Slow neutron mapping technique for level interface measurement

Abstract

Abstract. Modern industrial plant operations often require accurate level measurement of process liquids in production and storage vessels. A variety of advanced level indicators are commercially available to meet the demand, but these may not suit specific need of situations. The neutron backscatter technique is exceptionally useful for occasional and routine determination, particularly in situations such as pressure vessel with wall thickness up to 10 cm, toxic and corrosive chemical in sealed containers, liquid petroleum gas storage vessels. In level measurement, high energy neutrons from 241 Am-Be radioactive source are beamed onto a vessel. Fast neutrons are slowed down mostly by collision with hydrogen atoms of material inside the vessel. Parts of thermal neutron are bounced back towards the source. By placing a thermal detector next to the source, these backscatter neutrons can be measured. The number of backscattered neutrons is directly proportional to the concentration of the hydrogen atoms in front of the neutron detector. As the source and detector moved by the matrix around the side of the vessel, interfaces can be determined as long as it involves a change in hydrogen atom concentration. This paper presents the slow neutron mapping technique to indicate level interface of a test vessel.

Prompt gamma-ray methods for industrial process evaluation: A simulation study

“…This work investigates the use of neutron sources to irradiate the structural material of the process equipment and stable isotopes injected into the process to prompt gamma-ray as an alternative to gamma-ray emitters applied to the industrial process investigations. Neutrons are used in industrial diagnosis under the category of sealed sources applications in level measurement in storage tanks and chemical reactors [15,16]. Other neutrons' industrial applications include neutron radiography [17][18][19], neutron CT [20], and in moisture-based measurements like in paper industry [21].…”