Radiation Measurements Flashcards
What is the base unit for measuring radioactivity?
Becquerel (Bq)
1 Becquerel is defined as 1 decay per second.
What is the equivalent of 1 Microbecquerel (µBq) in Becquerels?
0.000001 Bq
Millionth
## Footnote
1 µBq corresponds to 1 decay per million seconds.
What is the value of 1 Kilobecquerel (kBq) in Becquerels?
1,000 Bq
Thousands
## Footnote
1 kBq represents 1,000 decays per second.
What is the equivalent of 1 Curie (Ci) in Becquerels?
37,000,000,000 Bq
Ci is used for high radioactivity sources.
What is the base unit for absorbed dose?
Gray (Gy)
1 Gray is defined as 1 joule per kilogram.
1 Rad is equivalent to how many Grays?
0.01 Gy
Rad is an older unit for measuring absorbed dose.
What is the value of 1 Megagray (MGy) in Grays?
1,000,000 Gy
Millions
## Footnote
MGy represents 1 million Grays.
What is the base unit for effective dose?
Sievert (Sv)
1 Sv is defined as 1 Gray multiplied by the radiation weighting factor.
What is the equivalent of 1 Microsievert (µSv) in Sieverts?
0.000001 Sv
1 µSv is equal to 1 millionth of a Sievert.
How many Sieverts are in 1 Megasievert (MSv)?
1,000,000 Sv
MSv represents 1 million Sieverts.
What is the base unit for exposure to radiation?
Roentgen (R)
R measures ionization of air.
What is the equivalent of 1 Milliroentgen (mR) in Roentgens?
0.001 R
Thousandths
## Footnote
mR is a common background level of exposure.
Fill in the blank: 1 Gray (Gy) is equivalent to _______/kg
1 joule/kg
What are the smaller units of Radioactivity?
In Bq?
- Microbecquerel (µBq)
- Millibecquerel (mBq)
These units are used for measuring lower levels of radioactivity.
What are the lethal amounts of Absorbed Dose?
5Gy 50% fatality
10Gy near 100%
100Gy instant tissue destruction
1000Gy vaporization of tissue
True or False: 1 Rem is equivalent to 0.01 Sv.
True
What are the lethal units of Effective Dose?
4-5 Sv 50% fatality
10 Sv near 100%
50 Sv immediate nervous system failure-certain death soon
100 Sv immediately fatal
List the smaller units of Exposure.
- Microroentgen (µR)
- Milliroentgen (mR)
These units represent smaller levels of radiation exposure.
Is exposure (Roentgen, R) the only measurement that indicates dangerous radiation levels?
No, it is not the only measurement
The actual danger depends on multiple factors, including the type of radiation and its effects on the body.
What does exposure (Roentgen, R) measure?
Ionization of air
High R levels indicate potential for harm but do not account for biological effects.
What is absorbed dose measured in?
Gray (Gy)
It measures the energy deposited in material/tissue.
What level of absorbed dose (Gy) can cause acute radiation sickness?
> 1 Gy
Absorbed dose is a critical measure of radiation exposure.
What is effective dose measured in?
Sievert (Sv)
It measures biological damage to human tissue.
What effective dose (Sv) is harmful to humans?
> 1 Sv
A dose of >4 Sv is lethal for 50% of people.