scholarly journals Fast neutron spectrum unfolding of a TRIGA Mark II reactor and measurement of spectrum-averaged cross sections: integral tests of differential cross sections of neutron threshold reactions

2013 ◽  
Vol 101 (10) ◽  
pp. 613-620 ◽  
Author(s):  
M. S. Uddin ◽  
S. Sudár ◽  
S. M. Hossain ◽  
R. Khan ◽  
M. A. Zulquarnain ◽  
...  
Keyword(s):  
Fast Neutron ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Neutron Field ◽  
Fast Neutrons ◽  
Metal Foils ◽  
Spectrum Unfolding ◽  
Fission Spectrum ◽  
Data Files ◽  
Triga Mark Ii

Summary The spectrum of fast neutrons having energies from 0.5 to 20 MeV in the core of the 3MW TRIGA Mark II reactor at Savar, Dhaka, Bangladesh, was unfolded by activating several metal foils to induce threshold nuclear reactions covering the whole spectrum, and then doing necessary iterative calculations utilizing the activation results and the code SULSA. The analysed shape of the spectrum in the TRIGA core was found to be similar to that of the pure 235U-fission spectrum, except for the energies between 0.5 and 1.5 MeV, where it was slightly higher than the fission spectrum. Spectrum-averaged cross sections were determined by integral measurements. The integral values measured in this work were compared with the recommended values for a pure fission spectrum as well as with the integrated data deduced from measured and evaluated excitation functions of a few reactions given in some data files. The good agreement between integral measurements and integrated data in case of well-investigated reactions shows that the fast neutron field at the TRIGA Mark II reactor can be used for validation of evaluated data of neutron threshold reactions.

Integral measurement of spectrum-averaged cross sections of a few threshold reactions induced by fast neutrons of a TRIGA reactor: comparison with integrated data from excitation functions given in various data libraries

2020 ◽  
Vol 108 (7) ◽  
pp. 511-516
Author(s):  
Md. Shuza Uddin ◽  
K. A. Rafee ◽  
S. M. Hossain ◽  
R. Khan ◽  
S. M. Qaim
Keyword(s):  
Excitation Function ◽  
Cross Sections ◽  
Fast Neutrons ◽  
Integral Test ◽  
Triga Reactor ◽  
Fission Spectrum ◽  
Data Libraries ◽  
First Time ◽  
Prompt Fission ◽  
Fast Neutron Spectrum

AbstractIntegral cross sections of the reactions 24Mg(n,p)24Na, 27Al(n,p)27Mg, 27Al(n,α)24Na, 58Ni(n,d + np)57Co and 60Ni(n,p)60Co were measured for the first time using the fast neutron spectrum of a TRIGA reactor extending from 0.5 to 20 MeV. The values obtained in this work were comparable with the recommended values for a pure 235U prompt fission spectrum. The measured integral value was utilized for integral test of excitation function of each reaction given in some data libraries, namely ENDF/B-VIII.0, TENDL-2017, IRDFF-1.05 and ROSFOND-2010. The integral measurements are generally consistent with the integrated values within 5 %, except for a few cases, e. g. the reaction 60Ni(n,p)60Co, where the data libraries appear to need improvement.

A comparison of some absolute methods of measuring fast neutron flux

1950 ◽  
Vol 46 (2) ◽  
pp. 339-352 ◽  
Author(s):  
K. W. Allen ◽  
D. L. Livesey ◽  
D. H. Wilkinson
Keyword(s):  
Neutron Flux ◽  
Fast Neutron ◽  
Cross Sections ◽  
Absolute Measurement ◽  
Fast Neutrons ◽  
Fast Neutron Flux ◽  
Cavendish Laboratory ◽  
The Individual ◽  
Nuclear Processes

The absolute measurement of fast neutron flux presents several difficult problems. Few methods have yet been described in the literature, although the experimental techniques developed by several authors for the detection of fast neutrons (Baldinger, Huber and Staub(7), Barshall and Kanner(9), Amaldi, Bocciarelli, Ferretti and Trabacchi (3), Gray (19), Barshall and Battat(8)) may easily be adapted to this type of measurement. It is, however, most important to have available methods of measuring fast neutron flux to permit the determination of cross-sections for nuclear processes induced by fast neutrons, and several such methods have been developed in the Cavendish Laboratory in recent years. They are the subjects of separate papers (Bretscher and French (13), Kinsey, Cohen and Dainty (21), Allen (l), Allen and Wilkinson (2)). The main purpose of the present paper is to describe the results of experiments carried out to compare these methods in order to test the validity of the assumptions implicit in the individual methods.

