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This special issue of Fusion Science and Technology is devoted to new achievements reached in the field of fusion neutronics aswell as its contemporary and innovative tasks. It is composed of 11 papers, thematically covering methodology... more
This special issue of Fusion Science and Technology is devoted to new achievements reached in the field of fusion neutronics aswell as its contemporary and innovative tasks. It is composed of 11 papers, thematically covering methodology and modeling advances (the first 6 papers) and achievements in computation neutronics analysis (the final 5 papers) of large fusion machines such as ITER, DEMO, ARIES, JET, NIF, and IFMIF-DONES, the geometrical and physical complexity of which are very challenging to reproduce accurately. Of course, each analysis presented in this issue is unique and requires significant computation efforts and sometimes code or interface developments. Therefore, the issue is split into parts as described. Here I introduce briefly the content of each paper. Recently, the importance of methodological and modeling developments has increased significantly because of the ITER tokamak construction, which requires high accuracy of the neutronics results of full-scale model...
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Neutronics support for designing the Charge Exchange Recombination Spectroscopy (CXRS) system viewed Edge plasma from the ITER Equatorial Port #3 (EP3). Creating MCNP neutronics model of CXRS-Edge installed inside the DSM #1 and #2... more
Neutronics support for designing the Charge Exchange Recombination Spectroscopy (CXRS) system viewed Edge plasma from the ITER Equatorial Port #3 (EP3).
Creating MCNP neutronics model of CXRS-Edge installed inside the DSM #1 and #2 of EP3 as part of ITER tokamak C-Model, without any other Diagnostic systems planned for EP3 (MSE, GDC, and VisIR) – because engineering designs of these systems are not matured enough. The model does not include Diagnostics Neutral Beam (DNB), no any Neutral Beam Injectors (NBI) in the adjacent ports.
Local approach was applied for neutronics analysis, it is aimed on investigation of the impact of CXRS-Edge system on radiation environment inside the Inter-Space Structure (ISS) area of EP3 and to study radiation effects for the CXRS-Edge components themselves.
Creating MCNP neutronics model of CXRS-Edge installed inside the DSM #1 and #2 of EP3 as part of ITER tokamak C-Model, without any other Diagnostic systems planned for EP3 (MSE, GDC, and VisIR) – because engineering designs of these systems are not matured enough. The model does not include Diagnostics Neutral Beam (DNB), no any Neutral Beam Injectors (NBI) in the adjacent ports.
Local approach was applied for neutronics analysis, it is aimed on investigation of the impact of CXRS-Edge system on radiation environment inside the Inter-Space Structure (ISS) area of EP3 and to study radiation effects for the CXRS-Edge components themselves.
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FNS-ST is a fusion neutron source project based on a spherical tokamak (R/a = 0.5 m/0.3 m) with a steady-state neutron generation of ~1018 n/s. Neutral beam injection (NBI) is supposed to maintain steady-state operation, non-inductive... more
FNS-ST is a fusion neutron source project based on a spherical tokamak (R/a = 0.5 m/0.3 m) with a steady-state neutron generation of ~1018 n/s. Neutral beam injection (NBI) is supposed to maintain steady-state operation, non-inductive current drive and neutron production in FNS-ST plasma. In a low aspect ratio device, the toroidal magnetic field shape is not optimal for fast ions confinement in plasma, and the toroidal effects are more pronounced compared to the conventional tokamak design (with R/a > 2.5). The neutral beam production and the tokamak plasma response to NBI were efficiently modeled by a specialized beam-plasma software package BTR-BTOR, which allowed fast optimization of the neutral beam transport and evolution within the injector unit, as well as the parametric study of NBI induced effects in plasma. The “Lite neutral beam model” (LNB) implements a statistical beam description in 6-dimensional phase space (106–1010 particles), and the beam particle conversions ar...
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Abstract This paper presents new results of the MCNP neutronics analysis for the core imaging X-ray spectrometer (CIXS) system of the ITER Equatorial Port Plug #17 (EPP#17). Substantial radiation shielding design improvements of the CIXS... more
Abstract This paper presents new results of the MCNP neutronics analysis for the core imaging X-ray spectrometer (CIXS) system of the ITER Equatorial Port Plug #17 (EPP#17). Substantial radiation shielding design improvements of the CIXS system have been suggested as the outcomes of this analysis. These suggested improvements allow reaching two major goals: (1) radiation protection of the CIXS Port Interspace (PI) to provide personnel access for maintenance of the vacuum extension flange; (2) reduction of the neutron and gamma loads on the detectors to reduce the need for maintenance itself. By implementing the improvements in our models such as filling void spaces around the CIXS beams with boron carbide and inserting the tungsten collimators in the narrowed beam channel, we were able to reduce the Shut-Down Dose Rate (SDDR) in the PI by 100× from 2 mSv/h in the original CIXS design to 20 microSv/h. In case of non-changed MCNP geometry, the D1S method was applied in calculations of SDDR. To allow the maintenance access to the flange, a part of shielding was removed, therefore the R2Smesh methodology was applied instead of D1S. During the maintenance access of CIXS from the PI side, a screen plate was proposed to introduce behind which a worker receives much less SDDR.
