Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “biasing”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,603 records · Page 89

Sink strength and dislocation bias of three-dimensional microstructures

Irradiation induces significant changes in the microstructure of structural materials, many of which are driven by the preferential capture of point defects at particular sinks, such as dislocations. To quantify the kinetics of defect absorption at sinks, theoretical models of radiation damage generally rely on the concept of sink strength. However, analytical approaches to estimating the sink strength of dislocations rely, in turn, on a series of geometrical assumptions, idealizing the dislocation network as a series of infinite straight dislocations or isolated loops, often with artificial boundary conditions. In this paper, we use a recently developed technique to quantify point defect capture in three-dimensional dislocation networks. We integrate this technique with discrete dislocation dynamics to analyze the sink strengths of realistic dislocation microstructures consisting of a mixture of edge, screw, and junction segments, complete with an accurate description of the strain fields these microstructures produce and the resultant energetic interactions experienced by point defects. Furthermore, we show that the effective kinetics for absorbing point defects can vary significantly with the arrangement of the microstructure with a strong dependence on the structure and character of its dislocation content and introduce a surrogate model for sink strength which incorporates these effects.

36 MATERIALS SCIENCE↗

Measurement of event shapes in minimum-bias events from proton-proton collisions at $\sqrt{s}$ = 13

A measurement of event-shape variables is presented, using a data sample produced in a special run with approximately one inelastic proton-proton collision per bunch crossing. The data were collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 64 μ⁢b −1 . A number of observables related to the overall distribution of charged particles in the collisions are corrected for detector effects and compared with simulations. Inclusive event-shape distributions, as well as differential distributions of event shapes as functions of charged-particle multiplicity, are studied. None of the models investigated are able to satisfactorily describe the data. Moreover, there are significant features common amongst all generator setups studied, particularly showing data being more isotropic than any of the simulations. Multidimensional unfolded distributions are provided, along with their correlations.

Chekhovsky, V. [Yerevan Physics Institute]↗