Publikasjoner
-
Bell, Lauren Tracy; Siem, Sunniva; Larsen, Ann-Cecilie; Bürger, A.; Markova, Maria & Ingeberg, V. W.
[Vis alle 12 forfattere av denne artikkelen]
(2026).
Extracting the nuclear level density and γ-ray strength function of 90Zr.
Physical Review C.
ISSN 2469-9985.
114(1).
doi:
10.1103/p9y9-xxjf.
Fulltekst i vitenarkiv
Vis sammendrag
In this work, we have extracted the nuclear level density (NLD) and 𝛾-ray strength function (𝛾SF) using the Oslo method on particle-𝛾 coincidence data from the 90Zr(𝑝,𝑝′𝛾)90Zr reaction. We have applied the shape method to the same data set, providing a model-independent 𝛾SF and a cross-check on the slope of the Oslo-method NLD and 𝛾SF. Further, we have combined the 𝛾SF from this work with photonuclear data, thus covering the 2.5<𝐸𝛾<18MeV energy range. We see an increase in strength in the region around 𝐸𝛾≈9MeV, consistent with previous (𝛾,𝛾′) and (𝛾,𝑛) data. On the other hand, surprisingly, we do not observe a strong low-energy increase at low transition energies. The resulting NLD and 𝛾SF were used as inputs to the nuclear reaction code talys to estimate the cross sections and astrophysical reaction rates for the 89Zr(𝑛,𝛾)90Zr 89Y(𝑝,𝛾)90Zr reactions. We find good agreement with available experimental cross sections and JINA calculations for the 89Y(𝑝,𝛾) results, but not for the 89Zr(𝑛,𝛾) reaction rate for stellar temperatures above 0.7 GK. Based on our data, we provide a much more narrow uncertainty band for the 89Zr(𝑛,𝛾) cross section and reaction rate.
-
Markova, Maria; Larsen, Ann-Cecilie; Neumann-Cosel, P. von; Litvinova, E.; Goriely, S. & Bell, Lauren Tracy
[Vis alle 17 forfattere av denne artikkelen]
(2026).
Exploring the statistical properties of the neutron-deficient 109In isotope with the Oslo method.
Physical Review C.
ISSN 2469-9985.
113(4).
doi:
10.1103/qrvh-s12k.
Fulltekst i vitenarkiv
Vis sammendrag
The nuclear level density and the 𝛾-ray strength function of the neutron-deficient 109In isotope were extracted for the first time with data from the 106Cd(𝛼,𝑝𝛾)109In reaction using a combination of the Oslo and the shape methods. Both quantities are consistent with those of neighboring Cd and Sn nuclei but show substantial discrepancies with currently available model predictions. In contrast to earlier observations in the neighboring isotopic chains, 109In does not exhibit any significant enhancement of the dipole strength near the neutron separation energy. To interpret this feature, random-phase time-blocking approximation calculations have been performed for 109In and the neighboring 110,112Sn nuclei. The experimental data were also employed to estimate cross sections and rates of the radiative neutron- and proton-capture reactions, 108In(𝑛,𝛾)109In and 108Cd(𝑝,𝛾)109In, respectively, with the reaction code talys. Our (𝑝,𝛾) cross section is in excellent agreement with direct measurements over a wide range of proton energies, while the (𝑛,𝛾) cross section demonstrates notable deviations from predictions in the jina reaclib library. The new results on the statistical properties of 109In provide valuable constraints that may help address the problem of large model uncertainties compromising the accuracy of astrophysical 𝑝-process simulations.
-
Greaves, B.; Mücher, D.; Spyrou, A.; Goriely, S.; Rochman, D. & Berg, H. C.
[Vis alle 27 forfattere av denne artikkelen]
(2025).
Probing the limits of statistical neutron capture for the r process: Experimental constraints on<sup>141</sup>Cs nuclear level densities.
Physics Letters B.
ISSN 0370-2693.
871.
doi:
10.1016/j.physletb.2025.139992.
