Design and construction of a 9 MeV γ-ray source based on capture of moderated plutonium-beryllium neutrons in nickel

• Published in: Applied radiation and isotopes 2023-01, Vol.191, p.110559-110559, Article 110559
• Main Authors: Söderström, P.-A., Balabanski, D.L., Ban, R.S., Ciocan, Gh, Cuciuc, M., Dhal, A., Fugaru, V., Iancu, V., Rotaru, A., Şerban, A.B., State, A., Testov, D., Turturică, G.V., Vasilca, V.
• Format: Article
• Language: English
• Subjects: Composite radioactive sources; High-energy γ-rays; Neutron sources; Scintillator detectors
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2022.110559

We have designed and constructed a high-energy γ-ray source for detector characterisation and calibration. The source is a composite type based on a plutonium-beryllium neutron emitter embedded in a paraffin moderator, which is homogeneously mixed with nickel powder. The 9 MeV γ-ray source produces approximately 450 photons per second in 4π when 2.2×105 neutrons per second are emitted, corresponding to a surface flux of 9 MeV γ-rays of approximately 2.5×10−6 cm−2 per emitted neutron. Here we discuss the properties and design of this source, including the characterisation of homogeneity and high-energy γ-ray emission spectra. •A spherical source of 9 MeV gamma rays optimised for use in multi-element detector arrays, based on the method of neutron capture in nickel, have been designed and constructed.•The composite source has been characterised in terms of gamma yield and geometrical distribution of neutron capture events from a radioisotopic PuBe primary neutron field.•The gamma-ray spectrum has been evaluated in two of the setups for intended use, the ELIGANT-GN large-volume LaBr3:Ce/CeBr3 array and the ELIADE segmented HPGe Clover array.