04 Protection
Quality factor (older H = QD)
Legacy ICRU equivalent dose H = Q D. Q ≈ 1 photons, ~10 neutrons, 20 α.
Listen
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Simulation
Quality factor (older H = QD) — Change the numbers; the scene follows.
Where it works
Treatment vault
Primary barrier
In the bunker maze and barriers — time, distance, TVL, WUT, and weekly controlled-area dose.
Open this machineFormula
Variables
Results
H
Dose equivalent (ICRU)
10mSv
Explanation
What it means
Older ICRU dose equivalent H = Q D uses a quality factor Q (≈ 1 photons, ~10 neutrons, 20 α) instead of ICRP w_R. Numerically similar for many fields; legally, new reports should use ICRP 103. This is a working relation in Radiation protection.
Where it is used
Clinically it sits on the Treatment vault — Primary barrier. In the bunker maze and barriers — time, distance, TVL, WUT, and weekly controlled-area dose. Protection equations are the wall, the occupancy factor, and the badge: time, distance, shielding, and WUT. They turn a room into a legal design.
Treatment vault · Open this machineHow to use it
Use when reading legacy surveys quoted in rem with a stated Q. Prefer the equivalent-dose calculator for new work. Change one input and watch the curve and the simulation follow.
Symbols
- DAbsorbed dose1 mGy
- QQuality factor10
Worked example
A typical case from the default values: D = 1 mGy (Absorbed dose); Q = 10 (Quality factor). Substituting into the relation gives H = 10 mSv. These are teaching numbers — align them with your machine.
Typical values give
- H = 10mSv
Where it comes from
The displayed formula is the working relation. Legacy ICRU equivalent dose H = Q D. Q ≈ 1 photons, ~10 neutrons, 20 α. Usual reference: ICRU 51 (historical; prefer ICRP 103 wR). Derive it in the specialty lesson, then return here to pin the numbers.
Reference: ICRU 51 (historical; prefer ICRP 103 wR)
Assumptions & limits
Q is LET-dependent and was defined at a point in ICRU tissue. Not ICRP effective dose.
Pitfalls
Tenth-value layers are for the broad beam in that material and that energy — not a photocopy from another bunker. Occupancy T is not a guess; it is a use pattern. Inverse-square fails against a large scatter source. Q is LET-dependent and was defined at a point in ICRU tissue. Not ICRP effective dose.
Keep this
Time, distance, shielding — in that order — then calculate the wall. Q is LET-dependent and was defined at a point in ICRU tissue. Not ICRP effective dose.
In this specialty