On the breaking of a plasma wave in a thermal plasma. II. Electromagnetic wave interaction with the breaking plasma wave

In thermal plasma, the structure of the density singularity formed in a relativistically large amplitude plasma wave close to the wavebreaking limit leads to a refraction coefficient with discontinuous spatial derivatives. This results in a non-exponentially small above-barrier reflection of an electromagnetic wave interacting with the nonlinear plasma wave

Deconvolution of multi-Boltzmann x-ray distribution from linear absorption spectrometer via analytical parameter reduction

The design of a hard x-ray linear absorption spectrometer (hx-LAS) and data analysis protocol to deduce the x-ray spectrum is presented. By scintillators and metallic filters one can attenuate and characterise the x-ray signal simultaneously. We also present a concise temperature analysis routine that is able to characterise multiple temperature components within the spectral emission by analytically reducing the number of parameters. This routine is suitable for real-time data processing at multi-Hz repetition rate

Corrigendum: Relativistically upshifted higher harmonic generation via relativistic flying mirrors (Plasma Physics and Controlled Fusion (2018) 60 (074007) DOI: 10.1088/1361-6587/aac068)

In the calculation of the reflection coefficient for the partial reflection of an electromagnetic wave from a breaking plasma wave in section 2.1 Low Intensity regime (as ≤ 1), an incorrect value for γph was used. The two sentences after equation (3) should be corrected to Taking θ = 0 and using equation (2) giving γph ≈ 2.1 for Np = 1 and ωs/ωpe = 1.57 we get that Rδ ≈ 9.47 × 10-2. This can be seen to be in rough agreement with the ratio of the reflected spectrum broad peak around 15≲kx/ks ≲ 24 (blue solid line) to that of the original pulse kx/ks ≈1 (thick solid line) in figure 4. In addition, upon closer examination of figure 6, the last sentence in section 2.2. Near-relativistic Intensity regime (as ≈ 1) should be corrected to It can be seen that the ratio of the reflected spectrum region aound kx/ks ≈10 (blue solid line) to that of the original pulse kx/ks ≈1 (thick solid line) in figure 6 is roughly 10 times lower than that of the low intensity case. These modifications do not change our conclusions

Relativisitcally upshifted higher harmonic generation via relativistic flying mirrors

We have previously shown that laser light can be upshifted to higher frequencies by its reflection off relativistically moving mirrors in plasma. These mirrors were generated with ultra-high intensity laser pulses. However, the laser light which was reflected off the mirrors had relatively low intensity. We show via simulations that even high intensity light can be reflected off the mirrors and that this can generate relativistically upshifted harmonics

Relativistic flying laser focus by a laser-produced parabolic plasma mirror

The question of electromagnetic field intensification towards the values typical for strong field quantum electrodynamics is of fundamental importance. One of the most promising intensification schemes is based on the relativistic-flying mirror concept, which shows that the electromagnetic radiation reflected by the mirror will be frequency upshifted by a factor of 4γ2 (γ is the Lorentz factor of the mirror). In laser-plasma interactions, such a mirror travels with relativistic velocities through plasma and typically has a parabolic form, which is advantageous for light intensification. Thus, a relativistic-flying parabolic mirror reflects the counterpropagating radiation in the form of a focused and flying electromagnetic wave with a high frequency. The relativistic-flying motion of the laser focus makes the electric and magnetic field distributions of the focus complicated, and the mathematical expressions describing the field distributions of the focus become of fundamental interest. We present analytical expressions describing the field distribution formed by an ideal flying mirror which has a perfect reflectance over the entire surface and wavelength range. The peak field strength of an incident laser pulse with a center wavelength of λ0 and an effective beam radius of we is enhanced by a factor proportional to γ3(we/λ0) in the relativistic limit. Electron-positron pair production is investigated in the context of invariant fields based on the enhanced electromagnetic field. The pair production rate under the relativistic-flying laser focus is modified by the Lorentz γ-factor and the beam radius-wavelength ratio (we/λ0). We show that the electron-positron pairs can be created by colliding two counterpropagating relativistic-flying laser focuses in vacuum, each of which is formed when a 180 TW laser pulse is reflected by a relativistic-flying parabolic mirror with γ=12.2

Relativistic flying laser focus by a laser-produced parabolic plasma mirror

The question of electromagnetic field intensification towards the values typical for strong field quantum electrodynamics is of fundamental importance. One of the most promising intensification schemes is based on the relativistic-flying mirror concept, which shows that the electromagnetic radiation reflected by the mirror will be frequency upshifted by a factor of 4γ2 (γ is the Lorentz factor of the mirror). In laser-plasma interactions, such a mirror travels with relativistic velocities through plasma and typically has a parabolic form, which is advantageous for light intensification. Thus, a relativistic-flying parabolic mirror reflects the counterpropagating radiation in the form of a focused and flying electromagnetic wave with a high frequency. The relativistic-flying motion of the laser focus makes the electric and magnetic field distributions of the focus complicated, and the mathematical expressions describing the field distributions of the focus become of fundamental interest. We present analytical expressions describing the field distribution formed by an ideal flying mirror which has a perfect reflectance over the entire surface and wavelength range. The peak field strength of an incident laser pulse with a center wavelength of λ0 and an effective beam radius of we is enhanced by a factor proportional to γ3(we/λ0) in the relativistic limit. Electron-positron pair production is investigated in the context of invariant fields based on the enhanced electromagnetic field. The pair production rate under the relativistic-flying laser focus is modified by the Lorentz γ-factor and the beam radius-wavelength ratio (we/λ0). We show that the electron-positron pairs can be created by colliding two counterpropagating relativistic-flying laser focuses in vacuum, each of which is formed when a 180 TW laser pulse is reflected by a relativistic-flying parabolic mirror with γ=12.2