Sökning: "pulsed neutron source"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden pulsed neutron source.

  1. 1. Pulsed Neutron Activation for Determination of Water Flow in Pipes

    Författare :Håkan Mattsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Flowmeter; Pulsed Neutron Activation; CFD; Pipe flow; PNA;

    Sammanfattning : In a Pulsed Neutron Activation (PNA) flowmeter neutron induced activity is used to measure water flow in pipes. The water in the pipe is bombarded with neutron pulses which introduce activity into the pipe. The activity is then transported and mixed with the flow. LÄS MER

  3. 2. A Study of Using Pulsed Neutron Activation for Accurate Measurements of Water Flow in Pipes

    Författare :Per Lindén; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pulsed neutron activation; turbulent flow; neural networks; pipe flow; flow measurements; eddy diffusion; time averaging;

    Sammanfattning : The objectives of this work were 1) to investigate the performance of the pulsed neutron activation (PNA) method for determination of mass flow of water in pipes, and 2) to improve the accuracy such that an error less than 1% become possible with the PNA method. The ultimate purpose is to develop this method into a high-accuracy portable and non-intrusive flow-meter that easily can be used as a calibration tool at a number of field applications, e. LÄS MER

  4. 3. Accelerator-driven systems : source efficiency and reacitvity determination

    Författare :Andrei Fokau; Jan Wallenius; Viktor Tikhomirov; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nuclear physics; Kärnfysik;

    Sammanfattning : Accelerator-driven systems (ADS) are being investigated and designed for transmutation of the long-lived nuclear waste. Application of ADS allows to safely transmute large fractions of minor actinides (MA) per reactor core, while the fraction in critical reactors is limited to a few percent due to the safety constraints. LÄS MER

  5. 4. On measurement and monitoring of reactivity in subcritical reactor systems

    Författare :Carl Berglöf; Janne Wallenius; Vasily Arzhanov; Massimo Salvatores; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; reactor; ADS; accelerator-driven systems; subcriticality determination; noise techniques; pulsed neutron source; reactivity monitoring; Nuclear physics; Kärnfysik;

    Sammanfattning : Accelerator-driven systems have been proposed for incineration of transuranic elements from spent nuclear fuel. For safe operation of such facilities, a robust method for reactivity monitoring is required. Experience has shown that the performance of reactivity measurement methods in terms of accuracy and applicability is highly system dependent. LÄS MER

  7. 5. Radiation Detection Techniques for the Enhancement of Nuclear Safety

    Författare :Petty Bernitt Cartemo; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; whole body counting; depth profiling; voxel phantom; nuclear safeguards; Monte Carlo; orphan sources; radiation-induced material damage; pulsed beam; positron lifetime;

    Sammanfattning : The hazard originating from the use of nuclear materials in various areas of the society necessitates a number of experimental techniques for controlling and increasing the safety connected to radioactive substances.The following thesis is divided into two parts, representing different aspects to the detection of radiation effects. LÄS MER