Decay Chain Calculator
Calculate daughter nuclide activity buildup and decay from parent decay using the Bateman equation.
Inputs
Bq
Results
Daughter Activity
795,310.04 Bq
Total Activity
1,589,010.57 Bq
Parent Activity Remaining793,700.53 Bq
Daughter/Parent Ratio1
Equilibrium Type2
Time of Max Daughter Activity9.91
Max Daughter Activity795,329.54 Bq
How to Use This Calculator
- Enter Initial Parent Activity, Parent Half-Life, and Daughter Half-Life.
- Set Elapsed Time and Time Unit.
- Review Daughter Activity (Bq) and Total Activity (Bq).
- Use Parent Activity Remaining (Bq) and Daughter/Parent Ratio to inform your decision.
- Use the chart to visualize the results and explore different scenarios by adjusting inputs.
How the result changes with Initial Parent Activity
| Initial Parent Activity | Daughter Activity | Total Activity |
|---|---|---|
| 100,000,000,000,000,000 | 79,531,004,340,374,030 Bq | 158,901,056,938,784,000 Bq |
| 350,000,000,000,000,000 | 278,358,515,191,309,120 Bq | 556,153,699,285,744,000 Bq |
| 650,000,000,000,000,000 | 516,951,528,212,431,200 Bq | 1,032,856,870,102,096,100 Bq |
| 900,000,000,000,000,000 | 715,779,039,063,366,100 Bq | 1,430,109,512,449,056,000 Bq |
What each input means
- Initial Parent Activity
- Initial activity of the parent nuclide in becquerels.
- Parent Half-Life
- Half-life of the parent nuclide in the selected time unit.
- Daughter Half-Life
- Half-life of the daughter nuclide in the selected time unit. Cs-137m: 2.55 min, Ba-137m from Cs-137.
- Elapsed Time
- Time elapsed since the start of observation, in the selected time unit.
- Time Unit
- 1=Seconds, 2=Minutes, 3=Hours, 4=Days, 5=Years.
What each result means
- Equilibrium Type
- 1=Secular, 2=Transient, 3=No Equilibrium
How this is calculated
Worked example, using the default values
- Identify Input Parameters4 parametersInitial Parent Activity = 1000000, Parent Half-Life = 30, Daughter Half-Life = 2.55, Elapsed Time = 10 = 5 input(s) provided
- Calculate Daughter ActivityDaughter Activity795310.043 = 795310.043
- Calculate Total ActivityTotal Activity1589010.569 = 1589010.569
- Calculate Parent Activity RemainingParent Activity Remaining793700.526 = 793700.526
- Calculate Daughter/Parent RatioDaughter/Parent Ratio1.002 = 1.002
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