Jump to content
Main menu
Main menu
move to sidebar
hide
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Special pages
Niidae Wiki
Search
Search
Appearance
Create account
Log in
Personal tools
Create account
Log in
Pages for logged out editors
learn more
Contributions
Talk
Editing
Photomultiplier tube
(section)
Page
Discussion
English
Read
Edit
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
View history
General
What links here
Related changes
Page information
Appearance
move to sidebar
hide
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
==History== The invention of the photomultiplier is predicated upon two prior achievements, the separate discoveries of the [[photoelectric effect]] and of [[secondary emission]]. ===Photoelectric effect=== The first demonstration of the [[photoelectric effect]] was carried out in 1887 by [[Heinrich Hertz]] using ultraviolet light.<ref>{{cite journal |author=H. Hertz |title=Ueber einen Einfluss des ultravioletten Lichtes auf die electrische Entladung |journal=Annalen der Physik |volume=267 |issue=8 |pages=983–1000 |year=1887 |url= https://books.google.com/books?id=79SWAAAAIAAJ&q=Annalen%20der%20Physik%20und%20Chemie%20hertz%201887&pg=PA983 |doi=10.1002/andp.18872670827|bibcode = 1887AnP...267..983H }}</ref> Significant for practical applications, Elster and Geitel two years later demonstrated the same effect using ''visible'' light striking alkali metals (potassium and sodium).<ref>{{cite journal|last1=Elster|first1=Julius|last2=Geitel|first2=Hans|title=Ueber die Entladung negativ electrischer Körper durch das Sonnen- und Tageslicht|journal=Annalen der Physik|volume=274|page=497|year=1889|doi=10.1002/andp.18892741202|bibcode = 1889AnP...274..497E|issue=12 |url=https://zenodo.org/record/1423862}}</ref> The addition of [[caesium]], another [[alkali metal]], has permitted the range of sensitive wavelengths to be extended towards longer wavelengths in the red portion of the visible spectrum. Historically, the photoelectric effect is associated with [[Albert Einstein]], who relied upon the phenomenon to establish the fundamental principle of [[quantum mechanics]] in 1905,<ref>{{cite journal |author=A. Einstein |title=Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt |url=http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1905_17_132-148.pdf |journal=Annalen der Physik |volume=322 |issue=6 |pages=132–148 |year=1905 |doi=10.1002/andp.19053220607 |bibcode=1905AnP...322..132E |url-status=live |archive-url=https://web.archive.org/web/20110709180735/http://www.physik.uni-augsburg.de/annalen/history/einstein-papers/1905_17_132-148.pdf |archive-date=2011-07-09 |doi-access=free }}</ref> an accomplishment for which Einstein received the 1921 [[Nobel Prize]]. It is worthwhile to note that Heinrich Hertz, working 18 years earlier, had not recognized that the kinetic energy of the emitted electrons is proportional to the frequency but independent of the optical intensity. This fact implied a discrete nature of light, i.e. the existence of ''quanta'', for the first time. ===Secondary emission=== The phenomenon of [[secondary emission]] (the ability of [[electrons]] in a vacuum tube to cause the emission of additional electrons by striking an [[electrode]]) was, at first, limited to purely electronic phenomena and devices (which lacked [[photosensitivity]]). In 1899 the effect was first reported by Villard.<ref>{{cite book|url=https://books.google.com/books?id=pksGCAAAQBAJ&q=Secondary+Emission+1899&pg=PA9|title=Interaction of Atomic Particles with a Solid Surface / Vzaimodeistvie Atomnykh Chastits S Poverkhnost'yu Tverdogo Tela / Взаимодействие Атомных Частиц С Поверхностью Твердого Тела|first=U. A.|last=Arifov|date=14 December 2013|publisher=Springer|via=Google Books|url-status=live|archive-url=https://web.archive.org/web/20170312055330/https://books.google.co.uk/books?id=pksGCAAAQBAJ&pg=PA9&lpg=PA9&dq=Secondary+Emission+1899&source=bl&ots=ejD3YmKcMc&sig=5jk2lIaSN7vbF0wPJfCtOe9gRIs&hl=en&sa=X&ved=0ahUKEwiI_8yN6N3QAhXNFsAKHSq7AzIQ6AEIJzAB#v=onepage&q=Secondary+Emission+1899&f=false|archive-date=12 March 2017|isbn=9781489948090}}</ref> In 1902, Austin and Starke reported that the metal surfaces impacted by electron beams emitted a larger number of electrons than were incident.<ref>H. Bruining, Physics and applications of secondary electron emission, (McGraw-Hill Book Co., Inc.; 1954).