| 1. |
- Aamodt, K., et al.
(författare)
-
The ALICE experiment at the CERN LHC
- 2008
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Ingår i: Journal of Instrumentation. - 1748-0221. ; 3:S08002
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Forskningsöversikt (refereegranskat)abstract
- ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
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| 2. |
- Abel, I, et al.
(författare)
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Overview of the JET results with the ITER-like wall
- 2013
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 53:10, s. 104002-
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Tidskriftsartikel (refereegranskat)abstract
- Following the completion in May 2011 of the shutdown for the installation of the beryllium wall and the tungsten divertor, the first set of JET campaigns have addressed the investigation of the retention properties and the development of operational scenarios with the new plasma-facing materials. The large reduction in the carbon content (more than a factor ten) led to a much lower Z(eff) (1.2-1.4) during L- and H-mode plasmas, and radiation during the burn-through phase of the plasma initiation with the consequence that breakdown failures are almost absent. Gas balance experiments have shown that the fuel retention rate with the new wall is substantially reduced with respect to the C wall. The re-establishment of the baseline H-mode and hybrid scenarios compatible with the new wall has required an optimization of the control of metallic impurity sources and heat loads. Stable type-I ELMy H-mode regimes with H-98,H-y2 close to 1 and beta(N) similar to 1.6 have been achieved using gas injection. ELM frequency is a key factor for the control of the metallic impurity accumulation. Pedestal temperatures tend to be lower with the new wall, leading to reduced confinement, but nitrogen seeding restores high pedestal temperatures and confinement. Compared with the carbon wall, major disruptions with the new wall show a lower radiated power and a slower current quench. The higher heat loads on Be wall plasma-facing components due to lower radiation made the routine use of massive gas injection for disruption mitigation essential.
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| 3. |
- Romanelli, F, et al.
(författare)
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Overview of the JET results
- 2011
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Ingår i: Nuclear Fusion. - : IOP Publishing. - 1741-4326 .- 0029-5515. ; 51:9
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Tidskriftsartikel (refereegranskat)abstract
- Since the last IAEA Conference JET has been in operation for one year with a programmatic focus on the qualification of ITER operating scenarios, the consolidation of ITER design choices and preparation for plasma operation with the ITER-like wall presently being installed in JET. Good progress has been achieved, including stationary ELMy H-mode operation at 4.5 MA. The high confinement hybrid scenario has been extended to high triangularity, lower ρ*and to pulse lengths comparable to the resistive time. The steady-state scenario has also been extended to lower ρ*and ν*and optimized to simultaneously achieve, under stationary conditions, ITER-like values of all other relevant normalized parameters. A dedicated helium campaign has allowed key aspects of plasma control and H-mode operation for the ITER non-activated phase to be evaluated. Effective sawtooth control by fast ions has been demonstrated with3He minority ICRH, a scenario with negligible minority current drive. Edge localized mode (ELM) control studies using external n = 1 and n = 2 perturbation fields have found a resonance effect in ELM frequency for specific q95values. Complete ELM suppression has, however, not been observed, even with an edge Chirikov parameter larger than 1. Pellet ELM pacing has been demonstrated and the minimum pellet size needed to trigger an ELM has been estimated. For both natural and mitigated ELMs a broadening of the divertor ELM-wetted area with increasing ELM size has been found. In disruption studies with massive gas injection up to 50% of the thermal energy could be radiated before, and 20% during, the thermal quench. Halo currents could be reduced by 60% and, using argon/deuterium and neon/deuterium gas mixtures, runaway electron generation could be avoided. Most objectives of the ITER-like ICRH antenna have been demonstrated; matching with closely packed straps, ELM resilience, scattering matrix arc detection and operation at high power density (6.2 MW m-2) and antenna strap voltages (42 kV). Coupling measurements are in very good agreement with TOPICA modelling. © 2011 IAEA, Vienna.
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| 4. |
- Abdellaoui, G., et al.
(författare)
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First observations of speed of light tracks by a fluorescence detector looking down on the atmosphere
- 2018
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25(th) of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.
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| 5. |
- Abdellaoui, G., et al.
(författare)
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Meteor studies in the framework of the JEM-EUSO program
- 2017
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Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 143, s. 245-255
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Tidskriftsartikel (refereegranskat)abstract
- We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
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| 6. |
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| 7. |
- Bisconti, F, et al.
