| 1. |
- Badelek, B, et al.
(författare)
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The photon collider at TESLA
- 2004
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Ingår i: International Journal of Modern Physics A. - 0217-751X. ; 19:30, s. 5097-5186
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Forskningsöversikt (refereegranskat)abstract
- High energy photon colliders (gammagamma,gammae) are based on e(-)e(-) linear colliders where high energy photons are produced using Compton scattering of laser light on high energy electrons just before the interaction point. This paper is a part of the Technical Design Report of the linear collider TESLA.(1) Physics program, possible parameters and some technical aspects of the photon collider at TESLA are discussed.
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| 2. |
- Ter-Avetisyan, S., et al.
(författare)
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Absolute extreme ultraviolet yield from femtosecond-laser-excited Xe clusters
- 2001
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Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - 1063-651X .- 1095-3787. ; 6403:3
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Tidskriftsartikel (refereegranskat)abstract
- Large Xe clusters (10(5)-10(6) atoms per cluster) have been irradiated with ultrashort (50 fs) and high-intensity (similar to2 x 10(18) W/cm(2)) pulses from a Ti:sapphire multi-TW laser at 800 nm wavelength. Scaling and absolute yield measurements of extreme ultraviolet (EUV) emission in a wavelength range between 7 and 15 nm in combination with cluster target characterization have been used for yield optimization. Maximum emission as a function of the backing pressure and a spatial emission anisotropy covering a factor of two at optimized yields is discussed with a simple model of the source geometry and EUV-radiation absorption. Circularly polarized laser light instead of linear polarization results in a factor of 2.5 higher emission in the 11 to 15 nm wavelength range. This indicates the initial influence of optical-field ionization for the interaction parameter range used and contrasts to collisional heating that seems to influence preferentially higher ionization. Absolute emission efficiency at 13.4 nm of up to 0.5% in 2 pi sr and 2.2% bandwidth has been obtained.
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| 3. |
- Legall, H., et al.
(författare)
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Compact X-ray microscope for the water window based on a high brightness laser plasma source
- 2012
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Ingår i: Optics Express. - 1094-4087. ; 20:16, s. 18362-18369
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Tidskriftsartikel (refereegranskat)abstract
- We present a laser plasma based x-ray microscope for the water window employing a high-average power laser system for plasma generation. At 90 W laser power a brightness of 7.4 x 10(11) photons/(s x sr x mu m(2)) was measured for the nitrogen Ly alpha line emission at 2.478 nm. Using a multilayer condenser mirror with 0.3 % reflectivity 10(6) photons/(mu m(2) x s) were obtained in the object plane. Microscopy performed at a laser power of 60 W resolves 40 nm lines with an exposure time of 60 s. The exposure time can be further reduced to 20 s by the use of new multilayer condenser optics and operating the laser at its full power of 130 W.
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| 4. |
- Schnurer, M., et al.
(författare)
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Influence of laser pulse width on absolute EUV-yield from Xe-clusters
- 2001
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Ingår i: European Physical Journal D. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 14:3, s. 331-335
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Tidskriftsartikel (refereegranskat)abstract
- Using 50 fs (similar to 2 x 10(18) W/cm(2)) and 2 ps (similar to 5 x 10(16) W/cm(2)) pulses from a Ti:Sa multi-TW laser at 800 nm wavelength large Xe-clusters (10(5)...10(6) atoms per cluster) have been excited. Absolute yield measurements of EUV-emission in a wavelength range between 10 nm and 15 nm in combination with cluster target variation were carried out. The ps-laser pulse has resulted in about 30% enhanced and spatially more uniform EUV-emission compared to fs-laser excitation. Circularly polarized laser light instead of linear polarization results in enhanced emission which is probably caused by electrons gaining higher energies by the polarization dependent optical field ionization process. An absolute emission efficiency at 13.4 nm of up to 0.8% in 2 pi sr and 2.2% bandwidth has been obtained.
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| 5. |
- Antel, C., et al.
(författare)
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Feebly-interacting particles : FIPs 2022 Workshop Report
- 2023
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Ingår i: European Physical Journal C. - : Springer. - 1434-6044 .- 1434-6052. ; 83:12
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Forskningsöversikt (refereegranskat)abstract
- Particle physics today faces the challenge of explaining the mystery of dark matter, the origin of matter over anti-matter in the Universe, the origin of the neutrino masses, the apparent fine-tuning of the electro-weak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves new physics at mass scales comparable to familiar matter, below the GeV-scale, or even radically below, down to sub-eV scales, and with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and indeed, existing data provide numerous hints for such possibility. A vibrant experimental program to discover such physics is under way, guided by a systematic theoretical approach firmly grounded on the underlying principles of the Standard Model. This document represents the report of the FIPs 2022 workshop, held at CERN between the 17 and 21 October 2022 and aims to give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs.
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| 6. |
- Beck, M., et al.
(författare)
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A pulse-train laser driven XUV source for picosecond pump-probe experiments in the water window
- 2001
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Ingår i: Optics Communications. - 0030-4018 .- 1873-0310. ; 190:06-jan, s. 317-326
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Tidskriftsartikel (refereegranskat)abstract
- We describe the development of a table top soft X-ray source based on a laser produced plasma. The plasma is produced by a Nd:YLF pulse-train laser which delivers pulse trains of up to 400 pulses each of about 25 ps duration, Number and energy of the micropulses are fully computer controlled adjustable for an optimum interaction with a rotating solid target. Spectral, spatial and temporal characteristics of the X-ray emission from Mylar and copper targets have been studied. A calibrated back-illuminated CCD camera together with a slit grating spectrograph were utilized for the measurement of the absolute soft X-ray photon fluxes. The temporal measurements were performed using a streak camera while the plasma size was measured with a zone plate. An application of the system in a X-ray absorption experiment is shown, The advantages of the system in view of possible optical pump and soft X-ray probe experiments will be discussed.