Fulltekst i vitenarkiv
Vis sammendrag
The r-process abundance peaks, particularly near mass number A ∼ 130, reflect underlying nuclear structure effects such as closed neutron shells, yet modeling the nucleosynthesis in this region remains hindered by uncertain neutron-capture rates. These rates are especially sensitive to nuclear level densities (NLDs) and γ-ray strength functions of neutron-rich nuclei, where experimental data are scarce. We present the first experimental constraint on the NLD of 141Cs using the β-Oslo method, extending sensitivity to the neutron-rich regime near the 𝑁 = 82 closed shell. Our data allow for critical calibration of microscopic NLD models and reveal that 141Cs lies near the limit of statistical model applicability. Using this experimental input, we evaluate radiative neutron-capture rates across neighboring isotones using both Hauser–Feshbach (HF) and High Fidelity Resonance (HFR) models. Our results show order-of-magnitude rate increases for nuclei along the 𝑁 = 86 line, signaling a transition to resonance-dominated capture in this region. These findings underscore the importance of constraining NLDs to improve r-process reaction network predictions, particularly in environments where the validity of statistical models breaks down.
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2025).
PYGMY DIPOLE RESONANCE IN Sn ISOTOPES AND ITS ASTROPHYSICAL IMPACT.
Acta Physica Polonica B, Proceedings Supplement.
ISSN 1899-2358.
18(2).
doi:
10.5506/APhysPolBSupp.18.2-A3.
Fulltekst i vitenarkiv
Vis sammendrag
The low-lying electric dipole strength in 111−113,116−122,124Sn was extracted with the Oslo method to systematically investigate the pygmy dipole resonance (PDR) and its evolution in Sn isotopes. The nuclear level densities (NLD) and the γ-ray strength functions (GSF) obtained from the Oslo data were used as inputs in the TALYS reaction code to produce radiative neutron-capture cross sections, Maxwellian-averaged cross sections, and rates relevant for the heavy-element nucleosynthesis. Despite a relatively small observed impact of the PDR, the experimentally extracted 121,123Sn(n, γ) 122,124Sn cross sections provide a notable reduction of a currently available theoretical uncertainty for the abundances of Sb isotopes in the i-process simulations.
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2025).
Approaching the pygmy dipole resonance in Sn isotopes with the Oslo method.
The European Physical Journal Conferences.
ISSN 2101-6275.
322(04002).
doi:
10.1051/epjconf/202532204002.
Fulltekst i vitenarkiv
Vis sammendrag
The γ-ray strength functions (GSF) and nuclear level densities (NLD) below the neutron separation energy were extracted for 111−113,116−122,124Sn from particle-γ coincidence data with the Oslo method in a model consistent way. Combined with results of a recent systematic Coulomb excitation study, the Oslo GSFs were used to extract bulk characteristics of the low-lying electric dipole response, commonly associated with the pygmy dipole resonance (PDR). A resonance-like peak on top of the tail of the isovector giant dipole resonance was observed in all of the isotopes. It is centered at 8 MeV and exhausts ≈2% of the classical Thomas-Reiche-Kuhn (TRK) sum. For the heaviest isotopes, the data suggest also a second peak located at ≈6.5 MeV, which might potentially be the isovector component of the PDR. At variance with microscopic calculations, no clear increase of the total low-lying E1 strength with neutron excess was observed in the experimental data. The results also suggest that association of the full low-lying electric dipole strength with the PDR, especially in its neutron skin interpretation, might be unfounded.
-
Markova, Maria; Neumann-Cosel, Peter von & Litvinova, Elena
(2025).
Systematics of the low-energy electric dipole strength in the Sn isotopic chain.
Physics Letters B.
ISSN 0370-2693.
860.
doi:
10.1016/j.physletb.2024.139216.
Fulltekst i vitenarkiv
Vis sammendrag
We present a systematic study of the mass dependence of the low-energy electric dipole strength (LEDS) in Sn isotopes in the range 𝐴 = 111 − 124 based on data obtained with the Oslo method and with relativistic Coulomb excitation in forward-angle (𝑝, 𝑝′) scattering. The combined data cover an energy range of 2 − 20 MeV which permits, with minimal assumptions, a decomposition of the total strength into the contribution from the lowenergy tail of the isovector giant dipole resonance (IVGDR) and possible resonance-like structures on top of it. In all cases, a resonance peaked at about 8.3 MeV is observed, exhausting an approximately constant fraction of the Thomas-Reiche-Kuhn (TRK) sum rule. For heavier isotopes (𝐴 ≥ 118) a consistent description of the data requires the inclusion of a second resonance centered at 6.5 MeV, representing the isovector response of the pygmy dipole resonance (PDR). Its strength corresponds to a small fraction of the total LEDS only and shows an approximately linear dependence on mass number. The experimental results are compared to microscopic calculations to investigate the importance of an inclusion of quasiparticle vibration coupling (qPVC) for a realistic description of the LEDS. A possible interpretation of the experimentally observed two-bump structure is given.
