Example embodiments and methods are directed to irradiation target positioning devices and systems that are configurable to permit accurate irradiation of irradiation targets and accurate production of daughter products, including isotopes and radioisotopes, therefrom. These include irradiation target plates having precise loading positions for irradiation targets, where the targets may be maintained in a radiation field. These further include a target plate holder for retaining and positioning the target plates and irradiation targets therein in the radiation field. Example embodiments include materials with known absorption cross-sections for the radiation field to further permit precise, desired levels of exposure in the irradiation targets. Example methods configure irradiation target retention systems to provide for desired amounts of irradiation and daughter product production.