176Luisotope properties as a cosmothermometer

Modification of nuclear transitions in stellar plasma by electronic processes:Kisomers inLu176andGosselin1, Morel2, Mohr3 2010Phys. Rev. C130160View full textAdd to dashboardCite

“…This value is in the experimental limits 10 ps ≤ τ ≤ 433 ps for the lifetime of the 839 keV state because this state predominantly (branching > ∼ 80 %) decays by the 839 → 0 transition. In agreement with the theoretical arguments in [47] and the experimental photoactivation yields [25,26] (see discussion in [5] where τ ≈ 12 ps is suggested with an uncertainty of about a factor of two) we use a value close to the upper experimental limit of the width (or lower limit of the lifetime).…”

“…In the so-called interpulse phase neutrons are produced by the 13 C(α,n) 16 O reaction at relatively low temperatures around kT ≈ 8 keV for about 10 4 −10 5 years; this temperature is too low to affect isomer production and destruction [5,7]. During thermal pulses the 22 Ne(α,n) 25 Mg neutron source is activated for a few years at temperatures around 25 keV and densities of the order of 10 3 g/cm 3 [52]. For the present analysis we adopt this density, and we study the temperature dependence of various transitions in the chosen examples 176 Lu and 180 Ta.…”

Properties of the5−state at 839 keV inLu176and theMohr1, Bisterzo2, Gallino3 et al. 2009Phys. Rev. C252300View full textAdd to dashboardCite

“…Photon scattering [6] and photoactivation of 176 Lu [7] have been measured using bremsstrahlung at the Stuttgart dynamitron, and earlier experiments with bremsstrahlung have been performed using medical and technical electron accelerators [8,9,10,11] which are known to provide high photon intensities [12]. Activation after Coulomb excitation was studied at the Tandem accelerator at IPN, Orsay [13], activation using positron annihilation was measured at the Kyoto research reactor [14], and photoactivation experiments with various radioactive sources were reported in [10,15,16,17]. High-resolution gamma-spectroscopic studies were performed using the 175 Lu(n,γ) 176 Lu reaction at the GAMS spectrometer at ILL, Grenoble [18,19,20], using HPGe detectors [19,21], and using the 176 Yb(p,n) 176 Lu reaction at the Berkeley cyclotron [22].…”

“…The obtained information is compiled in the ENSDF online data base [27] which is based on [28]. Further information on IS can be deduced from a Coulomb excitation and activation experiment [13] which has detected the activity of the isomer in 176 Lu recoil nuclei after Coulomb excitation by a 32 S projectile, and from various photoactivation experiments using bremsstrahlung and radioactive sources [8,9,10,11,15,16,17]. Finally, a photoactivation experiment has been performed [7] using the high photon flux of the bremsstrahlung setup of the dynamitron accelerator at Stuttgart [29].…”

“…Finally, a photoactivation experiment has been performed [7] using the high photon flux of the bremsstrahlung setup of the dynamitron accelerator at Stuttgart [29]. Although a final analysis of these data is unfortunately not available, the data analysis in [7] is sufficient to derive the integrated cross section of the IS at 839 keV unambiguously in combination with the other available data [13,18,19,20].…”