Decay Simulator: Hafnium-161

General data

Radioactive decay series

• Hafnium-161 18.4 s
• Lutetium-161 77 s · 99.7%
• Ytterbium-161 4.2 min · 99.7%
• Thulium-161 30.2 min · 99.7%
• Erbium-161 3.21 h · 99.7%
• Holmium-161 2.48 h · 99.7%
• Dysprosium-161 stable · 99.7%
• Ytterbium-157 38.6 s · 0.3%
• Thulium-157 3.63 min · 0.3%
• Erbium-157 18.65 min · 0.3%
• Holmium-157 12.7 min · 0.3%
• Dysprosium-157 8.14 h · 0.3%
• Terbium-157 71 a · 0.3%
• Gadolinium-157 stable · 0.3%

Rare branches (below 0.01%)

Rare branches are transformations that occur in fewer than 0.01% of decays, e.g. double beta decay or cluster emission. The nuclides they produce are practically absent from a sample, so they are hidden by default to keep the main path clear. In this series: branches - 1, nuclides - 14.

• Holmium-153 2.01 min · 2.2×10⁻⁶%
• Dysprosium-153 6.42 h · 2.2×10⁻⁶%
• Terbium-153 2.34 d · 2.2×10⁻⁶%
• Gadolinium-153 240.4 d · 2.2×10⁻⁶%
• Europium-153 stable · 2.2×10⁻⁶%
• Terbium-149 4.12 h · 1.1×10⁻⁹%
• Gadolinium-149 9.28 d · 1.2×10⁻⁹%
• Europium-149 93.1 d · 1.2×10⁻⁹%
• Samarium-149 stable · 1.2×10⁻⁹%
• Europium-145 5.93 d · 1.9×10⁻¹⁰%
• Samarium-145 340 d · 1.9×10⁻¹⁰%
• Promethium-145 17.7 a · 1.9×10⁻¹⁰%
• Neodymium-145 stable · 1.9×10⁻¹⁰%
• Praseodymium-141 stable · 5.4×10⁻¹⁹%

How to read the simulation

Grid: each pixel is one atom of the starting isotope. When an atom decays, the pixel takes the colour of the decay product - in decay series mode the product can decay further. The moment each atom decays is random, but the probability follows from the half-life, so after one T½ about half of the atoms remain, after two - about a quarter.

Chart N(t): what percentage of the sample atoms each nuclide makes up at a given moment. The line of the starting isotope falls (by half after each T½), the lines of stable products rise, and those of short-lived ones first rise, then fall.

Chart A(t): activity, i.e. the number of decays per second (becquerel, Bq). It depends on the number of atoms and on how fast they decay: for the same number of atoms, the shorter the T½, the higher the activity.

Simulation time runs faster (or slower) than real time - the time scale slider sets the multiplier. This way you can watch the decay of isotopes that live from fractions of a second to billions of years.

Well-known isotopes

• H-3 - Tritium - glowing watch hands, nuclear fusion fuel.
• C-14 - Radiocarbon dating.
• K-40 - Natural radioactivity - in bananas and in our bodies.
• Co-60 - Radiotherapy and radiation sterilization.
• I-131 - Thyroid treatment; Chernobyl fallout.
• Cs-137 - Long-lasting contamination after Chernobyl and Fukushima.
• Rn-222 - Radon in basements and mines.
• Ra-226 - The longest-lived isotope of radium - the element discovered by Marie and Pierre Curie in 1898.
• U-235 - Nuclear power plant fuel; start of the actinium series.
• U-238 - Age of the Earth; start of the uranium series.
• Pu-238 - Power source for space probes (Voyager, Curiosity rover).
• Am-241 - Ionization smoke detectors.