X-ray Spectrum Calculator
Calculate a tungsten X-ray spectrum, filtration, half-value layers and air kerma from 40 to 150 kVp.
Air kerma for selected mAs: 83.93 µGy · Mean energy (fluence-weighted): 42.9 keV
| Mean energy (fluence-weighted) | 42.9 keV |
|---|---|
| Half-value layer in aluminium | 2.712 mm Al |
| Half-value layer in copper | 0.09141 mm Cu |
| Air kerma per mAs at 1 m | 83.93 µGy/mAs |
| Air kerma per mAs at selected distance | 83.93 µGy/mAs |
| Air kerma for selected mAs | 83.93 µGy |
| Kerma removed by added filters | 0 % |
Tungsten anode, 12° angle, 2.5 mm Al inherent filtration. Intermediate kVp interpolates the continuum on a normalized energy axis and tungsten lines at fixed energies. HVL halves air kerma and is solved iteratively. Inverse-square distance; narrow beam without scatter.
Spectra computed with SpekPy 2.5.4 (Poludniowski et al.); attenuation NIST XCOM; air mu_en/rho NIST SRD 126. Densities: NIST ESTAR; elementary charge: CODATA 2018.
At 80 kVp, a tungsten tube with 2.5 mm Al filtration has a mean photon energy of 42.90 keV and an aluminium half-value layer of 2.734 mm (SpekPy). Add filters below to calculate the hardened spectrum, air kerma and half-value layers.
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Batch runs over a table of inputs, a PDF report with inputs, method and citations, CSV export and saved cases. Join the waiting list and we will write once, when it opens.
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https://scienceshot.com/mcpConnector tool: xray_spectrum
Example: How does 0.2 mm copper change the HVL and air kerma of an 80 kVp tube at 1 m?
Tungsten anode, 12° angle, 2.5 mm Al inherent filtration. Intermediate kVp interpolates the continuum on a normalized energy axis and tungsten lines at fixed energies. HVL halves air kerma and is solved iteratively. Inverse-square distance; narrow beam without scatter.
Stored SpekPy spectra
Original SpekPy values. Live results recompute air kerma and HVL using the bundled NIST tables with log-log interpolation and may differ slightly (air kerma about 2.4% at 80 kVp).
| kVp | Half-value layer in aluminium (mm Al) | Mean energy (fluence-weighted) (keV) | Air kerma per mAs at 1 m (µGy/mAs) |
|---|---|---|---|
| 40 | 1.384 | 28.1 | 18.84 |
| 50 | 1.75 | 32.22 | 33.36 |
| 60 | 2.082 | 35.95 | 48.89 |
| 70 | 2.397 | 39.4 | 64.9 |
| 80 | 2.734 | 42.9 | 81.97 |
| 90 | 3.092 | 46.18 | 100 |
| 100 | 3.459 | 49.15 | 118.9 |
| 110 | 3.844 | 51.92 | 138.7 |
| 120 | 4.22 | 54.45 | 158.7 |
| 130 | 4.603 | 56.85 | 179.4 |
| 140 | 4.99 | 59.15 | 200.9 |
| 150 | 5.373 | 61.37 | 222.8 |
Cite this
ScienceShot. X-ray tube spectrum and filtration calculator. https://scienceshot.com/x-ray-spectrum-calculator.
Spectra computed with SpekPy 2.5.4 (Poludniowski et al.); attenuation NIST XCOM; air mu_en/rho NIST SRD 126. Densities: NIST ESTAR; elementary charge: CODATA 2018. SpekPy; NIST XCOM; NIST SRD 126.
Reviewed by a physicist with CERN and data-centre industry experience
ScienceShot calculation.
Cite this page
ScienceShot. (2026). X-ray Spectrum Calculator [Online calculator]. https://scienceshot.com/x-ray-spectrum-calculator
@misc{scienceshot-x-ray-spectrum-calculator-2026,
author = {{ScienceShot}},
title = {{X-ray Spectrum Calculator}},
year = {2026},
note = {Online calculator},
url = {https://scienceshot.com/x-ray-spectrum-calculator}
}