Using the surface term in the von Weizsäcker formula The surface tension is also the tension force at the perimeter of the Potential energy of the surface molecules. Length of a rectangular surface area must equal the increased Potential energy per unit surface area. “ surface tension.” Surface tension is defined as increased Macroscopically, this effect is explained as
QUICK DRAFT ROTATION FULL
Surface of the nucleus are not surrounded by a full set of attracting The von Weizsäcker formula showed that the nuclear potential energy ( 14.9) for the nuclear radius, and it greatly simplifies This assumption is consistent with the formula It will further be assumed that the nuclear liquid preserves its But a two-liquid model, suchĪs found in, is beyond the Proton and neutron motions are the same. Model of a nucleus there is no a priori reason to assume that the That is a somewhat doubtful assumption for a It will be assumed that the nuclear liquid is This is needed to allow for the very important destabilizingĮffect of the Coulomb forces in a nucleus. Included that you would be unlikely to see in a drop of water: it willīe assumed that the liquid contains distributed positively charged However, there will be one additional effect This section reviews the mechanics of a classical liquid drop, like Deformed nuclei can displayĮffects of rotation of the nuclei. Nuclear deformation or nuclear fission.
The vibrations can become unstable, providing a model for permanent Which the nucleons as a group participate nontrivially. Vibrating states provide a model for low-energy excited states in Model was quite successful in explaining the size and ground stateĮnergy levels of nuclei in section 14.10.īut liquid drops are not necessarily static they can vibrate. Based on that idea, physicists hadĪnother look at the classical liquid drop model for nuclei. Nuclei with many nucleons and densely spaced energy levels bear some Mathematically unsound in the case of deformed nuclei. On a perturbed basic shell model alone would be very difficult, and Trying to explain such organized massive nucleon participation based It seems clear that many or all nuclei participate in these effects. Written in stone.) In terms of figure 14.19, they are the Unstable lighter nuclei are quite nonspherical too. In terms of the mass number, the ranges are about 150 190 and 220. The line of most stable nuclei, they are roughly the “rareĮarth” lanthanides and the extremely heavy actinides that areĭeformed. They are called the nonspherical or deformed nuclei. Then there are nuclei for which the normal shell model does not workĪt all. Model excitations combine forces, as in section 14.12.5. Within a shell model context, you are led to the idea that many shell If you try to explain the excitation energy One example is ruthenium-104 in figure 14.20,Īnd many other even-even nuclei with such energies may be found inįigure 14.19. Therefore physicists have developedįor example, nuclei may have excited states with unexpectedly lowĮnergy. Some nuclear properties are difficult to explain using the shell modelĪpproach as covered here. 4 Draft: Bands with intrinsic spin zero 3 Draft: Bands with intrinsic spin one-half 1 Draft: Basic notions in nuclear rotation
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