Chalk River Laboratories

About: Chalk River Laboratories is a based out in . It is known for research contribution in the topics: Neutron diffraction & Neutron scattering. The organization has 2297 authors who have published 2700 publications receiving 73287 citations.

Sediment focusing and210Pb dating: a new approach

Abstract: In this paper we test the utility of the mud deposition boundary depth (mud DBD) theory (Rowanet al. 1992) as a means of maximizing sampling efficiency in paleolimnological investigations, particularly those that apply to210Pb dating. The mud DBD is defined by the relationship between near bottom wave velocity and particle threshold velocity, with wave and particle threshold theory simplified to terms of exposure and depth. Mud DBD theory can be used to define the depositional zone in lakes, and within the depositional zone defined by the mud DBD: 1) there is a high probability of obtaining a representative core, 2) variation in mass sediment accumulation rate (MSAR) is not correlated with water depth, and 3) variation in MSAR is considerably reduced from the whole lake average. This suggests that mud DBD theory can account for the effects of sediment focusing, and that the mud DBD defined depositional zone is the zone to which fine-grained sediments are focused. Finally, we have shown that to optimize sampling effort, 5 to 10 cores within the depositional zone are necessary for a reasonably precise estimate of the mean mass sediment accumulation rate. In addition, the use of mud DBD theory prior to sampling can dramatically reduce the cost associated with analyzing large numbers of cores for210Pb.

Neutron study of in-plane skyrmions in MnSi thin films

Abstract: Chiral magnetic thin films have been a recent source of interest due to their ability to stabilize topological magnetic states, known as skyrmions. However, there exists disagreement in the literature over their existence in epitaxial MnSi films, grown on Si(111) substrates. The authors have combined polarized neutron reflectometry and small-angle neutron reflectometry to uncover direct evidence for a unique skyrmion geometry in MnSi/Si(111) films where the core magnetization of the vortex-like magnetic textures points in the plane of the film.

Probing the hydration of ultrathin antifouling organosilane adlayers using neutron reflectometry.

Abstract: Neutron reflectometry data and modeling support the existence of a relatively thick, continuous phase of water stemming from within an antifouling monoethylene glycol silane adlayer prepared on oxidized silicon wafers. In contrast, this physically distinct (from bulk) interphase is much thinner and only interfacial in nature for the less effective adlayer lacking internal ether oxygen atoms. These results provide further insight into the link between antifouling and surface hydration.

Effect of suppression of the inelastic scattering rate on the penetration depth and conductivity in a d{sub x{sup 2}{minus}y{sup 2}} superconductor

Abstract: We use a separable d-wave model to describe the momentum dependence of the pairing interaction in the gap channel We include the inelastic scattering through a spectral density which describes the fluctuation spectrum responsible for superconductivity The collapse of the scattering rate observed in microwave experiments is modeled through a low-frequency cutoff on the fluctuation spectrum The effect of this cutoff on the temperature dependence of the magnetic-field penetration depth and on the infrared conductivity and associated scattering rates is calculated {copyright} {ital 1997} {ital The American Physical Society}