MEASUREMENT OF 79Br(n, 2n)78Br, 63Cu(n,2n)62Cu, 58Ni(n,2n)57Ni, 54Fe(n,2n)53Fe, 50Cr(n, 2n)49Cr AND 46Ti(n, 2n)45Ti REACTION CROSS-SECTIONS AT 14.7 MeV NEUTRON ENERGY

1993 ◽  
Vol 02 (01) ◽  
pp. 259-264 ◽  
Author(s):  
G.R. PANSARE ◽  
V.N. BHORASKAR

Cross-sections of the reactions 79 Br (n, 2n)78 Br , 63 Cu (n,2n)62 Cu , 58 Ni (n, 2n)57 Ni , 54 Fe (n, 2n)53 Fe , 50Cr(n, 2n)49Cr and 46 Ti (n, 2n)45 Ti induced by 14.7 MeV neutrons are measured with reference to 27Al(n, ∝)24 Na and 56 Fe (n, p)56 Mn reactions using activation technique and also derived theoretically using compound nucleus model, semiempirical relation and ALICE code. Accuracy around 5% was achieved in measurement of these reaction cross-sections which is better compared to existing literature values.

2019 ◽  
Vol 21 ◽  
pp. 160
Author(s):  
A. Kalamara ◽  
R. Vlastou ◽  
M. Diakaki ◽  
M. Kokkoris ◽  
M. Anastasiou ◽  
...  

The 241Am(n,2n)240Am reaction cross section has been measured at neutron beam energy 17.5 MeV, relative to the 27Al(n,α)24Na, 197Au(n,2n)196Au and 93Nb(n,2n)92mNb reference reaction cross sections, using the activation technique. The irradiation was carried out at the Van der Graaff 5.5 MV Tandem accelerator laboratory of NCSR “Demokritos” with monoenergetic neutron beam provided by means of the 3H(d,n)4He reaction, implementing a new Ti-tritiated target. The high purity Am target has been constructed at IRMM, Geel, Belgium and consisted of 40 mg 241Am in the form of AmO2 pressed into pellet with Al2O3 and encapsulated into Al container. Due to this high radioactivity (5 GBq), the Am target was enclosed in a Pb container for safety reasons. After the end of the irradiation, the activity induced by the neutron beam at the target and reference foils, was measured off-line by two 100%, a 50% and a 16% relative efficiency, HPGe detectors.


2020 ◽  
Vol 15 ◽  
pp. 104
Author(s):  
S. Galanopoulos ◽  
R. Vlastou ◽  
P. Demetriou ◽  
M. Kokkoris ◽  
C. T. Papadopoulos ◽  
...  

Systematic experimental and theoretical investigations of the 72,73Ge(n,p)72,73 Ga and 72,74Ge(n,α)69,71Znm reaction cross sections are presented in the energy range from thresh- old to about 17 MeV neutron energy. The above reaction cross sections were measured from 8.8 to 11.4 MeV by using the activation method, relative to the 27Al(n,α)24Na refer- ence reaction. The quasi-monoenergetic neutron beams were produced via the 2H(d,n)3He reaction at the 5 MV VdG Tandem T11/25 accelerator of NCSR “Demokritos”. Statisti- cal model calculations using the code EMPIRE-II (version 2.19) taking into consideration pre-equilibrium emission were performed on the data measured in this work as well as on data reported in literature.


2020 ◽  
Vol 325 (3) ◽  
pp. 831-840
Author(s):  
Sangeetha Prasanna Ram ◽  
Jayalekshmi Nair ◽  
Saraswatula Venkata Suryanarayana ◽  
Laxman Singh Danu ◽  
Saroj Bishnoi ◽  
...  

1989 ◽  
Vol 67 (9) ◽  
pp. 870-875 ◽  
Author(s):  
I. A. Rizvi ◽  
M. K. Bhardwaj ◽  
M. Afzal Ansari ◽  
A. K. Chaubey

The stacked foil activation technique and Ge(Li) γ-ray spectroscopy have been employed for the determination of the excitation functions, up to 60 MeV, of six reactions, 69Ga(α,n), (α,2n), (α,3n), (α,p3n); 71Ga(α,n) and (α,4n). Since natural gallium used as the target has two odd-mass stable isotopes of abundance, 69Ga(60.1%) and 71Ga(39.9%), their activation in some cases gives the same residual nucleus through different reaction channels, but with very different Q values. In such cases, the individual reaction cross sections are separated with the help of the ratio of their theoretical cross sections. A preliminary theoretical comparison with the preequilibrium geometry-dependent hybrid (GDH) model has been done using an initial exciton number no = 4 (2n + 2p + 0h), and general agreement was found for all reactions at high energies.


1964 ◽  
Vol 42 (6) ◽  
pp. 1030-1036 ◽  
Author(s):  
D. C. Santry ◽  
J. P. Butler

Excitation curves for the reactions Fe56(n, p)Mn56 and Co59(n, α)Mn56 have been measured by the activation method from near threshold energies to 20.3 Mev. The measurements are relative to the known cross section for the S32(n, p)P32 reaction. Cross sections for both reactions increase smoothly with neutron energy and reach maximum values of 119 ± 4 mb for the Fe56(n, p) reaction at 13.6 Mev and 30.0 ± 0.9 mb for the Co59(n, α) reaction at 14.5 Mev. Above 15 Mev both cross sections decrease with neutron energy. From the excitation curves effective cross-section values for a fission-neutron spectrum have been calculated as 1.04 ± 0.05 mb for the (n, p) reaction and 0.140 ± 0.007 mb for the (n, α) reaction.


1996 ◽  
Vol 74 (9-10) ◽  
pp. 618-625 ◽  
Author(s):  
H. B. Patel ◽  
M. S. Gadkari ◽  
Bhruna Dave ◽  
N. L. Singh ◽  
S. Mukherjee

Excitation functions of the reactions 107Ag[(α, n); (α, 2n); (α, αn); (α, α2n)] and,109Ag[(α, 2n); (α, 3n); (α, 4n); (α, α3n); (α, α4n)] were investigated up to 70 MeV by the stacked foil activation technique and Ge(Li) gamma-ray spectroscopy method. Since the natural silver used as the target has two odd mass stable isotopes of abundance 51.83% (107Ag) and 48.17% (109Ag), their activation in some cases gives the same residual nucleus through different reaction channels, but with very different Q values. In such cases, the individual reaction cross sections are separated with the help of the ratio of theoretical cross sections. The experimental cross sections were compared with the predictions of a pre-equilibrium hybrid model. The (α, xn) reactions are fairly well reproduced with initial exciton number n0 = 4(4p0h), whereas (α, αxn) reactions are underestimated in magnitude by a factor of five to six.


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