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Electrical performance degradation of a-Si/a-SiGe/a-SiGe triple-junction solar cells due to irradiation of protons with different energies and their performance recovery at room temperature just after irradiation are reported. The current-voltage characteristics are measured in-situ and the results show that all the parameters recover with time after proton irradiation is stopped. In particular, the short-circuit current remarkably recovers. It is also shown that the degradation is scaled by a unit of displacement damage dose independent of proton energy. This indicates that the proton-induced degradation is mainly caused by the displacement damage effect. [ABSTRACT FROM PUBLISHER]

Reduction of time and cost of proton irradiation tests on space solar cells are considered by adopting state-of-the-art proton beam technologies developed at the Japan Atomic Energy Agency (JAEA). An irradiation area of about 80mm × 40mm is achieved with excellent uniformity in current density by the uniform-beam formation technique which employs multipole magnets. The experimental result of 10 MeV-proton irradiation using this ‘flash’ (nonscanned, short-pulse) technique indicates no significant difference in the degradation trend of InGaP/GaAs/Ge triple-junction space solar cells compared to the results using our conventional beam-scanning method. The uniform-beam-formation approach enables irradiation over a time duration that is about an order of magnitude less than that required for the conventional scanned spot beam. Development of laser-driven proton beams is also being conducted at JAEA in which divergent proton yields with broad spectra similar to the space environment are typical. Laser-acceleration of protons is the result of intense irradiation of thin foil targets (such as aluminum) by high power lasers. For proton spectra that adequately simulate the space environment many irradiation tests with different specified proton energies will be unnecessary affording great simplification of complex radiation degradation prediction such as the relative damage coefficient method or the displacement damage dose method. Ground tests with a suitable compact laser-driven source can also enhance access and experiment diversity for irradiation studies. [ABSTRACT FROM PUBLISHER]

The 200MHz RAD750™ PowerPC™ Microprocessor is a second generation RAD750 fabricated in the BAE Systems' RH18, 180nm radiation hardened process technology. The processor was evaluated in the various radiation environments and demonstrated significant improvements in performance, power and radiation tolerance over the first generation 133MHz RAD750. [ABSTRACT FROM PUBLISHER]

Poly crystalline Yb6W1O12 and Y6W1O12 samples, which possess rhombohedral symmetry (structure known as the δ-phase, closely related to cubic fluorite structure), were irradiated with 280 keV Kr++ ions to fluences up to 2×1020 ions/m2 at cryogenic temperature (100 K). Ion irradiation damage effects in these samples were examined using grazing incidence X-ray diffraction (GIXRD) and cross-sectional transmission electron microscopy (TEM). Irradiation-induced amorphization in both compounds has been observed by GIXRD and TEM, while the amorphization dose for Yb6W1O12 is lower than that for Y6W1O12. Experimental results also revealed that both irradiated samples experience an ordered rhombohedral to disordered cubic fluorite (O-D) transformation before amorphization. Factors influencing the irradiation damage response of these two compounds will be discussed in terms of cation radius ratio and cation antisite formation energy calculated by density functional theory (DFT). [ABSTRACT FROM AUTHOR]