| 1. |
- Aamodt, K., et al.
(författare)
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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. |
- Greiner, J., et al.
(författare)
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Gamma-ray burst investigation via polarimetry and spectroscopy (GRIPS)
- 2009
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Ingår i: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:1, s. 91-120
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Tidskriftsartikel (refereegranskat)abstract
- The primary scientific goal of the GRIPS mission is to revolutionize our understanding of the early universe using gamma-ray bursts. We propose a new generation gamma-ray observatory capable of unprecedented spectroscopy over a wide range of gamma-ray energies (200 keV-50 MeV) and of polarimetry (200-1000 keV). The gamma-ray sensitivity to nuclear absorption features enables the measurement of column densities as high as 10(28)cm (-aEuro parts per thousand 2). Secondary goals achievable by this mission include direct measurements of all types of supernova interiors through gamma-rays from radioactive decays, nuclear astrophysics with massive stars and novae, and studies of particle acceleration near compact stars, interstellar shocks, and clusters of galaxies.
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| 3. |
- Romet, I., et al.
(författare)
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Interconfigurational d-f luminescence of Pr3+ ions in praseodymium doped Li6Y(BO3)3 single crystals
- 2024
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Ingår i: Journal of Luminescence. - 0022-2313. ; 265
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Tidskriftsartikel (refereegranskat)abstract
- Luminescence properties of undoped Li6Y(BO3)3 (LYB) crystals grown by the Bridgman method as well as undoped and praseodymium doped LYB crystals grown by the Czochralski method were studied under excitation by ultraviolet light, synchrotron radiation and electron beam in the temperature region of 5–300 K. The emission bands peaking at 4.8, 3.76 and 2.95 eV were found in undoped Czochralski-grown crystals, while the band at 3.34 eV was dominant in the Bridgman-grown crystals. These bands are presumably ascribed to excitons localized at regular and defect-perturbed lattice sites. Intense emission bands peaking at 4.75, 4.50, 4.17 and 3.98 eV were discovered in Pr doped crystals at low temperatures and related to the interconfigurational 4f15d1 → 4f2 radiative transitions in Pr3+ ions. The structure of the emission spectrum is shown to be determined by the 3H4, 3H5, 3H6, 3F2, 3F3, 3F4 terms of the Pr3+ ion. The characteristic decay time of the 4f15d1 → 4f2 emission is τ = 24 ns at low temperatures, however, it shortens to 9 ns by room temperature due to a strong thermal quenching. The study of glow curves and spectra of thermostimulated luminescence in Li6Y(BO3)3:Pr crystal irradiated by 10-keV electron beam shows that Pr3+ ions do not participate in an electron-hole recombination process.
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| 4. |
- Wang, W., et al.
(författare)
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A new user-friendly materials science end station at the FinEstBeAMS beamline of MAX IV
- 2022
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 2380
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Konferensbidrag (refereegranskat)abstract
- FinEstBeAMS is an atmospheric and materials science beamline located at the 1.5 GeV storage ring of the MAX IV Laboratory in Lund, Sweden. It offers a very wide photon energy range 4.5-1300 eV and radiation with different polarization characteristics. The beamline has three end stations installed at two branch lines. The new solid state end station (SSES) is described in this paper. It is a high-throughput apparatus with flexible sample preparation options for X-ray photoemission, angle-resolved photoemission, and X-ray absorption spectroscopy. Three examples of experiments at room temperature demonstrate the capabilities of the SSES in the research field of surface science and condensed matter physics.
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| 5. |
- Assylbayev, R., et al.
(författare)
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Defect-related luminescence of MgO single crystals irradiated with swift 132Xe ions
- 2022
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Ingår i: Optical Materials. - : Elsevier BV. - 0925-3467. ; 127
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Tidskriftsartikel (refereegranskat)abstract
- Low-temperature cathodo- and photoluminescence connected with the F and F+ centers (oxygen vacancies in different charge states) and bivacancies have been investigated in MgO single crystals preliminarily irradiated by 230-MeV 132Xe ions with varying fluence (up to 1014 ions/cm2). The cathodoluminesence bands (result of decomposition into Gaussians) related to the F, F+ and P centers have intensified with Xe-irradiation fluence up to Φ = 1013 ions/cm2, while drastic emission attenuation in a whole spectral region occurs at higher fluences. The limitations of the use of luminescence methods for the detection of structural point defects induced by heavy irradiation have been considered.
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| 6. |
- Gorokhova, E. I., et al.
