Which detector operates by producing light flashes in scintillating material when hit by ionizing radiation?

Which detector operates by producing light flashes in scintillating material when hit by ionizing radiation?

• A. Ionization chamber
• B. Geiger-Muller counter
• C. Semiconductor detector
• D. Scintillation detectors

Answer: (D)

When ionizing radiation interacts with a scintillating material, it transfers energy to the atoms in the crystal or liquid, exciting them. As these excited states relax back to the ground state, they emit photons—a flash of light. That light is then picked up by a photodetector, typically a photomultiplier tube, which converts the light pulses into electrical signals that can be measured. This light-emission mechanism is the hallmark of scintillation detectors. Other detectors use different ways to senses radiation. An ionization chamber relies on the creation of ion pairs in a gas and measures the resulting current, without light production. A Geiger-Muller counter also depends on ionization in gas, with visible amplification but not light emission from the material. Semiconductor detectors measure changes in electrical conductivity within a solid-state junction caused by generated charge carriers, again not through scintillation light.

When ionizing radiation interacts with a scintillating material, it transfers energy to the atoms in the crystal or liquid, exciting them. As these excited states relax back to the ground state, they emit photons—a flash of light. That light is then picked up by a photodetector, typically a photomultiplier tube, which converts the light pulses into electrical signals that can be measured. This light-emission mechanism is the hallmark of scintillation detectors.

Other detectors use different ways to senses radiation. An ionization chamber relies on the creation of ion pairs in a gas and measures the resulting current, without light production. A Geiger-Muller counter also depends on ionization in gas, with visible amplification but not light emission from the material. Semiconductor detectors measure changes in electrical conductivity within a solid-state junction caused by generated charge carriers, again not through scintillation light.