Measurements and Calculations (Introduction to Radiochemistry)
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Which detector did you use?
Note down the values from the background counting you started the day before.
Counting number Nbck= counts
Counting time tbck= sec
Counting speed = cps
Standard deviation = cps
Do a one minute count on every shelf. Use these measurements to calculate the counting-efficiency of the GM-detector in %, for 234mPa. The activity of the sample can be calculated from the amount of UO3 used.
|Counting number for each shelf (CPM)||Counting Efficency|
Twenty Measurements with Constant Distance from the Source
Do twenty measurements on 1 minute with the source in the same position. Calculate the standard deviation and complete the table:
Mean value of the counting numbers
The squere of the mean value
Discuss the results from and ?
Assessment of the Results
Write down the given measurements and calculate how many % of the countings that are outside of the intervals <N-SN,N+SN and <N-2SN,N+2SN>:
Is there, in your opinion, to many single measurements outside of the given areas? Give a answer based on statistical normal distribution.