ELFT HÍRADÓ

[Zimányiné Horváth Vera <Vera.Horvath AT eli-alps.hu>]

Előadók és előadáscímek:           1.  Szilárd Majorosi (ELI ALPS):
                                                               Numerical 
representation of tightly focused ultra-short laser pulses with different 
beam modes
2. Zsolt Lécz (ELI ALPS):
                                                               Proposals for 
particle acceleration in plasma at high repetition rate using few-cycle laser 
pulses

Időpont:              2023. Június 30., 9 óra
Helyszín:             az ELI ALPS konferenciaterme (Szeged, Wolfgang Sandner 
utca 3.)

Az előadások rövid kivonata:

  1.  Recent progresses in development of broad-band laser systems lead to 
the stable production of nearly single-cycle pulses at high repetition rates 
which then require tight focusing optics in order to reach highly 
relativistic intensities, needed for laser-plasma experiments. Most of the 
laser-driven particle acceleration schemes rely on particle-in-cell 
simulations where the laser pulses are usually initialized with Gaussian 
transverse profiles, employing the paraxial approximation at the beginning of 
the interaction. For tightly focused ultrashort pulses, however, a more 
accurate description is needed, otherwise the arising numerical artifacts may 
detrimentally affect the simulation outcome.
We present a general analytical-numerical framework going beyond the paraxial 
description for the laser electric and magnetic fields valid up to the near 
single-cycle pulse durations and focused beam spot sizes. We introduce 
corrections regarding spatial-temporal coupling, and corrections for the 
vector components of the electric- and magnetic-fields that could give 
precise initial fields for existing Maxwell-solvers ready to be used in 
particle-in-cell simulations. We combine this framework with beams based on 
the multimodal decomposition on the real Laguerre-Gaussian mode basis, to 
model pulses that have - more realistic- high order super-Gaussian profiles 
away from the focus in the same way.


  1.  Since the invention of laser wakefields, generated by high intensity, 
femtosecond pulses in gaseous targets, the electron acceleration in dilute 
plasmas has been investigated both theoretically and experimentally. This 
scheme looks extremely promising to partially replace the conventional 
accelerators and to generate high quality relativistic electron bunches 
reaching several GeV maximum energies. However, in the case of ultrashort 
pulses new physical effects emerge, which are not yet fully understood, or 
not explored in the literature. Since the propagation of ultrashort laser 
pulses in plasma is highly nonlinear, it is necessary to model the 
interaction by means of numerical simulations. With the help of such 
(particle-in-cell) simulations I studied the electron acceleration process 
driven by very short (few-cycle) pulses and identified several negative 
effects which are not so important (or not present) in the case of longer 
pulses. Based on the knowledge acquired in the last two years I designed a 
three-component target, which is suitable for very efficient electron 
acceleration and allows for high energy gain within 2-millimeter distance. In 
my talk I will present the theoretical description of the short-pulse 
propagation in the proposed millimeter-long, three-stage target and I will 
show that, theoretically, GeV-class electron bunches can be accelerated by a 
half-Joule laser pulse in this new scheme.
In the second part of my talk, I will briefly discuss the possibility of 
proton (or deuteron) acceleration from high density gas jets using ~ 100 mJ 
laser pulses, which is highly relevant to the SYLOS-2 laser installed at 
ELI-ALPS. I will present a realistic 3D simulation which indicates that 1 MeV 
mono-energetic proton bunch can be generated by such ultra-short laser pulses 
at ~kHz repetition rate.

Az előadás az alábbi link használatával online is meghallgatható:
https://teams.microsoft.com/l/meetup-join/19%3ameeting_ZTY5YmJhZmItNjI3ZS00Njg5LWFlYzQtNGE0Y2FhZTdjNThi%40thread.v2/0?context=%7B%22Tid%22%3A%22b207389a-c5cb-4cb0-a1ad-227b94e96448%22%2C%22Oid%22%3A%22c993efcb-59ae-4652-9f68-d7a313727128%22%2C%22IsBroadcastMeeting%22%3Atrue%2C%22role%22%3A%22a%22%7D&btype=a&role=a

Minden érdeklődőt szívesen látunk.

Vera HORVÁTH (Ms)
Head of Science Outreach Centre

ELI ALPS, ELI-HU Non-Profit Ltd.
H-6728 Szeged, Wolfgang Sandner utca 3.
Mobile: +36 70 491 14 12
E-mail: Vera.Horvath AT eli-alps.hu
Website: www.eli-alps.hu<http://www.eli-alps.hu/>
[cid:image001.png AT 01D9A8E8.0B80CDD0]

P Kérem, óvja a természetet, ha nem szükséges, ne nyomtassa ki ezt az e-mailt!
Before printing, think about ENVIRONMENTAL responsibility.