NRRPT - National Registry of Radiation Protection Technicians Detection and Measurement Questions and Answers

Question 1

A radiation protection technologist is using a Geiger-Mueller (GM) survey meter in a high-count-rate field.
The instrument reading appears to be erroneously low.
Which of the following phenomena is the most likely cause for this inaccurate reading?

Accepted Answer

Dead time

Answer

Gas amplification

Answer

Quenching agent depletion

Answer

Wall effect

Question 2

Which of the following detectors is best suited for accurately measuring the energy of gamma radiation and performing isotopic identification?

Accepted Answer

Sodium Iodide (NaI) scintillation detector

Answer

Ionization chamber

Answer

Proportional counter

Answer

Geiger-Mueller tube

Question 3

A technician needs to measure the dose from a low-energy beta source on the skin. Which type of detector would be most appropriate for this scenario?

Accepted Answer

A pancake-style Geiger-Mueller probe with a thin window

Answer

A thick-walled ionization chamber

Answer

An uncompensated Geiger-Mueller tube

Answer

A Sodium Iodide (NaI) detector

Question 4

The operating principle of a thermoluminescent dosimeter (TLD) is based on which of the following phenomena?

Accepted Answer

Emission of light proportional to deposited energy upon heating

Answer

Gas ionization and multiplication

Answer

Darkening of a photographic emulsion

Answer

Creation of electron-hole pairs in a semiconductor

Question 5

Which of the following describes the 'intrinsic efficiency' of a radiation detector?

Accepted Answer

The ratio of pulses produced to the number of particles striking the detector.

Answer

The ratio of pulses produced to the total number of particles emitted by the source.

Answer

The ability of the detector to resolve two closely spaced energy peaks.

Answer

The total number of counts recorded in the full-energy peak.

Question 6

A technician is tasked with surveying for neutrons. Which of the following instruments is designed specifically for neutron detection?

Accepted Answer

A Boron Trifluoride (BF3) proportional counter

Answer

A cadmium-lined Geiger-Mueller tube

Answer

A zinc sulfide (ZnS) scintillator

Answer

An air-filled ionization chamber