How to Simulate the Microstructure Induced by a Nuclear Reactor with an Ion Beam Facility : DART

2009 ◽  
Vol 1215 ◽  
Author(s):  
Laurence Luneville ◽  
David Simeone ◽  
Gianguido Baldinozzi ◽  
Dominique Gosset ◽  
yves serruys
Keyword(s):  
Cross Sections ◽  
Nuclear Reactor ◽  
Nuclear Reactions ◽  
Ion Beam ◽  
Fast Neutrons ◽  
Relaxation Processes ◽  
Pressurized Water ◽  
Water Reactors ◽  
Displacement Per Atom ◽  
The Impact

AbstractEven if the Binary Collision Approximation does not take into account relaxation processes at the end of the displacement cascade, the amount of displaced atoms calculated within this framework can be used to compare damages induced by different facilities like pressurized water reactors (PWR), fast breeder reactors (FBR), high temperature reactors (HTR) and ion beam facilities on a defined material. In this paper, a formalism is presented to evaluate the displacement cross-sections pointing out the effect of the anisotropy of nuclear reactions. From this formalism, the impact of fast neutrons (with a kinetic energy En superior to 1 MeV) is accurately described. This point allows calculating accurately the displacement per atom rates as well as primary and weighted recoil spectra. Such spectra provide useful information to select masses and energies of ions to perform realistic experiments in ion beam facilities.

Reference dosimetry for fast neutron and proton therapy

2001 ◽  
Vol 89 (4-5) ◽  
Author(s):  
D.T.L. Jones
Keyword(s):  
Fast Neutron ◽  
Proton Therapy ◽  
Proton Energy ◽  
Nuclear Reactions ◽  
Absorbed Dose ◽  
Fast Neutrons ◽  
Ionization Chambers ◽  
Atomic Electrons

Fast neutrons and protons undergo fundamentally different interactions in tissue. The former interact with nuclei, while the latter, as in the case of photons, interact mainly with atomic electrons. Protons do, however, also undergo some nuclear reactions, the probability of which increases with proton energy. The determination of the reference absorbed dose in a patient for the two modalities is described. Two internationally accepted protocols have been formulated and have been published in ICRU reports. For both modalities the practical means for determining the reference absorbed dose in a patient involves the use of thimble ionization chambers calibrated in

scholarly journals Measurements of the neutron activation cross sections for Bi at 287 and 370 MeV

2011 ◽  
Vol 1 (1) ◽  
pp. 135-139
Author(s):  
H. Yashima ◽  
S. Sekimoto ◽  
T. Utsunomiya ◽  
K. Ninomiya ◽  
T. Omoto ◽  
...  
Keyword(s):  
Neutron Activation ◽  
Proton Beam ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Data ◽  
Neutron Field ◽  
Low Energy ◽  
Energy Neutron ◽  
Data Files ◽  
Activation Cross Sections

AbstractWe present cross section measurements for neutron-induced activation of Bi, at 287 and 370 MeV. These values were derived from the activation method using a quasi-monoenergetic neutron field based on the 7Li(p,n) reaction. In separate experiments, samples were irradiated with neutrons derived from 7Li(p,n) reaction at either 0º or 30º for proton beam axis. This approach allows the subtraction of the low energy neutron components. The measured cross sections are compared with the findings of other studies, and evaluated in relation to nuclear data files.

scholarly journals VOID COEFFICIENT SENSITIVITY ANALYSIS FOR THE TRIGA MARK II REACTOR AT L.E.N.A. (UNIPV)

2021 ◽  
Vol 247 ◽  
pp. 15005
Author(s):  
D. Portinari ◽  
A. Cammi ◽  
S. Lorenzi ◽  
M. Aufiero ◽  
Y. Calzavara ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Cross Sections ◽  
Research Reactor ◽  
Multiplication Factor ◽  
Delayed Neutron ◽  
Reactor Physics ◽  
Fission Spectrum ◽  
Challenging Tasks ◽  
Generalized Perturbation Theory ◽  
Triga Mark Ii

