6 Colo. Code Regs. § 1007-1-A
1A.1 Table 1A-1 lists the quality factors for converting absorbed dose in gray equal to 1 Sv or the absorbed dose in rad equal to 1 rem.
TABLE 1A-1: QUALITY FACTORS AND ABSORBED DOSE EQUIVALENCIES
Type of radiation | Quality factor (Q) | Absorbed dose equal to a unit dose equivalent |
X, gamma, or beta radiation and high-speed electrons | 1 | 1 |
Alpha particles, multiple-charged particles, fission fragments and heavy particles of unknown charge | 20 | 0.05 |
Neutrons of unknown energy | 10 | 0.1 |
High-energy protons | 10 | 0.1 |
1A.2 If it is more convenient to measure the neutron fluence rate than to determine the neutron dose equivalent rate in sievert per hour or rem per hour, 0.01 Sv (1 rem) of neutron radiation of unknown energies may be assumed to result from a total fluence of 25 million neutrons per square centimeter incident upon the body. If sufficient information exists to estimate the approximate energy distribution of the neutrons, the licensee or registrant may use the fluence rate per unit dose equivalent or the appropriate Q value from Table 1A-2 to convert a measured tissue dose in gray or rad to dose equivalent in sievert or rem.
TABLE 1A-2: MEAN QUALITY FACTORS (Q) AND FLUENCE PER UNIT DOSE EQUIVALENT FOR MONOENERGETIC NEUTRONS
Neutron energy (MeV) | Quality factor6 (Q) | Fluence per unit dose equivalent7 (neutrons cm-2 rem-1) | Fluence per unit dose equivalent7 (neutrons cm-2 Sv-1) |
2.5x10-8 (thermal) | 2 | 980x106 | 980x108 |
1x10-7 | 2 | 980x106 | 980x108 |
1x10-6 | 2 | 810x106 | 810x108 |
1x10-5 | 2 | 810x106 | 810x108 |
1x10-4 | 2 | 840x106 | 840x108 |
1x10-3 | 2 | 980x106 | 980x108 |
1x10-2 | 2.5 | 1010x106 | 1010x108 |
1x10-1 | 7.5 | 170x106 | 170x108 |
5x10-1 | 11 | 39x106 | 39x108 |
1 | 11 | 27x106 | 27x108 |
2.5 | 9 | 29x106 | 29x108 |
5 | 8 | 23x106 | 23x108 |
7 | 7 | 24x106 | 24x108 |
TABLE 1A-2: MEAN QUALITY FACTORS (Q) AND FLUENCE PER UNIT DOSE EQUIVALENT FOR MONOENERGETIC NEUTRONS
Neutron energy (MeV) | Quality factor6 (Q) | Fluence per unit dose equivalent7 (neutrons cm-2 rem-1) | Fluence per unit dose equivalent7 (neutrons cm-2 Sv-1) |
10 | 6.5 | 24x106 | 24x108 |
14 | 7.5 | 17x106 | 17x108 |
20 | 8 | 16x106 | 16x108 |
40 | 7 | 14x106 | 14x108 |
60 | 5.5 | 16x106 | 16x108 |
100 | 4 | 20x106 | 20x108 |
200 | 3.5 | 19x106 | 19x108 |
300 | 3.5 | 16x106 | 16x108 |
400 | 3.5 | 14x106 | 14x108 |
6 Value of quality factor (Q) at the point where the dose equivalent is maximum in a 30-centimeter diameter cylinder tissue-equivalent phantom.
7 Monoenergetic neutrons incident normally on a 30-centimeter diameter cylinder tissue-equivalent phantom.
6 CCR 1007-1-A