Abstract: A gamma radiation source comprises 75Selenium wherein the 75Selenium is provided in the form of compounds, alloys or mixtures with one or more nonmetals which upon irradiation do not produce products capable of sustained emission of radiation which would unacceptably interfere with the gamma radiation of 75Selenium. A further gamma radiation source comprises 75Selenium wherein the 75Selenium is provided in the form of compounds, alloys or mixtures with one or more metals or nonmetals, the neutron irradiation of which does produce products capable of sustained emission of radiation which would acceptably complement the gamma radiation of 75Selenium. Further, the gamma radiation source may have components that are separately irradiated before being combined and the components may be of natural isotopic composition or of isotopically modified composition so that the subsequent radiation peaks may also be adjusted in relative frequency.

Abstract: A gamma radiation source comprises 75Selenium wherein the 75Selenium is provided in the form of compounds, alloys or mixtures with one or more nonmetals which upon irradiation do not produce products capable of sustained emission of radiation which would unacceptably interfere with the gamma radiation of 75Selenium. A further gamma radiation source comprises 75Selenium wherein the 75Selenium is provided in the form of compounds, alloys or mixtures with one or more metals or nonmetals, the neutron irradiation of which does produce products capable of sustained emission of radiation which would acceptably complement the gamma radiation of 75Selenium. Further, the gamma radiation source may have components that are separately irradiated before being combined and the components may be of natural isotopic composition or of isotopically modified composition so that the subsequent radiation peaks may also be adjusted in relative frequency.

Abstract: One gamma radiation source comprises 75Selenium or a precursor thereof, wherein the 75Selenium is provided in the form of one or more thermally stable compounds, alloys or mixtures with one or more nonmetals which upon irradiation do not produce products capable of sustained emission of radiation which would unacceptably interfere with the gamma radiation of 75Selenium. A further gamma radiation source comprises 75Selenium or a precursor thereof, wherein the 75Selenium is provided in the form of one or more thermally stable compounds, alloys or mixtures with one or more metals or nonmetals, the neutron irradiation of which does produce products capable of sustained emission of radiation which would acceptably complement the gamma radiation of 75Selenium.

Abstract: Manufacturing a gamma radiation source includes providing an unacceptable material that is a combination of acceptable and unacceptable isotopes, transforming the unacceptable material into an acceptable material by removing unacceptable isotopes from the unacceptable material, leaving only acceptable isotopes, mixing selenium-74 and the acceptable material and heating the mixture to cause the constituents to inter-react and subsequently subjecting the reaction product to irradiation to convert at least a proportion of the selenium-74 to selenium-75. Manufacturing a gamma radiation source may also include adding at least one other acceptable material to the mixture. The at least one other acceptable material may be added to the mixture prior to heating the mixture. The unacceptable material may be selected from the group consisting of: Zinc, Titanium, Nickel, Zirconium, Ruthenium, Iron, Silver, Indium, Thallium, Samarium, Ytterbium, Germanium, and Iridium.