A Geiger-Muller tube works by detecting ionizing radiation and converting it into an electrical pulse. The tube is filled with a gas, typically argon or helium, and has a central wire electrode surrounded by a metal tube. When radiation enters the tube, it ionizes the gas, creating a brief conductive path between the central electrode and the outer tube. This results in a measurable electrical pulse.
A Geiger-Muller tube is constructed using glass or metal materials to house the gas-filled chamber. The central wire electrode is usually made of tungsten or stainless steel, while the outer tube is typically made of aluminum or copper. The tube also has a mica window for radiation to enter and a thin metal foil to act as a cathode. A high voltage power supply is also needed to create an electric field within the tube.
The gas in a Geiger-Muller tube serves as the medium for detecting radiation. When ionizing radiation enters the tube, it ionizes the gas atoms, creating an electrical current that can be measured. Different gases have different ionization properties, making them suitable for detecting specific types of radiation.
The main hazard of working with a Geiger-Muller tube is exposure to ionizing radiation. The tube itself can also pose a risk if it is damaged or broken, as the gas inside may be flammable or toxic. It is important to follow proper safety protocols and handle the tube with care to avoid any potential hazards.
To calibrate a Geiger-Muller tube, a known source of radiation is used to determine the tube's response. The tube is placed at a fixed distance from the source, and the resulting electrical pulses are measured. This data is then used to create a calibration curve, which can be used to convert future electrical pulses into radiation dose measurements.