</ref> The application of the newly discovered secondary emission to the amplification of signals was only proposed after [[World War I]] by [[Westinghouse Electric (1886)|Westinghouse]] scientist [[Joseph Slepian]] in a 1919 patent.<ref>J. Slepian, Westinghouse Electric, "Hot Cathode Tube" {{US Patent|1450265}}, Issued April 3, 1923 (Filed 1919)</ref> ====The race towards a practical electronic television camera==== The ingredients for inventing the photomultiplier were coming together during the 1920s as the pace of vacuum tube technology accelerated. The primary goal for many, if not most, workers was the need for a practical television camera technology. Television had been pursued with primitive prototypes for decades prior to the 1934 introduction of the first practical video camera (the [[iconoscope]]). Early prototype television cameras lacked sensitivity. Photomultiplier technology was pursued to enable television camera tubes, such as the iconoscope and (later) the [[orthicon]], to be sensitive enough to be practical. So the stage was set to combine the dual phenomena of [[photoemission]] (i.e., the photoelectric effect) with [[secondary emission]], both of which had already been studied and adequately understood, to create a practical photomultiplier. ====First photomultiplier, single-stage (early 1934)==== The first documented photomultiplier demonstration dates to the early 1934 accomplishments of an [[RCA|RCA group]] based in Harrison, NJ. Harley Iams and Bernard Salzberg were the first to integrate a photoelectric-effect cathode and single secondary emission amplification stage in a single vacuum envelope and the first to characterize its performance as a photomultiplier with electron amplification gain. These accomplishments were finalized ''prior'' to June 1934 as detailed in the manuscript submitted to [[Proceedings of the Institute of Radio Engineers]] (Proc. IRE).<ref>{{cite journal|last1=Iams|first1=H.|last2=Salzberg|first2=B.|title=The Secondary Emission Phototube|journal=Proceedings of the IRE|volume=23|page=55|year=1935|doi=10.1109/JRPROC.1935.227243 |s2cid=51654002}}</ref> The device consisted of a semi-cylindrical [[photocathode]], a secondary emitter mounted on the axis, and a collector grid surrounding the secondary emitter. The tube had a gain of about eight and operated at frequencies well above 10 kHz. ====Magnetic photomultipliers (mid 1934–1937)==== Higher gains were sought than those available from the early single-stage photomultipliers. However, it is an empirical fact that the yield of secondary electrons is limited in any given secondary emission process, regardless of acceleration voltage. Thus, any single-stage photomultiplier is limited in gain. At the time the maximum first-stage gain that could be achieved was approximately 10 (very significant developments in the 1960s permitted gains above 25 to be reached using negative electron affinity [[dynode]]s). For this reason, multiple-stage photomultipliers, in which the photoelectron yield could be multiplied successively in several stages, were an important goal. The challenge was to cause the photoelectrons to impinge on successively higher-voltage electrodes rather than to travel directly to the highest voltage electrode. Initially this challenge was overcome by using strong magnetic fields to bend the electrons' trajectories. Such a scheme had earlier been conceived by inventor J. Slepian by 1919 (see above). Accordingly, leading international research organizations turned their attention towards improving photomultipliers to achieve higher gain with multiple stages. In the [[USSR]], RCA-manufactured radio equipment was introduced on a large scale by [[Joseph Stalin]] to construct broadcast networks, and the newly formed All-Union Scientific Research Institute for Television was gearing up a research program in vacuum tubes that was advanced for its time and place. Numerous visits were made by RCA scientific personnel to the [[USSR]] in the 1930s, prior to the [[Cold War]], to instruct the Soviet customers on the capabilities of RCA equipment and to investigate customer needs.