[phys4phys] SCL online seminar: Marija Vranic and Thomas Grismayer, Thursday, 21 April, 14:00

[Antun Balaz]

Dear colleagues,

You are cordially invited to a double-feature SCL online seminar of the Center for the Study of Complex Systems, which will be held on Thursday, 21 April 2022 at 14:00 on Zoom (link is given below). The first talk, entitled

Sources of electrons, positrons, and gamma-rays from lasers within plasma channels

will be given by Dr. Marija Vranić (GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Portugal). Abstract of the talk:

The recent rise in laser intensities accompanied by the ongoing construction of new laser facilities such as ELI, the Vulcan 10 PW, and APOLLON will place intensities above 10^23 W/cm^2 within reach. While propagating through a pre-formed plasma channel, a laser of such intensity allows for direct laser acceleration (DLA) of leptons in the radiation reaction dominated regime. The DLA scheme has already been demonstrated to provide high-charge electron beams (at a nC level) with moderate laser intensities  (10^20 W/cm^2). In this talk we will show what can be accomplished with near-future laser facilities. We find that increasing the laser power is bound to augment the charge content even further. The field structure formed due to electron beam loading allows for accelerating positrons. What is more, the interaction in the radiation dominated regime will provide a high flux of emitted photons, in hard x-ray and gamma-ray range. These photons can then be used as a seed for electron-positron pair creation, as well as a radiation source for applications. 

The second talk, entitled

Electron-positron-photon cascades in ultrastrong electromagnetic fields

will be given by Dr. Thomas Grismayer (GoLP/Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Universidade de Lisboa, Portugal). Abstract of the talk:

Electron-positron pair plasmas are tightly related to extreme astrophysical objects such as pulsar magnetospheres or gamma-ray bursts. Due to the inherent difficulties of studying these remote objects, it is desirable to study dense pair plasmas in the laboratory, both for fundamental purposes and astrophysical applications. The magnitude of the laser fields expected in the next generation of laboratories overlaps with the estimated fields of milliseconds pulsars. Producing pair plasmas in ultrastrong fields may demonstrate that we can mimic the conditions appropriate to these astrophysical environments in laboratories. The pair creation in such energy density environments is caused by the decay of gamma rays in intense fields. As pulsars efficiently convert the large-scale Poynting flux to gamma rays, the laboratory analog of a pulsar isexpected to efficiently convert optical laser light into gamma rays. This process usually leads to quantum electrodynamics (QED) cascades, as the pairs created re-emit hard photons that decay anew in pairs, eventually resulting in electron-positron-photon plasmas. In this talk we will present the QED cascades in the laboratory where the electromagnetic trap is comprised of colliding lasers, and in Pulsar magnetospheres.

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Time: Apr 21, 2022 14:00 Belgrade
https://us02web.zoom.us/j/82700938432?pwd=QnFwNVNwVlg5WlJhTVVLcG1TTG1Cdz09

Meeting ID: 827 0093 8432
Passcode: 008340
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Best regards,
Antun Balaž

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Dr. Antun Balaž
Research Professor

http://www.scl.rs/antun
Phone: +381 11 3713152
Fax: +381 11 3162190

Scientific Computing Laboratory
Center for the Study of Complex Systems

Institute of Physics Belgrade
National Institute of the Republic of Serbia
Pregrevica 118, 11080 Belgrade, Serbia
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