As one of the main components of the injector II of China ADS LINAC project, an RFQ working at 162.5 MHzis used to accelerate proton beams of 15 mA from 30 keV to 2.1 MeV. The four vane RFQ has been designed incollabo...As one of the main components of the injector II of China ADS LINAC project, an RFQ working at 162.5 MHzis used to accelerate proton beams of 15 mA from 30 keV to 2.1 MeV. The four vane RFQ has been designed incollaboration with Lawrence Berkeley National Laboratory and built at the workshop of the Institute of ModernPhysics, Chinese Academy of Sciences (IMP, CAS).展开更多
The internal stress induced by a porous layer or passive layer can assist the applied stress to promote dislocation emission and crack propagation, e.g. when the pipeline steel is buried in the soil containing water, ...The internal stress induced by a porous layer or passive layer can assist the applied stress to promote dislocation emission and crack propagation, e.g. when the pipeline steel is buried in the soil containing water, resulting in stress corrosion cracking (SCC). Molecular dynamics (MD) simulation is performed to study the process of dislocation emission and crack propagation in a slab of Fe crystal with and without a porous layer on the surface of the crack. The results show that when there is a porous layer on the surface of the crack, the tensile stress induced by the porous layer can superimpose on the external applied stress and then assist the applied stress to initiate crack tip dislocation emission under lowered stress intensity KI, or stress. To respond to the corrosion accelerated dislocation emission and motion, the crack begins to propagate under lowered stress intensity KI, resulting in SCC.展开更多
文摘As one of the main components of the injector II of China ADS LINAC project, an RFQ working at 162.5 MHzis used to accelerate proton beams of 15 mA from 30 keV to 2.1 MeV. The four vane RFQ has been designed incollaboration with Lawrence Berkeley National Laboratory and built at the workshop of the Institute of ModernPhysics, Chinese Academy of Sciences (IMP, CAS).
基金supported by the National Natural Science Foundation of China (Grant No. 50731003)the NSAF Foundation (Grant No. 10776068)+1 种基金Meng acknowledges grants from the National Natural Science foundation of China (Grant No. 50902009)The authors are indebted to Professor J. Rifkin from Center for Materials Simulation of University of Connecticut for providing the XMD code
文摘The internal stress induced by a porous layer or passive layer can assist the applied stress to promote dislocation emission and crack propagation, e.g. when the pipeline steel is buried in the soil containing water, resulting in stress corrosion cracking (SCC). Molecular dynamics (MD) simulation is performed to study the process of dislocation emission and crack propagation in a slab of Fe crystal with and without a porous layer on the surface of the crack. The results show that when there is a porous layer on the surface of the crack, the tensile stress induced by the porous layer can superimpose on the external applied stress and then assist the applied stress to initiate crack tip dislocation emission under lowered stress intensity KI, or stress. To respond to the corrosion accelerated dislocation emission and motion, the crack begins to propagate under lowered stress intensity KI, resulting in SCC.
