Plasma,called the fourth form of matter,not only plays an important role in astrophysics,but also becomes the new interest in atomic physics,material science and other aspects.Ion beam–plasma interaction can be a new...Plasma,called the fourth form of matter,not only plays an important role in astrophysics,but also becomes the new interest in atomic physics,material science and other aspects.Ion beam–plasma interaction can be a new solution to understand the plasma properties.For instance the collision of ion and free electrons dominate in plasma,which can induce the higher energy loss and the change of charge state,as well as the wake-field can modify the ion beam from a continues mode to a pulsed mode with a focused/unfocused spot.展开更多
The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are...The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are treated with the morphological characterization. To compare the structures and evolution of characteristic regimes under various temperature thresholds, we introduce two concepts, structure similarity and process similarity. It is found that the temperature pattern dynamics may show high similarity under various conditions. Within the same material, the structures and evolution of high-temperature regimes may show high similarity if the shock strength and temperature threshold are chosen appropriately. For process similarity in materials with high porosity, the required temperature threshold increases parabolically with the impact velocity. When the porosity becomes lower, the increasing rate becomes higher. For process similarity in different materials, the required temperature threshold and the porosity follow a power-law relationship in some range.展开更多
基金National Key R&D Program of China(2017YFA0402300)National Natural Science Foundation of China(U1532263,11505248,11775042,11775278)。
文摘Plasma,called the fourth form of matter,not only plays an important role in astrophysics,but also becomes the new interest in atomic physics,material science and other aspects.Ion beam–plasma interaction can be a new solution to understand the plasma properties.For instance the collision of ion and free electrons dominate in plasma,which can induce the higher energy loss and the change of charge state,as well as the wake-field can modify the ion beam from a continues mode to a pulsed mode with a focused/unfocused spot.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10702010, 10775018, and 10771019)Science Foundation of Laboratory of Computational Physics and Science Foundation of China Academy of Engineering Physics (Grant Nos. 2009A0102005 and 2009B0101012)
文摘The physical fields in porous materials under strong shock wave reaction are very complicated. We simulate such systems using the grain contact material point method. The complex temperature fields in the material are treated with the morphological characterization. To compare the structures and evolution of characteristic regimes under various temperature thresholds, we introduce two concepts, structure similarity and process similarity. It is found that the temperature pattern dynamics may show high similarity under various conditions. Within the same material, the structures and evolution of high-temperature regimes may show high similarity if the shock strength and temperature threshold are chosen appropriately. For process similarity in materials with high porosity, the required temperature threshold increases parabolically with the impact velocity. When the porosity becomes lower, the increasing rate becomes higher. For process similarity in different materials, the required temperature threshold and the porosity follow a power-law relationship in some range.
