Retreat FOR2783

27.04.2021, 13:00 → 28.04.2021, 18:00 Europe/Berlin

VIRTUAL SPACE (VIA WEBEX)

Carsten Müller (Uni Düsseldorf)

Retreat FOR2783

WEBEX Link

Dienstag, 27. April

Block: E1, T1, T2

1 Quantum Vacuum Simulation Algorithm and Code (QVSP)

A numerical scheme for solving the nonlinear Heisenberg-Euler equation in up to 3 spatial dimensions plus time is derived and its properties are discussed. This "quantum vacuum simulation algorithm" is tested against a set of already known analytical results and its power to go beyond analytically solvable scenarios is shown.

Sprecher: Baris Ölmez, Andreas Maximilian Lindner (LMU Munich)

qvsp.pdf

2 Vacuum birefringence and diffraction at XFEL: from analytical estimates to optimal parameters

We study vacuum birefringence and x-ray photon scattering in the head-on collision of x-ray free electron and high-intensity laser pulses. Resorting to analytical approximations for the numbers of attainable signal photons, we analyze the behavior of the phenomenon under the variation of various experimental key-parameters and provide new analytical scalings. Our optimized approximations allow for quantitatively accurate results on the one-percent level. We in particular demonstrate that an appropriate choice of the x-ray focus and pulse duration can significantly improve the signal for given laser parameters, using the experimental parameters to be available at the Helmholtz International Beamline for Extreme Fields at the European XFEL as example.

Sprecher: Elena Mosman (Tomsk Polytechnic University)

FOR Mosman.pdf

3 Numerical Simulation of Colliding Laser Pulses

The nonlinear optical properties of colliding high field laser pulses in HE weak field approximation is investigated numerically. The numerical approach is detailed.

Sprecher: Andreas Maximilian Lindner (LMU Munich), Baris Ölmez

qvsp.pdf

Break: Coffee and discussions

Block: T1, T2, E2

4 Photon merging in the collision of two laser pulses

Quantum vacuum nonlinearity allows for the effect of laser photon merging in the collision of two (or more) laser beams. As the merged photons origin from a manifestly inelastic process, their energy differs significantly from the background photons of the driving lasers, making them accessible for experiments. However, the number of merged photons is typically considered to be very small.
In this talk, results on the emission characteristics of the merged signal photons will be presented, demonstrating that the availability of just two laser beams is sufficient to achieve a sizable signal in experiments with state-of-the-art technology.

Sprecher: Chantal Sundqvist (FSU Jena)

FOR_Merging.pdf

5 Experiments at the JETI laser

First strong field experiments at the JETI super laser in Jena are reported.

Sprecher: Herr Pooyan Khademi

6 First measurement of background signals

In August 2020, a first experimental campaign was conducted to investigate light scattered from a single laser focus in vacuum. Any photons measured constitute an undesired background signal for an actual multi-beam collision experiment. Key findings will be presented and possible improvements as well as the expected scaling towards higher power collision experiments will be discussed.

Sprecher: Herr Leonard Doyle (LMU)

20210427_E2_FirstBeamtimeResults_toUpload.pdf

Break: Coffee and discussions

Discussions

Mittwoch, 28. April

Block: T1, T2, T3

7 Signatures of quantum vacuum non-linearity in laser-pulse collisions at finite focal offsets

We study optical signatures of two-photon scattering processes by collision of two Gaussian beams. Effects on the signal photon distribution by focal shifts are observed for an XFEL probe and an optical pump while taking the beams' curvatures into account.

Sprecher: Ricardo Oude Weernink (Helmholtz Institute Jena / FSU Jena)

Pres_SignaturesFocalShift.pdf

8 Radiation Reaction and Emergent Inertia in Strong Electromagnetic Fields

Inertia in strong electromagnetic fields is an emergent quantity. The way to show this is with the help of a new approach to radiation reaction. Hence, we first review radiation reaction and explain what the concept of emergent inertia is.

Sprecher: Herr Christian Bild (LMU)

9 Nonlinear Breit-Wheeler pair production: effects of laser focusing

A discussion about effects of focusing on nonperturbative pair production rate when considering laser and bremsstrahlung photons

Sprecher: Alina Golub (Heinrich-Heine-Universität Düsseldorf)

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Break: Coffee and discussions

Block: E2, E3

10 Latest results on fluid dynamic simulations for new laser wakefield acceleration targets

Sprecher: Andreas Seidel

Seidel-FOR-Retreat2021.pdf

11 Detector development for diagnosing single particles at strong-field QED experiments

A detection particle system composed of LYSO scintillating screens and a Cherenkov calorimeter is proposed for diagnosing single electron-positron pairs created due to the nonlinear Breit-Wheeler process. Moreover, Monte-Carlo simulations to estimate the signal-to-noise ratio of the detectors are presented.

Sprecher: Felipe Salgado (FSU Jena / Helmholtz-Institut Jena)

Salgado_FOR2783_2021_Retreat.pdf

Break: Lunch

Block: E3, T3

12 Electrons from elongated tragetts with up to GeV energies

First experiments are reported that show electrons with up to GeV energies.

Sprecher: Frau Katinka von Grafenstein (Ludwig-Maximilians-Universität München)

13 Quantum Meanfield Theory with Feedback

Renormalisation method for pair creation with feedback in time-dependent electric fields.

Sprecher: Yukiko Song (Chair Ruhl, LMU)

retreat_presentation.pdf

Break: Coffee and discussions

Discussions

Break: Coffee and discussions

Block: PI Meeting