-
-
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2024).
The pygmy dipole resonance in Sn isotopes studied with the Oslo method.
Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics.
ISSN 1124-1896.
47(2),
s. 1–4.
doi:
10.1393/ncc/i2024-24033-0.
Fulltekst i vitenarkiv
Vis sammendrag
The evolution of bulk properties of the low-lying electric dipole response (LEDR) in 111−113,116−122,124Sn has been studied on the basis of the γ-ray strength functions extracted from particle-γ coincidence data with the Oslo method and from Coulomb excitation data. The LEDR was found to be concentrated at ≈ 8.0–8.3 MeV and exhausts ≈ 2–3% of the Thomas-Reiche-Kuhn sum rule in all isotopes. No clear increase of the strength from the lightest 111Sn to the heaviest studied 124Sn, predicted with the majority of theoretical approaches, was observed.
-
Söderström, P.-A.; Kuşoglu, A.; Balabanski, D.L.; Brezeanu, M.; Choudhury, D. & Gavrilescu, A.
[Vis alle 61 forfattere av denne artikkelen]
(2024).
From implementation to operation and the first measurements with the ELIGANT detectors from ELI-NP.
Nuovo cimento della societa italiana de fisica. C, Geophysics and space physics.
ISSN 1124-1896.
47(2).
doi:
10.1393/ncc/i2024-24058-3.
Fulltekst i vitenarkiv
Vis sammendrag
The ELIGANT set of instruments is a dedicated tool being developed at ELI-NP for studying high-energy collective nuclear excitations using gamma beams. The topics of interest in these studies range from fundamental nuclear structure properties of the Giant Dipole Resonance and the low-energy strength enhancement in the Pygmy Dipole Resonance region, to applications in p-process nucleosynthesis and propagation of Ultra-High Energy Cosmic Rays. The equipment consists of large-volume LaBr3:Ce and CeBr3 detectors for high-energy γ-rays, liquid scintillators and lithium glass scintillators for high- and low-energy neutron time-of-flight, and a proportional counter system of 3He tubes for cross-section measurements. These instruments have been installed and commissioned with sources and via inbeam measurements, in different configurations, at the IFIN-HH Tandem/Tandetron accelerators with terminal voltages of 3 MV and 9 MV. This contribution gives an overview of the present and future activities with ELIGANT.
-
Markova, Maria; Larsen, Ann-Cecilie; Neumann-Cosel, Peter von; Litvinova, E.; Choplin, A. & Goriely, S.
[Vis alle 11 forfattere av denne artikkelen]
(2024).
Systematic study of the low-lying electric dipole strength in Sn isotopes and its astrophysical implications.
Physical Review C.
ISSN 2469-9985.
109(5).
doi:
10.1103/PhysRevC.109.054311.
Fulltekst i vitenarkiv
Vis sammendrag
The 𝛾-ray strength functions (GSFs) and nuclear level densities (NLDs) below the neutron threshold have been extracted for 111–113,116–122,124 Sn from particle-𝛾 coincidence data with the Oslo method. The evolution of bulk properties of the low-lying electric dipole response has been investigated on the basis of the Oslo GSF data and results of a recent systematic study of electric- and magnetic dipole strengths in even-even Sn isotopes with relativistic Coulomb excitation. The obtained GSFs reveal a resonance-like peak on top of the tail of the isovector giant dipole resonance centered at ≈8 MeV and exhausting ≈2% of the classical Thomas-Reiche-Kuhn (TRK) sum. For mass numbers ≥118 the data suggest also a second peak centered at ≈6.5 MeV. It corresponds to 0.1%–0.5% of the TRK sum rule and shows an approximate linear increase with the mass number. In contrast with predictions of the relativistic quasiparticle random-phase and time-blocking approximation calculations, no monotonic increase in the total low-lying 𝐸1 strength was observed in the experimental data from 111 Sn to 124 Sn, demonstrating rather similar strength distributions in these nuclei. The Oslo GSFs and NLDs were further used as inputs to constrain the cross sections and Maxwellian-averaged cross sections of (𝑛,𝛾) reactions in the Sn isotopic chain using talys. The obtained results agree well with other available experimental data and the recommended values from the JINA REACLIB, BRUSLIB, and KADoNiS libraries. Despite relatively small exhausted fractions of the TRK sum rule, the low-lying electric dipole strength makes a noticeable impact on the radiative neutron-capture cross sections in stable Sn isotopes. Moreover, the experimental Oslo inputs for the 121,123 Sn (𝑛,𝛾) 122,124 Sn reactions were found to affect the production of Sb in the astrophysical 𝑖 process, providing new constraints on the uncertainties of the resulting chemical abundances from multizone low-metallicity asymptotic giant branch stellar models.
