Measurement of ultra-fast γ-ray transitions from heavy-ion compound-nucleus reactions

1995 ◽  
Vol 354 (2-3) ◽  
pp. 591-594 ◽  
Author(s):  
B. Cederwall ◽  
I.Y. Lee ◽  
S. Asztalos ◽  
M.J. Brinkman ◽  
J.A. Becker ◽  
...  
Keyword(s):  
Compound Nucleus ◽  
Heavy Ion ◽  
Γ Ray

DYNAMICAL DIPOLE MODE IN FUSION HEAVY-ION REACTIONS

2010 ◽  
Vol 19 (05n06) ◽  
pp. 1031-1042 ◽  
Author(s):  
DIMITRA PIERROUTSAKOU
Keyword(s):  
Compound Nucleus ◽  
Transport Model ◽  
Heavy Ion ◽  
Mass Region ◽  
Dipole Mode ◽  
Fusion Reactions ◽  
Excitation Energies ◽  
Spin Distribution ◽  
Γ Ray ◽  
Experimental Findings

The prompt γ-ray emission, associated with the dynamical dipole mode decay, was investigated in the 32,36 S + 100,96 Mo and 36,40 Ar + 96,92 Zr fusion-evaporation reactions in the energy range E lab= 6 - 16 MeV / nucleon . The above reaction pairs populate, through entrance channels having different charge asymmetries, a compound nucleus in the 132 Ce mass region at excitation energies of 117, 174 and 284 MeV with identical spin distribution. By studying the differential γ-ray multiplicity spectra of the considered systems, the features of the dynamical dipole mode as a function of the beam energy were extracted while the γ-ray angular distributions were used to prove its pre-equilibrium character. The experimental findings were compared with theoretical predictions performed within a BNV transport model and based on a collective bremsstrahlung analysis of the entrance channel reaction dynamics. As a fast cooling mechanism on the fusion path, the prompt dipole radiation could be of interest for the synthesis of super heavy elements through hot fusion reactions providing a way to cool down the hot fusion paths, so ending up with a larger survival probability. To shed light on this hypothesis, the dynamical dipole mode investigation was extended to a heavier compound nucleus, 192 Pb , by means of the 40 Ca + 152 Sm and 48 Ca + 144 Sm reactions at E lab= 11 and 10.1 MeV/nucleon, respectively. Preliminary results of this measurement, concerning both fusion-evaporation and fission events are presented.

Predicted limits for production of new proton-rich nuclei by a heavy-ion compound-nucleus mechanism

1972 ◽  
Vol 188 (2) ◽  
pp. 423-429 ◽  
Author(s):  
W.G. Winn ◽  
H.H. Gutbrod ◽  
M. Blann
Keyword(s):  
Compound Nucleus ◽  
Heavy Ion

High energy γ-ray emission in heavy-ion collisions

1986 ◽  
Vol 456 (1) ◽  
pp. 159-172 ◽  
Author(s):  
W. Bauer ◽  
W. Cassing ◽  
U. Mosel ◽  
M. Tohyama ◽  
R.Y. Cusson
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
High Energy ◽  
Ion Collisions ◽  
Γ Ray

γ-ray spectroscopy of proton neutron-hole nucleus208Bifrom deep inelastic heavy ion reactions

2003 ◽  
Vol 67 (3) ◽  
Author(s):  
B. Fornal ◽  
R. Broda ◽  
K. H. Maier ◽  
P. J. Daly ◽  
P. Bhattacharyya ◽  
...  
Keyword(s):  
Heavy Ion ◽  
Heavy Ion Reactions ◽  
Neutron Hole ◽  
Γ Ray

Gamma-ray production in the 170Er(p,n)170Tm nuclear reaction

Open Physics ◽  
2010 ◽  
Vol 8 (4) ◽  
Author(s):  
Alexandru Mihailescu ◽  
Gheorghe Cata-Danil
Keyword(s):  
High Resolution ◽  
Energy Range ◽  
Nuclear Reaction ◽  
Gamma Rays ◽  
Compound Nucleus ◽  
Beam Energy ◽  
Gamma Ray ◽  
Excitation Functions ◽  
Γ Ray ◽  
First Time

