ASTM ISO/ASTM51538-09
(Main)Standard Practice for Use of the Ethanol-Chlorobenzene Dosimetry System
Standard Practice for Use of the Ethanol-Chlorobenzene Dosimetry System
SIGNIFICANCE AND USE
4.1 The ECB dosimetry system provides a reliable means of measuring absorbed dose in materials. It is based on a process of radiolytic formation of hydrochloric acid (HCl) in aqueous ethanolic solutions of chlorobenzene by ionizing radiation (7,8).
4.2 The dosimeters are partly deoxygenated solutions of chlorobenzene (CB) in 96 volume % ethanol in an appropriate container, such as a flame-sealed glass ampoule. The irradiated solutions indicate absorbed dose by the amount of HCl formed. Anumber of analytical methods are available for measuring the amount of HCl in ethanol (9).
4.3 Effect of Irradiation Temperature:
4.3.1 The temperature dependence of dosimeter response is a complex function of dose and temperature for each concentration of chlorobenzene (that is, for each formulation). The analysis of the published data (10) shows that the temperature dependence between 20°C and 80°C at any chlorobenzene concentration can be described by a simple exponential expression: Gt 5 G0 exp[k~t 2 20!# (3) where: Gt = the radiation chemical yield in μmol J−1 at a given temperature t in °C, G0 = the radiation chemical yield in μmol J−1 at 20°C ((G0 for different ECB solutions are given in Table 1), and k = the temperature coefficient in (°C)−1 applicable at a given dose.
4.3.2 The values of k are given in Table 2.
4.3.3 Between −30°C and 50°C the temperature coefficient 0.015 kGy/°C applies at 30 kGy dose (12). Information on the temperature dependence of dosimeter response during irradiation between 20 and 80°C is found in Ref (10), and between −40 and 20°C in Ref (13).
4.4 The concentration of chlorobenzene in the solution can be varied so as to simulate a number of materials in terms of the photon mass energy-absorption coefficients (μen/r) for X and gamma radiation, and electron mass collision stopping powers (S/r), over a broad energy range from 10−2 to 100 MeV(14-17).
4.5 The absorbed dose that is determined is the dose absorbed in the water. Absorbed dose i...
SCOPE
1.1 This practice covers the preparation, handling, testing, and procedure for using the ethanol-chlorobenzene dosimetry system to measure absorbed dose in materials irradiated by photons and electrons in terms of absorbed dose in water. The system consists of a dosimeter and appropriate analytical instrumentation. For simplicity, the system will be referred to as the ECB system. It is classified as a reference-standard dosimeter and is also used as a routine dosimetry system (see ISO/ASTM Guide 51261).
1.2 This practice describes the titration analysis as a standard readout procedure for the ECB dosimeter. Other applicable readout methods (spectrophotometric, oscillometric) are described in Annex A1 and Annex A2.
1.3 This practice applies only to gamma rays, X rays, and high-energy electrons.
1.4 This practice applies provided the following are satisfied:
1.4.1 The absorbed dose range shall be from 10 Gy to 2 MGy (1).
1.4.2 The absorbed dose rate does not exceed 10 6 Gy s1 (2).
1.4.3 For radionuclide gamma-ray sources, the initial photon energy shall be greater than 0.6 MeV. For bremsstrahlung photons, the initial energy of the electrons used to produce the bremsstrahlung photons shall be equal to or greater than 2 MeV. For electron beams, the initial electron energy shall be equal to or greater than 4 MeV (3) (see ICRU Reports 34 and 35).
Note 1—The lower limits of electromagnetic radiation energy given are appropriate for a cylindrical dosimeter ampoule of 12-mm diameter. Corrections for dose gradients across an ampoule of that diameter or less are not required. The ECB system may be used at energies of incident electrons lower than 4 MeV by employing thinner (in the beam direction) dosimeter containers (see ICRU Report 35). The ECB system may also be used at X-ray energies as low as 120 kVp (4). In this range of photon energies the effect caused by the wall is considerable.
1.4.4 The irradiation temperature ...
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
ISO/ASTM 51538:2009(E)
Standard Practice for
1
Use of the Ethanol-Chlorobenzene Dosimetry System
This standard is issued under the fixed designation ISO/ASTM 51538; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision.