(författare)
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Mini-EUSO engineering model : Tests in open-sky condition
- 2019
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Ingår i: 36th International Cosmic Ray Conference, ICRC 2019. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- Mini-EUSO is a UV telescope that will look downwards to the Earth’s atmosphere onboard the International Space Station. With the design of the ultra-high energy cosmic ray fluorescence detectors belonging to the JEM-EUSO program, it will make the first UV map of the Earth by observing atmospheric phenomena such as transient luminous events, sprites and lightning, as well as meteors and bioluminescence from earth. Diffused light from laser shots from the ground, which mimic the fluorescence light emitted by Nitrogen molecules when extensive air showers pass through the atmosphere, can be used to verify the capability of this kind of detector to observe ultra-high energy cosmic rays. To validate the electronics and the trigger algorithms developed for Mini-EUSO, a scaled down version of the telescope with 1:9 of the original focal surface and a lens of 2.5 cm diameter has been built. Tests of the Mini-EUSO engineering model have been made in laboratory and in open sky condition. In this paper, we report results of observations of the night sky, which include the detection of stars, meteors, a planet and a rocket body reflecting the sunlight. Interesting results of the observation of city lights are also reported.
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| 8. |
- Casolino, M, et al.
(författare)
-
Mini-EUSO experiment to study UV emission of terrestrial and astrophysical origin onboard of the International Space Station
- 2019
-
Ingår i: 36th International Cosmic Ray Conference, ICRC 2019. - : Sissa Medialab Srl.
-
Konferensbidrag (refereegranskat)abstract
- Mini-EUSO will observe the Earth in the UV range (300 - 400 nm) offering the opportunity to study a variety of atmospheric events such as Transient Luminous Events (TLEs), meteors and marine bioluminescence. Furthermore it aims to search for Ultra High Energy Cosmic Rays (UHECR) above 1021 eV and Strange Quark Matter (SQM). The detector is expected to be launched to the International Space Station in August 2019 and look at the Earth in nadir mode from the UV-transparent window of the Zvezda module of the International Space Station. The instrument comprises a compact telescope with a large field of view (44?), based on an optical system employing two Fresnel lenses for light collection. The light is focused onto an array of 36 multi-anode photomultiplier tubes (MAPMT), for a total of 2304 pixels and the resulting signal is converted into digital, processed and stored via the electronics subsystems on-board. In addition to the main detector, Mini-EUSO contains two ancillary cameras[4] for complementary measurements in the near infrared (1500 - 1600 nm) and visible (400 - 780 nm) range and also a 8 × 8 SiPM imaging array.
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| 9. |
- Fraerman, A. A., et al.
(författare)
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Magnetic force microscopy of helical states in multilayer nanomagnets
- 2008
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 103:7, s. 073916-
-
Tidskriftsartikel (refereegranskat)abstract
- We have used magnetic force microscopy (MFM) to investigate noncollinear helical states in multilayer nanomagnets, consisting of a stack of single domain ferromagnetic disks separated by insulating nonmagnetic spacers. The nanomagnets were fabricated from a [Co/Si]x3 multilayer thin film structure by electron beam lithography and ion beam etching. The structural parameters (Co layer and spacer thicknesses) were optimized to obtain a clear spiral signature in the MFM contrast, taking into account the magnetostatic interaction between the layers. MFM contrast corresponding to the helical states with different helicities was observed for the optimized structure with Co layer thicknesses of 16, 11, and 8 nm, and with 3 nm Si spacer thickness.
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| 10. |
- Fraerman, A. A., et al.
(författare)
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Magnetic force microscopy to determine vorticity direction in elliptical Co nanoparticles
- 2004
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Ingår i: Physics of low-Dimensional structures. - 0204-3467. ; 1-2, s. 35-40
-
Tidskriftsartikel (refereegranskat)abstract
- We present a magnetic force microscopy investigation into the magnetic properties of arrays of Co nanoparticles fabricated by electron be am lithography. Vorticity directions are determined in zero applied magnetic fields. Experimental dependence of height on stable magnetic states of the particles is investigated. The statistics of the vorticity direction distribution is discussed.
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| 11. |
- Miyamoto, H, et al.
(författare)
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Space debris detection and tracking with the techniques of cosmic ray physics
- 2019
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Ingår i: 36th International Cosmic Ray Conference, ICRC 2019. - : Sissa Medialab Srl.
