NUCLEAR PHYSICS Tran Thi Ngoc Dung – Huynh Quang Linh – Physics A2 HCMUT 2016 OUTLINE • BINDING ENERGY BINDING ENERGY PER NUCLEON • NUCLEAR FORCE • RADIOACTIVITY ALPHA, BETA, GAMMA DECAY • RADIOACTIVE[.]
NUCLEAR PHYSICS Tran Thi Ngoc Dung – Huynh Quang Linh – Physics A2 HCMUT 2016 OUTLINE • BINDING ENERGY-BINDING ENERGY PER NUCLEON • NUCLEAR FORCE • RADIOACTIVITY-ALPHA, BETA, GAMMA DECAY • RADIOACTIVE CARBON DATING • NUCLEAR REACTIONS - FISSION, FUSION NUCLEAR COMPONENTS Nucleus contains nucleons: protons and neutrons • Atomic number Z = number of protons • Neutron number N = number of neutrons • Mass number A = number of nucleons = Z + N • Each element has unique Z value • Isotopes of element have same Z, but different N and A values Notion: A Z X Isotopes H , H , 1 1H 16 17 18 O , O , 8 8O RADIUS of a NUCLEUS R R oA 1/ A=N+Z: Mass Number R o 1.2 10 15 m 1.2fm NUCLEAR DENSITY • All nuclei have approximately the same density 17 2.3 10 kg / m Volume of the nucleus: : 4 1/ 3 V R (R o A ) R o A 3 Mass density mpA M nucleus 1.67 10 27 2.3.1017 kg / m 4 3 R R o A (1.2 10 15 ) 3 3 Nucleus Charge and Mass Particle Charge Mass (kg) Mass (u) Mass (MeV/c2) Proton +e 1.6726 x10−27 1.007 276 938.28 Neutron 1.6750 x10−27 1.008 665 939.57 Electron −e 9.109 x 10−31 5.486x10−4 0.511 • Unified mass unit, u, defined using Carbon 12 • Mass of atom of 12C ≡ 12 u u = 1.660539 10 27 kg = 931.494 MeV / c NUCLEAR SPINS • Protons and neutrons are also spin ẵ particle ã The magnitude of Spin angular momentum S of a nucleon: S s(s 1) • The z component is 1 ( 2 1) Sz In addition to the spin angular momentum, there may be orbital angular momentum associated with their motions within the nucleus The total angular momentum 𝐽 of the nucleus is the vector sum of the individual spin and orbital angular momenta of all the nucleons Total angular momentum J i L i Si • Total angular momentum of nucleon: • Total angular momentum of the nucleus: J J i L i Si i i i • The magnitude: of nuclear angular momentum: J j( j 1) • and z component: J z m j (m j j, j 1, , j 1, j) Total angular momentum j=nuclear spin • When A is even, j is an integer; 0,1,2,3 • When A is odd, j is a half interger ẵ, 3/2 ã All nuclides for which both Z and N are even have J=0, which suggests that pairing of particles with opposite spin components may be an important consideration in nuclear structure • The total nuclear angular momentum number j is usually called the nuclear spin Magnetic Moment • Associted with nuclear angular momentum is a magnetic moment • Nuclear magneton: e 5.05078 10 27 J / T n 2m p • The z component of the spin magnetic moment of sz the proton: proton 2.7928 n • The neutron, which has zero charge, has a spin magnetic moment The z component of the spin magnetic moment of the neutron: sz neutron 1.9130 n ... consideration in nuclear structure • The total nuclear angular momentum number j is usually called the nuclear spin Magnetic Moment • Associted with nuclear angular momentum is a magnetic moment • Nuclear. .. ENERGY-BINDING ENERGY PER NUCLEON • NUCLEAR FORCE • RADIOACTIVITY-ALPHA, BETA, GAMMA DECAY • RADIOACTIVE CARBON DATING • NUCLEAR REACTIONS - FISSION, FUSION NUCLEAR COMPONENTS Nucleus contains... Si i i i • The magnitude: of nuclear angular momentum: J j( j 1) • and z component: J z m j (m j j, j 1, , j 1, j) Total angular momentum j =nuclear spin • When A is even, j