4.1 The alanine-EPR dosimetry system provides a means for measuring absorbed dose. It is based on the measurement of specific stable free radicals in crystalline alanine generated by ionizing radiation.

4.2 Alanine-EPR dosimetry systems are used in reference- or transfer-standard or routine dosimetry systems in radiation applications that include: sterilization of medical devices and pharmaceuticals, food irradiation, polymer modifications, medical therapy and radiation damage studies in materials (1, 13-15).

1.1 This practice covers dosimeter materials, instrumentation, and procedures for using the alanine-EPR dosimetry system to measure the absorbed dose in the photon or electron radiation processing of materials. The alanine system is based on electron paramagnetic resonance (EPR) spectroscopy of free radicals derived from the amino acid alanine.2

1.2 The alanine dosimeter is classified as a type I dosimeter as it is affected by individual influence quantities in a well-defined way that can be expressed in terms of independent correction factors (see ISO/ASTM Practice 52628). The alanine dosimeter may be used in either a reference standard dosimetry system or in a routine dosimetry system.

1.3 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ISO/ASTM 52628 “Practice for Dosimetry in Radiation Processing” for alanine dosimetry system. It should be read in conjunction with ISO/ASTM 52628.

1.4 This practice covers the use of alanine-EPR dosimetry systems under the following conditions:

1.4.1 The absorbed dose range is between 0.001 kGy and 150 kGy.

1.4.2 The absorbed dose rate is up to 1 × 10² Gy s^-1 for continuous radiation fields and up to 3 × 10¹⁰ Gy s^-1 for pulsed radiation fields (1-4).3

1.4.3 The radiation energy for photons and electrons is between 0.1 MeV and 30 MeV (1, 2, 5-8).

1.4.4 The irradiation temperature is between –78 °C and +70 °C (2, 9-12).

1.5 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.

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