-
Markova, Maria; Larsen, Ann-Cecilie; Tveten, Gry Merete; Neumann-Cosel, Peter von; Eriksen, Tomas Kvalheim & Garrote, Frank Leonel Bello
[Vis alle 16 forfattere av denne artikkelen]
(2023).
Nuclear level densities and γ -ray strength functions of Sn 111,112,113 isotopes studied with the Oslo method.
Physical Review C.
ISSN 2469-9985.
108(1).
doi:
10.1103/PhysRevC.108.014315.
Fulltekst i vitenarkiv
Vis sammendrag
The 111,112,113Sn isotopes have been studied with (p,dγ), (p,p′γ), and (d,pγ) reactions to extract the nuclear level densities (NLDs) and γ-ray strength functions (GSFs) of these nuclei below the neutron separation energy by means of the Oslo method. The experimental NLDs for all three nuclei demonstrate a trend compatible with the constant-temperature model below the neutron separation energy while also being in good agreement with the NLDs of neighboring Sn isotopes, obtained previously with the Oslo-type and neutron evaporation experiments. The extracted microcanonical entropies yield ≈1.5 kB entropy of a valence neutron in both 111Sn and 113Sn. Moreover, the deduced microcanonical temperatures indeed suggest a clear constant-temperature behavior above ≈3 MeV in 111,113Sn and above ≈4.5 MeV in 112Sn. We observe signatures for the first broken neutron pairs between 2 and 4 MeV in all three nuclei. The GSFs obtained with the Oslo method are found to be in good agreement below the neutron threshold with the strengths of 112,114Sn extracted in the (p,p′) Coulomb excitation experiments.
-
-
-
Pogliano, Francesco; Garrote, Frank Leonel Bello; Larsen, Ann-Cecilie; Berg, Hannah Christine; Gjestvang, Dorthea & Görgen, Andreas
[Vis alle 19 forfattere av denne artikkelen]
(2023).
Observation of a candidate for the M1 scissors resonance in odd-odd Ho 166.
Physical Review C.
ISSN 2469-9985.
107(3).
doi:
10.1103/PhysRevC.107.034605.
Fulltekst i vitenarkiv
Vis sammendrag
The γ -strength function and the nuclear level density for the odd-odd, rare-earth nucleus 166 Ho have been
extracted from 163 Dy(α, pγ ) 166 Ho data using the Oslo method. A structure at ≈3 MeV in the γ -strength function
is interpreted as the M1 scissors resonance. By employing three different methods we find that its strength
depends rather strongly on the modeling of the E 1 strength, while its centroid does not. The 166 Ho scissors
resonance parameters are consistent with previous results on other rare-earth nuclei.
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2023).
Nuclear level densities and γ-ray strength functions of 120,124Sn and their application in astrophysics.
The European Physical Journal Conferences.
ISSN 2101-6275.
275(02007),
s. 1–4.
doi:
10.1051/epjconf/202327502007.
Fulltekst i vitenarkiv
Vis sammendrag
Nuclear level densities (NLDs) and γ -ray strength functions (GSFs)of 120;124 Sn have been extracted with the Oslo method and additionally constrained with the novel Shape method. The GSFs were found to be in excellent agreement with the strengths from the inelastic relativistic proton scattering experiment. This comparison suggests the validity of the Brink-Axel hypothesisused as one of the key assumptions in astrophysical calculations. The extracted NLDs and GSFs were further used as experimental inputs to constrain the Maxwellian-averaged cross sections (MACS) for the radiative neutron capture process 119;123 Sn ( n, γ ) 120;124 Sn using the the nuclear reaction code TALYS.
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2023).
Nuclear level densities and γ-ray strength functions of 120,124Sn for astrophysical purposes.
The European Physical Journal Conferences.
ISSN 2101-6275.
279(12001),
s. 1–6.
doi:
10.1051/epjconf/202327912001.
