed within this high-order adiabatic representation. Key words: dynamics, dressed molecule, intense laser field, adiabatic separation, laser-induced molecular structure.


2012 ◽  
Vol 78 (4) ◽  
pp. 483-489 ◽  
Author(s):  
XIAOFANG WANG ◽  
GUANGHUI WANG ◽  
ZHANNAN MA ◽  
KEGONG DONG ◽  
BIN ZHU ◽  
...  

AbstractFor high-energy gain of electron acceleration by a laser wakefield, a stable or guiding propagation of an ultrashort, high-intensity laser pulse in a gas-target plasma is of fundamental importance. Preliminary experiments were carried out for the propagation of 30-fs, ~100-TW laser pulses of intensities ~1019W/cm2 in plasma of densities ~1019/cm3. Self-guiding length of nearly 1.4 mm was observed in a gas jet and 15 mm in a hydrogen-filled capillary. Fluid-dynamics simulations are used to characterize the two types of gas targets. Particle-in-cell simulations indicate that in the plasma, after the pulse's evolution of self-focusing and over-focusing, the high-intensity pulse could be stably guided with a beam radius close to the plasma wavelength. At lower plasma densities, a preformed plasma channel of a parabolic density profile matched to the laser spot size would be efficient for guiding the pulse.


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