1.1This test method is intended for quantitative determination of effective boron-10 (10B) areal density (mass per area of 10B, usually measured in grams-10B/cm2 ) in aluminum neutron absorbers. The attenuation of a thermal neutron beam transmitted through an aluminum neutron absorber is compared to attenuation values for calibration standards allowing determination of the effective 10B areal density. This test is typically performed in a laboratory setting. This method is valid only under the following conditions:
1.1.1The absorber contains 10B in an aluminum or aluminum alloy matrix.
1.1.2The primary neutron absorber is 10B.
1.1.3The test specimen has uniform thickness.
1.1.4The test specimen has a testing surface area at least twice that of the thermal neutron beam’s surface cross-sectional area.
1.1.5The calibration standards of uniform composition span the range of areal densities being measured.
1.1.6The areal density is between 0.001 and 0.080 grams of 10B per cm2.
1.1.7The thermalized neutron beam is derived from a fission reactor, sub-critical assembly, accelerator or neutron generator.
1.2The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3This 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.