Radiation Detector

When radiation causes ionizations in a gas-filled detector, the ___ created move faster than the ____.

• positive ions, electrons
• electrons, positive ions
• protons, neutrons
• alpha particles, beta particles

The parts of a gas-filled detector include:

• a cathode, anode, power supply and a meter
• an anode and meter only
• power supply and sometimes 2 meters
• a cathode and anode only

How does an ionization survey meter differ from a GM meter in terms of "operational modes"?

• An ionization survey meter operates in CURRENT mode but a GM meter operates in PULSE mode
• An ionization survey meter operates in PULSE mode but a GM meter operates in CURRENT mode
• They both operate in PULSE mode
• They both operate in CURRENT mode

An example of "dead time" is:

• a Geiger counter reading stops increasing as the distance between the detector and the source increases
• a Geiger counter reading stops increasing as the distance between the detector and the source decreases
• the Gieger counter needs a new battery since the current one is "dead"
• None of the above

In the "recombination region," electrons and positive ions are recombining before they can reach an anode or cathode.

• True
• False

Ionization region

• refers to the region when all electrons reach an anode and cathode and are registered by electronic circuitry
• refers to the region when all electrons and positive ions reachthe anode and are registered by electronic circuitry
• refers to the region when all positive ions reach an anode and cathode and are registered by electronic circuitry
• refers to the region when all electrons and positive ions reach an anode and cathode and are registered by electronic circuitry

Which detector function as energy is stored until material is heated then light is emitted. Provides rapid read out.

• Thermoluminescent detectors

• Scintillation Counters

• Proportional Counter

• Gas Amplification

The region of continuous discharge is harmful to detection equipment since the voltage applied in the GM meter causes spontaneous ionizations to occur in the absence of radiation

• True
• False

In the GM region,___

• deals with 1 ionization pair at a time.
• there are spontaneous ionizations occurring in the gas in the absence of any radiation interactions.
• each electron created causes many ionizations and excitations, resulting in an avalanche of ionizations within the gas chamber, that produces a laarge pulse of electricity for each radiation interaction.
• electrons and positive ions recombine before the reach the anode or cathode.

If a patient receives a high treatment dose of radiation, the best radiation detection instrument to use would be______.

• a Geiger counter operating in current mode.

• an ionization survey meter operating in current mode.

• a Geiger counter operating in pulse mode.

• an ionization survey meter operating in pulse mode.