-
Konferensbidrag (refereegranskat)abstract
- Space Debris (SD) consist of non-operational artificial objects orbiting around the Earth, which could possibly damage space vehicles, such as the International Space Station (ISS) or other manned spacecrafts. The vast majority of such objects are cm-sized, not catalogued and usually the tracking data are not precise enough. Here we present the feasibility study of SD detection and tracking with techniques usually employed in cosmic-ray physics. For this purpose, we have evaluated the possibility of using Mini-EUSO, a space-borne fluorescence telescope to be deployed on the ISS, to track SD illuminated by the Sun. By means of ESAF (EUSO Simulation and analysis Framework) simulation and by developing the trigger algorithms, we estimated the minimum size and maximum distances of detectable SD. We then studied the number of possible SD detections using an ESA software called MASTER (Meteoroid and SD Terrestrial Environment Reference). With the Mini-EUSO Engineering Model (Mini-EUSO EM), we performed some measurements to estimate the reflectance of the most common SD materials and to demonstrate the ability of Mini-EUSO to detect SD events. We also performed some tests in open-sky conditions, identifying and tracking fast-moving objects. In particular, the detection of a rocket body allowed us to confirm the simulation outcomes predictions and the expected performance of the detector.
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| 12. |
- Miyamoto, H., et al.
(författare)
-
The Euso@turlab : Test of mini-EUSO engineering model
- 2019
-
Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
-
Konferensbidrag (refereegranskat)abstract
- The TurLab facility is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located in the Physics Department of the University of Turin. Originally, it was mainly built to study systems of different scales where rotation plays a key role in the fluid behavior such as in atmospheric and oceanic flows. In the past few years the TurLab facility has been used to perform experiments related to the observation of Extreme Energy Cosmic Rays (EECRs) from space using the fluorescence technique. For example, in the case of the JEM-EUSO mission, where the diffuse night brightness and artificial light sources can vary significantly in time and space inside the Field of View of the telescope. The Focal Surface of Mini-EUSO Engineering Model (Mini-EUSO EM) with the level 1 (L1) and 2 (L2) trigger logics implemented in the Photo-Detector Module (PDM) has been tested at TurLab. Tests related to the possibility of using an EUSO-like detector for other type of applications such as Space Debris (SD) monitoring and imaging detector have also been pursued. The tests and results obtained within the EUSO@TurLab Project on these different topics are presented.
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| 13. |
- Savin, S., et al.
(författare)
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High energy jets in the Earth's magnetosheath : Implications for plasma dynamics and anomalous transport
- 2008
-
Ingår i: JETP Letters. - 0021-3640 .- 1090-6487. ; 87:11, s. 593-599
-
Tidskriftsartikel (refereegranskat)abstract
- High energy density Jets in the magnetosheath near the Earth magnetopause were observed by Interball-1 [1]. In this paper, we continue the investigation of this important physical phenomenon. New data provided by Cluster show that the magnetosheath kinetic energy density during more than one hour exhibits an average level and a series of peaks far exceeding the kinetic energy density in the undisturbed solar wind. This is a surprising finding because the kinetic energy of the upstream solar wind in equilibrium should be significantly diminished downstream in the magnetosheath due to plasma braking and thermalization at the bow shock. We suggest resolving the energy conservation problem by the fact that the nonequilibrium Jets appear to be locally superimposed on the background equilibrium magnetosheath, and, thus, the energy balance should be settled globally on the spatial scales of the entire dayside magnetosheath. We show that both the Cluster and Interball jets are accompanied by plasma superdiffusion and suggest that they are important for the energy dissipation and plasma transport. The character of the Jet-related turbulence strongly differs From that of known standard cascade models. We infer that these Jets may represent the phenomenon of the general physical occurrence observed in other natural systems, such as heliosphere, astrophysical, and fusion plasmas [2-10].
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| 14. |
- Barrillon, P., et al.
