Mazzola F.,Norwegian University of Science and Technology |
Nematollahi M.,Norwegian University of Science and Technology |
Li Z.S.,Institute for Storage Ring Facilities |
Cooil S.,Norwegian University of Science and Technology |
And 3 more authors.
Applied Physics Letters | Year: 2015
Resonant photoemission spectroscopy is used to study the intermediate-band material Cr doped ZnS. Using resonant photoemission, we show that the intermediate-band can be characterized, revealing the filling and specific orbital character of the states contributing to the resonant photoemission signal. We demonstrate that resonant photoemission spectroscopy is a powerful approach for understanding the origin of intermediate bands in doped ZnS. The methodology can be widely extended to a large variety of materials, providing useful information towards engineering of high efficiency intermediate band solar cells and of other optoelectronic devices. © 2015 AIP Publishing LLC.
Rondeau A.,PSN RES SCA |
Merrison J.,Institute for Storage Ring Facilities |
Iversen J.J.,Institute for Storage Ring Facilities |
Peillon S.,PSN RES SCA |
And 4 more authors.
Fusion Engineering and Design | Year: 2015
During the normal operating condition of the future ITER tokamak, a massive production of dust in the toroidal vacuum vessel is expected. This dust, originating from the erosion of tungsten and beryllium internal walls of the torus by the plasma, would be mobilized to some extent during a loss of vacuum accident (LOVA). For safety reasons, it is essential to quantify the re-suspended dust fraction during such an event. Here, we provide preliminary experimental data of dust re-suspension obtained in the wind tunnel of the European Space Agency (ESA) at low pressures (300, 130 and 10mbar). The experimentations were performed with multilayer deposits. We used two powders with a median diameter at 15.5μm and 21.8μm. A negative influence of the low pressure in the re-suspension mechanism is observed. For example, given a re-suspension fraction of 10%, increasing friction shear velocities are derived for decreasing absolute pressures: 300mbar/0.66ms-1; 130mbar/1.08ms-1; and 10mbar/1.84ms-1. In addition, we highlight the friction reduction for Kundsen numbers greater than 0.1 by an analysis of the airflow forces. © 2015 Elsevier B.V.