Fulltekst i vitenarkiv
Vis sammendrag
The nuclear level densities (NLDs) and γ-ray strength functions (GSFs) of 120,124Sn were extracted with the Oslo method, compared and combined with other experimental data to be used as inputs in the TALYS reaction code to constrain the Maxwellian-averaged cross sections (MACS) for the 119,123Sn(n, γ)120,124Sn reactions. For 120Sn, the MACS are in relatively good agreement with the JINA REACLIB, BRUSLIB libraries, while no clear agreement was found for 124Sn. In addition, the pygmy dipole resonance (PDR) was found to contribute with up to ≈ 3 − 8% of the total MACS in these nuclei.
-
Markova, Maria; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
(2023).
Evolution of the Pygmy Dipole Resonance in Sn Isotopes.
Acta Physica Polonica B, Proceedings Supplement.
ISSN 1899-2358.
16(4-A5),
s. 1–4.
doi:
10.5506/APhysPolBSupp.16.4-A5.
Fulltekst i vitenarkiv
-
Pogliano, Francesco; Larsen, Ann-Cecilie; Markova, Maria; Garrote, Frank Leonel Bello; Bjørøen, Marianne Møller & Eriksen, Tomas Kvalheim
[Vis alle 17 forfattere av denne artikkelen]
(2022).
Indirect measurement of the (n,γ) Sb 127 cross section.
Physical Review C.
ISSN 2469-9985.
106(1).
doi:
10.1103/PhysRevC.106.015804.
Fulltekst i vitenarkiv
Vis sammendrag
Nuclei in the 135I region have been identified as being a possible bottleneck for the i process. Here we present an indirect measurement for the Maxwellian-averaged cross section of 126Sb(n,γ). The nuclear level density and the γ-ray strength function of 127Sb have been extracted from 124Sn(α,pγ)127Sb data using the Oslo method. The level density in the low-excitation-energy region agrees well with known discrete levels, and the higher-excitation-energy region follows an exponential curve compatible with the constant-temperature model. The strength function between Eγ≈1.5–8.0 MeV presents several features, such as an upbend and a possibly double-peaked pygmy-like structure. None of the theoretical models included in the nuclear reaction code talys seem to reproduce the experimental data. The Maxwellian-averaged cross section for the 126Sb(n,γ)127Sb reaction has been experimentally constrained by using our level-density and strength-function data as input to talys. We observe a good agreement with the jina reaclib, tendl, and bruslib libraries, while the endf/b-viii.0 library predicts a significantly higher rate than our results.
-
Guttormsen, Magne Sveen; Ay, Kursad Osman; Ozgur, Mustafa; Algin, Emel; Larsen, Ann-Cecilie & Garrote, Frank Leonel Bello
[Vis alle 26 forfattere av denne artikkelen]
(2022).
Evolution of the γ -ray strength function in neodymium isotopes.
Physical Review C.
ISSN 2469-9985.
106(3).
doi:
10.1103/PhysRevC.106.034314.
Fulltekst i vitenarkiv
Vis sammendrag
The experimental γ-ray strength functions (γSFs) of 142,144–151Nd have been studied for γ-ray energies up to the neutron separation energy using the Oslo method. The results represent a unique set of γSFs for an isotopic chain with increasing nuclear deformation. The data reveal how the low-energy enhancement, the scissors mode, and the pygmy dipole resonance evolve with nuclear deformation and mass number. This indicates that the mechanisms behind the low-energy enhancement and the scissors mode are decoupled from each other.
-
Markova, Maria; Larsen, Ann-Cecilie; Neumann-Cosel, Peter von; Bassauer, Sergej; Görgen, Andreas & Guttormsen, Magne Sveen
[Vis alle 23 forfattere av denne artikkelen]
(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.
Fulltekst i vitenarkiv
Vis sammendrag
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
[Vis alle 25 forfattere av denne artikkelen]
(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.
Fulltekst i vitenarkiv
Vis sammendrag
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.
Se alle arbeider i NVA
-
Torsvoll, Marius; Wirgenes, Maia Oline Grund; Al-Adili, Ali; Haug, Henrik Sørlie; Heines, Johannes Sørby & Siem, Sunniva
[Vis alle 13 forfattere av denne artikkelen]
(2026).
Very asymmetric fission yields of 233U(nth, f) at LOHENGRIN.