(författare)
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The EUSO@TurLab project in the framework of the JEM-EUSO program
- 2023
-
Ingår i: Experimental astronomy. - : Springer Nature. - 0922-6435 .- 1572-9508. ; 55:2, s. 569-602
-
Tidskriftsartikel (refereegranskat)abstract
- The EUSO@TurLab project aims at performing experiments to reproduce Earth UV emissions as seen from a low Earth orbit by the planned missions of the JEM-EUSO program. It makes use of the TurLab facility, which is a laboratory, equipped with a 5 m diameter and 1 m depth rotating tank, located at the Physics Department of the University of Turin. All the experiments are designed and performed based on simulations of the expected response of the detectors to be flown in space. In April 2016 the TUS detector and more recently in October 2019 the Mini-EUSO experiment, both part of the JEM-EUSO program, have been placed in orbit to map the UV Earth emissions. It is, therefore, now possible to compare the replicas performed at TurLab with the actual images detected in space to understand the level of fidelity in terms of reproduction of the expected signals. We show that the laboratory tests reproduce at the order of magnitude level the measurements from space in terms of spatial extension and time duration of the emitted UV light, as well as the intensity in terms of expected counts per pixel per unit time when atmospheric transient events, diffuse nightlow background light, and artificial light sources are considered. Therefore, TurLab is found to be a very useful facility for testing the acquisition logic of the detectors of the present and future missions of the JEM-EUSO program and beyond in order to reproduce atmospheric signals in the laboratory.
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| 15. |
- Björk, Gunnar, et al.
(författare)
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Central-moment description of polarization for quantum states of light
- 2012
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 85:5, s. 053835-
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Tidskriftsartikel (refereegranskat)abstract
- We present a moment expansion for the systematic characterization of the polarization properties of quantum states of light. Specifically, we link the method to the measurements of the Stokes operator in different directions on the Poincare sphere and provide a scheme for polarization tomography without resorting to full-state tomography. We apply these ideas to the experimental first-and second-order polarization characterization of some two-photon quantum states. In addition, we show that there are classes of states whose polarization characteristics are dominated not by their first-order moments (i.e., the Stokes vector) but by higher-order polarization moments.
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| 16. |
- Gustafsson, Georg, et al.
(författare)
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First results of electric field and density observations by Cluster EFW based on initial months of operation
- 2001
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Ingår i: Annales Geophysicae. - : Copernicus GmbH. - 0992-7689 .- 1432-0576. ; 19:12-okt, s. 1219-1240
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Tidskriftsartikel (refereegranskat)abstract
- Highlights are presented from studies of the electric field data from various regions along the CLUSTER orbit. They all point towards a very high coherence for phenomena recorded on four spacecraft that are separated by a few hundred kilometers for structures over the whole range of apparent frequencies from I mHz to 9 kHz. This presents completely new opportunities to study spatial-temporal plasma phenomena from the magnetosphere out to the solar wind. A new probe environment was constructed for the CLUSTER electric field experiment that now produces data of unprecedented quality. Determination of plasma flow in the solar wind is an example of the capability of the instrument.
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| 17. |
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| 18. |
- Shitov, A V, et al.
(författare)
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A carbonic anhydrase inhibitor induces bicarbonate-reversible suppression of electron transfer in pea photosystem 2 membrane fragments
- 2011
-
Ingår i: Journal of Photochemistry and Photobiology. B. - : Elsevier. - 1011-1344 .- 1873-2682. ; 104:1-2, s. 366-371
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Tidskriftsartikel (refereegranskat)abstract
- The effects of suppression of the carbonic anhydrase (CA) activity by a CA-inhibitor, acetazolamide (AA), on the photosynthetic activities of photosystem II (PS II) particles from higher plants were investigated. AA along with CA-activity inhibits the PS II photosynthetic electron transfer and the AA-induced suppression is totally reversed by the addition of bicarbonate (3-5 mM). Similar effect of recovery in the PS II photosynthetic activity was also revealed upon the addition of known artificial electron donors (potassium ferrocyanide and TMPD). Significance and possible functions of CA for the PS II donor side are discussed.
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| 19. |
- Zabelina, Svetlana A., et al.
