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Nuclear Physics Study. 2009/08/01 Grass. From CERN, Summer Student Program 2005. Do you recognize me?. Do you recognize me?. http://www.lbl.gov/abc/wallchart/index.html. Strong v.s . Electromagnetic. Radioactivity. b - decay: n p + e - + n - PowerPoint PPT Presentation

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Nuclear Physics Study2009/08/01GrassFrom CERN, Summer Student Program 20051Do you recognize me?2

2Do you recognize me?3

34http://www.lbl.gov/abc/wallchart/index.html

4Strong v.s. Electromagnetic5

bN =ZN =ZZbN>ZAA(A-1)ZZZ5

Radioactivityb- decay: n p + e- + n

b+ decay: p n + e+ + n (e.g., 14O8 14N7 + e+ + n)

a decay: (e.g., 238U8 234Th90 + 4He2 )6

b2700280602300500018-10ZN18-10bbb(A< 40)bN =ZbN >Zb()bb

6

3a reaction : a+a+a 12Cap process : 14O+a 17F+p 18Ne 18Ne+a ...Capture Process7Proton capture Neutron capture

7The Liquid Drop ModelTheir interior densities are the sameTheir heats of vaporization are proportional to their masses.8

A VA atargetmeta stablecompound neucleusenergyseperation energytargetA+ZCompound neucleusY+b

magic numberMayerJensenshell model8Magic number9

See the movie30 75%25% 2656 1014 (r-process)

9Shell ModelIncluding a spin-orbit interactionPredicted magic numbers1st Shell: 2 states (n = 0, j = 1/2). 2=22nd Shell: 6 states (n = 1, j = 1/2 or 3/2). 8 = 2+63rd shell: 12 states (n = 2, j = 1/2, 3/2 or 5/2). 20 = 2+6+124th shell: 8 states (n = 3, j = 7/2). 28 = 2+6+12+85th shell: 22 states (n = 3, j = 1/2, 3/2 or 5/2; n = 4, j = 9/2). 50 = 2+6+12+8+22 6th shell: 32 states (n = 4, j = 1/2, 3/2, 5/2 or 7/2; n = 5, j = 11/2). 82 = 2+6+12+8+22+32 7th shell: 44 states (n = 5, j = 1/2, 3/2, 5/2, 7/2 or 9/2; n = 6, j = 13/2). 126 = 2+6+12+8+22+32+448th shell: 58 states (n = 6, j = 1/2, 3/2, 5/2, 7/2, 9/2 or 11/2; n = 7, j = 15/2). 184 = 2+6+12+8+22+32+44+5810

the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels.

(spin-orbitPauli principlemagic No.model)shell modelQuadrupole moment20~30Unified model ()() ()10

Super-nova

X-ray BursterNucleosynthesis PathsP-

rp-S-R- :1 x 109 k1K Rp-,pRp-+Rp-1 x 108 KRp-Rp-X .

R-R-R-S-AGBThe End12 33 Type II Supernova Type Ia 1.4 (Chandrasekhar limit) Type Ia Type Ia s-processbeta Tc, Bi Pb Li, Be, B WILKINSON MICROWAVE ANISOTROPY PROBE (WMAP) ()( )

12131314

The S-process acting in the range from Ag to Sb.http://en.wikipedia.org/wiki/S-process14151516

16

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