# Counting Statistics

Recommended for High School.

## Introduction

Radioactive decays follow some curious rules that are a consequence of quantum mechanics. Regardless of when a particular nucleus was created, all nuclei of the same species (Cobalt-60 in this experiment) have exactly the same probability of decay. We might expect that the longer a nucleus has been around, the more likely it is to decay, but that is not what is observed. Even though the *probability* that a given nucleus will decay is fixed, there is no way to predict *when* it will decay. In this sense the decay process is completely random. Despite this randomness, a collection of many identical and independent nuclei will exhibit certain predictable behaviors, such as a consistent average decay rate when measured over a long time.

## Objectives

In this experiment, you will

- Use a radiation counter to determine the distribution of count rates from a nearly constantrate source.
- Compare the distribution of experimental nuclear counting data to the Poisson distribution.
- Observe the gradual transition of count distribution from Poisson statistics to Gaussian statistics as the average count rate increases.

## Sensors and Equipment

This experiment features the following Vernier sensors and equipment.

### Additional Requirements

You may also need an interface and software for data collection. What do I need for data collection?

## Standards Correlations

See all standards correlations for *Nuclear Radiation with Vernier* »

*Nuclear Radiation with Vernier*

*Nuclear Radiation with Vernier*

See other experiments from the lab book.

1 | α, β, and γ |

2 | Distance and Radiation |

3 | Lifetime Measurement |

4 | Counting Statistics |

5 | Background Radiation Sources |

6 | Radiation Shielding |