Radiative strength functions in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mmultiscripts><mml:mi mathvariant="normal">Mo</mml:mi><mml:mprescripts /><mml:none /><mml:mrow><mml:mn>93</mml:mn><mml:mo>−</mml:mo><mml:mn>98</mml:mn></mml:mrow></mml:mmultiscripts></mml:math>

Guttormsen, M.; Chankova, R.; Agvaanluvsan, U.; Algin, E.; Bernstein, L. A.; Ingebretsen, F.; Lönnroth, T.; Messelt, S.; Mitchell, G. E.; Rekstad, J.; Schiller, A.; Siem, S.; Sunde, A. C.; Voinov, A.; Ødegård, S. W.

doi:10.1103/physrevc.71.044307

Cited by 155 publications

(252 citation statements)

References 33 publications

Supporting

Mentioning

221

Contrasting

Order By: Relevance

“…An enhancement of the PSF was observed at low E γ in all Mo isotopes and a soft pole -an extrapolation of PSF toward very low E γ which diverges at E γ → 0 -was proposed in Ref. [1] as the most probable PSF energy dependence. There were no experimental points from 3 He-induced reactions for…”

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

“…Data from the ( 3 He,αγ) and ( 3 He, 3 He'γ) reactions measured at the Oslo Cyclotron Laboratory indicated a low-energy enhancement of PSFs at energies E γ < ∼ 3 MeV for the whole chain of Mo isotopes [1] when compared with conventional models for E1 and M 1 PSFs. The PSF consistent with such a low-energy enhancement was recently reported in 95 Mo also from analysis of 94 Mo(d,pγγ) data [2].…”

Section: Introductionmentioning

confidence: 99%

“…To confirm these results we performed simulations with a few temperature-independent PSF models which repro- The experimental data corresponding to the 98 Mo(γ,n) reaction are from (Beil 1974) [30] and (Utsunomiya 2013) [32], the 98 Mo( 3 He, 3 He'γ) data from (Guttormsen 2005) [1], the ELBE 98 Mo(γ,γ') data from (Rusev 2008) [9], the preliminary 98 Mo(γ,γ') HIγS data from (Rusev 2009) [10] and the Stuttgart 98 Mo(γ,γ') data from (Rusev 2006) [8]. For discussion of the Stuttgart data [8] and data from primary transitions from the (n,γ)reaction, see Sec.…”

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

“…The recorded data were filtered and sorted according to time-of-flight gates, adjusted to cover narrow energy regions in which individual resonances reside, and auxiliary regions between the resonances. As a result, parameters characterizing each filtered event were rewritten into a sequence {i, m, E (1) γ , E (2) γ , . .…”

Section: B Data Reductionmentioning

confidence: 99%

“…The PSFs in a series of Mo isotopes have been determined using the so-called Oslo method [33] from γ-ray spectra measured at the Oslo cyclotron in 3 He-induced reactions; the reaction 98 Mo( 3 He, 3 He'γ) was used for determination of the PSF in 98 Mo [1]. An enhancement of the PSF was observed at low E γ in all Mo isotopes and a soft pole -an extrapolation of PSF toward very low E γ which diverges at E γ → 0 -was proposed in Ref.…”

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

See 4 more Smart Citations

Measurement of theMo97(n,γ)reaction with the DANCEγcalorimeter array

et al. 2015

Self Cite

View full text Add to dashboard Cite

Spectra of γ rays following the 97 Mo(n, γ) reaction were measured as a function of incident neutron energy with the DANCE (Detector for Advanced Neutron Capture Experiments) array of 160 BaF2 scintillation detectors at the Los Alamos Neutron Science Center using an enriched 97 Mo target. These spectra were used for the assignment of spins of the 97 Mo resonances up to neutron energy En = 1.7 keV, as well as in the study of photon strength functions (PSFs) in 98 Mo. Analysis of the spectra with the nuclear statistical model showed that they can be well reproduced with the same PSF models which well described the γ decay following slow neutron capture in 95 Mo. On the other hand, the spectra are inconsistent with PSFs describing some other experimental data in 98 Mo.

show abstract

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

Section: B Data Reductionmentioning

confidence: 99%

Section: Psfs That Reproduce Data From 3 He-induced Reactionsmentioning

confidence: 99%

See 3 more Smart Citations

Measurement of theMo97(n,γ)reaction with the DANCEγcalorimeter array

et al. 2015

Self Cite

View full text Add to dashboard Cite

show abstract

Pygmy dipole strength close to particle-separation energies—The case of the Mo isotopes

Rusev¹,

Grosse²,

Erhard³

et al.

