systematical calculations on superheavy nuclei n.
Download
Skip this Video
Download Presentation
Systematical calculations on superheavy nuclei

Loading in 2 Seconds...

play fullscreen
1 / 48

Systematical calculations on superheavy nuclei - PowerPoint PPT Presentation


  • 104 Views
  • Uploaded on

Systematical calculations on superheavy nuclei. Zhongzhou REN Department of Physics, Nanjing University, Nanjing, China Center of Theoretical Nuclear Physics, National Laboratory of Heavy-Ion Accelerator, Lanzhou, China. Outline. Introduction

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Systematical calculations on superheavy nuclei' - jacqueline-nieves


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
systematical calculations on superheavy nuclei
Systematical calculations on superheavy nuclei
  • Zhongzhou REN
  • Department of Physics, Nanjing University, Nanjing, China
  • Center of Theoretical Nuclear Physics,

National Laboratory of Heavy-Ion Accelerator,

Lanzhou, China

outline
Outline
  • Introduction
  • Nuclear structure calculations on superheavy nuclei (RMF, SHF, MM)
  • Alpha decay: density-dependent cluster model (DDCM)
  • Spontaneous Fission: new formula on half-lives of SF.
  • Summary
1 introduction experiments
1. introduction: experiments
  • Z=110 (Ds), 111(Rg), 112 were produced at

GSI, Hofmann, Muenzenberg…. Z. Phys. A, 1995-1996

  • Z=114-116, 118, at Dubna, by Oganessian et al….

Nature, 1999; PRL. 1999;PRC, 2000-2005.

  • Z=110-111, new results, at Berkeley, PRL 2004….
  • Z=113, RIKEN, Morita,…, J. P. S. J., 2004.
  • 270Hs, Duellman, Turler, …, Nature 2003, EPJA 04.
  • 265Bh, Lanzhou, Gan, Qin, …, EPJA 2004.
1 introduction theory
1. introduction: theory.
  • J. A. Wheeler, 1950s: Superheavy nuclei
  • Werner and Wheeler, Phys. Rev., 109 (1958) 126.
  • 1960s-2000s, macroscopic-microscopic model (MM): Nilsson et al, Z=114 and N=184….
  • 1970s-2000s: Skyrme-Hartree-Fock (SHF) Model; Z=126? N=184?
  • 1990s-2000s: Relativistic Mean-Field model :
  • Z=120 ? N=184?
  • Spherical or deformed for superheavy nuclei ???
2 nuclear structure calculations
2. nuclear structure calculations
  • 2.1. RMF calculations on superheavy nuclei
  • Z=90-120:binding energies, deformations,…
  • Compare RMF with experimental data
  • RMF predictions on experiments
  • Ren et al. , PRC (2002-2005) ; NPA(2003-2005)…
  • 2. 2 New idea: shape coexistence and superdeformation
  • Ren and Toki, 2001, NPA, Ren et al,…
  • 2.3. Shape coexistence from other models
  • SHF model and MM model
  • Nature 433, 2005.
  • Atom. Data. Nucl. Data Tab. 77 (2001) 311 .
2 1 rmf results and discussion
2.1 RMF results and discussion
  • Nuclei: Z =94—120; N=130—190.
  • Comparison of theoretical binding energy with exprimental data.
  • Comparison of theoretical alpha decay energy with exprimental data.
  • Comparison of theoretical quadrupole deformation with exprimental data.
table 2 rmf results for cm tma and nlz2
Table 2, RMF results for Cm. (TMA and NLZ2)

Experimental deformation Beta2=0.30 for 244-248Cm

table 5 rmf results for no tma and nlz2
Table 5, RMF results for No. (TMA and NLZ2)

Experimental deformation Beta2=0.27 for 254No

fig 3 binding energy of the z 112 a 277 alpha decay chain from the rmf and moller et al
Fig. 3 Binding energy of the Z=112, A=277 alpha-decay chain from the RMF and Moller et al.
fig 4 theoretical and experimental alpha decay energies for gsi data z 110 111 112 2 1 0 shift
Fig. 4 Theoretical and experimental alpha decay energies for GSI Data: Z=110, 111, 112 ( +2, +1, 0 shift).
2 new shape coexistence superdeformation
2 new: shape coexistence,superdeformation

?Ren and Toki, Nucl. Phys. A 689 (2001) 691.

  • Z. Ren, Shape coexistence in even-even superheavy nuclei, Phys. Rev. C65, 051304 (2002)
  • Z. Ren et al., Phys. Rev. C66, 064306 (2002)
  • Z. Ren et al., Phys. Rev. C67, 064302 (2003)
  • Sharma, …,Munzenberg, PRC, 2005;
  • ..,Stevenson, Gupta, Greiner, JPG, 2006.
  • S. Goriely, F. Tondeur, J. Pearson, SHF Model
  • Atom Data and Nucl. Data Tables 77 (2001) 311.
  • Superdeformation for some superheavy nuclei
15 ren z shape coexistence in even even superheavy nuclei phys rev c65 051304 2002
15. Ren, Z. Shape coexistence in even-even superheavy nuclei. Phys. Rev. C65, 051304 (2002)

To be cited: shape coexistence, Ref. [15]

Nature, 433 (2005) 475

64 z ren phys rev c65 2002 051304 r 65 z ren et al phys rev c66 2002 064306
64. Z. Ren, Phys. Rev. C65, (2002) 051304(R) 65. Z. Ren et al., Phys. Rev. C66, (2002) 064306

Exp. Def. : 0.28, RMF Def.: 0.26-0.32,cited.

z ren et al prc 67 2003 064302 npa 722 2003 543 prediction for 265 107 q a and t a
Z. Ren et al, PRC 67 (2003) 064302; NPA 722 (2003) 543.Prediction for 265107: Qa and Ta

Expt: Gan et al, EPJA 2004, Qa=9.24 , Ta=0.94 s.