(författare)
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Carbon emission from thermokarst lakes in NE European tundra
- 2021
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Ingår i: Limnology and Oceanography. - : John Wiley & Sons. - 0024-3590 .- 1939-5590. ; 66:S1, s. S216-S230
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Tidskriftsartikel (refereegranskat)abstract
- Emission of greenhouse gases (GHGs) from inland waters is recognized as highly important and an understudied part of the terrestrial carbon (C) biogeochemical cycle. These emissions are still poorly quantified in subarctic regions that contain vast amounts of surface C in permafrost peatlands. This is especially true in NE European peatlands, located within sporadic to discontinuous permafrost zones which are highly vulnerable to thaw. Initial measurements of C emissions from lentic waters of the Bolshezemelskaya Tundra (BZT; 200,000 km2) demonstrated sizable CO2 and CH4 concentrations and fluxes to the atmosphere in 98 depressions, thaw ponds, and thermokarst lakes ranging from 0.5 × 106 to 5 × 106 m2 in size. CO2 fluxes decreased by an order of magnitude as waterbody size increased by > 3 orders of magnitude while CH4 fluxes showed large variability unrelated to lake size. By using a combination of Landsat‐8 and GeoEye‐1 images, we determined lakes cover 4% of BZT and thus calculated overall C emissions from lentic waters to be 3.8 ± 0.65 Tg C yr−1 (99% C‐CO2, 1% C‐CH4), which is two times higher than the lateral riverine export. Large lakes dominated GHG emissions whereas small thaw ponds had a minor contribution to overall water surface area and GHG emissions. These data suggest that, if permafrost thaw in NE Europe results in disappearance of large thermokarst lakes and formation of new small thaw ponds and depressions, GHG emissions from lentic waters in this region may decrease.
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| 20. |
- Bisconti, F., et al.
(författare)
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Pre-flight qualification tests of the Mini-EUSO telescope engineering model
- 2022
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Ingår i: Experimental astronomy. - : Springer Nature. - 0922-6435 .- 1572-9508. ; 53:1, s. 133-158
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Tidskriftsartikel (refereegranskat)abstract
- Mini-EUSO is part of the JEM-EUSO program and operates on board the International Space Station (ISS). It is a UV-telescope with single-photon counting capability looking at nighttime downwards to the Earth through a nadir-facing UV-transparent window. As part of the pre-flight tests, the Mini-EUSO engineering model, a telescope with 1/9 of the original focal surface and a lens of 2.5 cm diameter, has been built and tested. Tests of the Mini-EUSO engineering model have been made in laboratory and in open-sky conditions. Laboratory tests have been performed at the TurLab facility, located at the Physics Department of the University of Turin, equipped with a rotating tank containing different types of materials and light sources. In this way, the configuration for the observation of the Earth from space was emulated, including the Mini-EUSO trigger schemes. In addition to the qualification and calibration tests, the Mini-EUSO engineering model has also been used to evaluate the possibility of using a JEM-EUSO-type detector for applications such as observation of space debris. Furthermore, observations in open-sky conditions allowed the studies of natural light sources such as stars, meteors, planets, and artificial light sources such as airplanes, satellites reflecting the sunlight, and city lights. Most of these targets could be detected also with Mini-EUSO. In this paper, the tests in laboratory and in open-sky conditions are reported, as well as the obtained results. In addition, the contribution that such tests provided to foresee and improve the performance of Mini-EUSO on board the ISS is discussed.
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| 21. |
- Demidov, V. V., et al.
(författare)
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Magnetic Anisotropy of Strained Epitaxial Manganite Films
- 2011
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Ingår i: Journal of Experimental and Theoretical Physics. - : Pleiades Publishing Ltd. - 1090-6509 .- 1063-7761. ; 112:5, s. 825-832
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Tidskriftsartikel (refereegranskat)abstract
- The in-plane magnetic anisotropy of epitaxial La(0.7)Sr(0.3)MnO(3) (LSMO) films is studied at room temperature by the following three independent techniques: magnetooptical Kerr effect, ferromagnetic resonance at a frequency of 9.61 GHz, and recording of absorption spectra of electromagnetic radiation at a frequency of 290.6 MHz. The films are deposited onto NdGaO(3) (NGO) substrates in which the (110) NGO plane is tilted at an angle of 0-25.7 degrees to the substrate plane. The uniaxial magnetic anisotropy induced by the strain of the film is found to increase with the tilt angle of the (110) NGO plane. A model is proposed to describe the change in the magnetic anisotropy energy with the tilt angle. A sharp increase in the radio-frequency absorption in a narrow angular range of a dc magnetic field near a hard magnetization axis is detected The anisotropy parameters of the LSMO films grown on (110) NGO, (001) SrTiO(3), and (001)[(LaAlO(3))(0.3) + (Sr(2)AlTaO(6))(0.7)] substrates are compared.
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| 22. |
- Fausti, F., et al.
