Instrumental Photon Activation and Applications in a Nuclear-Waste Inspection Purpose

2003 ◽  
Author(s):  
F. Jeanneau ◽  
M. Gmar ◽  
N. Huot ◽  
F. Laine´ ◽  
A. Lyoussi ◽  
...  
Keyword(s):  
Waste Management ◽  
Nuclear Waste ◽  
Cross Sections ◽  
Detection Limits ◽  
Current Method ◽  
High Energy ◽  
Monte Carlo Code ◽  
Photon Activation ◽  
Simulation Code ◽  
Passive Noise

The development of non-destructive methods to inspect nuclear-waste containers is important for radioactive-waste management and non-proliferation purposes. This paper will present studies and results carried out by a method based on photon interrogation (photofission) which allows the determination of the actinide quantity contained in the waste. High-energy photons (produced by an electron accelerator associated with a Bremsstrahlung tungsten target) will induce photofission reactions on the actinides. Then the flux of delayed neutrons, which is directly proportional to the amount of actinides, is measured with 3He detectors. Since the beginning of 1990’s, our team in CEA has been working on the development of this method and the improvement of the existing simulation code. The two main tools will be introduced: OPERA (tool for the simulation of photonuclear reactions) which includes photonuclear cross sections in a Monte-Carlo code based on MCNP4C, and SAPHIR (Irradiation and Photon-Activation System), a device allowing experimentations for research and development programs. The applications of these tools will be illustrated mainly with two examples: 1) The feasibility study of an inspection device for old concrete containers will be reported. Two campaigns of measurements have been performed in order to determine the sensitivity and the detection limits in the case of four different types of concrete containers, in terms of nature and geometry. 2) Nuclear-waste producers and managers have been interested by the active photon interrogation possibilities to measure actinide quantity in wastes of high activity, vitrified or compacted, with constraints like a dose rate around 400 Gy/h at 27 cm from the container. The simulation-code improvement has allowed some calculations, based on the SAPHIR facility, which have shown a good linearity between the actinide mass and the number of detected neutrons, in spite of a very high passive noise and the presence of a lead protection. Several R&D programs will be also presented. On one hand, measurements are performed on real wastes, chosen for parameter which could define a limitation of the measurements, in order to improve the method and to evaluate the detection limits. For instance, tomography can be performed with this experimental device: quantity and position of actinides in the waste can be calculated. On the other hand, a new method is studied, using the delayed-gamma flux in order to quantify and to identify the different actinide isotopes contained in the waste. These methods and device offer a large panel of results in terms of measurements and simulations. Our team is now involved in several prospecting and R&D programs in order to improve the current method and to find some new applications for nuclear-waste management.

scholarly journals 3-D COUPLED SIMULATION OF A VVER 1000 WITH PARCS/ATHLET

2021 ◽  
Vol 247 ◽  
pp. 06015
Author(s):  
Romain Henry ◽  
Yann Périn ◽  
Kiril Velkov ◽  
Sergei Pavlovich Nikonov
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Nuclear Data ◽  
Monte Carlo Code ◽  
Simulation Code ◽  
Control Rod ◽  
Lattice Codes ◽  
Physics Simulation ◽  
Two Phases ◽  
Effective Multiplication

A new OECD/NEA benchmark entitled “Reactivity compensation with diluted boron by stepwise insertion of control rod cluster” is starting. This benchmark, based on high quality measurements performed at the NPP Rostov Unit 2, aims to validate and assess high fidelity multi-physics simulation code capabilities. The Benchmark is divided in two phases: assembly wise and pin-by-pin resolution of steady-state and transient multi-physics problems. Multi-physics simulation requires the generation of parametrized few-group cross-sections. This task used to be done with deterministic (2-D) lattice codes, but in the past few years the Monte-Carlo code SERPENT has demonstrate its ability to generate accurate few-group homogenized cross-section without approximations, neither on the geometry nor in the nuclear data. Since the whole core SERPENT models for production of such cross-section libraries would be computationally costly (and the standard 2-D approach may introduce unnecessary large approximations), 3-D models of each assembly type in infinite radial lattice configurations have been created. These cross-sections are then used to evaluate effective multiplication factors for different core configurations with the diffusion code PARCS. The results are compared with the reference SERPENT calculations. In the next step, a thermal-hydraulic model with the system code ATHLET applying an assembly-wise description of the core (i.e. one channel per fuel assembly) has been developed for coupled PARCS/ATHLET transient test calculations. This paper describes in detail the models and techniques used for the generation of the few-group parameterized cross section libraries, the PARCS model and the ATHLET model. Additionally, a simple exercise with coupled code system PARCS/ATHLET is presented and analysed.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

SPALLATION YIELDS FROM HIGH ENERGY PROTON BOMBARDMENT OF HEAVY ELEMENTS

1957 ◽  
Vol 35 (1) ◽  
pp. 21-37 ◽  
Author(s):  
J. D. Jackson
Keyword(s):  
Cross Sections ◽  
High Energy ◽  
Heavy Elements ◽  
Collective Effects ◽  
Comparison With Experiment ◽  
Energy Proton ◽  
Stringent Test ◽  
Neutron Evaporation ◽  
Nuclear Processes ◽  
Mev Protons

The Monte Carlo calculations of McManus and Sharp (unpublished) for the prompt nuclear processes occurring upon bombardment of heavy elements by 400 Mev. protons are combined with a description of the subsequent neutron evaporation to determine spallation cross sections for comparison with experiment. The model employed is a schematic one which suppresses the detailed characteristics of individual nuclei, but gives the over-all behavior to be expected. Many-particle and collective effects such as alpha particle emission and fission are ignored. The computed cross sections are presented in a variety of different graphical forms which illustrate quantitatively the qualitative picture of high energy reactions first given by Serber (1947). The calculations are in general agreement with existing data when fission is not an important effect, but the agreement does not imply a very stringent test of the various features of the model.

scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.

scholarly journals Saturation effects in SIDIS at very forward rapidities

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
E. Iancu ◽  
A. H. Mueller ◽  
D. N. Triantafyllopoulos ◽  
S. Y. Wei
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Cross Sections ◽  
Virtual Photon ◽  
Large Fraction ◽  
Quark Distribution ◽  
High Energy ◽  
Longitudinal Momentum ◽  
Black Disk ◽  
Gluon Saturation

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.

Total Cross Sections of Liquefied Gases for High-Energy Neutrons

1954 ◽  
Vol 96 (1) ◽  
pp. 115-120 ◽  
Author(s):  
Peter Hillman ◽  
R. H. Stahl ◽  
N. F. Ramsey
Keyword(s):  
Cross Sections ◽  
High Energy ◽  
Total Cross Sections
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