Sensitivity analysis studies the effect of a change in a given parameter to a response function of the system under investigation. In reactor physics, this usually translates into the study of how cross sections and fission spectrum modifications affect the value of the multiplication factor, the delayed neutron fraction or the void coefficient for example. Generalized Perturbation Theory provides a useful tool for the assessment of adjoint weighed functions such as keff and void coefficient sensitivities. In this work, the capability of SERPENT code to perform sensitivity calculation based on GPT is used to study the TRIGA Mark II research reactor installed at L.E.N.A. of University of Pavia. A general sensitivity analysis to the most important reactor’s cross sections has been performed in order to highlight the biggest reactivity contributions. Two numerically challenging tasks related to GPT calculation have been performed thanks to the relatively quick Monte Carlo approach allowed by this reactor: investigating the linearity of the reactivity injection caused by the flooding of the central channel, and calculating the fuel void coefficient sensitivity to the coolant density.

The cross sections for different channels in heavy ion nuclear reactions

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago
Keyword(s):  
Cross Sections ◽  
Nuclear Reactions ◽  
Heavy Ion ◽  
The Cross

Proposed Solutions to Achieve Nuclear Fusion

Engevista ◽  
2017 ◽  
Vol 19 (5) ◽  
pp. 1496
Author(s):  
Relly Victoria Virgil Petrescu ◽  
Raffaella Aversa ◽  
Antonio Apicella ◽  
Florian Ion Petrescu
Keyword(s):  
Nuclear Reactor ◽  
Nuclear Reactions ◽  
Nuclear Fusion ◽  
Nuclear Fission ◽  
Light Nuclei ◽  
Fast Neutrons ◽  
Fusion Reactions ◽  
Nuclear Fusion Reactions ◽  
The Masses ◽  
Fusion Products

Despite research carried out around the world since the 1950s, no industrial application of fusion to energy production has yet succeeded, apart from nuclear weapons with the H-bomb, since this application does not aims at containing and controlling the reaction produced. There are, however, some other less mediated uses, such as neutron generators. The fusion of light nuclei releases enormous amounts of energy from the attraction between the nucleons due to the strong interaction (nuclear binding energy). Fusion it is with nuclear fission one of the two main types of nuclear reactions applied. The mass of the new atom obtained by the fusion is less than the sum of the masses of the two light atoms. In the process of fusion, part of the mass is transformed into energy in its simplest form: heat. This loss is explained by the Einstein known formula E=mc2. Unlike nuclear fission, the fusion products themselves (mainly helium 4) are not radioactive, but when the reaction is used to emit fast neutrons, they can transform the nuclei that capture them into isotopes that some of them can be radioactive. In order to be able to start and to be maintained with the success the nuclear fusion reactions, it is first necessary to know all this reactions very well. This means that it is necessary to know both the main reactions that may take place in a nuclear reactor and their sense and effects. The main aim is to choose and coupling the most convenient reactions, forcing by technical means for their production in the reactor. Taking into account that there are a multitude of possible variants, it is necessary to consider in advance the solutions that we consider them optimal. The paper takes into account both variants of nuclear fusion, and cold and hot. For each variant will be mentioned the minimum necessary specifications.

Development of SiO2 based doped with LiF, Cr2O3, CoO4 and B2O3 glasses for gamma and fast neutron shielding

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bünyamin Aygün ◽  
Erdem Şakar ◽  
Abdulhalik Karabulut ◽  
Bünyamin Alım ◽  
Mohammed I. Sayyed ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fast Neutron ◽  
Cross Sections ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Neutron Shielding ◽  
Shielding Properties ◽  
Effective Neutron ◽  
Simulation Codes

AbstractIn this study, the fast neutron and gamma-ray absorption capacities of the new glasses have been investigated, which are obtained by doping CoO,CdWO4,Bi2O3, Cr2O3, ZnO, LiF,B2O3 and PbO compounds to SiO2 based glasses. GEANT4 and FLUKA Monte Carlo simulation codes have been used in the planning of the samples. The glasses were produced using a well-known melt-quenching technique. The effective neutron removal cross-sections, mean free paths, half-value layer, and transmission numbers of the fabricated glasses have been calculated through both GEANT4 and FLUKA Monte Carlo simulation codes. Experimental neutron absorbed dose measurements have been carried out. It was found that GS4 glass has the best neutron protection capacity among the produced glasses. In addition to neutron shielding properties, the gamma-ray attenuation capacities, were calculated using newly developed Phy-X/PSD software. The gamma-ray shielding properties of GS1 and GS2 are found to be equivalent to Pb-based glass.

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