A Geiger-Mueller detector with a “pancake” probe is being used to monitor workers leaving a radiologically controlled area for contamination.
The probe is sensitive to alpha, beta, and gamma radiation.
The background count rate is 20 cpm.
As one worker’s shoe is scanned the count rate increases to 1,000 cpm.
Given the following separate actions:
• When a sheet of paper is placed between the probe and the shoe, the count rate decreases to 600 cpm.
• When a sheet of aluminum foil is placed between the probe and the shoe, the count rate decreases to 600 cpm.
Which one of the following lists the type(s) of radiation being emitted by the contamination?
A. Beta only
B. Alpha only
C. Beta and gamma
D. Alpha and gamma
Show Answer
Answer: D
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