Radioactivity & Decay
Every radioactivity & decay calculator on CalcEngines — each with its formula, a worked example, the standard it follows and the assumptions it makes.
4 calculators in this section
- Decay Correction to a Calibration Date CalculatorWhat a vial assayed for a stated calibration time holds now, what it will hold at administration, and the volume to draw — with the two intervals kept apart and the direction named in every label, because the sign is what goes wrong.
- Half-Life, Decay Constant and Mean Life Calculatorλ = ln2/t½ and the mean life that is 1.4427 times the half-life rather than 0.6931 — with NPL's published uncertainties, the time to one per cent, a tenth of one and a millionth, and the ten nuclides whose published half-lives disagree.
- Radioactive Decay and Activity CalculatorThe activity left after an interval, the activity the interval implies going backward, and the time to reach a target — from one set of inputs, with twenty-two nuclides' half-lives from NPL and the direction written into every label.
- Specific Activity and Source Mass Calculatora = ln2·N_A/(t½·M), and therefore how many milligrams a 37 GBq cobalt-60 source is and how many nanograms of technetium are in a dose — checked against twelve published specific activities, ten of which reproduce to better than one per cent.