phys depth 2

Question 1

Main purpose

Answer 1

investigate the attentuation of ionising radiation of varying thickness of iron & lead, observing how the intensity of radiation changed

Question 2

what is the advantage of semilog grid?

Answer 2

Using this enables the advantage of visualising the exponential relationship without the need to manually calc. the logs. It simplifies the plottimng & allows interp. to determine the att coefficient

Question 3

explain the method

Answer 3

conducted with 137Cs source and the counter
1. measured bg count
2. measured the lead plate
3. measured the iron plate
calculated the natural log for only lead plates

Question 4

significance

Answer 4

concluded that lead provided better source of shielding than iron
lead had higher att coeff & x value

Question 5

higher attenuation means

Answer 5

greater ability to block out the xrays

Question 6

Smaller x-value means

Answer 6

less material is needed to reduce the intensity by half

Question 7

why was In chosen

Answer 7

because eqn 1 follows exponential decay - by taking log of both sides, we linearise the eqn to give us new eq. This allows us to determine the aatt coeff, providing a straight line.