| TABLE I | ||
| QUALITY FACTORS AND ABSORBED DOSE EQUIVALENCIES | ||
TYPE OF RADIATION |
Quality Factor (Q) |
Absorbed Dose
Equal to A Unit Dose Equivalenta |
| 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 |
| a | Absorbed dose in rad equal to 1 rem or the absorbed dose in gray equal to 1 Sv. |
| TABLE II |
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| MEAN QUALITY FACTORS, Q, AND FLUENCE PER UNIT DOSE EQUIVALENT FOR MONOENERGETIC NEUTRONS |
|||
| Neutron Energy (MeV) |
Quality
Factora (Q) |
Fluence per
Unit Dose Equivalentb (neutrons cm-2 rem-1) |
Fluence per
Unit Dose Equivalentb (neutrons cm-2 Sv-1) |
| (thermal) 2.5 x 10-8 | 2 | 980 x 106 | 980 x 108 |
| 1 x 10-7 | 2 | 980 x 106 | 980 x 108 |
| 1 x 10-6 | 2 | 810 x 106 | 810 x 108 |
| 1 x 10-5 | 2 | 810 x 106 | 810 x 108 |
| 1 x 10-4 | 2 | 840 x 106 | 840 x 108 |
| 1 x 10-3 | 2 | 980 x 106 | 980 x 108 |
| 1 x 10-2 | 2.5 | 1010 x 106 | 1010 x 108 |
| 1 x 10-1 | 7.5 | 170 x 106 | 170 x 108 |
| 5 x 10-1 | 11 | 39 x 106 | 39 x 108 |
| 1 | 11 | 27 x 106 | 27 x 108 |
| 2.5 | 9 | 29 x 106 | 29 x 108 |
| 5 | 8 | 23 x 106 | 23 x 108 |
| 7 | 7 | 24 x 106 | 24 x 108 |
| 10 | 6.5 | 24 x 106 | 24 x 108 |
| 14 | 7.5 | 17 x 106 | 17 x 108 |
| 20 | 8 | 16 x 106 | 16 x 108 |
| 40 | 7 | 14 x 106 | 14 x 108 |
| 60 | 5.5 | 16 x 106 | 16 x 108 |
| 1 x 102 | 4 | 20 x 106 | 20 x 108 |
| 2 x 102 | 3.5 | 19 x 106 | 19 x 108 |
| 3 x 102 | 3.5 | 16 x 106 | 16 x 108 |
| 4 x 102 | 3.5 | 14 x 106 | 14 x 108 |
| a | Value of quality factor (Q) at the point where the dose equivalent is maximum in a 30-cm diameter cylinder
tissue-equivalent phantom. |
| b | Monoenergetic neutrons incident normally on a 30-cm diameter cylinder tissue-equivalent phantom. |
| 175 (grams contained U-235) 350 |
+ | ||
| 50 (grams U-233) 200 |
+ | ||
| 50 (grams Pu) 200 |
< 1 | ||
| ORGAN DOSE WEIGHTING FACTORS | |||
| Organ or Tissue |
wT |
||
| Gonads | 0.25 | ||
| Breast | 0.15 | ||
| Red bone marrow | 0.12 | ||
| Lung | 0.12 | ||
| Thyroid | 0.03 | ||
| Bone surfaces | 0.03 | ||
| Remainder | 0.30a | ||
| Whole Body | 1.00b | ||
| a | 0.30 results form 0.06 for each of 5 "remainder” organs, excluding the skin and the lens of the eye, that receive the highest
doses. |
| b | For the purpose of weighting the external whole body dose, for adding it to the internal dose, a single weighting factor, wT = 1.0, has been specified. The use of other weighting factors for external exposure will be approved on a case-by-case basis until such time as specific guidance is issued. |