Good agreement between theory and data.

theoretical prediction 265 107 q a and t a z ren et al prc 67 2003 064302 jnrs 3 2002 195
Theoretical prediction: 265107 Qa and Ta Z. Ren et al, PRC 67 (2003) 064302; JNRS 3 (2002) 195.

Expt: Gan et al, EPJA 2004, Qa=9.38 , Ta=0.94 s.

Good agreement between theory and data.

slide21
Z. Ren, Prog. Theor. Phys. Supplement, No. 146 (2002) 498 (YKIS01, Japan).RMF prediction for 278113: Qa and Ta

Morita et al, JPSJ 2004, Qa=11.68, Ta=0.34 ms.

Good agreement between theory and data.

oganessian et al prc72 2005
Oganessian et al, PRC72 2005

Predictions of SHF and RMF compare well with MM results [12,13]

南京大学

oganessian et al prc72 20051
Oganessian et al, PRC72 2005

SHF [12,49-51] and RMF [13,52-57] compare well with the experimental results

南京大学

3 density dependent cluster model
3. Density-Dependent Cluster Model
  • DDCM is a new model of alpha decay:
  • 1) effectve potential based on the Reid potential.
  • 2) low density behavior included.
  • 3) exchange included
  • 4) agreement within a factor of three for half-lives
  • Z Ren, C Xu, Z Wang, PRC 70: 034304 (2004)
  • C Xu, Z Ren, NPA 753: 174 (2005)
  • C Xu, Z Ren, NPA 760: 303 (2005)
  • C. Xu, Z. Ren, PRC 73: 041301(Rapid Commun.) (2006)
slide25

3. DDCM for alpha decay:agreement is within a factor of three for half-lives although experimental half-lives vary from 10-6 s to 1019 year

ddcm prc 16
DDCM : 被PRC论文大段引用(共16处)

最近文献[7,16,18,28]研究了超重元素alpha衰变; 如图2为[7,18,28]的结果.我们的结果和[18]的结果基于不同的cluster模型.

文献[18]得到了超重核alpha衰变寿命好的符合.

文献[18]提出的结团模型理论很好描述了该区域.

slide30
Deformed DDCM: a spherical alpha-particle interacts with a deformed daughter nucleus with an axially symmetric deformation
slide31

The double-folding nuclear potential of 236U for two orientations, beta = 0◦ and beta = 90◦

slide32

In the multipole expansion, the density distribution of daughter nucleus is expanded as

The corresponding intrinsic form factor has the form

The double-folding potential can then be evaluated by a sum of different multipole components

slide33

The corresponding multipole components are

The polar-angle dependent penetration probability of alpha decay is given by

In the DDCM, thealpha-decay width has the following expression

slide34

The comparison of experimental alpha-decay half-lives and theoretical ones for even-even nuclei (Z= 52−104)

4 new formula of half lives ground state and isomer spontaneous fission
4. New formula of half-lives: Ground-State and isomer spontaneous fission.
  • Long lifetime line of G.S. fission: N=Z+52
  • Three formulas for G.S. fission.
  • New formula of fission half-lives of 33 isomers:
  • log10(T1/2) = -6 + c1(Z-92) + c2(N-Z-52)(N-146) + c3
  • C Xu, Z Ren, PRC 71: 014309 (2005)
  • Z Ren, C Xu, NPA 759: 64 (2005),….
summary
Summary
  • Nuclear structure calculation :
  • Agreement with data and new predictions
  • Shape coexistence: isomers of superheavy nuclei; maybe superdeformation
  • More and more people agree since 2005.
  • Density-dependent cluster model of alpha decay (spherical and deformed)
  • New formulas for spontaneous fission:
  • Ground state and isomeric state
eikonal
编写电子和晕核散射新程序:相对论Eikonal近似编写电子和晕核散射新程序:相对论Eikonal近似
  • 1. 理论结果与现有实验数据非常符合
  • 2. 预言电子-丰质子核散射,能清楚探测质子晕 结构, 这是电子-质子晕核散射的第一个理论结果
  • 3. 为将来的电子-丰质子核对撞实验预研
  • 参考文献
  • Z Wang, Z Ren, PRC 70: 034303 (2004)
  • Z Wang, Z Ren, PRC 71: 054323 (2005)
  • ……
eikonal1
编写电子和晕核散射新程序:相对论Eikonal近似编写电子和晕核散射新程序:相对论Eikonal近似