ASTM E526 : 17e1

Standard Test Method for Measuring Fast-Neutron Reaction Rates by Radioactivation of Titanium

Standard Details

1.1 This test method covers procedures for measuring reaction rates by the activation reactions ⁴⁶Ti(n,p)⁴⁶Sc + ⁴⁷Ti(n, np)⁴⁶Sc + ⁴⁷Ti(n,d)⁴⁶Sc.

Note 1: The cross section for the ⁴⁷Ti(n,np+d) reaction is relatively small for energies less than 12 MeV and is not easily distinguished from that of the ⁴⁶Ti(n,p) reaction. This test method will apply to the composite ^natTi(n,X)⁴⁶Sc reaction that is typically used for dosimetry purposes.

1.2 The reaction is useful for measuring neutrons with energies above approximately 4.4 MeV and for irradiation times, under uniform power, up to about 250 days (for longer irradiations, or for varying power levels, see Practice E261).

1.3 With suitable techniques, fission-neutron fluence rates above 10⁹ cm^–2·s^–1 can be determined. However, in the presence of a high thermal-neutron fluence rate, ⁴⁶Sc depletion should be investigated.

1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E261.

1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.6 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International StandardDetails, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.