Question

When nuclear radiations pass through, gas ionization is produced. This is the principle of which of the following detectors?

• A. Proportional counter
• B. Flow counter
• C. Geiger Muller counter
• D. Scintillation counter

Hint:

Gas Ionization Detectors. Ionization Chamber, Proportional Counter, Geiger-Müller (GM) Counter all work by detecting the ionization created by radiation passing through a gas. They differ in the operating voltage and the extent of gas multiplication.

Answer 1

The Correct Option is C

Several radiation detectors operate based on the principle that ionizing radiation (like alpha, beta, gamma rays) ionizes gas molecules as it passes through them
- Ionization Chamber: Collects the primary ions created by radiation
Operates at low voltage
- Proportional Counter: Operates at a higher voltage than ionization chambers
The primary ions are accelerated, causing secondary ionization (gas multiplication), producing a pulse proportional to the initial energy deposited
- Geiger-Müller (GM) Counter: Operates at a still higher voltage
The initial ionization triggers a complete avalanche discharge along the anode wire, producing a large, uniform pulse regardless of the initial radiation energy (detects presence, doesn't measure energy well)
Gas ionization is the fundamental principle
- Scintillation Counter: Radiation interacts with a scintillator material, producing flashes of light (scintillations), which are then detected by a photomultiplier tube
Does not directly rely on gas ionization for detection
- Flow counter is a type of gas ionization detector where gas flows continuously
Both proportional counters and GM counters rely on gas ionization
However, the GM counter is perhaps the most well-known detector operating fundamentally on the principle that radiation passing through a gas produces ionization, leading to a detectable electrical pulse
Given the options, the GM counter is a strong fit
Proportional counters also fit but GM counters operate based on a full avalanche triggered by the initial ionization