Fulltekst i vitenarkiv
Vis sammendrag
In this work we report on a fission yield experiment done with the LOHENGRIN recoil mass spectrometer. Understanding the dynamics of nuclear fission requires accurate knowledge of the charge and mass distributions of fission fragments, particularly in rare and poorly studied regions. We present a dedicated investigation of the assymetric fission yields in 233U(nth,f), targeting fragment masses below A = 70, a region previously unexplored for this system. A particular focus is on confirming an expected enhancement of the yields of fragments near mass 70, potentially indicative of a super-asymmetric fission mode influenced by nuclear structure effects, such as the Z = 28 major shell closure. The experiment employed the LOHENGRIN recoil mass spectrometer in combination with a ΔE/E Frischgrid ionization chamber. This allows the identification of the mass of light fission fragments. The far asymmetric mass region will serve for benchmarking theoretical models and improving our understanding of shell effects in fission.
During the presentation, we discussed the necessary correction steps during the analysis, including digital signal processing, scanning ionic charge and kinetic energy distributions, and target burn-up. Moreover, we discuss a comparison of different foil stacks that can be used as passive attenuators in the next beam-time campaign. Preliminary results from this work suggest a yield enhancement in the studied region, implying that the fissioning system U234* may exhibit a similar effect like the heavier systems. We finish by discussing the outlook and preparations for upcoming beam times at ILL.
-
Torsvoll, Marius; Wirgenes, Maia Oline Grund; Al-Adili, Ali; Solders, Andreas; Köster, Ulli & Daugas, Jean-Micheal
[Vis alle 13 forfattere av denne artikkelen]
(2026).
Very asymmetric fission yields in U(n,f) at LOHENGRIN.
Fulltekst i vitenarkiv
Vis sammendrag
The super assymmetric fission mode and yield enhancement around A = 70 has been observed in actinides as light as U. Modern fission codes modeling the fission process do not predict an enhancement like that found in U233 and heavier actinides. The super asymmetric region has not been measured for U233 and our goal is to explore the yields in the mass region from A = 90 to A = 67.
In summary our goal is to extract the unmeasured fission yields in the super asymmetric region of U233(nth, f) with a special emphasis on investigating the possibility of a yield enhancement at atomic mass number A = 70
-
-
Markova, Maria
(2024).
Approaching the pygmy dipole resonance
in Sn isotopes with the Oslo method.
Fulltekst i vitenarkiv
-
Markova, Maria
(2024).
Studying the pygmy dipole resonance in Sn isotopes
with the Oslo method.
Fulltekst i vitenarkiv
-
Markova, Maria
(2024).
Pygmy Dipole Resonance in Sn Isotopes and its
Astrophysical Impact.
Fulltekst i vitenarkiv
-
Markova, Maria
(2024).
Approaching the pygmy dipole resonance in Sn
isotopes with the Oslo method.
Fulltekst i vitenarkiv
-
Markova, Maria
(2023).
The pygmy dipole resonance in Sn isotopes studied
with the Oslo method.
Fulltekst i vitenarkiv
-
Markova, Maria
(2023).
Evolution of the pygmy dipole resonance in Sn nuclei
and its astrophysical implications.
Fulltekst i vitenarkiv
-
-
Markova, Maria
(2023).
Experimental study of the pygmy dipole resonance
and its evolution in Sn isotopes.
Fulltekst i vitenarkiv
-
Markova, Maria
(2022).
Nuclear level densities and γ−ray strength functions of 120,124Sn and their application in astrophysics.
Fulltekst i vitenarkiv
-
-
Markova, Maria
(2022).
Nuclear level densities and γ-ray strength functions of 120,124Sn.
Fulltekst i vitenarkiv
-
Markova, Maria
(2022).
Nuclear level densities and γ−ray strength functions of 120,124Sn
for astrophysical purposes.
Fulltekst i vitenarkiv
-
-
Markova, Maria
(2021).
Comprehensive Test of the Brink-Axel Hypothesis in the Energy Region of the Pygmy Dipole Resonance.
Fulltekst i vitenarkiv
-
Markova, Maria
(2021).
Test of the Brink-Axel hypothesis in the energy region of the
pygmy dipole resonance in Sn isotopes.
Fulltekst i vitenarkiv
-
Markova, Maria
(2021).
Testing of the Brink-Axel Hypothesis for 116,120,124Sn Isotopes
in the Energy Range of the Pygmy Dipole Resonance.
Fulltekst i vitenarkiv
Se alle arbeider i NVA
Publisert
1. sep. 2020 16:05
- Sist endret
19. aug. 2024 07:36