The Isotopes Division of Oak Ridge National Laboratory has developed procedures for providing accurately defined deposits of 239 PuO2 and 235 UO2 for use in precision neutron cross-section measurements. Encapsulated samples of 6Li, 10B, 45Sc, 232Th, 235U, 238 U, 237Np, 238Pu, 239Pu, and 241 Pu for use as neutron monitors in reactors can also be provided. These dosimeters are used to determine integral reaction rates from which the neutron energy spectrum, flux, and fluence at particular locations within a reactor can be computed. Methods for the preparation and characterization of reactor dosimeters and other reaction rate samples provide an accuracy of ≤±1% at the 95% confidence level (CL).