paulo roberto s. gomes instituto de fisica universidade ...fusion06/talks/sunday/gomes.pdf · bjp...
TRANSCRIPT
![Page 1: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/1.jpg)
Fusion, break-up and scattering of stable weakly bound nuclei
Paulo Roberto S. GomesInstituto de Fisica
Universidade Federal Fluminense Niterói, R.J, Brazil
![Page 2: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/2.jpg)
For a comprehensive review of this subject:Phys. Rep. 424 (2006), 1-111
![Page 3: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/3.jpg)
The break up of stable weakly bound nuclei
Suitable stable weakly bound nuclei
6Li → 4He + d Sa = 1.48 MeV7Li → 4He + t Sa = 2.45 MeV9Be → 8Be + n → 4He + 4He + n Sn = 1.67 MeV
![Page 4: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/4.jpg)
The Fusion X Break-up problem
•The full understanding of the fusion and break-up processes induced by stable weakly boundnuclei is an important reference for theinvestigation of similar systems involvingradioactive beams.
![Page 5: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/5.jpg)
Motivation for the investigation of thebreak-up effect on the fusion cross section
• Study of correlations and couplings between reaction
mechanisms in heavy ion collisions.
• Does the break-up coupling to fusion enhance its
cross section or does the BU compete with fusion and
suppress it?
• Important for astrophysical processes and
production of super-heavy elements.
![Page 6: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/6.jpg)
Fusion with tightly bound nucleiabove the Coulomb barrier
As the energy increases, other reaction mechanisms compete with the fusion, that becomes limited or saturated.
![Page 7: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/7.jpg)
Fusion with tightly bound nucleibelow the Coulomb barrier
-Important nuclear structure effects.
-Usual enhancement of the cross section, when comparedwith predictions from one dimensional barrier penetrationmodels.
![Page 8: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/8.jpg)
Role of coupled channels in the sub-barrierfusion cross section enhancement
Is is well stablished that inelastic excited states and transferchannels enhance the sub-barrier fusion cross section.
Inelastic couplings Inelastic and transfer couplings
![Page 9: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/9.jpg)
Where is the fusion decided?
There is controversy whether the Coulomb barrier shouldbe transposed (rf = 1.2 fm) or if the fusion is decided evenbefore the barrier is reached (rf = 1.5 fm).
P. Gomes et al; JP G23 (1997), 1315
![Page 10: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/10.jpg)
Threshold anomaly in the elastic scattering
• Optical Potencial : U(E) = V0 + ?V(E) + W(E)where W(E) = WV (E) + WS (E)
Tenreiro et al – PRC 53 (1996), 2870
![Page 11: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/11.jpg)
Processes to be considered in reactionswith weakly bound nuclei
CN
T1
2
DCF
T1
CN22
ICF 1
T2
1CN
1ICF 2
T1
2T
1
2CN
T1
2
ACN < AP+AT
ACN = AP+AT
B-Up
T1
2
Elastic Breakup
T1
2ACN = AP+AT
SCF
ICF
CF DCF
![Page 12: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/12.jpg)
Theoretical aspects to be considered
• Static effects: longer tail of the opticalpotential arising from the weakly boundnucleons.
• Dynamical effects: strong coupling betweenthe elastic channel and the continuum states representing the break-up channel.
? strong influence on reaction channels, particularly on fusion cross section.
• Relative motion of the fragments and their interactions. What are their trajectoriesfollowing the BU? EBU, ICF, CF?
![Page 13: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/13.jpg)
Usual questions
-Does the BU channel enhance or suppressthe fusion cross section? Is the effect on s CF or s TF= CF + ICF?
-What are the effects on different energy regimes and on different target mass regions?
- Different BU threshold energies should affect σBU
elastic significantly. Is that true for σCF or σCF + ICF?
![Page 14: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/14.jpg)
Theoretical methods• Schematic models: dynamical polarizatizion
potential; semiclassical trajectories, survivalprobabilities.
• More realistic calculations: CDCC (continuum discretized coupled channel) calculations: Bound-continuum states couplings, with or without resonance states, discretized continuum states, continuum-continuum couplings.
![Page 15: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/15.jpg)
Schematic representation of bound and continuum states and their couplings in CDCC calculations
Full lines: Hagino 2000. Dashed lines: additional couplingsby Diaz-Torres and Thompsom 2002
![Page 16: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/16.jpg)
Experimental aspects to be considered
• What is it measured? s CF or s TF= CF + ICF?
