Something like this infinite square well.Īs is common in such problems one appliesīoundry conditions to Schroedingers equation. Ordered discrete energy levels characterized byĬonserved quantized variables energy, angularĪ highly idealized nuclear potential looks That, in analogy to electrons in an atom, are in The nucleons have spin and angular momentum and It goes, but now we shall consider the fact that Sets of identical nucleons and protons comprising Our earlier discussions treated the nucleus as Shell Model Mayer and Jensen 1963 Nobel Prize step down when N goes across magic number at 82.Magic Neutron Numbers (stable isotones).Simple model does not apply for A lt 20.Consequence 2 or more even A, 1 or no odd A.There exists one and only one stable isotope there are nearly no stable o-o nuclei in natureīecause these can nearly all b-decay to an e-eĪn even-even nucleus must decay to an odd-odd.most e-e nuclei have two stable isotopes.lowest o-o nucleus often has two decay modes.The ones with the bigger (less negative) mass Nuclear masses Atomic masses Mass excesses Http//t2./data/astro/molnix96/massd.htmlĪudi and Wapstra, Nuc. Known) In 1961 the carbon-12 standard wasĪdopted. John Dalton proposed H in 1803 Wilhelm Ostwald This automatically includes the electron masses More commonly used is the Atomic Mass Excess Nuclei fromĤ6Fe to 72Fe are stable against strong decay. Or, in the last case where there exists a supplyįor Fe the neutron drip line is found at Aħ3 the proton drip is at A 45.

than the iron group are unstable, but it takes.However, one must take care in applying thisĬriterion, because while unstable, some nucleiĭefinition of unstable is that the isotope hasĪ measurable abundance and no decay has everīeen observed (ultimately all nuclei heavier.

An equivalent statement is that the nucleus AZ.

Than two 4He nuclei, hence 8Be quickly decays g., one 8Be nucleus has less binding energy That, for a collection of A nucleons, there Lecture 4 Basic Nuclear Physics 2 NuclearĪ sufficient condition for nuclear stability is

Nuclear physics lectures ppt