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The increasing power demands of spacecraft payloads and the realistic prospect of space based solar power (SBSP) stations as a means of providing zero carbon electricity in the 2030s, means that there is an emerging requirement for large area, yet lightweight, solar photovoltaic (PV) arrays that will provide far greater power (kW peak) than is currently available. To be practical, such arrays will need to use solar cells which have a much higher specific power (i.e., power per unit mass) and a much lower cost per watt than current space-rated solar PV technologies. To this end, the Centre for Solar Energy Research (CSER) at Swansea University have been working on a new solar cell technology, based on thin-film cadmium telluride (CdTe), deposited directly onto ultra-thin space qualified cover glass material. This offers a potentially high specific power and when adopting the conventional CdTe manufacturing process, a low-cost technology. The ultra-thin glass can produce a solar cell which is sufficiently flexible to allow "roll-out" deployment strategies. Four prototype cells were flown as part of the Thin-Film Solar Cell (TFSC) experimental payload, developed by CSER and the Surrey Space Centre (SSC), on the joint Algerian Space Agency (ASAL) – UK Space Agency AlSAT-1N Technology Demonstration CubeSat, launched into a 661 km × 700 km, 98.20° Sun Synchronous orbit, on September 26, 2016. The experiment has provided the first in-orbit current/voltage (I/V) measurements of this novel technology, and more than five years of flight results have now yielded new insights into its longer-term performance and inherent radiation hardness, which makes them particularly attractive for maintaining high end-of-life (EOL) performance for long duration space missions. The results help to strengthen the argument for further development of this technology for space application. The data, collected over ∼30,000 orbits, show no signs of cell delamination (a potential risk for such technologies), no deterioration in short circuit current or in series resistance. However, all four cell's fill factors were observed to decrease over the duration of the mission, caused primarily by a decrease in their shunt resistance. This has been attributed to the diffusion of gold atoms from the back electrical contacts. We conclude therefore that further development of this technology should utilize more stable back contacting methodologies more commonly employed for terrestrial CdTe modules. However, this flight has proven the basic soundness of the technology for use in space. • First detailed study of thin-film cadmium telluride solar cells operating in space. • Novel low-cost lightweight solar cell structure laid down on ultra-thin glass. • Thin-Film cadmium telluride solar cells show excellent radiation tolerance. • International spaceflight cooperation between Algeria and the UK via a CubeSat. [ABSTRACT FROM AUTHOR]

Molybdenum-rich radioactive waste streams in the UK will be vitrified into glass composite high-level waste (HLW) products containing powellite (CaMoO 4) crystals. These materials will be exposed to self-irradiation in a geological disposal facility for thousands of years. Our heavy-ion and electron irradiation results, together with a comprehensive review of previous studies, reveal new details on the radiation tolerance of powellite. In this study, powellite crystals were exposed to 500 keV Ar2+ and 600 keV Xe2+ ion irradiations between -160 and -80 °C and were analysed in situ via transmission electron microscopy (TEM). At low temperatures (between -160 and -105 °C), the critical amorphisation dose (D c) is higher for the Xe irradiation, most likely due to the significant defect recovery in the cascade core. Above -105 °C, the D c is higher for the Ar irradiation. The dynamic annealing of radiation-induced defects becomes more efficient as the temperature increases; our results suggest that point defects formed during Ar irradiation are more susceptible to dynamic annealing compared with defects in the cascades generated during Xe irradiation. We also present the first evidence of 300 keV electron beam-induced recrystallisation in amorphous powellite by studying its response from room temperature to cryogenic temperatures inside the TEM using a wide range of electron fluxes (0.6–5.2 × 1016 e/cm2/s). In contrast to previous research, our new data suggest that powellite is susceptible to amorphisation by alpha recoil nuclei, and that beta irradiation may cause defect recombination. [Display omitted] [ABSTRACT FROM AUTHOR]

• Glass composites were prepared and irradiated with Ni and Au ions. • Microcracks formed in powellite and in the glass around large zircon crystals. • Radioactive actinides are expected to accumulate in cerianite, powellite and zircon. • Powellite and zircon swelled and became amorphous after the heavy ion irradiations. • EBSD was an excellent complementary technique to GIXRD. Non-active molybdenum-rich Ca/Zn glass composite materials (GCM) were prepared on the Vitrification Test Rig (VTR) in the UK. The GCM samples were subjected to Ni and Au ion irradiations to simulate the effects of alpha recoil damage and to determine how the crystallinity characteristics might affect the overall radiation tolerance of high-level wastes (HLW) generated during post-operational clean-out (POCO) operations at the Sellafield nuclear site. The typical crystal phases identified in the GCM were: powellite, ruthenium dioxide, zincochromite, zircon and cerianite. Gadolinium (a proxy for radioactive elements) accumulated mainly in powellite, zircon and cerianite crystals. Scanning electron microscopy (SEM), electron backscatter diffraction (EBSD) and grazing incidence X-ray diffraction (GIXRD) analyses showed that cerianite is a highly radiation-tolerant phase, whereas powellite and zircon became amorphous and swelled considerably after the Ni and Au ion irradiations. This research shows the first evidence of powellite amorphisation under heavy-ion irradiation and suggests that powellite is susceptible to amorphisation by alpha recoils in HLW materials, in contrast to previous findings. The evolution of cooling-related and irradiation-induced microcracks is also described. In HLW glass composite materials, the formation of microcracks is expected in the middle of the canister, where relatively large powellite and zircon crystals appear. [Display omitted] [ABSTRACT FROM AUTHOR]

Objective: Radiobiological modelling the risks of second primary cancer (SPC) after proton therapy (PT) for childhood cranial cancer remains largely unknown. Organ‐specific dose‐response risk factors such as radiosensitivity require exploration. This study compared the influence of radiosensitivity data (slope of βEAR) on children's lifetime attributable risks (LAR) of SPC development in out‐of‐field organs following cranial scattering and scanning PT. Methods: Out‐of‐field radiosensitivity parameter estimates for organs (α/β and βEAR) were sourced from literature. Physical distances for 13 out‐of‐field organs were measured and input into Schneider's SPC model. Sensitivity analyses were performed as a function of radiosensitivity (α/β of 1–10 Gy) and initial slope (βEAR) from Japanese/UK data to estimate the influence on the risk of radiation‐induced SPC following scattering and scanning PT. Results: Models showed similar LAR of SPC estimates for age and sex‐matched paediatric phantoms, however, for breast there was a significant increase using Japanese βEAR data. For most organs, scattering PT demonstrated a larger risk of LAR for SPC which increased with α/β. Conclusion: Breast tissue exhibited the highest susceptibility in calculated LAR risk, demonstrating the importance for accurate data input when estimating LAR of SPC. Advances in knowledge: The findings of this study demonstrated younger female patients undergoing cranial proton therapy have a higher risk of developing second primary cancer of the breast tissue. Long‐term multicenter registries are important to improve predictive radiobiological modelling studies of side effects. [ABSTRACT FROM AUTHOR]

The article reports on the selection of structural materials for the application of fusion reactors in nuclear power plants of Great Britain. It mentions that the requirements for the reactor's materials include high radiation resistance and low activation response. Resistance to radiation is needed to ensure component integrity and performance satisfactory of the reactor while low response in activation shows low radioactivity and cause radioactive decay time.