(författare)
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A multi-level triggering system for the Mini-EUSO UV telescope
- 2017
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Ingår i: Proceedings of Science. - : Sissa Medialab Srl.
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Konferensbidrag (refereegranskat)abstract
- As a pathfinder for the JEM-EUSO mission, Mini-EUSO is a 25cm diameter telescope which is going to be launched and positioned inside the International Space Station (ISS) in 2018. The main scientific goal of this mission is the achievement of a state-of-the-art UV map of the Earth from a 400 Km altitude, with ∼ 6 km of pixel spatial resolution, collecting data though a multi-level triggering system. The signal is collected with Multi-Anode Photo Multiplier Tubes (MAPMTs) and digitized by means of custom chips. The raw data moves then to a central system, the Zynq Board, where the trigger operates a data selection dividing different classes of events characterized by specific time scales. The acquired UV map will be used as discrimination threshold for the Extreme Energy Cosmic-Ray detection.
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| 23. |
- Klimov, A. B., et al.
(författare)
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Assessing the Polarization of a Quantum Field from Stokes Fluctuations
- 2010
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Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 105:15, s. 153602-
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Tidskriftsartikel (refereegranskat)abstract
- We propose an operational degree of polarization in terms of the variance of the Stokes vector minimized over all the directions of the Poincare sphere. We examine the properties of this second-order definition and carry out its experimental determination. Quantum states with the same standard (first-order) degree of polarization are correctly discriminated by this new measure. We argue that a comprehensive quantum characterization of polarization properties requires a whole hierarchy of higher-order degrees.
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| 24. |
- Marcelli, L., et al.
(författare)
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Integration, qualification, and launch of the Mini-EUSO telescope on board the ISS
- 2023
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Ingår i: Rendiconti Lincei SCIENZE FISICHE E NATURALI. - : Springer Nature. - 2037-4631 .- 1720-0776. ; 34:1, s. 23-35
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Tidskriftsartikel (refereegranskat)abstract
- Mini-EUSO is a high-sensitivity imaging telescope that observes the Earth from the ISS in the near ultraviolet band (290÷ 430 nm), through the nadir-facing, UV-transparent window in the Russian Zvezda module. The instrument, launched in 2019, has a field of view of 44∘, a spatial resolution on the Earth’s surface of 6.3 km and a temporal sampling rate of 2.5 microseconds. Thanks to its triggering and on-board processing, the telescope is capable of detecting UV emissions of cosmic, atmospheric, and terrestrial origin on different time scales, from a few microseconds up to tens of milliseconds. The optics is composed of two Fresnel lenses focusing light onto an array of 36 Hamamatsu Multi-Anode PhotoMultiplier Tubes, for a total of 2304 pixels. The telescope also contains two cameras in the near-infrared and visible, an 8-by-8 array of Silicon-PhotoMultipliers and a series of UV sensors to manage night-day transitions. The scientific objectives range from the observation of atmospheric phenomena [lightning, Transient Luminous Events (TLEs), ELVES], the study of meteoroids, the search of interstellar meteoroids and strange quark matter, mapping of the Earth’s nocturnal emissions in the ultraviolet range, and the search of cosmic rays with energy above 1021 eV. The instrument has been integrated and qualified in 2019, with the final tests in Baikonur prior to its launch. Operations involve periodic installation in the Zvezda module of the station with observations during the crew night time, with periodic downlink of data samples, with the full data being sent to the ground via pouches containing the data disks. Mission planning involves the selection of the optimal orbits to maximize the scientific return of the instrument. In this work, we will describe the various phases of construction, testing, and qualification prior to the launch and the in-flight operations of the instrument on board the ISS.
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| 25. |
- Moskvin, O V, et al.
