Quantal3 1 Repaso 2 3 np 4 5

  • Slides: 54
Download presentation
Quantal_3 1

Quantal_3 1

Repaso 2

Repaso 2

3

3

<np> 4

<np> 4

5

5

6

6

7

7

8

8

no 9

no 9

10

10

 11

11

(va como z) 12

(va como z) 12

[*] 3/v z * Huang, Pathria, etc. 13

[*] 3/v z * Huang, Pathria, etc. 13

14

14

 15

15

T 16

T 16

entonces 17

entonces 17

18

18

 f 19

f 19

20

20

21

21

22

22

23

23

24

24

25

25

26

26

 k. T/ef Dividiendo…. 27

k. T/ef Dividiendo…. 27

(usando la aprox. para KT lnz) 28

(usando la aprox. para KT lnz) 28

equiparticion 29

equiparticion 29

30

30

Gas de Fermi situaciones intermedias 31

Gas de Fermi situaciones intermedias 31

32

32

33

33

34

34

35

35

36

36

37

37

38

38

39

39

40

40

41

41

Simetria Efecto Coulomb protones neutrones 42

Simetria Efecto Coulomb protones neutrones 42

Lo que se describe mediante: 43

Lo que se describe mediante: 43

Formula semiempirica de masas Termino de volumen asociado a una fuerza de rango corto

Formula semiempirica de masas Termino de volumen asociado a una fuerza de rango corto Termino de Coulomb Termino de Simetria (f 4) Termino de superficie 44

45

45

Energia de Union • Termino de Volumen • Termino de superficie – Nucleones en

Energia de Union • Termino de Volumen • Termino de superficie – Nucleones en la superficie estan menos unidos 46

Energia de Union • Coulomb • Para un nucleo de carga Ze, Bc es:

Energia de Union • Coulomb • Para un nucleo de carga Ze, Bc es: 47

Energia de Union Symmetry Term 48

Energia de Union Symmetry Term 48

FIN 49

FIN 49

Binding Energy • Symmetry Term The most stable nuclei are those with Z=N=A/2. For

Binding Energy • Symmetry Term The most stable nuclei are those with Z=N=A/2. For a nucleus with the same number of protons and neutrons (Z=N), they have the same energy called Fermi energy. If N>Z, the total energy must increase because of the exclusion principle. 50

Binding Energy • Pairing Energy Term Two protons and two neutrons are always more

Binding Energy • Pairing Energy Term Two protons and two neutrons are always more strongly bound than one proton and one neutron. The even-even nuclei are the most stable and have higher binding energies. Odd-odd nuclei have both unpaired protons and neutrons and have relatively low binding energies. The pairing energy is positive for even-even nuclei, zero for odd-even and even-odd nuclei, and negative for odd-odd nuclei. where 51

Binding Energy • The Weizsaecker formula is an empirically refined form of the liquid

Binding Energy • The Weizsaecker formula is an empirically refined form of the liquid drop model for the binding energy of a nucleus of mass number A with Z protons and N neutrons. It is also referred to as the "semi-empirical mass formula" and the "Bethe-Weizaecker formula". The Weizsaecker formula is 52

Binding Energy • Fit to experimental data to obtain: • The binding energy per

Binding Energy • Fit to experimental data to obtain: • The binding energy per particle becomes 53

Stable Nucleus • For most stable nucleus for a given A has the above

Stable Nucleus • For most stable nucleus for a given A has the above Z value: 54