| 1. |
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| 2. |
- Major, B., et al.
(författare)
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Investigation of high harmonic generation using a high-power, 5-fs laser in a loose-focusing geometry
- 2017
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Ingår i: 2017 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). - : IEEE. - 9781509067367
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Konferensbidrag (refereegranskat)abstract
- Summary form only given. Since its first observation almost three decades ago high-order harmonic generation (HHG) in gases became a reliable source of extreme ultraviolet (XUV) pulses, which gave the possibility to study electronic processes on their natural timescale [1, 2]. While the main building blocks of the experimental setups for gas HHG are the same in almost all cases, the focusing or medium geometry varies from realization to realization based on, for example, the available laser power [3, 4].In this work we study HHG in a loose focusing geometry by focusing a ~50-mm diameter (FWHM) beam with a mirror of 16-m focal length (f-number ~320). The main subject of this analysis is to compare low pressure - long interaction length (few millibars and tens of centimeters) with high pressure - short medium (hundreds of millibars and a few millimeters) scenarios and understand the underlying reasons for the observed XUV radiation parameters. The experiments are carried out with on target 35 mJ, sub-5 fs, 740 nm central wavelength pulses provided by an optical parametric synthesizer [5], producing high-energy pulses at the 100 eV spectral region [6]. The theoretical analysis is performed by simulation code based on a three-dimensional nonadiabatic model [7,8]. The good agreement between the experimental and simulation data (see Fig. 1) allows us to use the theoretical findings to gain better insight on the exact phase-matching processes providing the observed features. This detailed description is used to draw general conclusions of the high-harmonic generation process.
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| 3. |
- Arnold, C. L., et al.
(författare)
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Energy scaling of gas nonlinear optics
- 2017
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Ingår i: 30th Annual Conference of the IEEE Photonics Society, IPC 2017. - 9781509065783 ; 2017-January, s. 503-504
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Konferensbidrag (refereegranskat)abstract
- Nonlinear light-matter interactions, such as filamentation or high-order harmonic generation, are at the heart of nonlinear optics. Scaling of such effects is crucial to benefit optimally from novel laser developments. We introduce and discuss a general scaling model for nonlinear light-matter interactions in gases.
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| 4. |
- Coccolini, Federico, et al.
(författare)
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Pelvic trauma : WSES classification and guidelines
- 2017
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Ingår i: World Journal of Emergency Surgery. - London, United Kingdom : BioMed Central (BMC). - 1749-7922. ; 12:5
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Tidskriftsartikel (refereegranskat)abstract
- Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.
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| 5. |
- Di Saverio, Salomone, et al.
(författare)
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WSES Jerusalem guidelines for diagnosis and treatment of acute appendicitis
- 2016
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Ingår i: World Journal of Emergency Surgery. - : BIOMED CENTRAL LTD. - 1749-7922. ; 11:34
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Forskningsöversikt (refereegranskat)abstract
- Acute appendicitis (AA) is among the most common cause of acute abdominal pain. Diagnosis of AA is challenging; a variable combination of clinical signs and symptoms has been used together with laboratory findings in several scoring systems proposed for suggesting the probability of AA and the possible subsequent management pathway. The role of imaging in the diagnosis of AA is still debated, with variable use of US, CT and MRI in different settings worldwide. Up to date, comprehensive clinical guidelines for diagnosis and management of AA have never been issued. In July 2015, during the 3rd World Congress of the WSES, held in Jerusalem (Israel), a panel of experts including an Organizational Committee and Scientific Committee and Scientific Secretariat, participated to a Consensus Conference where eight panelists presented a number of statements developed for each of the eight main questions about diagnosis and management of AA. The statements were then voted, eventually modified and finally approved by the participants to The Consensus Conference and lately by the board of co-authors. The current paper is reporting the definitive Guidelines Statements on each of the following topics: 1) Diagnostic efficiency of clinical scoring systems, 2) Role of Imaging, 3) Non-operative treatment for uncomplicated appendicitis, 4) Timing of appendectomy and in-hospital delay, 5) Surgical treatment 6) Scoring systems for intra-operative grading of appendicitis and their clinical usefulness 7) Non-surgical treatment for complicated appendicitis: abscess or phlegmon 8) Pre-operative and post-operative antibiotics.
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| 6. |
- Heyl, C. M., et al.
(författare)
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High-average power high-harmonic and attosecond sources : Status and prospects
- 2016
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Ingår i: Compact EUV and X-ray Light Sources, EUVXRAY 2016. - 9781943580095 ; Part F14-EUVXRAY 2016
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Konferensbidrag (refereegranskat)abstract
- Experiments employing extreme ultraviolet sources based on high harmonic generation often suffer from photon flux limitations. We discuss current status and prospects for scaling such sources to higher repetition rate, pulse energy and average power.
