ASTM E2450

1.1 This practice describes a procedure for measuring gamma-ray absorbed dose in CaF2(Mn) thermoluminescence dosimeters (TLDs) exposed to mixed neutron-photon environments during irradiation of materials and devices. The practice has broad application, but is primarily intended for use in the radiation-hardness testing of electronics. The practice is applicable to the measurement of absorbed dose from gamma radiation present in fields used for neutron testing.

1.2 This practice describes a procedure for correcting for the neutron response of a CaF2(Mn) TLD. The neutron response may be subtracted from the total response to give the gamma-ray response. In fields with a large neutron contribution to the total response, this procedure may result in large uncertainties.

1.3 More precise experimental techniques may be applied if the uncertainty derived from this practice is larger than the user can accept. These techniques are not discussed here. The references in Section 8 describe some of these techniques.

1.4 This practice does not discuss effects on the TLD reading of neutron interactions with material surrounding the TLD to ensure charged particle equilibrium. These effects depend on the surrounding material and its thickness, and on the neutron spectrum (1).

2. Referenced Documents

E170 Terminology Relating to Radiation Measurements and Dosimetry
E1854 Practice for Assuring Test Consistency in Neutron-Induced Displacement Damage of Electronic Parts
E666 Practice for Calculating Absorbed Dose from Gamma or X Radiation
E668 Practice for Application of Thermoluminescence Dosimetry (TLD) Systems for Determining Absorbed Dose in Radiation-Hardness Testing of Electronics
E720 Guide for Selection and Use of Neutron-Activation Foils for Determining Neutron Spectra Employed in Radiation-Hardness Testing of Electronics
E721 Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics
E722 Practice for Characterizing Neutron Energy Fluence Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence for Radiation-Hardness Testing of Electronics
F1190 Guide for Neutron Irradiation of Unbiased Electronic Components

Index Terms

dosimetry; gamma; LET; mixed-field; neutron; TLD; ICS Number Code; 17.240

Citing ASTM Standards

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