ionization chamber
Date1960-1984
Inventory Number2003-1-0302
ClassificationIonization Chamber
Subject
Maker
Harvard Cyclotron Laboratory
1937 - 2002
Cultural Region
Place of Origin
Dimensions29 x 19 x 15.3 cm (11 7/16 x 7 1/2 x 6 in.)
Material
DescriptionThere is a good chance this instrument was shop-built at Harvard. Only the pressure gauge connected to the chamber would have been bought from a manufacturer.
The body of this chamber is cylindrical and made of brass and aluminum. It has translucent windows. There is one gas connector with a valve and two threaded electrical connectors. The H.V. connector stands for High Voltage. The SIG connector stands for Signal.
Inside are four metallic plates to which current is applied via the coaxial connector H.V. A coaxial connector named SIG is used to transmit the ionic signal generated inside the instrument. Above, a gauge measures the pressure of the gas in the chamber. Under, two aluminum feet so the instrument could be solidly fixed.
The body of this chamber is cylindrical and made of brass and aluminum. It has translucent windows. There is one gas connector with a valve and two threaded electrical connectors. The H.V. connector stands for High Voltage. The SIG connector stands for Signal.
Inside are four metallic plates to which current is applied via the coaxial connector H.V. A coaxial connector named SIG is used to transmit the ionic signal generated inside the instrument. Above, a gauge measures the pressure of the gas in the chamber. Under, two aluminum feet so the instrument could be solidly fixed.
In Collection(s)
Signedunsigned
Inscribedon pressure gauge: 480
on instrument: SIG.
on instrument: H.V.
FunctionAn ionization chamber is used in two different ways: to detect particles in air (as in a smoke detector) and to detect or measure ionizing radiation.
In our case, it was used for the latter purpose. The coaxial connectors are linked to the inside electrodes, which are immersed in a gas held within the chamber to a certain pressure. When high-energy particles (alpha, beta, X-rays, etc.) pass through the chamber, they ionize the gas and produce ions, which are then attracted by one of the electrodes. This movement of particules creates an ionization current that can be measured by a galvanometer or an electrometer.
In our case, it was used for the latter purpose. The coaxial connectors are linked to the inside electrodes, which are immersed in a gas held within the chamber to a certain pressure. When high-energy particles (alpha, beta, X-rays, etc.) pass through the chamber, they ionize the gas and produce ions, which are then attracted by one of the electrodes. This movement of particules creates an ionization current that can be measured by a galvanometer or an electrometer.
Historical AttributesThis ionization chamber was used at the Harvard Cyclotron Laboratory in order to measure electrical current. It is unusual in that it employed a transverse collection of the current.
Harvard Cyclotron Laboratory
Date: 1947-2002
Object number: 2003-1-0291
Varian Associates
Date: circa 1964
Accessories: metal maker's name plate is on top of the other maser's cavity on B18-E5.
Object number: 1998-1-1628
Hewlett-Packard Company
Date: circa 1965
Accessories: cavity resonator (1990-7-0004b), name plate (1990-7-0004c)
Object number: 1990-7-0004a.1
Hewlett-Packard Company
Date: circa 1965
Accessories: cavity resonator (1990-7-0004b)
Object number: 1990-7-004a.1
Hewlett-Packard Company
Date: circa 1965
Accessories: cavity resonator (1990-7-0004b), name plate (1990-7-0004c)
Object number: 1990-7-0004a.2
Edgerton, Germeshausen & Grier
Date: 1965-1970
Object number: 2003-1-0300