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Submitted to: Book Chapter
Publication Type: Book / Chapter Publication Acceptance Date: 2/21/2017 Publication Date: 5/24/2017 Citation: Kavetskiy, A.G., Yakubova, G.N., Prior, S.A., Torbert III, H.A. 2017. Neutron-stimulated gamma ray analysis of soil. In: Maghraby, A.M., editor. New Insights on Gamma Rays. Rijecka, Croatia: InTech. p. 133-178. doi:10.5772/68014. Interpretive Summary: The book chapter will summarize the possibilities of the method of using neutron stimulated gamma rays analysis for in situ determination of elements distributed in a given soil volume or on the soil surface without the requirement of destructive soil sampling. This will include a list of element which can be determined, detectable levels, and time needed for measurement. Results of application of this method for soil carbon mapping and disclosure or location of chlorine in soil (e.g., explosive detection and/or contaminated super fund sites) will be discussed. Technical Abstract: The chapter will discuss methods to use gamma rays to measure elements in soil. In regard to land management, there is a need to develop a non-destructive, non-contact, in-situ method of determining soil elements distributed in a soil volume or on soil surface. A unique method having all of above mentioned properties has been developed using neutron stimulated gamma ray. This chapter will describe the main ideas of this method (effect of neutrons - nuclei interaction, processes of inelastic neutron scattering INS, thermal neutron capture TNC, delay activation DA) and technique for measurements (neutron sources, gamma detectors). References to previous work regarding the application of the neutron stimulated gamma rays analysis for determination of carbon, nitrogen, hydrogen, oxygen, chlorine in bulk objects such as concrete and cement, for use in archeology, and for soil elemental analysis will be discussed. The advantages and disadvantages of this methodology will also be discussed. Specifically, the book chapter will be made up of the following parts. 1. Introduction – The problem of soil elemental content determination will be introduced. The different methods of using neutron-gamma analysis will be discussed as well as the advantage-disadvantage of the methods. 2. Description of the main ideas of the INS method and technique for measurement in some detail will be presented. 3. Specific areas to be addressed for the neutron stimulated gamma spectra of soil will include. 1. Monte-Carlo simulation of gamma spectra. 2. Real gamma spectra measurement. 3. Extracting of net peaks connected with element (carbon). 4. Carbon determination. The problem of non-uniform distribution of carbon in soil. Issues of choosing the best parameters to be used characterize carbon content in soil connected with carbon gamma peak in spectra will be addressed. 5. The use of this method to survey real fields for soil carbon mapping will be discussed. 6. Application of neutron stimulated gamma ray analysis for determination elements distributed on soil surface and in local buried objects will be discussed. |
