191. Mass Composition of Cosmic Rays with Energies above 10[sup]17.2 eV from the Hybrid Data of the Pierre Auger ObservatoryAlexey Yushkov, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, ultra-high energy cosmic rays (UHECR), UHECR hybrid detection, UHECR mass composition Objavljeno v RUNG: 21.12.2020; Ogledov: 2819; Prenosov: 74 Celotno besedilo (749,44 KB) |
192. Bounds on diffuse and point source fluxes of ultra-high energy neutrinos with the Pierre Auger ObservatoryFrancisco Pedreira, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: Pierre Auger Observatory, Auger Surface Detector, search for ultra-high energy (UHE) neutrinos, upper limits on diffuse and point source UHE neutrino fluxes Objavljeno v RUNG: 21.12.2020; Ogledov: 2923; Prenosov: 69 Celotno besedilo (447,71 KB) |
193. Advantages and disadvantages of experiments with ultrashort two-color pulsesMatija Stupar, 2020, doktorska disertacija Opis: Advances in the development of lasers have led to a new class of radiation sources generating coherent, tunable, ultrashort light pulses in the spectral region ranging from infrared to soft X-rays. This includes high-order harmonics generation in gas (HHG), on which relies the CITIUS facility at University of Nova Gorica (Slovenia), and free-electron lasers (FELs), such as the facility FERMI at Elettra-Sincrotrone Trieste (Italy). The distinctive structure of HHG and FEL radiation paved the way to time-resolved experiments, which are performed to investigate events occurring on a short, or very short, temporal scale, from picoseconds to femtoseconds.
This work focuses on the advantages and disadvantages of some experimental techniques based on using these novel light sources to investigate the microscopic and/or ultrafast dynamics of matter samples, which have been previously driven out of equilibrium.
Advantages rely on the implementation of various applications based on two-color schemes and, more specifically, include the possibility of acquiring two-dimensional frequency maps, measuring electrons’ effective masses, or investigating electronic properties decoupled from the influence of the lattice. Particular focus will be put on experimental methods relying on photoelectric effect and photoelectron spectroscopy. In all experiments, we took advantage of one or more specific properties of HHG and FEL sources, such as controllable chirp, to study laser dressed states in helium, variable polarization, to study electronic properties of iron-based pnictides and ultrashort pulses (< 10 fs) to study the purely electronic dynamics in transition metal dichalcogenides.
On the other hand, the study of the interface between a molecule and a topological insulator revealed some intrinsic limitations and physical drawbacks of the technique, such as spurious effects originating from the high power pulses, like multiphoton absorption and the space charge effect, or the reduction of experimental resolution when pushing for shorter and shorter pulse durations. Some disadvantages are also connected to the current state-of-the-art in the field of ultrashort laser systems, where a trade-off needs to be found between repetition rate and laser power.
Finally, state-of-the-art experiments based on the ability to generate ultrashort pulses carrying orbital angular momentum in visible, near-infrared as well as extreme UV range will be presented. The use of these pulses opens the door to the investigation of new physical phenomena, such as probing magnetic vortices using extreme ultraviolet light from a free-electron laser or imprinting the spatial distribution of an ultrashort infrared pulse carrying orbital angular momentum onto a photoelectron wave packet. Ključne besede: ultrafast lasers, two-color experiments, photoemission, high-order harmonic generation, free-electron lasers, hot-electrons dynamics, surface science, pump-probe photoemission, ultraviolet photoemission, orbital angular momentum Objavljeno v RUNG: 02.12.2020; Ogledov: 4700; Prenosov: 136 Celotno besedilo (19,78 MB) |
194. The muon component of extensive air showers above 10[sup]17.5 eV measured with the Pierre Auger ObservatoryFederico Sánchez, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Lili Yang, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2019, objavljeni znanstveni prispevek na konferenci Ključne besede: ultra-high energy cosmic rays, Pierre Auger Observatory, extensive air showers, muon shower component Objavljeno v RUNG: 29.11.2020; Ogledov: 3253; Prenosov: 0 Gradivo ima več datotek! Več... |
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197. A Search for Ultra-high-energy Neutrinos from TXS 0506+056 Using the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2020, izvirni znanstveni članek Ključne besede: ultra-high energy neutrinos, blazar TXS 0506+056, the Pierre Auger Observatory, high-energy astrophysics, neutrino astronomy, blazars, transient sources, active galaxies Objavljeno v RUNG: 20.10.2020; Ogledov: 3572; Prenosov: 0 Gradivo ima več datotek! Več... |
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199. Studies on the response of a water-Cherenkov detector of the Pierre Auger Observatory to atmospheric muons using an RPC hodoscopeA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2020, izvirni znanstveni članek Ključne besede: ultra-high energy cosmic rays, extensive air showers, Pierre Auger Observatory, water Cherenkov detectors, detector calibration, hodoscope-based calibration Objavljeno v RUNG: 11.09.2020; Ogledov: 3721; Prenosov: 117 Celotno besedilo (1,39 MB) |
200. Direct measurement of the muonic content of extensive air showers between 2 × 10[sup]17 and 2 × 10[sup]18 eV at the Pierre Auger ObservatoryA. Aab, Andrej Filipčič, Gašper Kukec Mezek, Samo Stanič, Marta Trini, Serguei Vorobiov, Danilo Zavrtanik, Marko Zavrtanik, Lukas Zehrer, 2020, izvirni znanstveni članek Ključne besede: ultra-high energy cosmic rays (UHECRs), extensive air showers, Pierre Auger Observatory, underground muon detectors, hybrid detection, muonic content in air showers Objavljeno v RUNG: 24.08.2020; Ogledov: 3212; Prenosov: 75 Celotno besedilo (1,41 MB) |