| 1. |
- Johansson, Håkan T, 1977, et al.
(författare)
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GGLAND - command line simulations
- 2014
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Ingår i: GSI Scientific Report 2013. - 0171-4546. ; 2014-1, s. 154-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Giuffrida, L., et al.
(författare)
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Manipulation of laser-accelerated proton beam profiles by nanostructured and microstructured targets
- 2017
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Ingår i: Physical Review Accelerators and Beams. - 2469-9888. ; 20:8, s. 081301-
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Tidskriftsartikel (refereegranskat)abstract
- Nanostructured and microstructured thin foils have been fabricated and used experimentally as targets to manipulate the spatial profile of proton bunches accelerated through the interaction with high intensity laser pulses (6 x 1019 W/cm(2)). Monolayers of polystyrene nanospheres were placed on the rear surfaces of thin plastic targets to improve the spatial homogeneity of the accelerated proton beams. Moreover, thin targets with grating structures of various configurations on their rear sides were used tomodify the proton beam divergence. Experimental results are presented, discussed, and supported by 3D particle-in-cell numerical simulations.
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| 3. |
- Giuffrida, L., et al.
(författare)
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Nano and micro structured targets to modulate the spatial profile of laser driven proton beams
- 2017
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 12:3, s. article no C03040 -
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Tidskriftsartikel (refereegranskat)abstract
- Nano and micro structured thin (μ m-scale) foils were designed, fabricated and irradiated with the high intensity laser system operating at LLC (Lund Laser Centre, Sweden) in order to systematically study and improve the main proton beam parameters. Nano-spheres deposited on the front (laser irradiated) surface of a flat Mylar foil enabled a small enhancement of the maximum energy and number of the accelerated protons. Nano-spheres on the rear side allowed to modify the proton beam spatial profile. In particular, with nanospheres deposited on the rear of the target, the proton beam spatial homogeneity was clearly enhanced. Silicon nitride thin foils having micro grating structures (with different step dimensions) on the rear surface were also used as targets to influence the divergence of the proton beam and drastically change its shape through a sort of stretching effect. The target fabrication process used for the different target types is described, and representative experimental results are shown and discussed along with supporting 3D particle-in-cell simulations. © 2017 IOP Publishing Ltd and Sissa Medialab srl.
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| 4. |
- Magnusson, Joel, 1991
(författare)
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Approaches to particle acceleration in intense laser-matter interaction
- 2018
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the interaction of ultra-intense laser fields with matter, the target is rapidly ionized and a plasma is formed. The ability of a plasma to sustain acceleration gradients, orders of magnitude larger than achievable with conventional accelerators, has led to a great interest in laser-driven plasma-based particle acceleration and radiation generation, with applications in materials science, biology and medicine. In this thesis we consider laser-driven plasma-based particle acceleration by studying the interaction of intense laser fields with solid density targets. The basics of such interactions are described and some of the most common acceleration schemes are presented. We study the effect of adding microstructures on the illuminated side of a solid target and show how this affects the resulting distribution of hot electrons. Furthermore, we discuss how to achieve controllable ion acceleration through displacement of electrons by standing waves. A recently proposed laser-driven ion acceleration scheme, called chirped-standing-wave acceleration, is introduced and described in detail. Finally, we analyze the robustness of this acceleration scheme under non-ideal conditions and discuss its prospects and limitations.
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| 5. |
- Magnusson, Joel, 1991, et al.
(författare)
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Effect of electron-beam energy chirp on signatures of radiation reaction in laser-based experiments
- 2023
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Ingår i: Physical Review Accelerators and Beams. - 2469-9888. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- Current experiments investigating radiation reaction employ high energy electron beams together with tightly focused laser pulses in order to reach the quantum regime, as expressed through the quantum nonlinearity parameter χ. Such experiments are often complicated by the large number of latent variables, including the precise structure of the electron bunch. Here we examine a correlation between the electron spatial and energy distributions, called an energy chirp, investigate its significance to the laser-electron beam interaction and show that the resulting effect cannot be trivially ignored when analyzing current experiments. In particular, we show that the energy chirp has a large effect on the second central moment of the electron energy, but a lesser impact on the first electron energy moment or the photon critical energy. These results show the importance of improved characterization and control over electron bunch parameters on a shot-to-shot basis in such experiments.
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| 6. |
- Magnusson, Joel, 1991, et al.
(författare)
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Energy partitioning and electron momentum distributions in intense laser-solid interactions
- 2017
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6079 .- 1434-6060. ; 71:9
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Tidskriftsartikel (refereegranskat)abstract
- Producing inward orientated streams of energetic electrons by intense laser pulses acting on solid targets is the most robust and accessible way of transferring the laser energy to particles, which underlies numerous applications, ranging from TNSA to laboratory astrophysics. Structures with the scale of the laser wavelength can significantly enhance energy absorption, which has been in the center of attention in recent studies. In this article, we demonstrate and assess the effect of the structures for widening the angular distribution of generated energetic electrons. We analyse the results of PIC simulations and reveal several aspects that can be important for the related applications.