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| 7. |
- Busch, S., et al.
(författare)
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Ion acceleration with ultrafast lasers
- 2003
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 82:19, s. 3354-3356
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Tidskriftsartikel (refereegranskat)abstract
- Hot-electron confinement can build up fields capable of accelerating ions up to MeV energies when an ultrashort 35-fs laser pulse at similar to2x10(18) W/cm(2) interacts with a small spherical target. Singly charged ions with different masses have similar energies. A simple phenomenological model describes how ultrashort and less-energy-consumptive pulses drive ions to MeV energies. The energetic and spatial-emission characteristics of protons, deuterons and oxygen ions released from water and heavy-water droplets of similar to15 mum in size was determined for this interaction scenario.
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| 8. |
- Gaudino, Mario, et al.
(författare)
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Outcomes by sex in the International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) trial.
- 2024
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Ingår i: EuroIntervention : journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology. - 1969-6213.
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Tidskriftsartikel (refereegranskat)abstract
- In the International Study of Comparative Health Effectiveness With Medical and Invasive Approaches (ISCHEMIA) trial, among participants with stable coronary artery disease, the risk of cardiac events was similar between an invasive (INV) strategy of angiography and coronary revascularisation and a conservative (CON) strategy of initial medical therapy alone. Outcomes according to participant sex were not reported.We aimed to analyse the outcomes of ISCHEMIA by participant sex.We evaluated 1) the association between participant sex and the likelihood of undergoing revascularisation for participants randomised to the INV arm; 2) the risk of the ISCHEMIA primary composite outcome (cardiovascular death, any myocardial infarction [MI] or rehospitalisation for unstable angina, heart failure or resuscitated cardiac arrest) by participant sex; and 3) the contribution of the individual primary outcome components to the composite outcome by participant sex.Of 5,179 randomised participants, 1,168 (22.6%) were women. Female sex was independently associated with a lower likelihood of revascularisation when assigned to the INV arm (adjusted odds ratio 0.75, 95% confidence interval [CI]: 0.57-0.99; p=0.04). The INV versus CON effect on the primary composite outcome was similar between sexes (women: hazard ratio [HR] 0.96, 95% CI: 0.70-1.33; men: HR 0.90, 95% CI: 0.76-1.07; pinteraction=0.71). The contribution of the individual components to the composite outcome was similar between sexes except for procedural MI, which was significantly lower in women (9/151 [5.9%]) than men (67/519 [12.9%]; p=0.01).In ISCHEMIA, women assigned to the INV arm were less likely to undergo revascularisation than men. The effect of an INV versus CON strategy was consistent by sex, but women had a significantly lower contribution of procedural MI to the primary outcome.
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| 9. |
- Ludewig, Kristin, et al.
(författare)
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Phenology and morphology of the invasive legume Lupinus polyphyllus along a latitudinal gradient in Europe
- 2022
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Ingår i: NeoBiota. - : Pensoft Publishers. - 1619-0033 .- 1314-2488. ; 78
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Tidskriftsartikel (refereegranskat)abstract
- Plant phenology, i. e. the timing of life cycle events, is related to individual fitness and species distributionranges. Temperature is one of the most important drivers of plant phenology together with day length.The adaptation of their phenology may be important for the success of invasive plant species. The presentstudy aims at understanding how the performance and the phenology of the invasive legume Lupinuspolyphyllus vary with latitude. We sampled data across a >2000 km latitudinal gradient from Centralto Northern Europe. We quantified variation in phenology of flowering and fruiting of L. polyphyllususing >1600 digital photos of inflorescences from 220 individual plants observed weekly at 22 sites. Theday of the year at which different phenological phases were reached, increased 1.3–1.8 days per degreelatitude, whereas the growing degree days (gdd) required for these phenological phases decreased 5–16 gddper degree latitude. However, this difference disappeared, when the day length of each day included inthe calculation of gdd was considered. The day of the year of the earliest and the latest climatic zone toreach any of the three studied phenological phases differed by 23–30 days and temperature requirementsto reach these stages differed between 62 and 236 gdd. Probably, the invasion of this species will furtherincrease in the northern part of Europe over the next decades due to climate warming. For invasive speciescontrol, our results suggest that in countries with a large latitudinal extent, the mowing date should shiftby ca. one week per 500 km at sites with similar elevations.
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| 10. |
- Ludewig, Kristin, et al.
(författare)
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Phenology of Lupinus polyphyllus from Central to Northern Europe
- 2022
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Annan publikationabstract
- Plant phenology, i. e. the timing of life cycle events, is related to individual fitness and species distribution ranges. Among the environmental factors, phenology is mostly driven by temperature and day length. Rapid adaptation of their phenology may also be important for the success of invasive plant species. Our main aim was to understand how the performance, timing, and temperature dependence of the phenology of the invasive legume Lupinus polyphyllus varies with latitude. L. polyphyllus is one of the most frequent invasive species in Europe, and the gained information may help to make management more effective by adjustments to latitude and phenology.Methods:We quantified variation in phenology across a >2000 km latitudinal gradient from Central to Northern Europe. We sampled data of flowering and fruiting of L. polyphyllus using >1600 digital photos of inflorescences from 220 individual plants observed weekly at 22 locations. We calculated the accumulated growing degree days for each observation date at each site from the temperature data of the meteorological stations, which are listed in the metadata of the dataset.
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