Real-Time Characterization of Neutron-Induced SEUs in Fusion Experiments at WEST Tokamak during D-D Plasma Operation

International audienceWe conducted a real-time soft-error rate characterization of CMOS bulk 65 nm SRAMs subjected to fusion neutrons during deuterium-deuterium (D-D) plasma operation at WEST tokamak. The test equipment, installed in the experimental hall at several locations of the tokamak, was irradiated during machine shots by a flux of particles dominated by primary 2.45 MeV neutrons. Real-time neutron metrology, neutron spectrometry, complementary characterization with monoenergetic neutrons and Monte Carlo numerical simulations at both material and circuit levels have been also performed to analyze experimental data. Our results suggest that higher energy neutrons, simultaneously produced by deuterium-tritium (D-T) reactions due to triton burn up in the D-D plasma, play a significant role in the radiation response of the SRAMs for which multiple cell upsets are detected and cannot be attributed to D-D neutrons

Initial Results from Boron Powder Injection Experiments in WEST Lower Single Null L-mode Plasmas

Using a recently installed impurity powder dropper (IPD), boron powder (< 150 μm) was injected into lower single null (LSN) L-mode discharges in WEST. IPDs possibly enable real-time wall conditioning of the plasma-facing components and may help to facilitate H-mode access in the full-tungsten environment of WEST. The discharges in this experiment featured Ip = 0.5 MA, BT = 3.7 T, q95 = 4.3, tpulse = 12–30 s, ne,0 ~ 4×1019 m-2, and PLHCD ~ 4.5 MW. Estimates of the deuterium and impurity particle fluxes, derived from a combination of visible spectroscopy measurements and their corresponding S/XB coefficients, showed decreases of ~ 50% in O+, N+, and C+ populations during powder injection and a moderate reduction of these low-Z impurities (~ 50%) and W (~ 10%) in the discharges that followed powder injection. Along with the improved wall conditions, WEST discharges with B powder injection observed improved confinement, as the stored energy WMHD, neutron rate, and electron temperature Te increased significantly (10–25% for WMHD and 60–200% for the neutron rate) at constant input power. These increases in confinement scale up with the powder drop rate and are likely due to the suppression of ion temperature gradient (ITG) turbulence from changes in Zeff and/or modifications to the electron density profile.README.txt should be consulted for table of contents information

Preliminary Study of Electronics Reliability in ITER Neutron Environment

International audienceWe validated a method for predicting the Soft Error Rate (SER) in the WEST tokamak operated with deuterium plasmas, and we applied it to predict the SER in the ITER tokamak operated with deuterium-tritium plasmas

Preliminary Study of Electronics Reliability in ITER Neutron Environment

International audienceWe validated a method for predicting the Soft Error Rate (SER) in the WEST tokamak operated with deuterium plasmas, and we applied it to predict the SER in the ITER tokamak operated with deuterium-tritium plasmas

Preliminary Study of Electronics Reliability in ITER Neutron Environment

International audienceWe validated a method for predicting the Soft Error Rate (SER) in the WEST tokamak operated with deuterium plasmas, and we applied it to predict the SER in the ITER tokamak operated with deuterium-tritium plasmas

Fusion Neutron-Induced Soft Errors During Long Pulse D-D Plasma Discharges in the WEST Tokamak

International audienceWe conducted real-time SER measurements on bulk 65 nm SRAMs in the WEST tokamak during long pulse deuterium-deuterium plasma discharges (~60 s), evidencing bursts of SEUs during the most efficient shots and 12% of MCU events

Fusion Neutron-Induced Soft Errors During Long Pulse D-D Plasma Discharges in the WEST Tokamak

International audienceWe conducted real-time SER measurements on bulk 65 nm SRAMs in the WEST tokamak during long pulse deuterium-deuterium plasma discharges (~60 s), evidencing bursts of SEUs during the most efficient shots and 12% of MCU events

Fusion Neutron-Induced Soft Errors During Long Pulse D-D Plasma Discharges in the WEST Tokamak

International audienceWe have performed real-time soft error rate (RT-SER) measurements on bulk 65-nm static random access memories (SRAMs) during deuterium–deuterium (D-D) plasma operation at W–tungsten–Environment in Steady-state Tokamak (WEST). The present measurement campaign was characterized by the production of several tens of long pulse discharges (∼60 s) and by a total neutron fluence (at the level of the circuits under test) up to ∼10 9 n·cm−2, improving the error statistics by a factor of more than 6 with respect to the first measurements obtained in 2020. The experimental results demonstrate the occurrence of bursts of single-event upsets (SEUs) during the most efficient shots and 12% of multiple cell upset (MCU) events. Time-resolved data also show that MCUs are preferentially detected in the last part of these long pulses, providing further evidence that higher energy neutrons, initiated by deuterium–tritium (D-T) reactions due to triton burn-up in the D-D plasma, may play a role in the production of MCUs that cannot be attributed in such large proportions to “low-energy” neutrons produced in D-D reactions

Les traditions économiques françaises

Les années 1848-1939 correspondent à une époque que l’on a pu caractériser par «l’essor des sciences sociales ». Les économistes français d’alors, et plus généralement les économistes francophones, tiennent dans ce mouvement une place importante. On observe un foisonnement d’idées, d’observations, de théories, tout un riche tissu intellectuel sur des thèmes tels que les crises, la monnaie, les marchés, l’équilibre, l’économie sociale, les questions de méthode, le socialisme ou le libéralisme. Un des intérêts de l’ouvrage est de mieux faire connaître ces travaux, y compris ceux d’auteurs considérés, à tort, comme mineurs. Les économistes français sont imprégnés par les traditions économiques nationales. Traditions en ce qui concerne les théories de la valeur axée sur l’utilité, le rôle donné aux mathématiques sociales, l’importance des sciences de l’ingénieur, l’intérêt pour une économie qui ne soit pas déshumanisée, le débat entre un libéralisme et un socialisme chacun eux-mêmes originaux. L’ouvrage permet de montrer l’importance des relations de l’économie avec d’autres disciplines comme le droit, la psychologie, la sociologie, l’histoire. Il met également l’accent sur les relations entre l’histoire de la pensée et celle des faits, entre les économistes français et ceux du reste du monde