AbstractFor the first time discrete gamma-rays following the nuclear reaction 170Er(p,n)170Tm with enriched target were measured with a high resolution GeHP spectrometer. Protons delivered by the Bucharest FN Tandem Van de Graaff accelerator bombarded a thin self-supporting film of enriched erbium. Measured γ-ray energies (Eγ), their relative intensities (Iγ) and corresponding excitation functions for the beam energy range 2.0–3.6 MeV are reported in the present work. The measured excitation functions were fairly well reproduced by compound nucleus calculations based on the Hauser-Feshbach formalism.

Non-equilibrium emission of neutrons in α-particle induced reactions with holmium

2008 ◽  
Vol 86 (3) ◽  
pp. 495-500 ◽  
Author(s):  
Avinash Agarwal ◽  
I A Rizvi ◽  
A K Chaubey
Keyword(s):  
Compound Nucleus ◽  
Computer Code ◽  
High Energy ◽  
Activation Technique ◽  
Excitation Functions ◽  
Equilibrium Reaction ◽  
Experimental Trend ◽  
Γ Ray ◽  
Stacked Foil Activation Technique ◽  
Equilibrium Emission

The stacked-foil activation technique followed by off line high-purity Ge γ-ray spectroscopy was used for the measurement of the excitation functions for energies up to 50 MeV for the 165Ho(α, 2n) 167Tm, 165Ho(α, 3n) 166Tm, and 165Ho(α, 4n) 165Tm reactions. The measured excitation functions were compared with theoretical predications considering equilibrium as well as pre-equilibrium reaction mechanisms according to the geometry-dependent hybrid (GDH) model of Blann using computer code ALICE-91. The high-energy parts of the excitation functions are due to the pre-equilibrium reaction mechanism, while the low-energy parts are mediated by compound-nucleus decay. It was found that the compound-nucleus-decay mechanism alone is unable to explain the experimental trend of our data. The pre-equilibrium fraction was also calculated. PACS Nos.: 22.55.–e, 27.60.+j

Decay properties of 181Ir

1978 ◽  
Vol 56 (3) ◽  
pp. 321-326 ◽  
Author(s):  
I. M. Ladenbauer-Bellis ◽  
P. Sen ◽  
H. Bakhru
Keyword(s):  
Half Life ◽  
Decay Scheme ◽  
Heavy Ion ◽  
Heavy Ion Reactions ◽  
X Ray ◽  
Decay Properties ◽  
Helium Jet ◽  
Γ Rays ◽  
Ge Detector ◽  
Γ Ray

181Ir activity was produced via the following heavy-ion reactions: 169Tm (16O,4n)181Ir and 169Tm(19F,7n)181Pt (51 s) decaying to 181Ir. The half-life of 181Ir was found to be 4.90 ± 0.15 min. Singles and coincidence γ-ray measurements were performed using 30–40 cm3 Ge(Li) detectors. X-Ray measurements were carried out using an intrinsic Ge-detector. Additionally the helium jet system was used to study the properties of this isotope. The following γ rays were found to belong to the decay of 181Ir: 19.6, 65.3, 93.8, 107.6, 117.9, 123.5, 184.6, 189.9, 227.0, 231.6, 239.2, 309.0, 318.9, 350.5, 352.8, 375.2, 576.5, 700.1, 871.2, 1182.3, 1192.6, 1347.1, 1381.0, 1528.8, 1545.0, 1565.6, 1593.4, 1639.6, 1646.4, 1652.5, and 1714.9 keV. A tentative decay scheme is proposed for 181Ir, verifying levels in l8lOs that have been obtained by reaction work. The proposed decay scheme as well as spin and parity assignments of some of the 181Os levels are discussed.

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