Difference between revisions of "Quality factor"
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where <math>D</math> is the [[absorbed dose]] at that point, <math>D_L</math> is the distribution of <math>D</math> in unrestricted LET <math>L</math> at the point of interest, and <math>Q(L)</math> is the quality factor as a function of <math>L</math>. The integration is to be performed over <math>D_L</math>, due to all charged particles, excluding their secondary electrons. | where <math>D</math> is the [[absorbed dose]] at that point, <math>D_L</math> is the distribution of <math>D</math> in unrestricted LET <math>L</math> at the point of interest, and <math>Q(L)</math> is the quality factor as a function of <math>L</math>. The integration is to be performed over <math>D_L</math>, due to all charged particles, excluding their secondary electrons. | ||
| − | [[ICRP Publication 123]], 2013 | + | [[ICRP Publication 116]], 2010 and [[ICRP Publication 123]], 2013 |
'''Return to [[ICRP Glossary|Glossary]]''' | '''Return to [[ICRP Glossary|Glossary]]''' | ||
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== Previous glossary entries == | == Previous glossary entries == | ||
| − | === from [[ICRP Publication 103]], 2007 === | + | === from [[ICRP Publication 103]], 2007 and [[ICRP Publication 127]], 2014=== |
The factor characterising the biological effectiveness of a radiation, based on the ionisation density along the tracks of charged particles in tissue. <math>Q</math> is defined as a function of the unrestricted linear energy transfer, <math>L_\infty</math> (often denoted as <math>L</math> or LET), of charged particles in water: | The factor characterising the biological effectiveness of a radiation, based on the ionisation density along the tracks of charged particles in tissue. <math>Q</math> is defined as a function of the unrestricted linear energy transfer, <math>L_\infty</math> (often denoted as <math>L</math> or LET), of charged particles in water: | ||
Latest revision as of 19:14, 18 August 2021
A dimensionless factor defined to reflect the relative biological effectiveness of high-LET radiations compared with low-LET radiations at low exposure levels. [math]Q[/math] is usually given by a function [math]Q(L)[/math], where [math]L[/math] is the unrestricted LET in water. The quality factor at a point in tissue, is given by:
[math] Q = \frac{1}{D} \int_{L=0}^\infty Q(L)D_LdL [/math]
where [math]D[/math] is the absorbed dose at that point, [math]D_L[/math] is the distribution of [math]D[/math] in unrestricted LET [math]L[/math] at the point of interest, and [math]Q(L)[/math] is the quality factor as a function of [math]L[/math]. The integration is to be performed over [math]D_L[/math], due to all charged particles, excluding their secondary electrons.
ICRP Publication 116, 2010 and ICRP Publication 123, 2013
Return to Glossary
Previous glossary entries
from ICRP Publication 103, 2007 and ICRP Publication 127, 2014
The factor characterising the biological effectiveness of a radiation, based on the ionisation density along the tracks of charged particles in tissue. [math]Q[/math] is defined as a function of the unrestricted linear energy transfer, [math]L_\infty[/math] (often denoted as [math]L[/math] or LET), of charged particles in water:
[math] Q(L) = \begin{cases} 1, & \text{if } L \lt \text{10 keV/μm} \\ 0.32L - 2.2, & \text{if 10} \le L \le \text{100 keV/μm} \\ 300/\sqrt{L}, & \text {if } L \gt \text{100 keV/μm} \end{cases} [/math]
[math]Q[/math] has been superseded by the radiation weighting factor in the definition of equivalent dose, but it is still used in calculating the operational dose equivalent quantities used in monitoring.
