| 1. |
- Abgrall, N., et al.
(författare)
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The large enriched germanium experiment for neutrinoless double beta decay (LEGEND)
- 2017
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Ingår i: AIP Conference Proceedings. - : Author(s). - 1551-7616 .- 0094-243X. ; 1894
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Konferensbidrag (refereegranskat)abstract
- The observation of neutrinoless double-beta decay (0νββ) would show that lepton number is violated, reveal that neu-trinos are Majorana particles, and provide information on neutrino mass. A discovery-capable experiment covering the inverted ordering region, with effective Majorana neutrino masses of 15 - 50 meV, will require a tonne-scale experiment with excellent energy resolution and extremely low backgrounds, at the level of ∼0.1 count /(FWHM·t·yr) in the region of the signal. The current generation 76Ge experiments GERDA and the Majorana Demonstrator, utilizing high purity Germanium detectors with an intrinsic energy resolution of 0.12%, have achieved the lowest backgrounds by over an order of magnitude in the 0νββ signal region of all 0νββ experiments. Building on this success, the LEGEND collaboration has been formed to pursue a tonne-scale 76Ge experiment. The collaboration aims to develop a phased 0νββ experimental program with discovery potential at a half-life approaching or at 1028 years, using existing resources as appropriate to expedite physics results.
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| 2. |
- Pinsky, L., et al.
(författare)
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Measurement of Fragmentation Products including Angular Distributions for 3, 5, and 10 GeV/A C and Si on several nuclear targets at the AGS
- 2010
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Ingår i: 2009 12th International Conference on Nuclear Reaction Mechanisms, NRM 2009; Varenna; Italy; 15 June 2009 through 19 June 2009. - 2078-8835. - 9789290833413 ; 2, s. 431-437
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Konferensbidrag (refereegranskat)abstract
- Motivated by differences in the predicted fragmentation of heavy ions at energies around 5 GeV/A as employed in the event generators used by the FLUKA Monte Carlo Code [1], a set of measurements were carried out at the AGS facility at the Brookhaven National Laboratory to determine as much information as possible about the cross sections to allow harmonization of those event generators for these incident lab energies. The FLUKA Code employs the RQMD event generator of Sorge [2] for heavy ion interactions starting at 100 MeV/A and extending into the region around 5 GeV/A. Above those energies the DPMJET code of Ranft and Roesler [3] is typically employed to simulate such interactions. The detailed predictions of these event generators had some disagreement in the vicinity of this crossover energy and in order to tune these codes to be in closer harmony at the transition, and of course to be simulating nature as closely as possible, data were taken at 3, 5 and 10 GeV/A with beams of Fe, Si and C on a variety of targets including C, A1. Fe and Cu. The Fe data have not been fully analyzed, but results from the C and Si beams are available and the forward fragment spectrum along with a measurement of the charged particle angular distribution in a set of Si strip detectors out to about 45 degrees in the lab are available. These include sufficient statistics to provide the charged particle distributions as a function of the major projectile fragment. The detectors used in this measurement were based on what were reasonably available to us, and as such were limited in capability, and required separate data acquisition systems. Nevertheless, spectra were obtained that should be sufficient to enable the harmonization of the event generator codes at the crossover energy. This paper discusses only the experimental results and not the impact of those results on the FLUKA code.
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| 3. |
- Ankowski, A., et al.
(författare)
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Energy reconstruction of electromagnetic showers from Ν0 decays with the ICARUS T600 liquid argon TPC
- 2010
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Ingår i: Acta Physica Polonica, Series B.. - 1509-5770 .- 0587-4254. ; 41:1, s. 103-125
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Tidskriftsartikel (refereegranskat)abstract
- We discuss the ICARUS T600 detector capabilities in electromagnetic shower reconstruction through the analysis of a sample of 212 events, coming from the 2001 Pavia surface test run, of hadronic interactions leading to the production of π 0 mesons. Methods of shower energy and shower direction measurements were developed and the invariant mass of the photon pairs was reconstructed. The (γγ) invariant mass was found to be consistent with the value of the π 0 mass. The resolution of the reconstructed π 0 mass was found to be equal to 27.3%. An improved analysis, carried out in order to clean the full event sample from the events measured in the crowded environment, mostly due to the trigger conditions, gave a π 0 mass resolution of 16.1%, significantly better than the one evaluated for the full event sample. The trigger requirement of the coincidence of at least four photo-multiplier signals favored the selection of events with a strong pile up of cosmic ray tracks and interactions. Hence a number of candidate π 0 events were heavily contaminated by other tracks and had to be rejected. Monte Carlo simulations of events with π 0 production in hadronic and neutrino interactions confirmed the validity of the shower energy and shower direction reconstruction methods applied to the real data.
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| 4. |
- Battistoni, G., et al.
