Central force lattice dynamical model for zirconium hydride

On the impact of phonon spectrum shifts of the hydrogen binding in ZrH

“…The curves in figure 7 demonstrate that the reactivity coefficients for constant phonon spectrum have again only weak dependency on temperature as in the domain below 110 • C. Consequently, the reactivity coefficient will retain its previous level as is depicted in figure 1. The feasibility of such a postulated shift is realistic and in accordance with the conclusions of Malik [5] and the work of Slaggie [6] concerning the contribution of H-H forces to the vibration mode. Nevertheless, it is evident that more experiments and verifications are mandatory in respect to feedback experiments within the temperature range 100-150 • C. Such investigations could contribute to an improved model of the varying stoichiometry of the bound Hydrogen in zirconium embedded in a fuel matrix.…”

“…The phonon spectrum of hydrogen bound in zirconium suggested by Slaggie [6] and commonly used by NJOY [10] given in figure 3. This spectrum is based on a central force model of ZrH 2 .…”

“…In this study potential deviation of the phonon spectrum from the reference curve [6] are analysed in view of their impact on the criticality and the temperature dependent reactivity feedbacks.…”

“…Moreover the fine structure of the hydrogen admixture is associated with the optical peak [6]. The corollary of the above observation means that in the case of TRIGA fuel the phonon spectrum used could be not adequate.…”

Inelastic neutron scattering study of the hydrogenated (Zr55Cu30Chuang1, Udovic2, Liaw3 et al. 2011Phys. Rev. B

“…Previous theoretical simulations using the central force lattice dynamic model (CF model) suggested that the hydrogen-vibration energy of a particular occupation site only depends on the H-M distance as well as the local atomic arrangement (the site geometry) 24 . The peak width is mainly determined by the interaction of the surrounded M atoms to the second-nearest M atoms.…”