# Photon Calc — Cross sections gamma / x-ray

> Calculates gamma/x-ray photon cross sections, transmission, and attenuation for 94 elements. (iPhone/iPad app by Black Cat Systems.)

- Source: https://appshunter.io/ios/app/photon-calc/id304436071 (this page in markdown: same URL + `.md`)
- Developer: [Black Cat Systems](https://appshunter.io/developer/301047032)
- Category: Reference, Utilities
- Price: $2.99
- Rating: 5.00/5 from 1 App Store ratings
- Age rating: 4+
- Requires: iOS 12.0 · 1 MB
- Languages: American English
- Released: 2009-02-10
- Data updated: 2026-07-08
- Monetization: paid
- User reviews in markdown: https://appshunter.io/ios/app/photon-calc/id304436071/reviews.md

## What is Photon Calc?

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.

## Key features

- Cross sections for gamma/x-ray photons
- Fluorescence and edge energies
- Transmission and attenuation calculation
- Data for 94 elements
- Mean Free Path calculation
- Absorption Coefficient calculation


## Frequently asked questions about Photon Calc

### What is Photon Calc?

Photon Calc is a reference application that displays cross sections for gamma/x-ray photons and calculates transmission and attenuation for arbitrary photon energies. It provides data for 94 elements.

### What kind of data does Photon Calc provide?

Photon Calc provides mean free path, absorption coefficient, total cross section, coherent cross section, incoherent cross section, and photoelectric cross section. It also displays general element information like atomic number, mass, density, fluorescence, and edge energies.

### What is the price of Photon Calc?

Photon Calc is a paid application, priced at $2.99.

### On which devices can I use Photon Calc?

Photon Calc is available for iPhone, iPad, and iPod devices.

### How often is Photon Calc updated?

Photon Calc was last updated on January 25, 2024, with version 1.2. It was originally released on February 10, 2009.

### What is the age rating for Photon Calc?

Photon Calc has an age rating of 4+, making it suitable for a wide range of users.

### Does Photon Calc have ads?

No, Photon Calc does not contain advertisements.

### What is the user feedback on Photon Calc?

Photon Calc has received a perfect rating of 5.0 stars from one user review, indicating high user satisfaction.

## Version history (last 3 releases)

### 1.2 — 2024-01-25

Updates for latest iOS version

### 1.1 — 2015-10-21

This app has been updated by Apple to display the Apple Watch app icon.

Fixed a bug that could cause a crash with iOS 9.

### 1.0.0 — 2009-02-10

No release notes.

## Apps similar to Photon Calc

| App | Rating | Price | Category |
| --- | --- | --- | --- |
| [Model Airplane International](https://appshunter.io/ios/app/model-airplane-international/id393860589) | 4.4 (33) | Free | Reference |
| [Countdown : Stopwatch & Timer](https://appshunter.io/ios/app/countdown-stopwatch-and-timer/id1667091403) | 5.0 (2) | Free | Reference |
| [Cycles of Life](https://appshunter.io/ios/app/cycles-of-life/id6446702308) | 4.5 (8) | Free | Reference |

## More apps by Black Cat Systems

- [WireCalc](https://appshunter.io/ios/app/wirecalc/id301047029)
- [Transmission Line Calc](https://appshunter.io/ios/app/transmission-line-calc/id302734281)
- [RF Link Calc](https://appshunter.io/ios/app/rf-link-calc/id303034300)
- [dB Calc](https://appshunter.io/ios/app/db-calc/id303470503)
- [Drill Calc](https://appshunter.io/ios/app/drill-calc/id304434324)

All apps by Black Cat Systems: https://appshunter.io/developer/301047032

## Related topics

[photon xr](https://appshunter.io/ios/topics/photon-xr)

---

*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-07-08.*