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| 7. |
- Magnusson, Joel, 1991
(författare)
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Intense laser-plasma interactions
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the interaction of ultra-intense laser fields with matter, the target is rapidly ionized and a plasma is formed. The ability of a plasma to sustain acceleration gradients, orders of magnitude larger than achievable with conventional accelerators, has led to a great interest in laser-driven plasma-based particle and radiation sources, with applications in materials science, biology and medicine. In this thesis, two separate, yet highly related, topics are pursued. The first half of the thesis concerns plasma-based techniques for ion acceleration, through the interaction of intense laser fields with solid density targets. In the most accessible acceleration scheme, the ion acceleration is mediated by a population of suprathermal, hot , electrons produced by the rapid heating of the target surface. We study the effect of adding microstructures to the target surface, show how this affects the distribution of hot electrons and discuss its implications for ion acceleration. We further study a novel acceleration scheme, aimed at achieving controllable ion acceleration using a frequency chirped standing wave. We analyse the robustness of this scheme, named chirped-standing-wave acceleration, under non-ideal conditions and discuss its prospects and limitations. The second half of the thesis concerns laser-matter interactions where the emission of high-energy photons necessitates a quantum mechanical description of radiation reaction and enables a prolific production of electron-positron pairs. In this regime, we study the interaction of an energetic electron beam with an optimally focused laser field, in the form of a dipole wave, and highlight its capabilities as a multi-GeV photon source. We further discuss the phenomena observed in this setup, in particular investigating the emergence of pair production cascades, and provide a review of previous results. Finally, we highlight a number of regimes within reach of upcoming laser facilities.
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| 8. |
- Magnusson, Joel, 1991, et al.
(författare)
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Laser-Particle Collider for Multi-GeV Photon Production
- 2019
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 122:25
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Tidskriftsartikel (refereegranskat)abstract
- As an alternative to Compton backscattering and bremsstrahlung, the process of colliding high-energy electron beams with strong laser fields can more efficiently provide both a cleaner and brighter source of photons in the multi-GeV range for fundamental studies in nuclear and quark-gluon physics. In order to favor the emission of high-energy quanta and minimize their decay into electron-positron pairs, the fields must not only be sufficiently strong, but also well localized. We here examine these aspects and develop the concept of a laser-particle collider tailored for high-energy photon generation. We show that the use of multiple colliding laser pulses with 0.4 PW of total power is capable of converting more than 18% of multi-GeV electrons passing through the high-field region into photons, each of which carries more than half of the electron initial energy. © 2019 authors. Published by the American Physical Society.
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| 9. |
- Magnusson, Joel, 1991, et al.
(författare)
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Multiple colliding laser pulses as a basis for studying high-field high-energy physics
- 2019
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Ingår i: Physical Review A - Atomic, Molecular, and Optical Physics. - 2469-9926 .- 2469-9934. ; 100:6
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Tidskriftsartikel (refereegranskat)abstract
- Apart from maximizing the strength of optical electromagnetic fields achievable at high-intensity laser facilities, the collision of several phase-matched laser pulses has been identified theoretically as a trigger of and way to study various phenomena. These range from the basic processes of strong-field quantum electrodynamics to the extraordinary dynamics of the generated electron-positron plasmas. This has paved the way for several experimental proposals aimed at both fundamental studies of matter at extreme conditions and the creation of particle and radiation sources. Because of the unprecedented capabilities of such sources, they have the potential to open up new opportunities for experimental studies in nuclear and quark-gluon physics. We perform here a systematic analysis of different regimes and opportunities achievable with the concept of multiple colliding laser pulses, for both current and upcoming laser facilities. We reveal that several distinct regimes could be within reach of multi-petawatt laser facilities.
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| 10. |
- Magnusson, Joel, 1991, et al.
(författare)
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Prospects for laser-driven ion acceleration through controlled displacement of electrons by standing waves
- 2018
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Ingår i: Physics of Plasmas. - : AIP Publishing. - 1089-7674 .- 1070-664X. ; 25:5
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Tidskriftsartikel (refereegranskat)abstract
- During the interaction of intense femtosecond laser pulses with various targets, the natural mechanisms of laser energy transformation inherently lack temporal control and thus commonly do not provide opportunities for a controlled generation of a well-collimated, high-charge beam of ions with a given energy of particular interest. In an effort to alleviate this problem, it was recently proposed that the ions can be dragged by an electron bunch trapped in a controllably moving potential well formed by laser radiation. Such standing-wave acceleration (SWA) can be achieved through reflection of a chirped laser pulse from a mirror, which has been formulated as the concept of chirped-standing-wave acceleration (CSWA). Here, we analyse general feasibility aspects of the SWA approach and demonstrate its reasonable robustness against field structure imperfections, such as those caused by misalignment, ellipticity, and limited contrast. Using this, we also identify prospects and limitations of the CSWA concept.
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