ISO 6980-2:2022
Nuclear energy — Reference beta-particle radiation — Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field
Nuclear energy — Reference beta-particle radiation — Part 2: Calibration fundamentals related to basic quantities characterizing the radiation field
- Статус документа:
- Отменён
- Формат:
- Электронный (PDF)
- Количество страниц:
- 40
- Дата публикации:
- 1 ноября 2022 г.
- Издание:
- ISO IS 6980 edition 2 version 1
- ICS:
- 17.240
This document specifies methods for the measurement of the absorbed-dose rate in a tissue-equivalent slab phantom in the ISO 6980 reference beta-particle radiation fields. The energy range of the beta-particle-emitting isotopes covered by these reference radiations is 0,22 MeV to 3,6 MeV maximum beta energy corresponding to 0,06 MeV to 1,1 MeV mean beta energy. Radiation energies outside this range are beyond the scope of this document. While measurements in a reference geometry (depth of 0,07 mm or 3 mm at perpendicular incidence in a tissue‑equivalent slab phantom) with an extrapolation chamber used as primary standard are dealt with in detail, the use of other measurement systems and measurements in other geometries are also described, although in less detail. However, as noted in ICRU 56[5], the ambient dose equivalent, H*(10), used for area monitoring, and the personal dose equivalent, Hp(10), as used for individual monitoring, of strongly penetrating radiation, are not appropriate quantities for any beta radiation, even that which penetrates 10 mm of tissue (Emax > 2 MeV). This document is intended for those organizations wishing to establish primary dosimetry capabilities for beta particles and serves as a guide to the performance of dosimetry with an extrapolation chamber used as primary standard for beta‑particle dosimetry in other fields. Guidance is also provided on the statement of measurement uncertainties.
Abstract
Overview - ISO 6980-2:2022 (beta-particle radiation calibration fundamentals)
ISO 6980-2:2022 specifies methods for measuring the absorbed-dose rate in a tissue-equivalent slab phantom for ISO 6980 reference beta-particle radiation fields. It covers beta-emitting source energies from 0.22 MeV to 3.6 MeV (Emax), corresponding to mean beta energies of about 0.06 MeV to 1.1 MeV. The standard focuses on primary beta dosimetry using an extrapolation chamber at reference depths of 0.07 mm and optionally 3 mm in a slab phantom, while also describing other measurement systems and geometries. Guidance on calibration traceability and the statement of measurement uncertainties is included.
Key topics and technical requirements
- Reference absorbed dose definitions: measurement of absorbed dose to tissue at 0.07 mm (and 3 mm) depth and derivation of reference beta-particle absorbed dose.
- Primary standard method: detailed procedures for calibration using an extrapolation (ionization) chamber, including extrapolation curves, zero-point determination, and correction factors.
- Alternative detectors: calibration procedures and considerations for ionization chambers and other measurement systems are described (less detail than for extrapolation chambers).
- Field characterization: specification of reference geometry, penetrability metrics, transmission functions and scaling to derive equivalent material thicknesses.
- Corrections and factors: use of correction factors based on radiation-transport simulations, Spencer–Attix vs Bragg–Gray theory correction, stopping-power-ratio and source-to-chamber distance corrections.
- Non‑perpendicular incidence: methods for measurements at oblique angles and associated transmission functions.
- Uncertainty analysis: guidance and an example uncertainty budget for primary beta dosimetry.
Practical applications and users
ISO 6980-2 is intended for organizations that need to:
- Establish or operate primary dosimetry capabilities for beta particles.
- Calibrate and validate dosemeters and dose-rate meters used for occupational or area monitoring in nuclear energy, medical radiation, research, and industrial settings.
- Develop traceable calibration services using extrapolation chambers as a primary standard for beta dosimetry. Users include national metrology institutes, calibration laboratories, radiation protection specialists, and instrument manufacturers.
Related standards
- ISO 6980-1 - production and characterization of reference beta-particle fields
- ISO 6980-3 - calibration of dosemeters and dose-rate meters (response vs energy/angle)
- ISO 29661 and ISO/IEC Guide 99 (VIM) - definitions and metrology vocabulary
- ICRU reports referenced for operational quantities and tissue definitions (e.g., ICRU 56, ICRU 44)
Keywords: ISO 6980-2, beta-particle radiation, absorbed-dose rate, extrapolation chamber, tissue-equivalent slab phantom, calibration, primary dosimetry, dosemeter calibration, measurement uncertainty.
Технические детали
- Технический комитет
- ISO/TC 85/SC 2 - Radiological protection
- SKU
- ISO 6980-2:2022
Похожие стандарты
Стандарты, упомянутые в описании