title: Neutron reflectometry on highly absorbing films and its application to10B4C-based neutron detectors.
abstract: Neutron reflectometry is a powerful tool used for studies of surfaces and interfaces. The absorption in the typical studied materials is neglected and this technique is limited only to the reflectivity measurement. For strongly absorbing nuclei, the absorption can be directly measured by using the neutron-induced fluorescence technique which exploits the prompt particle emission of absorbing isotopes. This technique is emerging from soft matter and biology where highly absorbing nuclei, in very small quantities, are used as a label for buried layers. Nowadays, the importance of absorbing layers is rapidly increasing, partially because of their application in neutron detection; a field that has become more active also due to the3He-shortage. We extend the neutron-induced fluorescence technique to the study of layers of highly absorbing materials, in particular10B4C. The theory of neutron reflectometry is a commonly studied topic; however, when a strong absorption is present the subtle relationship between the reflection and the absorption of neutrons is not widely known. The theory for a general stack of absorbing layers has been developed and compared to measurements. We also report on the requirements that a10B4C layer must fulfil in order to be employed as a converter in neutron detection.
authors.affiliation: European Spallation Source ERIC, PO Box 176, Lund 22100, Sweden; Institut Laue-Langevin (ILL), 71, Avenue des Martyrs, Grenoble 38042, France; Department of Physics, University of Perugia, Piazza Università 1, Perugia 06123, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Piscitelli
authors.affiliation: European Spallation Source ERIC, PO Box 176, Lund 22100, Sweden; Institut Laue-Langevin (ILL), 71, Avenue des Martyrs, Grenoble 38042, France.
authors.forename: A
authors.initials: A
authors.lastname: Khaplanov
authors.affiliation: Ruhr-Universität Bochum , Bochum 44780, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Devishvili
authors.affiliation: European Spallation Source ERIC, PO Box 176, Lund 22100, Sweden; Thin Film Physics Division, Linköping University, Linköping 58183, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Schmidt
authors.affiliation: European Spallation Source ERIC, PO Box 176, Lund 22100, Sweden; Thin Film Physics Division, Linköping University, Linköping 58183, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Höglund
authors.affiliation: Thin Film Physics Division , Linköping University , Linköping 58183, Sweden.
authors.forename: J
authors.initials: J
authors.lastname: Birch
authors.affiliation: Institut Laue-Langevin (ILL), 71, Avenue des Martyrs, Grenoble 38042, France; Department of Physics and Astronomy, Uppsala University, BP 516, Uppsala 75120, Sweden.
authors.forename: A J C
authors.initials: AJ
authors.lastname: Dennison
authors.affiliation: Institut Laue-Langevin (ILL) , 71, Avenue des Martyrs, Grenoble 38042, France.
authors.forename: P
authors.initials: P
authors.lastname: Gutfreund
authors.affiliation: European Spallation Source ERIC, PO Box 176, Lund 22100, Sweden; Mid-Sweden University, Sundsvall 85170, Sweden.
authors.forename: R
authors.initials: R
authors.lastname: Hall-Wilton
authors.affiliation: Institut Laue-Langevin (ILL) , 71, Avenue des Martyrs, Grenoble 38042, France.
authors.forename: P
authors.initials: P
authors.lastname: Van Esch
keywords: boron-10; neutron detection; neutron reflectometry; neutron-induced fluorescence