the 13th national nuclear structure conference of china, chifeng fragments cross section...
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The 13th National Nuclear Structure Conference of China, Chifeng
Fragments cross section distributions of even 36-52Ca at intermediate energy
马春旺 Email: [email protected]
Outlook:
1. Backgrounds 2. The SAA Model 3. Results and Discussion 4. Conclusions
张艳芳 , 魏慧玲河南师范大学物理学系
The 13th National Nuclear Structure Conference of China, Chifeng
1. Backgrounds Projectile fragmentation is one of the basic
experimental method in RIB era.NSCL experiment: 40,48Ca+9Be/181Ta, 58,64Ni+9Be/181Ta, 86Kr+9Be
New generation or updated RIB facilities expand the nuclear chart to more neutron-rich and proton-rich sides.
Increasing interests in EOS of asymmetric nuclear matter: n-rich nuclei
Hotter in the research of ISOSPIN physics. Neutron density distribution of neutron-rich
nucleus hard to be extracted or measured. Neutron skin thickness important in nuclear phys.
etc.
The 13th National Nuclear Structure Conference of China, Chifeng
1. backgrounds– neutron skin thickness and EOS
The 13th National Nuclear Structure Conference of China, Chifeng
1. Backgrounds Neutron density distribution or neutron skin
thickness of asymmetric nuclear matter: not easy to know but important in nuclear physics.
Isospin phenomena are strongly related to the different proton and neutron density distribution of asymmetric nucleus.
Can the isospin phenomena be used to extract neutron density distribution of neutron skin thickness directly? The observable!
D.Q.Fang, et al., PhysRevC61(2000)044610;Ma Chun-Wang, et al., Chin.Phys.B,17(2008)1216;Ma Chun-Wang, et al., Phys.Rev.C79(2009)034606,Chin. Phys. B18(11)(2009), to be published
The 13th National Nuclear Structure Conference of China, Chifeng
Chin. Phys. B 17(04)(2008)1674
The 13th National Nuclear Structure Conference of China, Chifeng
1. Backgrounds Isospin dependence of PF
140A MeV 40,48Ca/ 58,64Ni+9Be
Ma Chun-Wang, et al., Chin. Phys. B18(11)(2009), to be published
Isospin effect in fragments production and it’s decreaseObvious in the productions of peripheral reactions. (big difference of proton and neutron density distribution in the surface of nucleus)Decrease and disappear in the productions of central collisions. (similar proton and neutron density distributions in the core of nucleus)
The 13th National Nuclear Structure Conference of China, Chifeng
1. Backgrounds How do the peak position of the
fragments distributions change in the PF of a series of isotopes?
If there are some parameters or observables that are related to neutron skin thickness? Find the correlation between neutron skin thickness and some observables.
The 13th National Nuclear Structure Conference of China, Chifeng
2. The statistical abrasion-ablation (SAA) model
Brohm & Schmidt, Fang, Zhong, etc, Simple and useful; 2-steps reactions:
Collisions—participant and spectator
De-excitation
Refs:NPA569(1994)821, PRC61(2000)044610, CPC 27(2003)39, EPJA10(2001)381,PRC79(2009)034606
The 13th National Nuclear Structure Conference of China, Chifeng
2. The statistical abrasion-ablation (SAA) modelThe colliding nuclei: parallel tubes.
transmission probabilities for neutrons (protons) at b:
the average absorbed mass in an infinitesimal tubes at b Density distributions: Fermi-type
Isotope production
De-excitation
Y.Eisenberg, PhysRev 52(1954)1378
Key for frag production
The 13th National Nuclear Structure Conference of China, Chifeng
3. Results
The 13th National Nuclear Structure Conference of China, Chifeng
3. PF of even even 36-5236-52CaCa isotopes
The 13th National Nuclear Structure Conference of China, Chifeng
4. Results and discussion
Isotonic distributionsIsotopic distribution
The 13th National Nuclear Structure Conference of China, Chifeng
Peak position (in A) as a function of ΔN, ΔZ
The 13th National Nuclear Structure Conference of China, Chifeng
4. Results and discussion
The 13th National Nuclear Structure Conference of China, Chifeng
4. Results and discussion
Peak vs A fit results
The 13th National Nuclear Structure Conference of China, Chifeng
4. Results and discussion
The 13th National Nuclear Structure Conference of China, Chifeng
4. Results and discussion
σ(iCa)- σ(40Ca)
The 13th National Nuclear Structure Conference of China, Chifeng
5. Conclusion The cross sections of fragments prod
uced in 80 A MeV even 36-52Ca PF on 12
C were calculated by the SAA model.