Mediaspace scheduled maintenance: Aug 25, 2026 07:00 - 12:00 AM. During this time, videos will be temporarily unavailable. Check status updates.

Lecture

Detection Principles: Gaseous Ionization Detectors

In course

PHYS-452: Radiation detection

The course presents the detection of ionizing radiation in the keV and MeV energy ranges. Physical processes of radiation/matter interaction are introduced. All steps of detection are covered, as well as detectors, instrumentations and measurements methods ...

Description

This lecture covers the principles of detection in gaseous ionization detectors, including the behavior of dead time, energy loss of particles, creation of electron-ion pairs, drift and collection of charges, and detection regions based on applied voltage. It also discusses the loss of charges due to recombination, electron attachment, and space charge, as well as the operation modes in pulse, current, and Campbell modes.

Instructor

Vincent Pierre Lamirand

After a PhD on the measurement of (p,n) reactions cross sections on small accelerators (IRSN, France), I have worked on the development of neutron detectors and measurement methods for reactor physics (CEA, France). I am part of the LRS staff since October 2014.

Official source

Related concepts (32)

Gaseous ionization detector

Gaseous ionization detectors are radiation detection instruments used in particle physics to detect the presence of ionizing particles, and in radiation protection applications to measure ionizing radiation. They use the ionising effect of radiation upon a gas-filled sensor. If a particle has enough energy to ionize a gas atom or molecule, the resulting electrons and ions cause a current flow which can be measured. Gaseous ionisation detectors form an important group of instruments used for radiation detection and measurement.

Particle detector

In experimental and applied particle physics, nuclear physics, and nuclear engineering, a particle detector, also known as a radiation detector, is a device used to detect, track, and/or identify ionizing particles, such as those produced by nuclear decay, cosmic radiation, or reactions in a particle accelerator. Detectors can measure the particle energy and other attributes such as momentum, spin, charge, particle type, in addition to merely registering the presence of the particle.

Ionization chamber

The ionization chamber is the simplest type of gaseous ionisation detector, and is widely used for the detection and measurement of many types of ionizing radiation, including X-rays, gamma rays, alpha particles and beta particles. Conventionally, the term "ionization chamber" refers exclusively to those detectors which collect all the charges created by direct ionization within the gas through the application of an electric field.

Semiconductor detector

A semiconductor detector in ionizing radiation detection physics is a device that uses a semiconductor (usually silicon or germanium) to measure the effect of incident charged particles or photons. Semiconductor detectors find broad application for radiation protection, gamma and X-ray spectrometry, and as particle detectors. In semiconductor detectors, ionizing radiation is measured by the number of charge carriers set free in the detector material which is arranged between two electrodes, by the radiation.

Drift velocity

In physics, drift velocity is the average velocity attained by charged particles, such as electrons, in a material due to an electric field. In general, an electron in a conductor will propagate randomly at the Fermi velocity, resulting in an average velocity of zero. Applying an electric field adds to this random motion a small net flow in one direction; this is the drift. Drift velocity is proportional to current. In a resistive material, it is also proportional to the magnitude of an external electric field.

Related lectures (26)

Gaseous Ionisation Detectors

Explores gaseous ionisation detectors, their principles, operation modes, applications, and properties in radiation detection and dosimetry.

Gaseous Ionisation Detectors

Explores gaseous ionisation detectors, including ionisation chambers, proportional counters, and Geiger-Müller counters, discussing their principles, operation, and applications.

Radiation Detection: Gaseous Ionisation Detectors

Explores gaseous ionisation detectors, including ionisation chambers, proportional counters, and Geiger-Müller counters, discussing their principles, operation modes, and applications.

Particle Detection and Detectors

Explores particle detection using scintillators, cloud chambers, and wire chambers for various applications.

Particle Detection: Stable Particles and Lifetime