Telegdi digital wire spark chamber spectrometer
date: label: date made
content: 1963-1964
name: label: maker
content: Telegdi, V. L.
label: maker
content: Sherwood, B. A.
label: maker
content: Fryberger, D.
notes: label: Description
content: Three disjoint parts comprise the spectrometer assembly, 1977.0532.01, as follows: 01.1, the spectrometer proper - a rectangular aluminum base on which are mounted four sets of wire spark chambers (7 total), each ca. 0.4 x 0.4 x 0.03 m; 01.2, an individual core memory plane; 01.3, three light aluminum tanks that in the spectrometer assembly are placed between the 4 sets of spark chambers. The whole object includes a fraction of the associated assembly wiring.
label: Description
content: The spectrometer proper (.01.1) consists of seven spark chambers, square planes mounted on edge on the surface of a rectangular metal base. Both the pulsed and read planes are made of 4 mil aluminum wires spaced 1 mm apart and enclosed in 1/2 mil Mylar windows. Four of the spark chambers have vertical wires and three have horizontal wires. The individual chambers are positioned on the base in order to measure the coordinates of charged particles as they trace helical orbits in a uniform perpendicular magnetic field. This data allows the energy and momentum of each particle to be determined.
label: Description
content: Basic Principles and History
label: Description
content: The complete Telegdi spectrometer system consists of a homogeneous magnet containing wire spark chambers with magnetic core readout. The spark chambers were covered with 0.5 mil Mylar, and a 9 to 1 neon-helium mixture flowed through them during operation. Within the spectrometer assembly, each wire chamber is connected to a corresponding memory plane containing ferrite cores. The ferrite core memory planes are located outside the spectrometer magnet in order to avoid interference from the magnetic field. Three aluminum tanks, with 5x10E-4 in. Mylar windows, serve as "helium boxes" placed between the 4 sets of spark chambers to reduce multiple scattering of charged particles (electrons) orbiting through the spectrometer.
label: Description
content: Wire spark chambers with magnetic-core readout differ from ordinary visual spark chambers in that one of the plane electrodes (the “write plane”) is divided into wires, each of which is grounded through a ferrite core. Plug-in cables make the connection between the wire chamber and a memory plane. When a spark strikes a write wire, current flows through the core and “sets” it, thus digitizing the spark location. This information may then be transmitted conveniently to an online computer or stored on magnetic tape. For technical details see B. A. Sherwood, Phys. Rev. 156, 1475 (1967).
label: Description
content: Between 1958 and 1965 bubble chambers dominated among particle detectors used in particle physics experiments. Bubble chambers enabled allowed photographs to be taken of the particle tracks in a three-dimensional volume and later analyzed exactly as to energy and momentum of each particle. However, accelerators soon provided such copious streams of particles that human scanning of bubble chamber photographs in search of events of interest became the most time-consuming part of the experiment.
label: Description
content: The wire spark chamber provided electronic information of the path of a charge particle and was immediately mated with a digital computer programmed to analyze each track for distinct characteristics of interest. The Telegdi wire spark chamber spectrometer, one of the earliest applications of electronic readout spark chambers and on-line computer analysis, was developed in 1964 by V. L. Telegdi and his students at the University of Chicago to measure the energy distribution of positrons in the decay of muons. For detailed information on this experiment, see B. A. Sherwood, ibid.
label: Location
content: Currently not on view
topic: label: general subject association
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Modern Physics
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content: Energy & Power
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content: Science & Mathematics
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content: Modern Physics
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content: Measuring & Mapping
creditLine: label: Credit Line
content: V. L. Telegdi, University of Chicago
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1977.0532.01.1
label: catalog number
content: 1977.0532.01.1
label: accession number
content: 1977.0532
objectType: label: Object Name
content: Spectrometer, Digital Wire Spark Chamber
label: Object Name
content: spectrometer, digital wire spark chamber
physicalDescription: label: Physical Description
content: metal; aluminum; mylar (overall material)
label: Measurements
content: overall (approx.): 65 cm x 160 cm x 65 cm; 25 19/32 in x 63 in x 25 19/32 in