1. |
- Abe, K., et al.
(författare)
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J-PARC Neutrino Beamline Upgrade Technical Design Report
- 2019
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Rapport (refereegranskat)abstract
- In this document, technical details of the upgrade plan of the J-PARC neutrino beamline for the extension of the T2K experiment are described. T2K has proposed to accumulate data corresponding to 2×1022 protons-on-target in the next decade, aiming at an initial observation of CP violation with 3σ or higher significance in the case of maximal CP violation. Methods to increase the neutrino beam intensity, which are necessary to achieve the proposed data increase, are described.
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2. |
- Abele, H., et al.
(författare)
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Particle physics at the European Spallation Source
- 2023
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Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 1023, s. 1-84
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Forskningsöversikt (refereegranskat)abstract
- Presently under construction in Lund, Sweden, the European Spallation Source (ESS) will be the world’s brightest neutron source. As such, it has the potential for a particle physics program with a unique reach and which is complementary to that available at other facilities. This paper describes proposed particle physics activities for the ESS. These encompass the exploitation of both the neutrons and neutrinos produced at the ESS for high precision (sensitivity) measurements (searches).
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3. |
- Jahnke, T., et al.
(författare)
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Inner-Shell-Ionization-Induced Femtosecond Structural Dynamics of Water Molecules Imaged at an X-Ray Free-Electron Laser
- 2021
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Ingår i: Physical Review X. - : American Physical Society. - 2160-3308. ; 11:4
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Tidskriftsartikel (refereegranskat)abstract
- The ultrafast structural dynamics of water following inner-shell ionization is a crucial issue in high-energy radiation chemistry. We have exposed isolated water molecules to a short x-ray pulse from a free-electron laser and detected momenta of all produced ions in coincidence. By combining experimental results and theoretical modeling, we can image dissociation dynamics of individual molecules in unprecedented detail. We reveal significant molecular structural dynamics in H2O2+, such as asymmetric deformation and bond-angle opening, leading to two-body or three-body fragmentation on a timescale of a few femtoseconds. We thus reconstruct several snapshots of structural dynamics at different time intervals, which highlight dynamical patterns that are relevant as initiating steps of subsequent radiation-damage processes.
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4. |
- Bolognesi, P., et al.
(författare)
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A study of the dynamical energy flow in uracil
- 2015
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Tidskriftsartikel (refereegranskat)abstract
- The time resolved photoionization of C 1s in uracil following excitation of the neutral molecule by 260 nm pulses has been studied at LCLS.
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5. |
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6. |
- Goldsztejn, G., et al.
(författare)
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Electronic-state-lifetime interference in the hard-x-ray regime : Argon as a showcase
- 2017
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Ingår i: PHYSICAL REVIEW A. - : AMER PHYSICAL SOC. - 2469-9926. ; 95:1
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Tidskriftsartikel (refereegranskat)abstract
- Electronic-state-lifetime interference is a phenomenon specific for ionization of atoms and molecules in the hard-x-ray regime. Using resonant KL2,3L2,3 Auger decay in argon as a showcase, we present a model that allows extracting the interference terms directly from the cross sections of the final electronic states. The analysis provides fundamental information on the excitation and decay processes such as probabilities of various decay paths and the values of the dipole matrix elements for transitions to the excited states. Our results shed light on the interplay between spectator, shake-down, and shake-up processes in the relaxation of deep core-hole states.
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7. |
- Goldsztejn, G., et al.
(författare)
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Ultrafast Dynamics And Electronic State - Lifetime Interferences In Chlorine-Containing Molecules
- 2015
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Ingår i: Journal of Physics, Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 635
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Tidskriftsartikel (refereegranskat)abstract
- In order to have access to fine phenomena such as ultrafast nuclear dynamics and electronic state - lifetime interferences (ELI) at high energies (few keV), one has to rely on great experimental resolution. The new experimental HAXPES endstation at the GALAXIES beamline of the French synchrotron SOLEIL provides photons in the 2-12 keV energy range along with a total instrumental resolution below 500 meV. In this work we show experimental evidences of ultrafast nuclear dynamics and ELI on HCl and CH3Cl excited around the Cl 1s resonance. We show also simulations that allow to disentangle the contribution of nuclear dynamics and ELI in our experimental spectra.
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8. |
- Guillemin, R., et al.
(författare)
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Postcollision interaction effects in KLL Auger spectra following argon 1s photoionization
- 2015
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 92:1
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Tidskriftsartikel (refereegranskat)abstract
- Postcollision interaction effects on the Auger decay of a deep core hole are studied both experimentally and theoretically. KL2,L-3(2),(3) decay spectra of the Ar 1s vacancy are measured with high-energy resolution with excess photon energies ranging from 0 to 200 eV above the ionization threshold. Interaction of the Auger electron with the photoelectron and the ion field manifests itself in the Auger spectra as a distortion of the energy distribution of the Auger electron close to threshold. Moreover, recapture of the photoelectron due to energy exchange is dominating in the low-photon-energy range above threshold. The experimental results are compared with calculations based on the semiclassical approach to the postcollision interaction. The energies of the discrete levels and individual recapture cross sections are computed in the Hartree-Fock approximation. Good agreement is found between the calculated and experimental spectra, validating the model used.
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9. |
- Kushawaha, R. K., et al.
(författare)
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Auger resonant-Raman decay after Xe L-edge photoexcitation
- 2015
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 92:1
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated resonant Auger decay of xenon following photoexcitation of each of the three L edges under resonant-Raman conditions, which allowed us to characterize several higher Rydberg transitions. Relative intensities for spectator final states reached after L-1-, L-2-, and L-3-edge excitations are studied in detail. Thanks to state-of-the-art experimental arrangements, our results not only reproduce the previously calculated 3d(-2)5d and nd (n > 5) state cross sections after L-3 excitation, but also allow extracting the 3d(-2)6d spectator state energy position and revealing its resonant behavior, blurred by the insufficient experimental resolution in previous data sets. The 3d(-2)6p and 3d(-2)7p states reached after L-1 excitation as well as the 3d(-2)5d and 3d(-2)6d states reached after L-2 excitation are also investigated and their relative intensities are reported and compared to ab initio Dirac-Hartree-Fock configuration-interaction calculations. We found the signature of electronic-state-lifetime interference effects between several coherently excited intermediate states, due to large lifetime broadening. Electron recapture processes are also identified above all three photoionization thresholds.
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10. |
- Puettner, R., et al.
(författare)
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Detailed assignment of normal and resonant Auger spectra of Xe near the L edges
- 2017
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Ingår i: Physical Review A: covering atomic, molecular, and optical physics and quantum information. - 2469-9926 .- 2469-9934. ; 96:2
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Tidskriftsartikel (refereegranskat)abstract
- We present a comprehensive experimental and theoretical investigation on the LMM, LMN, and LNN normal Auger spectra of xenon, which reveal excellent agreement with theory when core-hole lifetimes of the two-hole final states are taken into account. Generally, the spectra turned out to be highly complex due to a strong overlap of the Auger transitions subsequent to 2s(1/2)(-1), 2p(1/2)(-1), and 2p(3/2)(-1) ionization. This overlap is due to the splitting of the three initial L core holes and the different final M and N core holes being on the same order of magnitude of several hundred eV. The Auger transitions are assigned in detail based on the theoretical results. Most of the MM, MN, and NN final states are described well based on jj coupling. In addition, we present a detailed assignment of the resonant LM45M45 Auger transition subsequent to the 2s -> 6p, 7p and 2p -> 5d, 6d excitations.
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