60
NOTE 1—The same response relative to Co gamma radiation was
1. Scope
obtained in high-power bremsstrahlung irradiation produced bya5MeV
1.1 This practice covers the procedure for preparation,
electron accelerator (4). The lower limits of energy given are appropriate
handling, testing, and use of the ethanol-chlorobenzene (ECB)
for a cylindrical dosimeter ampoule of 12-mm diameter. Corrections for
dose gradients across an ampoule of that diameter or less are not required.
dosimetry system to determine absorbed dose (in terms of
The ECB system may be used at energies of incident electrons lower than
absorbed dose to water) in materials irradiated by photons
4 MeV by employing thinner (in the beam direction) dosimeters. The ECB
(gamma radiation or X-radiation/bremsstrahlung) or high en-
system may also be used at X-ray energies as low as 120 kVp (5).
ergy electrons. The system consists of a dosimeter and appro-
However, in this range of photon energies the effect caused by the
priate analytical instrumentation. For simplicity, the system ampoule wall is considerable.
will be referred to as the ECB system. It is classified as a
1.3.4 The irradiation temperature of the dosimeter is within
reference-standard dosimetry system and is also used as a
the range from −40°C to 80°C.
routine dosimetry system (see ISO/ASTM Guide 51261).
NOTE 2—The temperature dependence of dosimeter response is known
1.2 This practice describes the mercurimetric titration
only in this range (see 4.3). For use outside this range, the dosimetry
analysis as a standard readout procedure for the ECB dosimeter system should be calibrated for the required range of irradiation tempera-
tures.
when used as a reference standard dosimetry system. Other
readout methods (spectrophotometric, oscillometric) that are
1.4 The effects of size and shape of the dosimeter on the
applicable when the ECB system is used as a routine dosimetry
response of the dosimeter can adequately be taken into account
system are described in Annex A1 and Annex A2.
by performing the appropriate calculations using cavity theory
(6).
1.3 This practice applies provided the following conditions
are satisfied: 1.5 This standard does not purport to address all of the
1.3.1 The absorbed dose range is between 10 Gy and 2 MGy safety concerns, if any, associated with its use. It is the
for gamma radiation and between 10 Gy and 200 kGy for high responsibility of the user of this standard to establish appro-
2
current electron accelerators (1,2). (Warning—the boiling priate safety and health practices and determine the applica-
point of ethanol chlorobenzene solutions is approximately bility of regulatory limitations prior to use. Specific warnings
80°C. Ampoules may explode if the temperature during irra- are given in 8.2 and 9.2.
diation exceeds the boiling point. This boiling point may be
2. Referenced documents
exceeded if an absorbed dose greater than 200 kGy is given in
3
a short period of time.)
2.1 ASTM Standards:
6 −1
1.3.2 The absorbed-dose rate is less than 10 Gy s (2).
C912 Practice for Designing a Process for Cleaning Techni-
1.3.3 For radionuclide gamma-ray sources, the initial pho-
cal Glasses
ton energy is greater than 0.6 MeV. For bremsstrahlung
D1193 Specification for Reagent Water
photons, the energy of the electrons used to produce the
E170 Terminology Relating to Radiation Measurements and
bremsstrahlung photons is equal to or greater than 2 MeV. For
Dosimetry
electron beams, the initial electron energy is equal to or greater
E275 Practice for Describing and Measuring Performance of
than 4 MeV (3) (see ICRU Reports 34 and 35).
Ultraviolet and Visible Spectrophotometers
E666 Practice for Calculating Absorbed Dose From Gamma
or X Radiation
1
This practice is under the jurisdiction of ASTM Committee E61 on Radiation E668 Practice for Application of Thermoluminescence-
Processing and is the direct responsibility of Subcommittee E61.02 on Dosimetry
Dosimetry (TLD) Systems for Determining Absorbed
Systems, and is also under the jurisdiction of ISO/TC 85/WG 3.
Dose in Radiation-Hardness Testing of Electronic Devices
Current edition approved June 18, 2008. Published June 2009. Originally
published as ASTM E1538-93. Last previous ASTM edition E1538–99. ASTM
E1538–93 was adopted by ISO in 1998 with the intermediate designation ISO
3
15563:1998(E). The present International Standard ISO/ASTM 51538:2009 (E) is a For referenced ASTM and ISO/ASTM standards, visit the ASTM website,
major revision of ISO/ASTM 51538:2002(E
...








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