About this app
Photon Calc displays cross sections for gamma / x-ray photons, fluorescence and edge energies, and allows you to calculate the transmission and attenuation for an arbitrary photon energy. Information for 94 elements is available. General information about the element is displayed, such as the atomic number and mass, density, and the fluorescence and edge energies (the number displayed depends on the element selected). By entering in the photon energy in kV, the following values are calculated, based on the McMaster data: • Mean Free Path in cm • Absorption Coefficient in cm • Total cross section • Coherent cross section • Incoherent cross section • Photoelectric cross section Next you can enter in the thickness in cm, and the transmission and attenuation values (ranging from 0 to 1) will be calculated and displayed.
Latest release
What’s New
Updates for latest iOS version
Audience growth
Ratings growth
Baseline captured. Growth appears after the crawler observes a changed rating count.
Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.
Price tracking
Price intelligence
First snapshot captured. The trend line starts after the next crawler price observation.
- First observed Aug 16, 2026 · 5:30 PM $2.99
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