(författare)
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Carbonic anhydrase activities in pea thylakoids. : A photosystem II core complex-associated carbonic anhydrase
- 2004
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Ingår i: Photosynthesis Research. - 0166-8595. ; 79:1, s. 93-100
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Tidskriftsartikel (refereegranskat)abstract
- Pea thylakoids with high carbonic anhydrase (CA) activity (average rates of 5000 µmol H+ (mg Chl)–1 h–1 at pH 7.0) were prepared. Western blot analysis using antibodies raised against the soluble stromal beta-CA from spinach clearly showed that this activity is not a result of contamination of the thylakoids with the stromal CA but is derived from a thylakoid membrane-associated CA. Increase of the CA activity after partial membrane disintegration by detergent treatment, freezing or sonication implies the location of the CA in the thylakoid interior. Salt treatment of thylakoids demonstrated that while one part of the initial enzyme activity is easily soluble, the rest of it appears to be tightly associated with the membrane. CA activity being measured as HCO3 – dehydration (dehydrase activity) in Photosystem II particles (BBY) was variable and usually low. The highest and most reproducible activities (approximately 2000 µmol H+ (mg Chl)–1 h–1) were observed in the presence of detergents (Triton X-100 or n-octyl-beta-D-glucopyranoside) in low concentrations. The dehydrase CA activity of BBY particles was more sensitive to the lipophilic CA inhibitor, ethoxyzolamide, than to the hydrophilic CA inhibitor, acetazolamide. CA activity was detected in PS II core complexes with average rate of 13,000 µmol H+ (mg Chl)–1 h–1 which was comparable to CA activity in BBY particles normalized on a PS II reaction center basis.
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| 26. |
- Ovsyannikov, Gennady, 1948, et al.
(författare)
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Magnetotransport characteristics of strained La0.7Sr0.3MnO3 epitaxial manganite films
- 2009
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Ingår i: Journal of Experimental and Theoretical Physics. - 1090-6509 .- 1063-7761. ; 108:1, s. 48-55
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Tidskriftsartikel (refereegranskat)abstract
- The electrical and magnetic characteristics of La0.7Sr0.3MnO3 (LSMO) epitaxial manganite films are investigated by different methods under conditions when the crystal structure is strongly strained as a result of mismatch between the lattice parameters of the LSMO crystal and the substrate. Substrates with lattice parameters larger and smaller than the nominal lattice parameter of the LSMO crystal are used in experiments. It is shown that the behavior of the temperature dependence of the electrical resistance for the films in the low-temperature range does not depend on the strain of the film and agrees well with the results obtained from the calculations with allowance made for the interaction of electrons with magnetic excitations in the framework of the double-exchange model for systems with strongly correlated electronic states. Investigations of the magneto- optical Kerr effect have revealed that an insignificant (0.3%) orthorhombic distortion of the cubic lattice in the plane of the NdGaO3(110) substrate leads to uniaxial anisotropy of the magnetization of the film, with the easy-magnetization axis lying in the substrate plane. However, LSMO films on substrates (((LaAlO3)(0.3)+(Sr2AlTaO6)(0.7))(001)) ensuring minimum strain of the films exhibit a biaxial anisotropy typical of cubic crystals. The study of the ferromagnetic resonance lines at a frequency of 9.76 GHz confirms the results of magnetooptical investigations and indicates that the ferromagnetic phase in the LSMO films is weakly inhomogeneous.
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| 27. |
- Rothkaehl, H., et al.
(författare)
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Diagnostics of Space Plasma on Board International Space Station - ISS
- 2011
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Ingår i: Contributions to Plasma Physics. - : Wiley. - 0863-1042 .- 1521-3986. ; 51:2-3, s. 158-164
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Tidskriftsartikel (refereegranskat)abstract
- Electromagnetic emissions observed in the nearest Earth environment are a superposition of natural emissions and various types of man-made noises. Also, as a consequence of catastrophic events on the Earth surface such as: thunderstorm activity, earthquakes, volcanic eruptions, electromagnetic signals are registered on board low orbiting satellites. Therefore, a more accurate physical description of such a complex and dynamic system calls for a long term multi-point and multi-scales coordinated monitoring of space environment. The aim of OBSTANOVKA experiment on board ISS station is to monitor and diagnose the electromagnetic radiation and property of plasma around station, to enable the development theory of near Earth plasma interaction and for application purposes in space technology. To achieve these goals the Plasma-Wave Complex (PWC) was designed and constructed. Radio Frequency Analyser (RFA) has been developed jointly by SRC PAS in Warsaw and by IRF in Uppsala. New design radio receiver for frequency band 0.1-15 MHz, with three electric and magnetic field component of antenna system on board ISS was designed to monitoring and investigate the ionospheric plasma property and artificial noises generated around ISS. The instrument can be also used for monitoring the electromagnetic ecosystem for space weather purpose. New digital technology of this instrument creates a excellent possibility for monitoring the electromagnetic emissions in space and time domain.
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