Effect on impact properties of adding tantalum to V-4Cr-4Ti ternary vanadium alloy

Four V-Ta-4Cr-4Ti quaternary alloys containing different quantities of Ta were investigated to determine the effect of Ta content on the Charpy impact properties. Five button-shaped ingots of the V-4Cr-4Ti ternary alloy and V-xTa-4Cr-4Ti quaternary alloys (x = 3, 9, 15, and 22 wt.%) were fabricated on a laboratory scale by using non-consumable arc-melting in an argon atmosphere. Charpy impact tests were conducted at temperatures ranging from 77 K to 293 K using an instrumented impact tester. Both the upper shelf energy and the ductile–brittle transition temperature increased with increasing Ta content. The addition of 3 wt.% Ta resulted in solid solution strengthening without any degradation of the Charpy impact properties. Thus, the addition of 3 wt.% Ta (V-3Ta-4Cr-4Ti) is an appropriate amount to use in blanket structural materials for nuclear fusion reactors. The spectra of TEM-EDS for V-3Ta-4Cr-4Ti quaternary alloy indicate that there is no significant enrichment of Ta in the matrix as compared with that in the precipitate. However, thermal aging may result in the formation of the Laves phase, causing the degradation of Charpy impact properties. The characterization of precipitates, thermal aging, and creep tests of the V-3Ta-4Cr-4Ti quaternary alloy need to be investigated to determine the optimum Ta content

Phase Transformation by 100 keV Electron Irradiation in Partially Stabilized Zirconia

Partially stabilized zirconia (PSZ) is considered for use as an oxygen-sensor material in liquid lead-bismuth eutectic (LBE) alloys in the radiation environment of an acceleration-driven system (ADS). To predict its lifetime for operating in an ADS, the effects of radiation on the PSZ were clarified in this study. A tetragonal PSZ was irradiated with 100 keV electrons and analyzed by X-ray diffraction (XRD). The results indicate that the phase transition in the PSZ, from the tetragonal to the monoclinic phase, was caused after the irradiation. The deposition energy of the lattice and the deposition energy for the displacement damage of a 100 keV electron in the PSZ are estimated using the particle and heavy ion transport code system and the non-ionizing energy loss, respectively. The results suggest that conventional radiation effects, such as stopping power, are not the main mechanism behind the phase transition. The phase transition is known to be caused by the low-temperature degradation of the PSZ and is attributed to the shift of oxygen ions to oxygen sites. When the electron beam is incident to the material, the kinetic energy deposition and excitation-related processes are caused, and it is suggested to be a factor of the phase transition

Displacement Damage Dose Analysis on Alfa-ray Degradation of Output of a CIGS Solar Cell

Cupper indium gallium di-Selenide (CIGS) solar cell is expected to be a dosimeter devise under a harsh radiation environment since it has supreme radiation resistance. CIGS solar cell is considered to be another strong candidate for a dosimeter to measure radiation level in the damaged reactors at Fukushima Daiichi Nuclear Power Plant in addition to InGaP solar cell. Degradation characteristics of a CIGS solar cell against alfa-ray, which is one of the major radiation particles in the reactors, were obtained by 1 and 5-MeV helium-ion irradiation. The degradation was compared with electron and proton degradations and analyzed using the displacement damage dose method

Displacement damage dose analysis of the output characteristics of In0.5Ga0.5P and Cu(In,Ga)(S,Se)2 solar cells irradiated with alpha ray simulated helium ions

To investigate applicability of radiation-hard indium–gallium–phosphide (InGaP) and copper–indium–gallium–sulfide–selenide (CIGS) solar cells to dosimeter devices without any modification, we irradiated high-energy He+ ions, which were simulated α-ray particles, to an InGaP and a CIGS solar cell. We found that both types of solar cells have sufficient resistance to He+ ions. By using displacement damage dose (DDD) analysis, the obtained He+ ion-induced degradation trends were compared with those induced by high-energy electrons, and we found that the degradation trends due to He+-ions, electrons, and protons aligned on the same curve when we plotted the data as a function of a modified DDD conversion equation, which originally was applied to space solar cells. The obtained DDD formulas enable us to predict the device lifetime or correction of an output signal for degradation when such solar cells are employed as a dosimeter

Displacement Damage Dose Analysis of Alpha-ray Degradation on Output of an InGaP Solar Cell

Indium gallium phosphide (InGaP) solar cell is expected to be a dosimeter devise under a harsh radiation environment since it has high radiation resistance. InGaP solar cell is now considered to be one of strong candidates for a dosimeter to measure radiation level in the damaged reactors at Fukushima Daiichi Nuclear Power Plant. Degradation characteristics of an InGaP solar cell against alfa-ray, which is one of the major radiation particles in the reactors, are obtained by 5-MeV helium-ion irradiation, and the degradation is analyzed using displacement damage dose