Determination of Neutron Multiplication, (I)

Abstract

In a highly subcritical system with reflector, it is demonstrated that none of the methods so far developed serves usefully in determining the value of the multiplication factor with good accuracy, and that the fundamental difference between the essential properties of the prompt and the delayed neutron modes makes it to be extremely difficult to develop a new method to fulfil this need. Based on this judgement, it is proposed to abandon the widely used concept of multiplication factor, and to look for a new concept to represent the state of neutron multiplication, in the case of reflected highly subcritical systems. In this paper the authors present a new concept in which a fundamental prompt neutron decay constant a 000 is adopted to measure the neutron multiplication, this constant being of such nature as to satisfy the following two fundamental conditions: (1) It is uniquely measurable free from spatial and energetic dependence, and (2) it is amenable to direct calculation from the fundamental equation for neutron transportation.

Influence of Experimental Conditions on Deposition of Silver Nanoparticles Onto Surface of Graphene Oxide / Wpływ Warunków Eksperymentalnych Na Proces Osadzania Nanocząstek Srebra Na Powierzchni Tlenku Grafenu

“…Preparation of hybrid materials of high photocatalytic [1], biologic [2] and electrocatalytitic activity is one of the most important challenge for modern materials engineering. It is expected that this type of materials will exhibit high durability, thermodynamic stability and often high catalytic activity.…”

Measurements of the Neutron Slowing Down Times in Finite Graphite Systems by the Resonance Filter Method

“…As assumptions, (1) scattering is isotropic, (2) mean free path is constant, (3) the leakage term is approximated by the constant DB 2 , (4) source neutrons distribute homogeneously in space. Then the Laplace transform of Eq.…”

Suspension high velocity oxy-fuel spraying of TiO 2 : A quantitative approach to phase composition

“…Surface area of powder materials is commonly assessed by specific surface area defined as total area to mass of the solid sample and principles of Brunnauer-Emmett-Teller theory [28] are used for its measurement. When the effect of specific surface area on the (sono)photocatalytic activity of TiO2 is investigated, Langmuir-Hinshelwood behaviour [29] is often reported for the rate of photocatalytic reactions [30] and, thus, linear dependence of mass of the adsorbent on the photocatalyst surface (page 30 in [16]) is expected. Effectively, larger specific surface area leads to higher photocatalytic activity.…”

“…Furthermore, rutile-rich titania is considered as a better choice for sonophotocatalytic reaction of water (see e.g. page 211 in [16]) embodying another important application area aside from the self-cleaning and self-sterilizing surfaces [17]. Moreover, in the transformation from tetragonal anatase of the I41/amd space group into tetragonal rutile with P42/mnm space group (more on differences between these two crystal structures can be found e.g.…”