Radiation Detection and Measurement

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Questions and Answers

What is radon gas primarily produced from?

Decay of potassium-40

Decay of uranium (correct)

Decay of carbon-14

Collision of protons with molecules

Which food is specifically mentioned as having a higher amount of a radioactive element?

Carrots

Bananas (correct)

Spinach

Apples

Which method is used to determine the corrected count rate when measuring radiation?

Subtracting background count from the source count (correct)

Using an average of several readings

Measuring the source counts and adding background

Subtracting the time taken to measure

What happens to radiation readings when the source is moved far enough away?

They decrease to zero Signup and view all the answers

What type of radiation does the sun primarily emit that interacts with the atmosphere?

Gamma radiation Signup and view all the answers

What major event significantly contributes to radiation exposure in the environment?

Nuclear accidents Signup and view all the answers

What is background radiation primarily composed of?

Natural radioactive elements in the environment Signup and view all the answers

How is fall-out produced after a nuclear explosion?

By scattering radioactive material into the air Signup and view all the answers

What does photographic film do in response to radiation?

It becomes darker when it absorbs radiation. Signup and view all the answers

Which of the following materials might be found in a film badge used to monitor radiation exposure?

Aluminium Signup and view all the answers

What does a Geiger-Müller tube measure?

The levels of radiation in a particular location. Signup and view all the answers

If a Geiger-Müller tube records 16,000 decays in 1 hour, what is the count rate in decays per second?

4.5 decays per second Signup and view all the answers

Which of the following statements about background radiation is true?

It comes from natural sources like radon gas. Signup and view all the answers

How frequently should film badges worn by radiographers be checked?

Regularly Signup and view all the answers

What should not be referred to when naming a radiation detection device?

Radiation detector Signup and view all the answers

Which gas is a notable contributor to airborne background radiation?

Radon Signup and view all the answers

Study Notes

Radiation Detection and Measurement

Photographic film badges: Used to monitor radiation exposure; darker film indicates higher exposure; various materials in badge shield film from different types of radiation.
Geiger-Müller (GM) tube: Common radiation detector; measures radiation by detecting ionizations; count rate (number of decays per unit time) increases with proximity to radiation source; higher count rate signifies more radiation absorption.
Count rate calculation: Example: 16,000 decays in 1 hour = 4.5 decays per second (16,000 decays / 3600 seconds).
Background radiation: Constant radiation from natural sources; includes airborne radon gas from rocks, soil, or building materials. Uranium decay results in radon gas.
Sources of background radiation: Radon gas (a natural product from decay of Uranium and other radioactive elements), solar protons, and radioactive elements in food and water.

Background Radiation

Background radiation is natural radiation present in the environment.
Types of background radiation:
- Airborne radon gas from rocks and building materials (eg. stone & brick).
- Radioactive elements in food and water, present in minute amounts.
Significance of Background Radiation:
- Levels are generally low and not a health concern.
- Can vary significantly based on location.
- Important to account for in radiation measurements.

Radiation Sources (excluding Background)

Nuclear waste is not a significant contributor to background radiation, but can be dangerous for those handling it.
Fallout: Radioactivity from nuclear explosions; amount currently low, but increases with nuclear testing.
Nuclear accidents (e.g., Chernobyl): Can significantly increase environmental radiation.

Measuring Corrected Count Rate

Background count rate (without a radioactive source) is recorded to subtract from reading of a source, giving the corrected count rate.
To determine background radiation, a measurement is taken with no source present, this reading is subtracted from any measurement made with a present radiation source.
- Example: 24 counts per minute background rate subtracted from 285 counts per minute with a source (261 cpm corrected).
To get an accurate reading of the count rate from the radiation source, count rate readings need to be taken over time and the background count rate needs to be measured first.

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Description

This quiz covers key concepts in radiation detection and measurement, including the use of photographic film badges and Geiger-Müller tubes. It also explores the principles of count rate calculation and the sources of background radiation. Understand how these tools help monitor and assess radiation exposure in various environments.