Calculator Inputs
Example Data Table
These sample cases demonstrate how distance, shielding, area, and time change the final intensity, received energy, and estimated dose.
| Source Power | Distance | μ (1/m) | Shield Thickness | Area | Time | Final Intensity (W/m²) | Energy (J) | Dose (Gy) |
|---|---|---|---|---|---|---|---|---|
| 60 W | 2 m | 0.100 | 0.2 m | 0.04 m2 | 20 s | 1.053023 | 0.842419 | 0.468010 |
| 150 W | 4 m | 0.250 | 0.35 m | 0.06 m2 | 45 s | 0.546828 | 1.476435 | 0.671107 |
| 0.35 kW | 5 m | 0.150 | 0.5 m | 0.08 m2 | 2 min | 0.775189 | 7.441810 | 2.188768 |
| 800 mW | 120 cm | 0.050 | 8 cm | 900 cm2 | 10 s | 0.041832 | 0.037648 | 0.041832 |
Formula Used
The calculator combines inverse-square spreading and exponential attenuation.
| Effective emitted power | Peff = P × η |
|---|---|
| Unshielded intensity | I0 = Peff / (4πr²) |
| Transmission factor | T = e-μx |
| Final intensity | I = I0 × T |
| Incident detector power | Pdet = I × A |
| Received energy | E = Pdet × t |
| Dose estimate | D = E / m |
| Half-value layer | HVL = ln(2) / μ |
Here, P is source power, η is efficiency, r is distance, μ is attenuation coefficient, x is shield thickness, A is detector area, t is exposure time, and m is detector mass.
How to Use This Calculator
- Enter the radiation source power and choose its unit.
- Provide the source-to-detector distance and select the correct unit.
- Set source efficiency to represent useful emitted power.
- Enter the attenuation coefficient for the shielding material.
- Add the shield thickness and choose the shield unit.
- Provide detector area, exposure time, and detector mass.
- Press the calculate button to display results above the form.
- Review intensity, transmission, energy, dose, and the graph.
- Use CSV or PDF export to save the results.
FAQs
1) What does radiation intensity mean here?
It represents power distributed across area at the detector location. In this calculator, the main output is expressed as watts per square meter after distance loss and shielding attenuation are both applied.
2) Why does intensity drop with distance?
A point source spreads energy across a larger spherical surface as distance increases. Because the surface area grows with r², the intensity decreases according to the inverse-square relationship.
3) What is the attenuation coefficient?
It describes how strongly a material reduces radiation as it passes through shielding. Larger values mean faster reduction of intensity for the same shield thickness.
4) What does source efficiency change?
Efficiency scales the entered source power to the effective emitted power used in the calculations. This is useful when only part of the source output contributes to the radiation reaching the detector.
5) Is dose always the same as intensity?
No. Intensity is power per unit area, while dose estimates energy absorbed per unit mass. Dose depends on detector area, exposure time, and detector mass in addition to final intensity.
6) What is half-value layer?
Half-value layer is the shielding thickness needed to reduce intensity to one-half of its previous value. It is commonly used to compare shielding performance across materials.
7) Can I use different units safely?
Yes. The calculator converts supported power, distance, area, thickness, and time units into SI units before applying the formulas. That keeps the calculations consistent and easier to verify.
8) When should I use the CSV or PDF export?
Use CSV when you want structured data for spreadsheets, reports, or batch comparisons. Use PDF when you need a printable result snapshot with the calculated metrics visible in a formatted layout.