The 2nd International Conference on Nuclear Physics in Astrophysics

View full text Add to dashboard Cite

Abstract. The distribution of electromagnetic dipole strength in 92, 98, 100 Mo has been investigated by photon scattering using bremsstrahlung from the new ELBE facility. The experimental data for well separated nuclear resonances indicate a transition from a regular to a chaotic behaviour above 4 MeV of excitation energy. As the strength distributions follow a Porter-Thomas distribution much of the dipole strength is found in weak and in unresolved resonances appearing as fluctuating cross section. An analysis of this quasi-continuum -here applied to nuclear resonance fluorescence in a novel way -delivers dipole strength functions, which are combining smoothly to those obtained from (γ, n)-data. Enhancements at 6.5 MeV and at ∼ 9 MeV are linked to the pygmy dipole resonances postulated to occur in heavy nuclei.PACS. 21.10. .+k Dipole strength in heavy nucleiThe response of nuclei to dipole radiation is of special importance for the synthesis of the chemical elements in the cosmos: Particle thresholds may be crossed in hot or explosive scenarios leading to the production of new nuclides from previously formed heavier ones by dissociation in the thermal photon bath. This is likely to be the main path for the generation of the approximately 30 -40 neutrondeficient nuclides which cannot be produced in neutron capture reactions [1]. For the understanding and modelling of this so-called p-process the dipole strength function up to and near the particle thresholds has to be known accurately [2]. As shown previously [3], details of the dipole strength (now in n-rich nuclei) may as well have large consequences for the r-process path and also s-process branchings are influenced by nuclear excitations [4] induced by thermal photons. The experimental knowledge [5] on dipole strength is reasonably well established for many heavy and medium mass nuclei in the region of the giant dipole resonance (GDR) by (γ, xn) studies, which often also cover the region directly above the neutron threshold S n . At lower energies three features have been discussed to be of importance for processes in high-temperature cosmic environments: a) the fall-off [6-9] of the E1-strength on the low-energy slope of the GDR; b) the E1-strength between the ground-state (gs) and low energy excitations and its proper extension [10-12] into the regime (a); c) the occurrence of additional pygmy-resonances, [3,[13][14][15], which are assumed to be not as broad as the GDR, but wider as compared to the average level distance D -thus forming an intermediate structure enclosing many levels. Their low energy may well enhance their contribution to photo-dissociation processes in spite of their relatively low strength as compared to the GDR. In principle, also M1-transitions contribute to the dipole strength, but the average M1 strength is typically 1-2 orders of magnitude smaller as compared to E1, and they are frequently [1-3] not taken into account. A further approximation has to be introduced to estimate dipole strengths for transitions not connected to the g...

show abstract

Photoneutron Reaction Cross Section Measurements on 94Mo and 90Zr Relevant to the p-Process Nucleosynthesis

Banu

Meekins

Silano

et al. 2019

Springer Proceedings in Physics

View full text Add to dashboard Cite

The photodisintegration cross sections for the 94 Mo(γ , n) and 90 Zr(γ , n) reactions have been experimentally investigated with quasi-monochromatic photon beams at the High Intensity γ -ray Source (HIγ S) facility of the Triangle Universities Nuclear Laboratory (TUNL). The energy dependence of the photoneutron reaction cross sections was measured with high precision from the respective neutron emission thresholds up to 13.5 MeV. These measurements contribute to a broader investigation of nuclear reactions relevant to the understanding of the p-process nucleosynthesis. The results are compared with the predictions of Hauser-Feshbach statistical model calculations using two different models for the dipole γ -ray strength function. The resulting 94 Mo(γ , n) and 90 Zr(γ , n) photoneutron stellar reaction rates as a function of temperature in the typical range of interest for the p-process nucleosynthesis show how sensitive the photoneutron stellar reaction rate can be to the experimental data in the vicinity of the neutron threshold.

show abstract

Radiative strength functions inMo93−98

Cited by 155 publications

References 33 publications

Measurement of theMo97(n,γ)reaction with the DANCEγcalorimeter array

Measurement of theMo97(n,γ)reaction with the DANCEγcalorimeter array

Pygmy dipole strength close to particle-separation energies—The case of the Mo isotopes

Photoneutron Reaction Cross Section Measurements on 94Mo and 90Zr Relevant to the p-Process Nucleosynthesis

Contact Info

Product

Resources

About