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

STUDY OF EXCITATION FUNCTIONS IN Rh(α, xn) Ag REACTIONS

1996 ◽  
Vol 05 (02) ◽  
pp. 345-352 ◽  
Author(s):  
M. AFZAL ANSARI ◽  
N.P.M. SATHIK ◽  
B.P. SINGH ◽  
M.G.V. SANKARACHARYULU ◽  
R. PRASAD
Keyword(s):  
Experimental Data ◽  
Compound Nucleus ◽  
Alpha Particle ◽  
Computer Code ◽  
Particle Energy ◽  
Activation Technique ◽  
Excitation Functions ◽  
Foil Activation ◽  
Alpha Particle Energy ◽  
Stacked Foil Activation Technique

The excitation functions for the reactions 103 Rh (α, n)106 m Ag , 103 Rh (α, 2n)105 Ag , and 103 Rh (α, 3n)104 Ag have been measured between 10 and 40 MeV alpha-particle energy, using the stacked foil activation technique. Excitation functions are also calculated theoretically using the Geometry Dependent Hybrid (GDH) model. The computer code ALICE/LIVERMORE-82 has been used which takes into account the pre-equilibrium contribution along with the equilibrium decay of the compound nucleus. It has been found that initial exciton number n0=4 gives a satisfactory reproduction of experimental data.

Nonequilibrium effects in α-particle-induced reactions in Cs and I

2000 ◽  
Vol 78 (2) ◽  
pp. 133-139 ◽  
Author(s):  
M K Bhardwaj ◽  
I A Rizvi ◽  
A K Chaubey
Keyword(s):  
Cross Sections ◽  
Gamma Ray ◽  
Theoretical Calculations ◽  
High Energy ◽  
Particle Energy ◽  
Substantial Contribution ◽  
Equilibrium Geometry ◽  
Activation Technique ◽  
Excitation Functions ◽  
Stacked Foil Activation Technique

The excitation functions for the reactions 127I(α,n)130Cs, 127I(α,2n)129Cs, 127I(α,4n)127Cs, 133Cs(α,2n)135La, and 133Cs(α,4n)133La have been measured up to 50 MeV alpha-particle energy using the stacked-foil activation technique and Ge(Li) gamma-ray spectroscopy. The measured cross sections were compared with theoretical calculations considering equilibrium as well as the pre-equilibrium geometry-dependent hybrid models of Blann. The high-energy tails of the excitation functions show a substantial contribution from pre-equilibrium emission. A general agreement is observed between the experimental results and theoretical predictions with an initial exciton configuration n0 = 4(2n + 2p + 0h).PACS No. 25.40-h

ALPHA-INDUCED REACTIONS IN ANTIMONY

1994 ◽  
Vol 03 (01) ◽  
pp. 239-248 ◽  
Author(s):  
M.K. BHARDWAJ ◽  
I.A. RIZVI ◽  
A.K. CHAUBEY
Keyword(s):  
Excitation Function ◽  
Beam Energy ◽  
Gamma Ray ◽  
Computer Code ◽  
Reaction Yield ◽  
Activation Technique ◽  
Model Calculations ◽  
Equilibrium Fraction ◽  
Foil Activation ◽  
Stacked Foil Activation Technique

The excitation function of α-induced reactions on 121Sb and 123Sb has been measured. The α-beam energy ranges from 55.0±0.5 MeV to 21.9±1.2 MeV. In these experiments, the stacked foil activation technique was used. The reaction yield was measured by counting the gamma ray activity produced by the alpha-induced reactions. Results so obtained were compared with the calculations from the geometry-dependent hybrid (GDH) model. The assumption of initial exciton number n0=4 with n=2, p=2 and h=0 best satisfies the results measured in the present work. The model calculations were done using the ALICE/LIVERMORE-82 computer code. The pre-equilibrium fraction has also been calculated.

A study of pre-equilibrium emission in α-induced reactions on 121,123Sb

1991 ◽  
Vol 69 (11) ◽  
pp. 1376-1382 ◽  
Author(s):  
B. P. Singh ◽  
H. D. Bhardwaj ◽  
R. Prasad
Keyword(s):  
Compound Nucleus ◽  
Mass Number ◽  
Neutron Emission ◽  
Theoretical Calculations ◽  
Exciton Model ◽  
Excitation Functions ◽  
Stacked Foil Technique ◽  
Equilibrium Emission ◽  
Charged Particle Emission ◽  
Foil Technique

Excitation functions for the 121Sb (α, n)+ 123Sb(α, 3n),,21Sb(α, 2n)+ 123Sb(α, 4n), 121Sb(α, 4n), 121Sb(α, 3np), and 123Sb(α, n) reactions are measured in the energy range 30–60 MeV using the stacked foil technique. In the cases of the 121Sb(α, n)+ 123Sb(α, 3n) and 121Sb(α, 2n)+ 123Sb(α, 4n) reaction pairs, the excitation functions for individual reactions were deduced using theoretical calculations. Excitation functions are also calculated theoretically using the compound-nucleus model with and without the inclusion of a pre-equilibrium emission. As expected, inclusion of a pre-equilibrium contribution based on the exciton model along with compound-nucleus calculations using the Hauser–Feshbach formalism reproduces well the measured excitation functions. Analysis of the data indicates a preference for a first chance neutron emission over charged-particle emission, and interesting trends in the energy and mass-number dependence of the pre-equilibrium fraction are observed.

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.

