1. Energy Dependence of the Isotopic Composition in Nuclear Fragmentation
S. Yennello, D. Shetty, M. Veselsky, E. Martin, A. Keksis, G. Souliotis and D. Rowland
Texas A&M University
Cyclotron Institute

2. Single component liquid
Two component liquid
Single component liquid
Two component liquid
Free n/p ratio
t/3He ratio
N/Zfragments
Possible signatures:

3. 124Sn
124Sn
Veselsky, Phys. Rev. C 62, (2000).

4. Veselsky, Phys. Rev. C 62, (2000).

5. 28Si + 112,124Sn Veselsky,Phys Lett B 497,1(2001) E*=2.5-3.5

6. Ratio of isotopic yields 58Ni, 58Fe + 58Ni, 58Fe 30 Mev/nuc

7. Scaling factor

8. Relative free neutron and proton densities

9. Scaling factor at 30,40,47 MeV/nuc

10. neutron and proton densities at 30,40,47 MeV/nuc

11. Energy dependence of the scaling parameter a
58Fe + 58Fe / 58Ni + 58Ni
30 MeV
40 MeV
47 MeV a
0.372
0.269
0.23 b
-0.395
-0.372
-0.32
Tsang PRC64, (2002) .

12. Botvina Isoscaling R21 = C exp(a’A + b’(N-Z)
a ’ = D(mn + mp)/2T
b ’ = D(mn - mp)/2T
28Si + 112,124Sn
30 MeV/nuc
50 MeV/nuc
b’ = 0.237±0.038
b’ = 0.186±0.017

13. Botvina Isoscaling R21 = C exp(a’A + b’(N-Z)
28Si + 112,124Sn ; 50 MeV/nuc E*
(MeV) b’ 3
0.31 4
0.20 5
0.19 6
0.18 7
0.17

14. Summary
The enhancement in free neutrons of neutron-rich systems is greater at lower energies.
Isoscaling in 58Ni, 58Fe + 58Ni, 58Fe
3H/3He in 28Si + 112Sn, 124Sn
Isoscaling in 28Si + 112Sn, 124Sn

15. Theory Bao An Li PRL 2000 Baran Nucl Phys 1999 Chomaz
PLB 47, 221 (1999)

16. Theoretical comparisons are in progress.
Summary
The enhancement in free neutrons of neutron-rich systems is greater at lower energies.
Isoscaling in 58Ni, 58Fe + 58Ni, 58Fe
3H/3He in 28Si + 112Sn, 124Sn
Isoscaling in 28Si + 112Sn, 124Sn
Theoretical comparisons are in progress.
This work was supported in part by the Department of Energy and the Robert A Welch Foundation