- Bubble chamber
A bubble chamber is a vessel filled with a superheated transparent
liquid(most often liquid hydrogen) used to detect electrically charged particles moving through it. It was invented in 1952by Donald A. Glaser, for which he was awarded the 1960 Nobel Prize in Physics.
Anecdotally, Glaser was inspired by the bubbles in a glass of
beer. He also did experiments using beer to fill early prototypes.
Function and use
The bubble chamber is similar to a
cloud chamberin application and basic principle. It is normally made by filling a large cylinder with a liquid heated to just below its boiling point. As particles enter the chamber, a pistonsuddenly decreases its pressure, and the liquid enters into a superheated, metastablephase. Charged particles create an ionization track, around which the liquid vaporizes, forming microscopic bubbles. Bubble density around a track is proportional to a particle's energy loss.
Bubbles grow in size as the chamber expands, until they are large enough to be seen or photographed. Several cameras are mounted around it, allowing a three-dimensional image of an event to be captured. Bubble chambers with resolutions down to a few μm have been operated.
The whole chamber is subject to a constant magnetic field, which causes charged particles to travel in helical paths whose radius is determined by their
charge-to-mass ratios. Given that for all known charged long-lived subatomic particles, the magnitude of their charge is that of an electron, their radius of curvature is thus proportional to their momentum.
Recently, bubble chambers have been used in research on
WIMPs. [ [http://www-coupp.fnal.gov/ COUPP web site] ]
Although bubble chambers were very successful in the past, they are of only limited use in current very-high-energy experiments, for a variety of reasons:
* The need for a photographic readout rather than three-dimensional electronic data makes it less convenient, especially in experiments which must be reset, repeated and analyzed many times.
* The superheated phase must be ready at the precise moment of collision, which complicates the detection of short-lived particles.
* Bubble chambers are neither large nor massive enough to analyze high-energy collisions, where all products should be contained inside the detector.
* The high-energy particles' path radii may be too large to allow the precise estimation of momentum in a relatively small chamber.
Due to these issues, bubble chambers have largely been replaced by
wire chambers, which allow particle energies to be measured at the same time. Another alternative technique is the spark chamber.
External articles and references
* [http://teachers.web.cern.ch/teachers/archiv/HST2005/bubble_chambers/BCwebsite/index.htm General Information]
* cite journal
author = Donald A. Glaser
title = Some Effects of Ionizing Radiation on the Formation of Bubbles in Liquids
journal = Phys. Rev.
volume = 87
issue = 4
pages = 665–665
year = 1952
url = http://link.aps.org/abstract/PR/v87/p665
doi = 10.1103/PhysRev.87.665
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Look at other dictionaries:
bubble chamber — ☆ bubble chamber n. a container filled with a superheated, transparent liquid in which charged atomic particles and their collisions can be studied by photographing the bubbles and violent boiling that occur along their paths … English World dictionary
bubble chamber — Physics. an apparatus for determining the movements of charged particles, consisting of a chamber containing a superheated transparent liquid that, by boiling and producing bubbles in the path of an ionizing particle, indicates the path of the… … Universalium
bubble chamber — burbulinė kamera statusas T sritis fizika atitikmenys: angl. bubble chamber vok. Blasenkammer, f rus. пузырьковая камера, f pranc. chambre à bulle, f … Fizikos terminų žodynas
bubble chamber — noun Date: 1953 a chamber of superheated liquid in which the path of an ionizing particle is made visible by a string of vapor bubbles … New Collegiate Dictionary
bubble chamber — bub′ble cham ber n. phs cloud chamber • Etymology: 1950–55 … From formal English to slang
bubble chamber — noun A vessel filled with a superheated transparent liquid (most often liquid hydrogen) used to detect electrically charged particles moving through it … Wiktionary
bubble chamber — noun Physics an apparatus in which the tracks of ionizing particles are visible as a row of bubbles in a liquid … English new terms dictionary
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bubble chamber — noun an instrument that records the tracks of ionizing particles • Hypernyms: ↑particle detector … Useful english dictionary
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