Lesson 5 - Detecting Nuclear Radiation Flashcards
What type of radiation is most ionising?
Alpha
What radiation is most penetrating?
gamma
What type of radiation is the least ionising?
Gamma
What radiation is the most penetrating?
Alpha
What is the name of the instrument that helps you detect radiation?
Geiger-Muller Tube and Counter
How does the geiger-muller counter and tube work?
Radiation causes ionisation.
lost electron produces electrical current in the Geiger muller tube
A click is then produced.
How does photographic film help detect radiation?
When radiation hits the photographic film, it turns from white to black Attach the badge to someone’s clothes and we can monitor how quickly the film turns black. A worker in a nuclear powerstation may use this to monitor how much radiation they are exposed to.
The plastic case will block alpha. The thin aluminium sheet will stop beta Lead will stop all (alpha, beta, gamma)
Thin aluminium window will block beta and alpha
Why is photographic film used by people?
It helps control teh amount of radiation that people come in contact with. This is by if the photographic film becomes too black, then the person would be sent back away from the radiation place.
When a Geiger counter is left in a classroom, it may click. Why?
Background radiation makes it click.
What is background radiation?
Radiation that is not part is not part of the experiment.
Examples of background radiation.
Chair, table, etc.
what is natural background radiation?
Radiation from things that are not made from humans
Examples of background radiation.
Rocks, soil, air
What is artificial background radiation?
Radiation that is from things that are created by humans
Examples for artificial background radiation.
School, cars, hospitals
How do you determine if the radioactive source in front of a Geiger-muller tube is releasing alpha, beta or gamma?
●Place the radio active source in front of the geiger counter at a set distance.
● Record the number of counts (activity) in 1minute.
●Then add a piece of paper in between the geiger counter and source. If there is a significant decrease in the count rate (How quickly the counts rise) , the source emits alpha.
●If not, replace the thin sheet with a thin sheet of aluminium. Significant decrease means its beta, otherwise it is gamma.
●Replacing the thin sheet of aluminium with lead should cause the count rate to stop increasing as all radiation should be blocked.
How can you ensure that you account for the background radiation?
Turn the geiger counter on for the same time as one experiment. (E.g. 1 minute)
Record the amount of radiation detected from the surrounding subtract the background counts from the results you get
