Document: 10 CFR Part 20
Document ID: f68bc4a3-99ae-43c0-8356-76abed9a1225
Document Type: cfr
Title: Units of radiation dose.
Source: 10 CFR Part 20
Source URL: https://www.ecfr.gov/current/title-10/part-20/section-20.1004
Revision Date: 
Chapter: 
Section ID: 20.1004
CFR Part: 20
CFR Title: 10

Content:
pproximate energy distribution of the neutrons, the licensee may use the fluence rate per unit dose equivalent or the appropriate Q value from table 1004(b).2 to convert a measured tissue dose in rads to dose equivalent in rems. Table 1004( b ).2—Mean Quality Factors, Q, and Fluence per Unit Dose Equivalent for Monoenergetic Neutrons Neutron energy (MeV) Quality factor a (Q) Fluence per unit dose equivalent b (neutrons cm −2 rem −1 ) (thermal) 2.5 × 10 −8 2 980 × 10 6 1 × 10 −7 2 980 × 10 6 1 × 10 −6 2 810 × 10 6 1 × 10 −5 2 810 × 10 6 1 × 10 −4 2 840 × 10 6 1 × 10 −3 2 980 × 10 6 1 × 10 −2 2.5 1010 × 10 6 1 × 10 −1 7.5 170 × 10 6 5 × 10 −1 11 39 × 10 6 1 11 27 × 10 6 2.5 9 29 × 10 6 5 8 23 × 10 6 7 7 24 × 10 6 10 6.5 24 × 10 6 14 7.5 17 × 10 6 20 8 16 × 10 6 40 7 14 × 10 6 60 5.5 16 × 10 6 1 × 10 2 4 20 × 10 6 2 × 10 2 3.5 19 × 10 6 3 × 10 2 3.5 16 × 10 6 4 × 10 2 3.5 14 × 10 6 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.