(författare)
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The FLUKA code and its use in hadron therapy
- 2008
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Ingår i: Nuovo Cimento della Societa Italiana di Fisica C. - Italian Physical Society. - 1124-1896. ; 31:1, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- FLUKA is a multipurpose Monte Carto code describing transport and interaction with matter of a, large variety of particles over a wide energy range ill complex geometries. FLUKA is successfully applied ill several fields, including, but not only particle physics, cosmic-ray physics, dosimetry, radioprotection, hadron therapy. space radiation, accelerator design and neutronics. Here we briefly review recent model developments and provide examples of applications to hadron therapy, including calculation of physical and biological dose for comparison with analytical treatment planning engines as well as beta(+)-activation for therapy monitoring by means of positron emission tomography.
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| 5. |
- Bjorn, A., et al.
(författare)
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Review of life-cycle based methods for absolute environmental sustainability assessment and their applications
- 2020
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Ingår i: Environmental Research Letters. - : IOP Publishing Ltd. - 1748-9326 .- 1748-9318. ; 15:8
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Tidskriftsartikel (refereegranskat)abstract
- In many regions and at the planetary scale, human pressures on the environment exceed levels that natural systems can sustain. These pressures are caused by networks of human activities, which often extend across countries and continents due to global trade. This has led to an increasing requirement for methods that enable absolute environmental sustainability assessment (AESA) of anthropogenic systems and which have a basis in life cycle assessment (LCA). Such methods enable the comparison of environmental impacts of products, companies, nations, etc, with an assigned share of environmental carrying capacity for various impact categories. This study is the first systematic review of LCA-based AESA methods and their applications. After developing a framework for LCA-based AESA methods, we identified 45 relevant studies through an initial survey, database searches and citation analysis. We characterized these studies according to their intended application, impact categories, basis of carrying capacity estimates, spatial differentiation of environmental model and principles for assigning carrying capacity. We then characterized all method applications and synthesized their results. Based on this assessment, we present recommendations to practitioners on the selection and use of existing LCA-based AESA methods, as well as ways to perform assessments and communicate results to decision-makers. Furthermore, we identify future research priorities intended to extend coverage of all components of the proposed method framework, improve modeling and increase the applicability of methods. © 2020 The Author(s).
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| 6. |
- Fumagalli, R., et al.
(författare)
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Mobile orbitons in Ca2CuO3: Crucial role of Hund's exchange
- 2020
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Ingår i: Physical Review B. - 2469-9969 .- 2469-9950. ; 101:20
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the CuL3 edge resonant inelastic x-ray scattering (RIXS) spectra of a quasi-1D antiferromagnet Ca2CuO3. In addition to the magnetic excitations, which are well-described by the two-spinon continuum, we observe two dispersive orbital excitations, the 3d(xy) and the 3d(yz) orbitons. We carry out a quantitative comparison of the RIXS spectra, obtained with two distinct incident polarizations, with a theoretical model. We show that any realistic spin-orbital model needs to include a finite, but realistic, Hund's exchange J(H) approximate to 0.5 eV. Its main effect is an increase in orbiton velocities, so that their theoretically calculated values match those observed experimentally. Even though Hund's exchange also mediates some interaction between spinon and orbiton, the picture of spin-orbit separation remains intact and describes orbiton motion in this compound.
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| 7. |
- Krieger, G., et al.
(författare)
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Charge and Spin Order Dichotomy in NdNiO2 Driven by the Capping Layer
- 2022
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Ingår i: Physical Review Letters. - 1079-7114 .- 0031-9007. ; 129:2
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Tidskriftsartikel (refereegranskat)abstract
- Superconductivity in infinite-layer nickelates holds exciting analogies with that of cuprates, with similar structures and 3d-electron count. Using resonant inelastic x-ray scattering, we studied electronic and magnetic excitations and charge density correlations in Nd1-xSrxNiO2 thin films with and without an SrTiO3 capping layer. We observe dispersing magnons only in the capped samples, progressively dampened at higher doping. We detect an elastic resonant scattering peak in the uncapped x=0 compound at wave vector (∼⅓,0), remindful of the charge order signal in hole doped cuprates. The peak weakens at x=0.05 and disappears in the superconducting x=0.20 film. The role of the capping on the electronic reconstruction far from the interface remains to be understood.
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| 8. |
- Nogly, P., et al.
(författare)
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Lipidic cubic phase injector is a viable crystal delivery system for time-resolved serial crystallography
- 2016
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- Serial femtosecond crystallography (SFX) using X-ray free-electron laser sources is an emerging method with considerable potential for time-resolved pump-probe experiments. Here we present a lipidic cubic phase SFX structure of the light-driven proton pump bacteriorhodopsin (bR) to 2.3 angstrom resolution and a method to investigate protein dynamics with modest sample requirement. Time-resolved SFX (TR-SFX) with a pump-probe delay of 1ms yields difference Fourier maps compatible with the dark to M state transition of bR. Importantly, the method is very sample efficient and reduces sample consumption to about 1mg per collected time point. Accumulation of M intermediate within the crystal lattice is confirmed by time-resolved visible absorption spectroscopy. This study provides an important step towards characterizing the complete photocycle dynamics of retinal proteins and demonstrates the feasibility of a sample efficient viscous medium jet for TR-SFX.
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