(författare)
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Structural, optical, and luminescence properties of ZnO:Ga optical scintillation ceramic
- 2018
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Ingår i: Journal of Optical Technology (A Translation of Opticheskii Zhurnal). - 1070-9762. ; 85:11, s. 729-737
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the characteristics of ZnO and ZnO:Ga ceramics fabricated by uniaxial hot pressing. The short-wavelength transmission limit of zinc oxide ceramics is in the 370-nm region; the long-wavelength limit is determined by the free-charge-carrier concentration and lies in the interval from 5 to 9 μm. The total transmittance of such ceramics in the visible and near-IR regions is about 70% when the sample is 0.5 mm thick. The luminescence spectrum is represented by a broad emission band with maximum at 580 nm, having a defect nature. The introduction of 0.03–0.1 mass % gallium into the zinc oxide structure inhibits grain growth and increases the free-charge-carrier concentration to 3.44 × 1019 cm−3. As the gallium concentration increases in the range 0.05–0.1 mass % in a ceramic of composition ZnO:Ga, the defect luminescence band is suppressed and a characteristic exciton luminescence is formed with a maximum corresponding to 389 nm and a damping time constant of 1.1 ns.
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| 7. |
- Khanin, V., et al.
(författare)
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Variation of the conduction band edge of (Lu,Gd) 3 (Ga,Al) 5 O 12 :Ce garnets studied by thermally stimulated luminescence
- 2019
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Ingår i: Journal of Luminescence. - : Elsevier BV. - 0022-2313. ; 211, s. 48-53
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Tidskriftsartikel (refereegranskat)abstract
- The shift of the conduction band (CB) edge for thirty different (Lu,Gd) 3 (Ga,Al) 5 O 12 :Ce compositions, with simultaneous variation in Lu/Gd and Ga/Al content was studied using thermally stimulated luminescence (TSL). Specific TSL peaks were related to impurities of Ta, Cr, Yb, Ti and Eu in Lu 1 Gd 2 Ga 3 Al 2 O 12 :Ce ceramics. The shift of Yb-related peak positions (in temperature and trap depth) with composition modification was investigated as well. In Gd-containing (Lu,Gd) 3 (Ga,Al) 5 O 12 compositions a non-monotonous shift of the CB edge with increasing Ga content has been affirmed. The difference between thermal trap depths evaluated from our TSL experiments and optical trap depths obtained from the literature was explained by the role of lattice relaxation.
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| 8. |
- Omelkov, S. I., et al.
(författare)
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Recent advances in time-resolved luminescence spectroscopy at MAX IV and PETRA III storage rings
- 2022. - 1
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 2380
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Konferensbidrag (refereegranskat)abstract
- Short-wavelength synchrotron radiation excitation has been an indispensable tool in the studies of the properties of wide gap materials using time-resolved low-temperature luminescence spectroscopy. In recent years, several setups for such investigations have been launched at MAX IV Laboratory and Photon Science at DESY. Two permanently stationed time-resolved luminescence setups at FinEstBeAMS and P66 beamlines are in operation at MAX IV 1.5 GeV and Petra III storage rings, respectively. Mobile luminescence setups have been developed for studies at FemtoMAX and P23 beamlines. FinEstBeAMS, P66 and P23 provide time resolution from ?1/4160 to 100 ps. The FemtoMAX photon source based on an in-vacuum undulator getting an electron beam from the 3 GeV linear accelerator provides an exceptional time resolution of ?1/430 ps, limited by time response of the photodetector. The performance of the setups, achieved milestones and research challenges are discussed for four new luminescence stations available for the research community with the main focus on time-resolved techniques.
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| 9. |
- Pankratova, V., et al.
(författare)
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Temperature behavior of Ce3+ emission in (Lu,Y)2SiO5 single crystals excited by vacuum ultraviolet synchrotron light
- 2024
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Ingår i: Optical Materials: X. - 2590-1478. ; 22
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Tidskriftsartikel (refereegranskat)abstract
- Cerium doped (Lu,Y)2SiO5 (or LYSO) single crystals have been studied by means of luminescence excitation spectroscopy in the temperature range from 7 up to 300 K. Vacuum ultraviolet excitations in 4.5–8 eV energy range from synchrotron radiation of 1.5 GeV storage ring of MAX IV synchrotron facility. It is shown that both type of Ce3+ emission centers (seven and six coordinated centers) are excited under any excitation energy used. It was concluded that the same energy transfer processes from host lattice to impurity ions are involved independently on coordination of Ce3+. It is also demonstrated that excitonic mechanism of energy transfer is dominant under chosen excitation and intrinsic and bound excitons are included in excitation of Ce3+ luminescence in LYSO.
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| 10. |
- Radzhabov, E., et al.
(författare)
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Fine structure of 4f–5d absorption spectra of MeF2-Yb3+ in the vacuum ultraviolet region under synchrotron excitation
- 2023
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Ingår i: Optical Materials. - : Elsevier BV. - 0925-3467. ; 135
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Tidskriftsartikel (refereegranskat)abstract
- Narrow dips were found in the excitation spectra of crystals of alkaline earth fluorides doped with ErF3 or/and YbF3. The positions of the dips are in good agreement with the positions of the narrow absorption lines Er3+, Yb3+ measured earlier. The absorption lines of the crystals were calculated from the excitation spectra. The observed dips in the excitation spectra are due to the absorption lines of 4f–5d transitions in lanthanide ions.
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