Vala Maria Valsdottir

• Paulsen, Wanja; Li, Kevin Ching Wei; Siem, Sunniva; Ingeberg, Vetle Wegner; Larsen, Ann-Cecilie & Eriksen, Tomas Kvalheim [Show all 15 contributors for this article] (2025). Remeasuring the γ-decay branching ratio of the Hoyle state. Physical Review C. ISSN 2469-9985. 112. doi: 10.1103/2h2s-sbyx. Full text in Research Archive
• Markova, Maria; Larsen, Ann-Cecilie; Neumann-Cosel, Peter von; Bassauer, Sergej; Görgen, Andreas & Guttormsen, Magne Sveen [Show all 23 contributors for this article] (2022). Nuclear level densities and γ -ray strength functions in Sn 120,124 isotopes: Impact of Porter-Thomas fluctuations. Physical Review C. ISSN 2469-9985. 106(3). doi: 10.1103/PhysRevC.106.034322. Full text in Research Archive Show summary

  Nuclear level densities (NLDs) and γ-ray strength functions (GSFs) of 120,124Sn have been extracted with the Oslo method from proton-γ coincidences in the (p,p′γ) reaction. The functional forms of the GSFs and NLDs have been further constrained with the Shape method by studying primary γ-transitions to the ground and first excited states. The NLDs demonstrate good agreement with the NLDs of 116,118,122Sn isotopes measured previously. Moreover, the extracted partial NLD of 1− levels in 124Sn is shown to be in fair agreement with those deduced from spectra of relativistic Coulomb excitation in forward-angle inelastic proton scattering. The experimental NLDs have been applied to estimate the magnitude of the Porter-Thomas (PT) fluctuations. Within the PT fluctuations, we conclude that the GSFs for both isotopes can be considered to be independent of initial and final excitation energies, in accordance with the generalized Brink-Axel hypothesis. Particularly large fluctuations observed in the Shape-method GSFs present a considerable contribution to the uncertainty of the method and may be one of the reasons for deviations from the Oslo-method strength at low γ-ray energies and low values of the NLD (below ≈1×103–2×103MeV−1).

• Markova, Maria; Neumann-Cosel, Neumann-Cosel von; Larsen, A.C.; Bassauer, S.; Görgen, A. & Guttormsen, Magne Sveen [Show all 25 contributors for this article] (2021). Comprehensive Test of the Brink-Axel Hypothesis in the Energy Region of the Pygmy Dipole Resonance. Physical Review Letters. ISSN 0031-9007. 127(18). doi: 10.1103/PhysRevLett.127.182501. Full text in Research Archive Show summary

  The validity of the Brink-Axel hypothesis, which is especially important for numerous astrophysical calculations, is addressed for 116,120,124Sn below the neutron separation energy by means of three independent experimental methods. The γ-ray strength functions (GSFs) extracted from primary γ-decay spectra following charged-particle reactions with the Oslo method and with the shape method demonstrate excellent agreement with those deduced from forward-angle inelastic proton scattering at relativistic beam energies. In addition, the GSFs are shown to be independent of excitation energies and spins of the initial and final states. The results provide a critical test of the generalized Brink-Axel hypothesis in heavy nuclei, demonstrating its applicability in the energy region of the pygmy dipole resonance.

View all works in NVA

• Paulsen, Wanja; Li, Kevin Ching Wei; Siem, Sunniva; Ingeberg, Vetle Wegner; Larsen, Ann-Cecilie & Eriksen, Tomas Kvalheim [Show all 15 contributors for this article] (2026). CLUSTER'26. Full text in Research Archive
• Hjelmeland, Martin N. & Valsdottir, Vala Maria (2025). Kronikk: – Norges mulighet er å kobles på et nordisk kjernekraftprogram. doi: https:/energiwatch.no/debatt/article18655845.ece. Full text in Research Archive Show summary

  De erfarne kjernekraftnasjonene bruker milliarder på å øve, planlegge og lære. Kjernekraft må bygges, ikke importeres, skriver Hjelmeland og Valsdottir, tilknyttet Norsk Nukleært forskningssenter.

• Valsdottir, Vala Maria & Hjelmeland, Martin N. (2025). Norsk energi­kompetanse trengs | Klassekampen. doi: https:/klassekampen.no/artikkel/2025-01-14/norsk-energikompetanse-trengs. Full text in Research Archive Show summary

  Mens Europa snur om kjernekraft, bygger Norge ned sine forskningsreaktorer. Det er å gå glipp av en sårt tiltrengt mulighet.

• Valsdottir, Vala Maria; Hjelmeland, Martin N. & Siem, Sunniva (2025). Ekspertrapport: Etablering av kjernekraft i Norge | Crayon Consulting. doi: https:/crayonconsulting.no/vev/kjernekraftinorge. Full text in Research Archive Show summary

  Hva er mulighetene og utfordringene med en mulig etablering av kjernekraft i Norge? En Phd rapport av doktorgradsstipendiat Vala Maria Valsdottir

• Hjelmeland, Martin N.; Valsdottir, Vala Maria & Nøland, Jonas Kristiansen (2023). Kjernekraft kan bli en ny hjørnestein for norske industri- og lokalsamfunn. Full text in Research Archive Show summary

  Kjernekraft kan være nøkkelen for å skape lokale, stabile og godt betalte arbeidsplasser i Norge – med betydelige skatteinntekter – samtidig som den bidrar til å løse energi- og naturkrisen.

• Paulsen, Wanja; Li, Kevin Ching Wei; Siem, Sunniva; Ingeberg, Vetle Wegner; Larsen, Ann-Cecilie & Eriksen, Tomas Kvalheim [Show all 20 contributors for this article] (2023). Remeasuring the gamma-decay branching ratio of the Hoyle state. Full text in Research Archive
• Hjelmeland, Martin N.; Valsdottir, Vala Maria & Nøland, Jonas Kristiansen (2023). Kjernekraft – en ny hjørnestein? Full text in Research Archive Show summary

  Arbeiderpartiet, Høyre og Sp mener at vi skal videreutvikle oljenæringen slik at den på sikt gir nullutslipp. SV vil pumpe mindre olje, Venstre vil slutte å lete etter mer olje, mens MDG vil avvikle hele oljenæringen på 15 år. Bortsett fra MDG er det ingen svar på hvordan nullutslipp skal oppnås, og heller ingen gode svar på hva de 150.000 menneskene som jobber innenfor oljenæringen skal gjøre.

View all works in NVA