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| 7. |
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| 8. |
- Heyl, C. M., et al.
(författare)
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Scale-invariant nonlinear optical effects in gases
- 2016
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Ingår i: 2016 Conference on Lasers and Electro-Optics, CLEO 2016. - 9781943580118
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Konferensbidrag (refereegranskat)abstract
- A general scaling formalism for nonlinear light-matter interactions in gases is presented and experimentally verified. The formalism enables to conveniently extrapolate nonlinear phenomena, such as filamentation or high-order harmonic generation, to new laser parameters.
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| 9. |
- Heyl, C. M., et al.
(författare)
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Scale-invariant nonlinear optics in gases
- 2016
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Ingår i: Optica. - 2334-2536. ; 3:1, s. 75-81
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear optical methods have become ubiquitous in many scientific areas, from fundamental studies of timeresolved electron dynamics to microscopy and spectroscopy applications. They are, however, often limited to a certain range of parameters such as pulse energy and average power. Restrictions arise from, for example, the required field intensity as well as from parasitic nonlinear effects and saturation mechanisms. Here, we identify a fundamental principle of nonlinear light-matter interaction in gases and show that paraxial nonlinear wave equations are scaleinvariant if spatial dimensions, gas density, and laser pulse energy are scaled appropriately. As an example, we apply this principle to high-order harmonic generation and provide a general method for increasing peak and average power of attosecond sources. In addition, we experimentally demonstrate the implications for the compression of short laser pulses. Our scaling principle extends well beyond those examples and includes many nonlinear processes with applications in different areas of science.
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| 10. |
- Heyl, C. M., et al.
(författare)
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Scaling Nonlinear Optics in Gases
- 2016
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Ingår i: High Intensity Lasers and High Field Phenomena, HILAS 2016. - 9781943580095 ; Part F15-HILAS 2016
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Konferensbidrag (refereegranskat)abstract
- Extrapolating nonlinear phenomena, such as filamentation, to new parameters as e.g. to higher pulse energy is often challenging. We here present a general scaling model for nonlinear light-matter interactions in gases and proof it experimentally.
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| 11. |
- Kovács, K, et al.
(författare)
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Multi-parameter optimization of a loose focusing high flux high-harmonic beamline
- 2019
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 52:5, s. 055402-055402
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Tidskriftsartikel (refereegranskat)abstract
- We perform a multi-dimensional parameter scan in the generation of high-order harmonics, with the main purpose to find the macroscopic conditions that optimize the harmonic yield in a specific spectral domain, around 40 eV for this particular case. The scanned parameters are the laser pulse energy, gas pressure, interaction cell position relative to focus and the cell length, while the fixed parameters are chosen to model a loose focusing configuration which is used in many existing laboratories. We performed the simulations with a 3D non-adiabatic model complemented by a detailed analysis of the phase matching mechanisms involved in an efficient harmonic generation. Based on the results we identify a range of parameter combinations that lead to a high yield in the specified spectral domain. The method and results presented here can be the framework for the design and construction of high flux high-order harmonic generation beamlines.
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| 12. |
- Major, B., et al.
(författare)
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Macroscopic Optimization of High Harmonic Generation for High Power Laser Pulses
- 2016
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Ingår i: High Intensity Lasers and High Field Phenomena, HILAS 2016. - 9781943580095 ; Part F15-HILAS 2016
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Konferensbidrag (refereegranskat)abstract
- We study upscaling of gas high harmonic generation, to make efficient use of the ever increasing laser pulse powers. Loose focusing geometries optimizing phasematching are investigated and compared in HHG efficiency to shorter focusing arrangements.
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| 13. |
- Picetti, Edoardo, et al.
(författare)
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WSES consensus conference guidelines: monitoring and management of severe adult traumatic brain injury patients with polytrauma in the first 24 hours
- 2019
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Ingår i: World Journal of Emergency Surgery. - : BioMed Central (BMC). - 1749-7922. ; 14:1
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Forskningsöversikt (refereegranskat)abstract
- The acute phase management of patients with severe traumatic brain injury (TBI) and polytrauma represents a major challenge. Guidelines for the care of these complex patients are lacking, and worldwide variability in clinical practice has been documented in recent studies. Consequently, the World Society of Emergency Surgery (WSES) decided to organize an international consensus conference regarding the monitoring and management of severe adult TBI polytrauma patients during the first 24 hours after injury. A modified Delphi approach was adopted, with an agreement cut-off of 70%. Forty experts in this field (emergency surgeons, neurosurgeons, and intensivists) participated in the online consensus process. Sixteen recommendations were generated, with the aim of promoting rational care in this difficult setting.
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| 14. |
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