STUDY OF ISOMERIC CROSS-SECTION RATIO AND PRE-EQUILIBRIUM FRACTION IN PROTON AND ALPHA PARTICLE INDUCED NUCLEAR REACTIONS ON 197Au

2012 ◽  
Vol 21 (06) ◽  
pp. 1250059 ◽  
Author(s):  
B. SATHEESH ◽  
M. M. MUSTHAFA ◽  
B. P. SINGH ◽  
R. PRASAD
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Energy Difference ◽  
Activation Technique ◽  
Cross Section Ratio ◽  
Excitation Functions ◽  
Section Ratio ◽  
Isomeric Cross Section Ratio ◽  
Equilibrium Emission

Excitation functions for the reactions 197 Au(p,n) 197g Hg and 197 Au(p,n) 197m Hg have been measured over the energy ranges from threshold up to 20 MeV using stacked foil activation technique. The isomeric cross-section ratio σm/(σm+σg) for the formation of 197g, m Hg was determined. The excitation functions and isomeric cross-section ratios were calculated for the reactions 197 Au(p,n) 197g,m Hg , 197 Au(p,2n) 196 Hg , 197 Au(p,3n) 195g,m Hg , 197 Au(p,4n) 194 Hg , 197 Au(p,5n) 193g,m Hg , 197 Au (α, n )200 Tl , 197 Au (α, 2n )199 Tl , 197 Au (α, 3n )198g,m Tl , 197 Au (α, 4n )197 Tl and 197 Au (α, 5n )196g,m Tl from reaction threshold up to 40 MeV for proton induced reactions and 80 MeV for alpha induced reactions. The results were compared with the theoretical cross-sections calculated by means of the code EMPIRE-II and with the available literature data, which makes use of the Hauser Feshbach model for the compound nuclear calculations and the exciton model for the pre-equilibrium emission part. The isomeric cross-section ratio is found to depend strongly on the relative spins of the isomeric and ground state, energy difference between the levels, presence of intermediate states and some dependence on decay modes and on the onset of pre-equilibrium emission.

scholarly journals Excitation function of natCu(3He,x)65Zn nuclear reaction for 3He beam monitoring purpose

2020 ◽  
Vol 239 ◽  
pp. 20009
Author(s):  
Mayeen Uddin Khandaker ◽  
Kotaro Nagatsu ◽  
Honoka Obata ◽  
Katsuyuki Minegishi ◽  
Ming-Rong Zhang ◽  
...  
Keyword(s):  
Excitation Function ◽  
Nuclear Reaction ◽  
Incident Energy ◽  
Activation Technique ◽  
Monitor Reaction ◽  
Foil Activation ◽  
Experimental Works ◽  
Γ Ray ◽  
Stacked Foil Activation Technique ◽  
Beam Monitoring

The excitation function of the natCu(3He,x)65Zn nuclear reaction was measured from its threshold up to 53 MeV incident energy relative to the natTi(3He,x)48V monitor reaction by using the conventional stacked foil activation technique combined with HPGe γ-ray spectrometry. Our result is systematically higher than the IAEA recommendation, and more experimental works are desired especially above 25 MeV.

Measurement and analysis of excitation functions for alpha-particle-induced reactions in rhenium

2004 ◽  
Vol 82 (3) ◽  
pp. 227-237
Author(s):  
N L Singh ◽  
M S Gadkari
Keyword(s):  
Cross Sections ◽  
Residual Nucleus ◽  
Reaction Cross ◽  
Activation Technique ◽  
Excitation Functions ◽  
Theoretical Predictions ◽  
Reaction Channels ◽  
Stacked Foil Activation Technique ◽  
The Individual ◽  
First Time

Excitation functions of the reactions 185Re[(α,n); (α,2n); (α,3n)] and 187Re[(α,n); (α,2n); (α,3n); (α,4n)] were investigated up to 50 MeV using the stacked-foil activation technique and high-purity germanium γ-ray spectroscopy method. Since the natural rhenium used as a target has two odd-mass stable isotopes of abundance 37.4% (185Re) and 62.6% (187Re), 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 theoretical predictions considering equilibrium as well as pre-equilibrium contributions using code ALICE/90. It was found that the initial exciton configuration n0 = 4 (4p0h) appears to give a good fit to the experimental data. To the best of our knowledge, the excitation functions for 185Re[(α,n); (α,2n); (α,3n)] and 187Re[(α,3n); (α,4n)] reactions were measured for the first time. PACS No.: 25.55.–e

Measurements of excitation functions of α-particle induced reactions on natNi: possibility of production of the medical isotopes 61Cu and 67Cu

2018 ◽  
Vol 106 (2) ◽  
pp. 87-93 ◽  
Author(s):  
Md. Shuza Uddin ◽  
Kwangsoo Kim ◽  
Muhammad Nadeem ◽  
Sandor Sudár ◽  
Guinyun Kim
Keyword(s):  
Nuclear Model ◽  
Activation Technique ◽  
Isotopic Abundance ◽  
Energy Window ◽  
Excitation Functions ◽  
Model Calculations ◽  
Data Points ◽  
Stacked Foil Activation Technique ◽  
The Cost ◽  
Very High

AbstractExcitation functions of thenatNi(α,x)60,61Cu and64Ni(α,p)67Cu reactions were measured using the stacked-foil activation technique. The experimental data achieved were compared with literature data as well as with nuclear model calculations performed using the code TALYS-1.8. Integral yields from the respective thresholds to 44 MeV were deduced from the measured excitation curves. The >99% pure61Cu can be produced using the energy window of Eα=20→7 MeV, the yield amounting to 116 MBq/μAh. After a 2 h cooling time, the short-lived60Cu (T1/2=23 min) impurity will be reduced to <0.1%. Due to low isotopic abundance of64Ni, the enriched64Ni target would be needed for the production of67Cu via the (α,p) reaction. The cost would, however, be very high. In a few cases, particularly above 24 MeV, we have given new data points. In general, our measurements have strengthened the database.

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