1. Scope

1.1 This test method covers procedures for measuring reaction rates by the activation reaction ⁶³ Cu(n,) ⁶⁰ Co. The cross section for ⁶⁰ Co produced in this reaction increases rapidly with neutrons having energies greater than about 5 MeV. ⁶⁰ Co decays with a half-life of 1925.28 days (0.5 days) () and emits two gamma rays having energies of 1.1732228 and 1.332492 MeV () . The isotopic content of natural copper is 69.17 % ⁶³ Cu and 30.83 % ⁶⁵ Cu () . The neutron reaction, ⁶³ Cu(n,) ⁶⁴ Cu, produces a radioactive product that emits gamma rays which might interfere with the counting of the ⁶⁰ Co gamma rays.

1.2 With suitable techniques, fission-neutron fluence rates above 10 ⁹ cm ² s ¹ can be determined. The ⁶³ Cu(n,) ⁶⁰ Co reaction can be used to determine fast-neutron fluences for irradiation times up to about 15 years (for longer irradiations, see Practice E 261).

1.3 Detailed procedures for other fast-neutron detectors are referenced in Practice E 261.

This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

E170 Terminology Relating to Radiation Measurements and Dosimetry

E181 Test Methods for Detector Calibration and Analysis of Radionuclides

E261 Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques

E844 Guide for Sensor Set Design and Irradiation for Reactor Surveillance, E 706 (IIC)

E944 Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance, E 706 (IIA)

E1005 Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance, E 706 (IIIA)

E1018 Guide for Application of ASTM Evaluated Cross Section Data File, Matrix E706 (IIB)

Keywords

activation; activation reaction; copper; cross section; dosimetry; fast-neutron monitor; neutron metrology; pressure vessel surveillance; reaction rate; Fast neutron flux/fluence; Copper; Neutron activation reactions; Radioactivation--fast neutron flux; Threshold detectors--5 MeV; Titanium (Ti)/alloys;

ICS Code

ICS Number Code 17.240 (Radiation measurements); 27.120.30 (Fissile materials and nuclear fuel technology)

DOI: 10.1520/E0523-07

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