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.

Radiation environment measurements from CREAM and CREDO during the approach to solar maximum

Abstract: Results from the Cosmic Radiation Environment Monitors (CREAM and CREDO) have been reported from a range of platforms during the declining phase of solar cycle 22 and a number of implications drawn for radiation environment and shielding models. Since these reports, the CREAM monitor has flown on a number of Shuttle visits to MIR during 1997-1998 with an extended deployment on MIR during January to May 1998. In all cases an active monitor measured charge-deposition spectra at various locations, while passive packages comprising neutron activation foils, neutron bubble detectors and thermoluminescent dosimeters obtained integrated data at these and other sites. Movement of the South Atlantic Anomaly is observed and cannot be fitted by simply updating the geomagnetic field model. The data from MIR are compared with those from previous Shuttle missions and show comparable secondary neutron fluencies and dose rates. Meanwhile a CREDO-3 particle telescope has been included in the Microelectronics and Photonics Test Bed in highly eccentric, high inclination orbit and has been returning data since November 1997. This experiment measures proton fluxes greater than 38 MeV and linear energy transfer spectra of cosmic rays and solar particle events in the range 100-20000 MeV/(g cm-2). The data have been extended to July 2000 and are used both to correlate with device behavior and to compare with models of trapped radiation, cosmic rays and solar particles. A number of solar particle events have been observed as cycle 23 builds up. Following a relatively quiet year in 1999, the recent event of July 14, 2000 is observed to compete with the October 1989 events in terms of proton fluency but has a somewhat lower heavy ion fraction.

Thermoelectric Properties of Re3Ge0.6As6.4 and Re3GeAs6 in Comparison to Mo3Sb5.4Te1.6

Abstract: Heavily doped narrow gap semiconductors with complex crystal structures are prime candidates for thermoelectric materials. The arsenides Re3(Ge,As)7 are new examples with promising thermoelectric properties, comparable with the isostructural Mo3Sb5.4Te1.6, a competitive high-temperature material. Various doping levels may be achieved by using different Ge/As ratios. Re3(Ge,As)7 was prepared by heating the elements in the desired ratios in evacuated silica tubes between 600 and 800 °C. Re3GeAs6 crystallizes in the cubic Ir3Ge7 type, space group Im3m, with a = 8.73202(8) A. It exhibits high Seebeck coefficient, high electrical conductivity, and reasonably low thermal conductivity. Moreover, the thermoelectric figure-of-merit ZT = TS2σ/κ increases rapidly with increasing temperature, as desired for high-temperature thermoelectrics.

Hto and obt concentrations in a wetland ecosystem

Abstract: Tritiated water (HTO) and organically bound tritium (OBT) concentrations in the non-human biota inhabiting Duke Swamp were measured during the 2005 growing season Samples of surface water, soil, p

Bringing together scientific disciplines for collaborative undertakings: a vision for advancing the adverse outcome pathway framework

Abstract: Decades of research to understand the impacts of various types of environmental occupational and medical stressors on human health have produced a vast amount of data across many scientific discipl...

An overview of thermochemical modelling of CANDU fuel and applications to the nuclear industry

Abstract: Thermodynamic models of complex chemical systems provide an elegant and cost effective means to predict chemical interactions of materials and to provide guidance to experimental research to minimise costs. Starting in 1995 at the Royal Military College of Canada, a thermodynamic treatment of irradiated nuclear fuel has been developed that not only describes the thermochemistry of the fuel at elevated temperatures during a potential Loss-of-Coolant Accident (LOCA), but it can also be used to help predict the oxidation environment for fresh fuel measurements, irradiated fuel behaviour, the aqueous chemistry of fuel debris in coolant, nuclear waste disposal, and other systems involving nuclear fuel. Furthermore, this treatment was supported by several experimental campaigns at the Canadian Nuclear Laboratories and the Institute of Transuranium Elements for validation purposes. This paper will trace the development of this treatment and demonstrate its current practice and future potential in the general context of performance and safety of nuclear fuel.