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ABSTRACT Scientific and technical activities on JET focus on the issues likely to affect the ITER design and operation. Our understanding of the ITER reference mode of operation, the ELMy H-mode, has progressed significantly. The... more
ABSTRACT Scientific and technical activities on JET focus on the issues likely to affect the ITER design and operation. Our understanding of the ITER reference mode of operation, the ELMy H-mode, has progressed significantly. The extrapolation of ELM size to ITER has been re-evaluated. Neoclassical tearing modes have been shown to be meta-stable in JET, and their beta limits can be raised by destabilization (modification) of sawteeth by ion cyclotron radio frequency heating (ICRH). Alpha simulation experiments with ICRH accelerated injected 4 (He) beam ions provide a new tool for fast particle and magnetohydrodynamic studies, with up to 80-90% of plasma heating by fast 4 He ions. With or without impurity seeding, a quasi-steady-state high confinement (H-98 = 1), high density(n(e)/n(GW) = 0.9-1) and high beta (betaN = 2) ELMy H-mode has been achieved by operating near the ITER triangularity ( similar to 0.40-0.5) and safety factor (q(95) similar to 3), at Z(eff) similar to 1.5-2. In advanced tokamak (AT) scenarios, internal transport barriers (ITBs) are now characterized in real time with a new criterion, rhoT(*). Tailoring of the current profile with T lower hybrid current drive provides reliable access to a variety of q profiles, lowering access power for barrier formation. Rational q surfaces appear to be associated with ITB formation. Alfven cascades were observed in reversed shear plasmas, providing identification of q profile evolution. Plasmas with 'current holes' were observed and modelled. Transient high confinement AT regimes with H-89 = 3.3, beta(N) = 2.4 and ITER-relevant q < 5 were achieved with reversed magnetic shear. Quasi-stationary ITBs are developed with full non-inductive current drive, including similar to 50% bootstrap current. A record duration of ITBs was achieved, up to 11 s, approaching the resistive time. For the first time, pressure and current profiles of AT regimes are controlled by a real-time feedback system, in separate experiments. Erosion and co-deposition studies with a quartz micro-balance show reduced co-deposition. Measured divertor thermal loads during disruptions in JET could modify ITER assumptions.
Research Interests: Plasma Physics, Magnetohydrodynamics, Magnetic field, Control system, Nuclear Fusion, and 15 moreReal Time Control, Iterative Design, Feedback Control, Radio Frequency, Electron Transport, Real Time, Steady state, High Power, Infrared, Temperature Gradient, Simulation experiment, High Density Concrete, Feedback System, Integral Operator, and Safety Factor
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Provide neutronics support for Diagnostics designing in Port Plugs: UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS) UPP#18 including 3 systems: Vertical Neutron Camera (VNC) Vacuum ultra-violet (VUV) spectrometer... more
Provide neutronics support for Diagnostics designing in Port Plugs:
UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS)
UPP#18 including 3 systems:
Vertical Neutron Camera (VNC)
Vacuum ultra-violet (VUV) spectrometer
Neutron Activation System (NAS)
EPP#17 with Core Imaging X-Ray Spectrometer (CIXS)
EPP#17 neutronics analysis was focused on CIXS because of straight beamlines
(no labyrinths are allowed in CIXS) – weakest original shielding.
UPP#3 with Charge eXchange Recombination Spectroscopy (CXRS)
UPP#18 including 3 systems:
Vertical Neutron Camera (VNC)
Vacuum ultra-violet (VUV) spectrometer
Neutron Activation System (NAS)
EPP#17 with Core Imaging X-Ray Spectrometer (CIXS)
EPP#17 neutronics analysis was focused on CIXS because of straight beamlines
(no labyrinths are allowed in CIXS) – weakest original shielding.
This paper presents a new method for the activation analysis of fusion reactor materials. The review of existing methods for the activation calculation and dose characteristics of fusion reactor materials has been performed and the... more
This paper presents a new method for the activation analysis of fusion reactor materials. The review of existing methods for the activation calculation and dose characteristics of fusion reactor materials has been performed and the necessity for creating a new method is shown. It is demonstrated that the method allows one to analyze the complex objects activated by neutrons (e.g. fusion reactors) combining the advantages of the three-dimensional radiation transport with those of the decay activation calculations. The offered method is intended for the solution of the activation tasks with deep penetration of radiation. The method was used in the International Thermonuclear Experimental Reactor (ITER) engineering design.
