The Full Wiki

Geiger counter: Wikis

Advertisements
  
  

Note: Many of our articles have direct quotes from sources you can cite, within the Wikipedia article! This article doesn't yet, but we're working on it! See more info or our list of citable articles.

Encyclopedia

From Wikipedia, the free encyclopedia

Geiger counter
Geiger counter.jpg
A deflection needle type geiger counter
Other names Geiger-Müller counter
Uses Particle detector
Inventor Hans Geiger
Related items Geiger-Müller tube

A Geiger counter, also called a Geiger-Müller counter, is a type of particle detector that measures ionizing radiation. They are notable for being used to detect if objects emit nuclear radiation.

Description

Geiger counters are used to detect ionizing radiation (usually beta particles and gamma rays, but certain models can detect alpha particles). An inert gas-filled tube (usually helium, neon or argon with halogens added) briefly conducts electricity when a particle or photon of radiation makes the gas conductive. The tube amplifies this conduction by a cascade effect and outputs a current pulse, which is then often displayed by a needle or lamp and/or audible clicks. Modern instruments can report radioactivity over several orders of magnitude.

Some Geiger counters can be used to detect gamma radiation, though sensitivity can be lower for high energy gamma radiation than with certain other types of detector, because the density of the gas in the device is usually low, allowing most high energy gamma photons to pass through undetected (lower energy photons are easier to detect, and are better absorbed by the detector. Examples of this are the X-ray Pancake Geiger Tube). Improved gamma sensitive Geiger-Müller tubes with high density cathodes (walls) of lead or stainless steel were used to overcome this difficulty. Gamma photons interact with the walls producing high-energy electrons which are then detected.

A better device for detecting gamma rays is a sodium iodide scintillation counter. Good alpha and beta scintillation counters also exist, but Geiger detectors are still favored as general purpose alpha/beta/gamma portable contamination and dose rate instruments, due to their low cost and robustness. A variation of the Geiger tube is used to measure neutrons, where the gas used is boron trifluoride and a plastic moderator is used to slow the neutrons. This creates an alpha particle inside the detector and thus neutrons can be counted.

References

External links

Patents

Electric lamps and discharge devices of the Geiger-Müller type (Class 313/93)

Advertisements

Geiger counter
File:Geiger
A deflection needle type geiger counter
Other names Geiger-Müller counter
Uses Particle detector
Inventor Hans Geiger
Related items Geiger-Müller tube

A Geiger counter, also called a Geiger-Müller counter, is a type of particle detector that measures ionizing radiation. They are notable for being used to detect whether objects emit nuclear radiation.

Geiger counters are used to detect ionizing radiation (usually beta particles and gamma rays, but certain models can detect alpha particles). An inert gas-filled tube (usually helium, neon or argon with halogens added) briefly conducts electricity when a particle or photon of radiation makes the gas conductive. The tube amplifies this conduction by a cascade effect and outputs a current pulse, which is then often displayed by a needle or lamp and/or audible. Modern instruments can report radioactivity over several orders of magnitude. Some Geiger counters can be used to detect gamma radiation, though sensitivity can be lower for high energy gamma radiation than with certain other types of detector, because the density of the gas in the device is usually low, allowing most high energy gamma photons to pass through undetected (lower energy photons are easier to detect, and are better absorbed by the detector. Examples of this are the X-ray Pancake Geiger Tube). Improved gamma sensitive Geiger-Müller tubes with high density cathodes (walls) of lead or stainless steel were used to overcome this difficulty. Gamma photons interact with the walls producing high-energy electrons which are then detected.

A better device for detecting gamma rays is a sodium iodide scintillation counter. Good alpha and beta scintillation counters also exist, but Geiger detectors are still favored as general purpose alpha/beta/gamma portable contamination and dose rate instruments, due to their low cost and robustness. A variation of the Geiger tube is used to measure neutrons, where the gas used is boron trifluoride and a plastic moderator is used to slow the neutrons. This creates an alpha particle inside the detector and thus neutrons can be counted.

External links

Patents

Electric lamps and discharge devices of the Geiger-Müller type (Class 313/93)


Wiktionary

Up to date as of January 15, 2010

Definition from Wiktionary, a free dictionary

Contents

English

Wikipedia-logo.png
Wikipedia has an article on:

Wikipedia

Etymology

Named after Hans Geiger who developed the first such device in 1908 together with Ernest Rutherford.

Pronunciation

  • (RP) IPA: /ˈgaɪgə ˈkaʊntə/
  • (US) IPA: /ˈgaɪgɚ ˈkaʊntɚ/

Noun

Singular
Geiger counter

Plural
Geiger counters

Geiger counter (plural Geiger counters)

  1. A device designed to detect radioactivity and measure its intensity.

Synonyms

Quotations

  • 1988 — David Halliday & Robert Resnick, Fundamentals of Physics (3rd ed.), p 387
    Figure 27 shows a Geiger counter, used to detect ionizing radiation. The counter consists of a thin central wire, carrying a positive charge, surrounded by a concentric circular conducting cylinder, carrying an equal negative charge.

Simple English

A Geiger counter (sometimes called Geiger-Müller counter) is an instrument that measures radiation in an area. It works by measuring ionizing radiation by count rate. It was developed by Hans Geiger and Ernest Rutherford in 1908. It was improved by Walther Müller in 1928.

Geiger counters can detect the presence of radiation. Some can also detect the intensity of it, and the angle from which it comes.

Error creating thumbnail: sh: convert: command not found
Wikimedia Commons has images, video, and/or sound related to:

Advertisements






Got something to say? Make a comment.
Your name
Your email address
Message