• Can ICF be separated from transfer channels leading to the same compound nucleus?
• When one talks about enhancement or suppression, is that in relation to what?
![Page 17: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/17.jpg)
Measurements of 6,7Li + 209Bi and 9Be + 208Pb
ANU 0.9VB ≤ E ≤ 1.7 VB
Yields of α particles (on-line and off-line)s CF, s ICF and barrier distributions
M. Dasgupta et al; PRL82 (1999),1395 PRC66 (2002),041602R
![Page 18: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/18.jpg)
Measurements of 6,7Li, 9Be + 64Zn, 27Al TANDAR
E > VBToF and E- ?E
s TF = s CF + ICF
I. Padron et al; PRC66 (2002),044608 R.M. Anjos et al; PLB534 (2002),45
![Page 19: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/19.jpg)
Measurement of the inverse reaction 12C + 7LiANU E > VB
E-?E multi-anodes TF
A Mukherjee et al; PLB526 (2002), 295
![Page 20: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/20.jpg)
Measurements of 9Be + 64Zn
USP E ≥ VB
Gamma rays (on-line and off-line)s CF s ICF was found to be negligible.
S.B. Moraes et al; PRC61 (2000),064608
![Page 21: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/21.jpg)
Measurements of 9Be + 144SmTandar
0.8VB ≤ E ≤ 1.4 VB Detection of X-K rays (off-line)
s CF, s ICF
Gomes et al – BJP 35 (2005), 902
![Page 22: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/22.jpg)
Heavy Targets9Be + 208Pb
complete fusion cross section
M. Dasgupta et al – PRL 82 (1999), 1395
![Page 23: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/23.jpg)
6,7Li + 209Bi, 9Be + 208Pb Complete fusion cross section suppression factor
as a function of the energy
M. Dasgupta et al – PRC 70 (2004), 024606
![Page 24: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/24.jpg)
6,7Li + 209Bi and 9Be + 208Pbtotal fusion
(eventual transfer channels are included)(for 6,7Li + 209Bi , the data are lower limits at the highest energies)
Those results agree with CCC and SBPM predictions
Gomes et al;
BJP 34 (2004), 737
![Page 25: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/25.jpg)
9Be + 144Sm : CF and ICFSuppression factor: 0.90
Gomes et al –PLB 634(2006), 356
![Page 26: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/26.jpg)
Conclusions for Heavy Targets
• The BU inhibits s CF at E > VB
• There is a suppression factor for CF at this regime, but the BU threshold energy differences are notvery much reflected in s CF
• s TF is not affected by the BU at E > VB
• s ICF is important in the whole energy range.• At E ≤ VB, the situation is not so clear, as there is
competition between enhancement of CF due to couplings and suppression due to the BU.
![Page 27: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/27.jpg)
Care should be taken when comparingdifferent systems.How to “reduce”?
Gomes et al – PRC 71 (2005), 017601
![Page 28: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/28.jpg)
Care should be taken when comparingdifferent systems.How to “reduce”?
Gomes et al – PRC 71 (2005), 017601
64Zn target
![Page 29: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/29.jpg)
Different conclusions depending on
What is the potential to be used
How to perform CC calculations
![Page 30: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/30.jpg)
Reliable potential: the double folding São Paulo potential
• It reproduces, without any free parameter, calculationsobtained with potentials which match derived barrierdistributions. (Crema et al – PRC72 (2005) – 034610)
![Page 31: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/31.jpg)
2 24v /( ) ( ) cFoldV R V R e−=
finite-range approachnucleon distributions for ρ
→ M3Y – Reid or Paris( )rνr
1/31.31 0.84oR A fm= −0.50 fm a =
{
v = relative velocity between the nuclei
[ ])()(222 RVRVEE LECkinetic −−==µµ
v
ρ {
VFold(R) = ρ1(r1)ρ(r2) ν(R-r1+r2)dr1dr2? ? ? ? ? ? ??
![Page 32: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/32.jpg)
Analysis of the 4,6He + 238U fusionby the São Paulo Potential
Crema et al, subm. PRL SF = 0.84
![Page 33: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/33.jpg)
Analysis of the 6He + 209Bi fusionby the São Paulo Potential
SF = 0.81
There is no sub-barrierfusion enhancement!!
Crema et al - subm to PRL
![Page 34: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/34.jpg)
• What about elastic break-up cross sections?
• What about reaction cross sections?
• What about elastic scattering?
