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Description: | EMI Type 6097 S/N0. 27636 MADE IN GREAT BRITAIN (written and printed on a silver and blue self adhesive label). E.M.I. ELECTRONICS LTD VALVE DIVISION BURY STREET RUISLIP MIDDLESEX TYPE No 6097B SERIAL No 27636 MADE IN ENGLAND (stencilled on the glass envelope. N.B. The type ans serial numbers were written on two decals but are now almost entirely obliterated. 4799 (engraved with a vibro tool on the base of the lowest collector. MANU E.M.I. Electronics Ltd Valve Division. circa 1965 Bury Street, Ruislip, Middlesex, England. DES after ELSTER,Johann,Phillipp,Ludwig,Julius and GEITEL,Hans,Friedrich. circa 1888 ? Herzoglich Gymnasium, Wolfenbuttel, near Brunswick, Germany This is an E.M.I. type 6097B "polyatomic" gas-filled cascade fast photomultiplier (PMT). The mu or amplification factor for these devices is typically a factor of 6 for each dynode stage giving a total amplification of well over 1 million.
It is not known what coatings are present on the photocathode but presumably, in this valve, it is a non-radioctive alkaline earth or rare earth metal alloy, the first of which was developed in about 1929. Typically a photosensitive coating contains metals or their oxides such as sodium, potassium, barium, caesium, rubidium, silver, copper, antimony, arsenic, gallium, tellurium and indium. The composition of the alloy dictates the peak sensitivity of the device, which can vary from the infra red to the ultra violet.
There is much debate about the invention of the cascade photomultiplier, some sources give the credit to a Russian electrical engineer Leonid Alekandrovitch Kubetsky (1904-1959) who reputedly invented the device in 1930. However, Philo Farnsworth invented the cascade electron mulltipler system in 1927 incorporating it in his dissector television scanning tube, which he patented in 1930. He went on to develope, in 1934, an amplifier tube that used the electron cascade principle that he called the multipactor. The fast photomultiplier was developed commercially by Mullard Research Laboratories, Cross. Oak Lane, Redhill, Surrey, in 1959.
This valve is a top window type. The valve should be positioned so that photons pass through the wire filament (cathode) grid at right angles and strike the photocathode behind it. In this device the photo cathode is at about 90 degrees to the grid. As the photons hit the photocathode electrons are released, which impinge on the first auxilliary electrode or dynode, in the form of a dished metal plate. This plate carries an electrostatic focussing charge. The electrons are amplified i.e. multiplied by the electrostatic charge on the dynode. The electrons are then reamplified by nine further dynodes cascading through the valve to the anode. Each dynode is more positively charged than its predecessor. The total amplification is about 1 million. The last dynode encloses the plate (anode) on one side. The plate is in the form of a tungsten wire mesh. The photocathode and the anode are electrically isolated by a ceramic insulators. The valve is mounted on an all glass 16 pin base with one pin cut short because internally this becomes the cathode grid support.
This type of valve was used as a photon detector in scintillation counters and other scientific detectors.
It is not known which gases were used in this commercial valve but earlier experimental types were evacuated and then filled with argon and alcohol at partial pressures of 10cm and 1 cm of mercury, respectively. The polyatomic or self quenching gas prevented a charge building up on the cathode allowing the tube to operate at much higher speeds.
The potassium hydride cell, the first none selenium based photocell, was invented in Germany by Elster and Geitel.
The photo diode valve was invented by Professor Jakob Kunz (1874-1938) in 1912 at Illinois University, Urban-Champaign, Illinois in the United States of America.
The photovoltaic effect was discovered by Alexander Edmond Becquerel (1829-1891) the French physicist and chemist in 1839 at Paris, France.
The technology, to which the self quenching gas was first applied, was the radiation counting tube first invented by the New Zealand born physicist Ernest Rutherford, later1st Baron Rutherford of Nelson, (1871-1937) and the German physicist Wilhelm Geiger (1882-1945) in 1908, at Manchester, England.
The use of a self quenching polyatomic gas in counting tubes was introduced to Germany by A. Z. Tost, in 1935. | License: | http://www.hmag.gla.ac.uk/spirit/rights/ | Publisher: | Hunterian Museum and Art Gallery, University of Glasgow | Rights holder: | Hunterian Museum and Art Gallery, University of Glasgow | Subjects: | SCIENTIFIC COLLECTION : | Source: | Hunterian Museum | Creator: | Hunterian Museum and Art Gallery, University of Glasgow | Identifier: | http://www.huntsearch.gla.ac.uk/cgi-bin/... | Language: | en-GB | Go to resource |
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