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Research Interests: Mechanical Engineering, Physics, Monte Carlo Simulation, Monte Carlo, ITER Project, and 11 moreGoal Orientation, Interdisciplinary Engineering, Reaction Rate, Training Program, Test Blanket Module, Production Rate, TRIPOLI-4 Monte Carlo code, Frascati neutron generator, McAm, European Fusion Devlopment Agreement, and Eurobreed Eurotrainee program
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This paper elaborates computational challenges tackled for providing neutronics service supplied for developing the design of the Diagnostics Equatorial and Upper Port Plugs (EPP and UPP). The aim was to guide and assist the EPP and UPP... more
This paper elaborates computational challenges tackled for providing neutronics service supplied for developing the design of the Diagnostics Equatorial and Upper Port Plugs (EPP and UPP). The aim was to guide and assist the EPP and UPP design developers with optimal shielding solutions which are characterised of maintain the diagnostics purposes of the systems together with adequate radiation shielding performance. The target parameter for the shielding optimization was the minimum of Shut-Down Dose Rate (SDDR) inside the interspace between the port back-side and ITER bioshield. This aim was reached by parametric neutronic analyses of the shielding geometry and material composition, mitigating direct streaming of neutrons from the plasma by arranging the labyrinths and horizontal rails. Variation of many geometrical parameters of the labyrinths was possible only by applying the high performance parallel computations with MCNP5 using pure MPI and hybrid OpenMP/MPI parallelization techniques on several available supercomputers. MCNP5 parallel performance assessments were carried out to find an efficient way to run the code in a parallel regime. It was found a strong scaling (up to 4096 cores) performance of the MCNP5 jobs running with analogue Monte Carlo sampling and weak scaling for the tasks with biased sampling as a variance reduction technique, such as the MCNP5 intrinsic weight window generator. Deep penetrating radiation in the complex ITER tokamak geometry combined blocks of strong attenuation of the radiation together with the void gaps along which the particles are streamed freely contributes to computation challenges of radiation transport.
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ABSTRACT For plasma stabilisation in ITER, a reference design of an electron cyclotron (EC) wave launcher was developed (8 remotely steerable beamlines) and improved by advanced remote and front steering configurations. The key concepts... more
ABSTRACT For plasma stabilisation in ITER, a reference design of an electron cyclotron (EC) wave launcher was developed (8 remotely steerable beamlines) and improved by advanced remote and front steering configurations. The key concepts of their structural integration into the port plug environment are presented for assuring efficient neutron and thermal shielding.
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ABSTRACT Nuclear safety related analyses were performed for the Quasi-Optical (QO) design of the Electron Cyclotron Heating (ECH) launcher installed in the ITER upper port. The critical nuclear responses, effecting nuclear safety of the... more
ABSTRACT Nuclear safety related analyses were performed for the Quasi-Optical (QO) design of the Electron Cyclotron Heating (ECH) launcher installed in the ITER upper port. The critical nuclear responses, effecting nuclear safety of the launcher and nearby components, were calculated using the MCNP5 3D radiation transport code. The CAD interface programme McCad was applied for the conversion of the CAD model into MCNP geometry description. The radiation effects of the launcher's halved internal shield were estimated on the Chemical Vapor Deposit (CVD) diamond windows, vacuum vessel, and Toroidal Field Coils (TFC). It was revealed that the nuclear safety requirements were satisfied.
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... of cell flux tally F4 and surface flux tally F2 were used for the helium production calculation. ... 7.Fast neutron fluence (per square meter) per 0.63 fpy in point detectors P1P8 placed in ... A. Serikov, H. Shidara, C. Sozzi, P.... more
... of cell flux tally F4 and surface flux tally F2 were used for the helium production calculation. ... 7.Fast neutron fluence (per square meter) per 0.63 fpy in point detectors P1P8 placed in ... A. Serikov, H. Shidara, C. Sozzi, P. Spaeh, VS Udintsev, H. Zohm, and C. Zucca, Overview of ...
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Provide neutronics support for the ITER Equatorial and Upper Port Plug design development. Check the current design to satisfy the ITER radiation requirements. Find design solutions for possible shielding improvements in accordance with... more
Provide neutronics support for the ITER Equatorial and Upper Port Plug design development.
Check the current design to satisfy the ITER radiation requirements.
Find design solutions for possible shielding improvements in accordance with ALARA principle – for the Shut-Down Dose Rate (SDDR).
Check the current design to satisfy the ITER radiation requirements.
Find design solutions for possible shielding improvements in accordance with ALARA principle – for the Shut-Down Dose Rate (SDDR).