![Page 35: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/35.jpg)
Measurements of elastic breakup cross sections
D.J. Hinde et al; PRL 89 (2002), 272701
C. Signorini; NPA693 (2001), 190
C. Signorini; NPA693 (2001), 190
E.F. Aguilera et al; PRC63 (2001), 061603R
6He +209 Bi
![Page 36: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/36.jpg)
9Be + 144Sm : reaction, inelastic, CF and ICF
Gomes et al – PLB 634(2006), 356
![Page 37: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/37.jpg)
9Be + 144Sm : relative importance ofdifferent reaction mechanisms
Gomes et al –PLB 634(2006), 356
![Page 38: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/38.jpg)
A new type of threshold anomaly: break-up thereshold anomaly (BTA)
The large BUelastic at low energies produces a repulsive polarization potential and supress at E < VB .
Gomes et al –
J Phys G 31 (2005), S1669
![Page 39: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/39.jpg)
BTA
Hussein et al – PRC (RC) – in press
![Page 40: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/40.jpg)
Is the effect the same for medium and lightmass targets?
![Page 41: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/41.jpg)
Reaction, TF, CF, ICF and estimate of BUelastic cross sections for 9Be + 64Zn
Gomes et al, PLB 601 (2004), 20
![Page 42: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/42.jpg)
Reaction, TF and estimate of BUelastic crosssections for 6,7Li + 64Zn
Gomes et al, PLB 601 (2004), 20
![Page 43: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/43.jpg)
Reaction and TF cross sections for 16O , 6He + 64Zn
Gomes et al, PLB 601(2004), 20
Gomes et al, PLB 601 (2004), 20
Di Pietro et al, EPL 64 (2003), 309;
PRC69 (2004), 044613
![Page 44: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/44.jpg)
6He, 6,7Li, 9Be, 16O + 64Zn Reduced reaction cross sections
Gomes et al, PLB 601 (2004), 20
![Page 45: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/45.jpg)
Reaction, TF and estimate of BUelastic
cross sections for 9Be + 27Al
Marti et al – PRC 71 (2005), 027602
![Page 46: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/46.jpg)
Reduced reaction cross sections for 27Al target: here are the first experiments in theSouth Hemisphere with radioactive beams
Benjamin et al – subm PRL
![Page 47: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/47.jpg)
Light target – there were controverses12C + 7Li
Total Fusion
A. Mukherjee et al - PLB 526 (2002), 295
![Page 48: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/48.jpg)
Is there break-up thereshold anomaly (BTA) for light targets?
Gomes – J Phys G 31 (2005) S1669Figueira et al – unpubl.
![Page 49: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/49.jpg)
Conclusions for light and medium mass targets
•No s CF suppression was measured, at highenergies.•The incomplete fusion is much less important thanfor heavy targets.•Elastic break-up is still important, even with a weak Coulomb field.•Reaction cross sections are increased by the break-up process.•The break-up threshold anomaly is still present.
![Page 50: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/50.jpg)
Perspectives
- Need of additional data at the sub-barrierenergy regime.
- Need of more exclusive experiments on elasticbreak-up, elastic scattering, complete fusionand incomplete fusion, in order to obtainprecise information for the calculations.
- Need of more data with radioactive beams.
- Need of development of theoretical models andcalculations which take into account all relevantaspects.
![Page 51: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/51.jpg)
Main Collaborators
• USP (São Paulo): L.C. Chamon, D. Pereira, E. Crema, M.S. Hussein, A. Lepine, R. Lichtenhaler
• CEADEN (Havana): I. Padrón• Tandar (Buenos Aires): G.V. Marti, J.O. Fernandez
Niello, A.J. Pacheco, O.A. Capurro, J.E. Testoni, A. Arazi
• UFF (Niterói): J. Lubian, R.M. Anjos• UFRJ (Rio de Janeiro): L.F. Canto, R. Donangelo• ANU (Canberra): M. Dasgupta, D. Hinde• Tohoku (Sendai): K. Hagino• INFN (Napoli): M. Trotta
![Page 52: Paulo Roberto S. Gomes Instituto de Fisica Universidade ...fusion06/talks/Sunday/gomes.pdf · BJP 34 (2004), 737. 9Be + 144Sm : CF and ICF Suppression factor: 0.90 Gomes et al –PLB](https://reader036.vdocument.in/reader036/viewer/2022070905/5f7519ba0fd57e4c0430df63/html5/thumbnails/52.jpg)
www.nn2006.com.br