Targets for bulk hydrogen analysis using thermal neutrons

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 2002-03, Vol.480 (1), p.166-170
• Main Authors: Csikai, J., Király, B., Buczkó, Cs.M.
• Format: Article
• Language: English
• Subjects: Neutron elastic scattering; Neutron moderation; Neutron reflectometry; Nuclear data analysis
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(01)02086-1

The reflection property of substances can be characterized by the reflection cross-section of thermal neutrons, σ β. A combination of the targets with thin polyethylene foils allowed an estimation of the flux depression of thermal neutrons caused by a bulk sample containing highly absorbing elements or compounds. Some new and more accurate σ β values were determined by using the combined target arrangement. For the ratio, R of the reflection and the elastic scattering cross-sections of thermal neutrons, R= σ β/ σ EL a value of 0.60±0.02 was found on the basis of the data obtained for a number of elements from H to Pb. Using this correlation factor, and the σ EL values, the unknown σ β data can be deduced. The equivalent thicknesses, to polyethylene or hydrogen, of the different target materials were determined from the σ β values.