Practice question

Gas ionization detectors operate by collecting ion pairs formed when radiation traverses gas. Geiger-Muller tube maintains high potential difference, typically 800 to 1000 V, between central wire anode and cylindrical cathode filled with argon and quench gas. Primary ionization triggers Townsend avalanche, producing large uniform pulses regardless of incident energy, suitable for counting. Proportional counters work at intermediate voltage with pulse proportional to energy. Scintillation counters use phosphors and photomultipliers rather than gas ionization, while cloud chambers visualize tracks. Therefore high-voltage gas ionization characterizes Geiger-Muller.