Dear colleges,
If I wont to prepare an instant neutron source from available gamma source such as (88Y) and a light material target such as (9Be) depending on the interaction (Ɣ,n) by make a combination between them .
Why I couldn't use the 137Cs source? And what are the appropriate light materials that I can use them as a target if I use (88Y) as a source.
http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/14/792/14792880.pdf
very good report on neutron sources. Be is best material for Y-88 interaction to generate neutrons. Cs-137 has weak gamma rays
The process of generating neutrons using photons is called photo nuclear disintegration. Binding energy per nucleon is about 8 MeV or so and neutron will come only if you supply greater than 8 to 10 MeV. Further at higher energies photo neutrons generation is more. Cs has energy of 0.662 MeV so unable to break nucleus and generate neutrons. It's energy is more than 1000 times less than required. Compare 0.662 MeV with 10 MeV. Neutron generation is not feasible with gamma sources having energy less than 10 MeV practically or in general.
However Be9 has nuclear threshold of 1.65 MeV and y88 emit gamma photon having energy of 1.7 MeV, so photo neutrons are emitted. These neutrons has very low energy. Only those photons are capable of releasing neutrons from Be which has energy more than 1.65 MeV. Cs has maximum energy of .662MeV so no neutron emission. Other material is deutron or heavy water where gamma threshold for neutron release is 2.2 MeV. These are two exceptional materials where photons having energy 2 MeV release neutron from nucleus otherwise 10 MeV or so energy photons are required.
http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/14/792/14792880.pdf
very good report on neutron sources. Be is best material for Y-88 interaction to generate neutrons. Cs-137 has weak gamma rays
Dear Farhan Kadhim
Mr. Kumar has provided you with a valuable commentary which, together with the IAEA publication recommended by Mr. Ahmad, clarifies why Cs-137 can not be used for photonuclear reactions. See attached paper.
https://kanga.usask.ca/nucleus/sites/default/files/theses/Garrow-thesis.pdf
Be9 has nuclear threshold of 1.65 MeV and y88 emit gamma photon having energy of 1.2 MeV, so photo neutrons are emitted. These neutrons has very low energy. Only those photons are capable of releasing neutrons from Be which has energy more than 1.65 MeV. Cs has maximum energy of .662MeV so no neutron emission. Other material is deutron or heavy water where gamma threshold for neutron release is 2.2 MeV. These are two exceptional materials where photons having energy 2 MeV release neutron from nucleus otherwise 10 MeV or so energy photons are required.
If I wont to prepare neutron source from gamma source and a light material target depending on the interaction (Ɣ,n) . Why I couldn't use 137Cs ?. Available from: https://www.researchgate.net/post/If_I_wont_to_prepare_neutron_source_from_gamma_source_and_a_light_material_target_depending_on_the_interaction_n_Why_I_couldnt_use_137Cs [accessed Aug 2, 2017].
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