BEGIN:VCALENDAR VERSION:2.0 PRODID:-//linuxsoftware.nz//NONSGML Joyous v1.4//EN BEGIN:VEVENT SUMMARY:Structured laser-plasma interactions at ultra-high intensities DTSTART:20251003T100000Z DTEND:20251003T120000Z DTSTAMP:20260419T120504Z UID:c84738e2-69d1-4542-8e0c-ba183c04afe1 SEQUENCE:2 CREATED:20250828T081841Z DESCRIPTION:Laser-plasma interactions at ultra-high intensities provide a powerful platform for accelerating charged particles to high energies (10s −100sMeV) over microscopic distances\, offering a promising alternative to conventional accelerators. High-energy protons and electrons play a cru cial role in applications such as microscopy\, advanced radiation sources\ , medical treatments\, and high-energy-density physics. Advances in laser technology enable the generation of structured beams beyond Gaussian profi les at ultra-high intensities. Tailored phase\, polarization\, and spatiot emporal coupling introduce new degrees of freedom to manipulate plasma dyn amics. This thesis employs theoretical modeling and three-dimensional part icle-in-cell simulations to investigate the role of structured lasers in u nlocking novel mechanisms for compact particle accelerators. The first obj ective is to generate collimated high-energy proton beams. We explore effe cts such as reduced relativistic self-focusing through advanced target des igns and support experimental findings on twisted laser-driven proton acce leration\, bridging theory\, simulations\, and experiments. Furthermore\, we examine angular momentum gain in plasma electrons under different condi tions. We identify a mechanism in which local pump depletion of a laser wi th azimuthal polarization—but no net angular momentum—facilitates elec tron rotation. Additionally\, angular momentum transfer from lasers carryi ng spin and orbital angular momentum is analyzed across different plasma r egimes\, demonstrating their role in generating substantial magnetic field s. LAST-MODIFIED:20250828T081907Z LOCATION:Anfiteatro PA-3 (Piso -1 do Pavilhão de Matemática) do IST URL:http://df.vps.tecnico.ulisboa.pt/pt/eventos/structured-laser-plasma-in teractions-at/ X-ALT-DESC;FMTTYPE=text/html:

Laser-plasma intera ctions at ultra-high intensities provide a powerful platform for accelerat ing charged particles to high energies (10s−100sMeV) over microscopic di stances\, offering a promising alternative to conventional accelerators. H igh-energy protons and electrons play a crucial role in applications such as microscopy\, advanced radiation sources\, medical treatments\, and high -energy-density physics. Advances in laser technology enable the generatio n of structured beams beyond Gaussian profiles at ultra-high intensities.< br/>
Tailored phase\, polarization\, and spatiotemporal coupling intr oduce new degrees of freedom to manipulate plasma dynamics. This thesis em ploys theoretical modeling and three-dimensional particle-in-cell simulati ons to investigate the role of structured lasers in unlocking novel mechan isms for compact particle accelerators. The first objective is to generate collimated high-energy proton beams. We explore effects such as reduced r elativistic self-focusing through advanced target designs and support expe rimental findings on twisted laser-driven proton acceleration\, bridging t heory\, simulations\, and experiments.

Furthermore\, we examine angular momentum gain in plasma electrons under different conditions. We i dentify a mechanism in which local pump depletion of a laser with azimutha l polarization—but no net angular momentum—facilitates electron rotati on. Additionally\, angular momentum transfer from lasers carrying spin and orbital angular momentum is analyzed across different plasma regimes\, de monstrating their role in generating substantial magnetic fields.

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