<ref>A.B. Magoun [http://www.histech.nl/Shot2004/programma/txt/magoun.asp?file=magoun ''Adding Sight to Sound in Stalin's Russia: RCA and the Transfer of Television Technology to the Soviet Union''] {{webarchive|url=https://web.archive.org/web/20110724154432/http://www.histech.nl/Shot2004/programma/txt/magoun.asp?file=magoun |date=2011-07-24 }}, Society for the History of Technology (SHOT), Amsterdam (2004)</ref> During one of these visits, in September 1934, RCA's [[Vladimir Zworykin]] was shown the first multiple-dynode photomultiplier, or ''photoelectron multiplier''. This pioneering device was proposed by Leonid A. Kubetsky in 1930<ref>{{cite book|script-title=ru:Большая советская энциклопедия|trans-title=[[Great Soviet Encyclopedia]]|chapter=Кубецкий Леонид Александрович|trans-chapter=Kubetsky Leonid Aleksandrovich|language=ru|year=1973|volume=13|edition=3|publisher=Sovetskaya Entsiklopediya|location=Moscow|chapter-url=http://bse.sci-lib.com/article066966.html}}</ref> which he subsequently built in 1934. The device achieved gains of 1000x or more when demonstrated in June 1934. The work was submitted for print publication only two years later, in July 1936<ref>{{cite journal|last1=Kubetsky|first1=L.A.|title=Multiple Amplifier|journal=Proceedings of the IRE|volume=25|page=421|year=1937|doi=10.1109/JRPROC.1937.229045|issue=4 |s2cid=51643186}}</ref> as emphasized in a recent 2006 publication of the [[Russian Academy of Sciences]] (RAS),<ref>{{cite journal|last1=Lubsandorzhiev|first1=B|doi=10.1016/j.nima.2006.05.221|title=On the history of photomultiplier tube invention|year=2006|page=236|volume=567|issue=1|journal=Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment|arxiv=physics/0601159|bibcode = 2006NIMPA.567..236L }}</ref> which terms it "Kubetsky's Tube." The Soviet device used a magnetic field to confine the secondary electrons and relied on the Ag-O-Cs photocathode which had been demonstrated by General Electric in the 1920s. By October 1935, [[Zworykin|Vladimir Zworykin]], George Ashmun Morton, and Louis Malter of RCA in Camden, NJ submitted their manuscript describing the first comprehensive experimental and theoretical analysis of a multiple dynode tube — the device later called a ''photomultiplier''<ref>{{cite journal|last1=Zworykin|first1=V.K.|last2=Morton|first2=G.A.|last3=Malter|first3=L.|title=The Secondary Emission Multiplier-A New Electronic Device|journal=Proceedings of the IRE|volume=24|page=351|year=1936|doi=10.1109/JRPROC.1936.226435|issue=3 |s2cid=51654458}}</ref> — to Proc. IRE. The RCA prototype photomultipliers also used an Ag-O-Cs ([[silver oxide]]-[[caesium]]) photocathode. They exhibited a peak [[quantum efficiency]] of 0.4% at 800 [[nanometer|nm]]. ====Electrostatic photomultipliers (1937–present)==== Whereas these early photomultipliers used the magnetic field principle, electrostatic photomultipliers (with no magnetic field) were demonstrated by [[Jan A. Rajchman|Jan Rajchman]] of RCA Laboratories in Princeton, NJ in the late 1930s and became the standard for all future commercial photomultipliers. The first mass-produced photomultiplier, the Type 931, was of this design and is still commercially produced today.<ref>J. Rajchman and E.W. Pike, RCA Technical Report TR-362, "Electrostatic Focusing in Secondary Emission Multipliers," September 9, 1937</ref> ====Improved photocathodes==== Also in 1936, a much improved photocathode, Cs<sub>3</sub>Sb ([[caesium]]-[[antimony]]), was reported by P. Görlich.<ref>{{cite journal|last1=Görlich|first1=P.|title=Über zusammengesetzte, durchsichtige Photokathoden|journal=Zeitschrift für Physik|volume=101|page=335|year=1936|doi=10.1007/BF01342330|bibcode = 1936ZPhy..101..335G|issue=5–6 |s2cid=121613539}}</ref> The caesium-antimony photocathode had a dramatically improved quantum efficiency of 12% at 400 nm, and was used in the first commercially successful photomultipliers manufactured by RCA (i.e., the 931-type) both as a photocathode and as a secondary-emitting material for the [[dynode]]s. Different photocathodes provided differing spectral responses. ===Spectral response of photocathodes=== In the early 1940s, the [[JEDEC]] (Joint Electron Device Engineering Council), an industry committee on standardization, developed a system of designating spectral responses.<ref>"Relative spectral response data for photosensitive devices ("S" curves)," JEDEC Publication No. 50, Electronic Industries Association, Engineering Department, 2001 I Street, N.W., Washington, D.C. 20006 (1964)</ref> The philosophy included the idea that the product's user need only be concerned about the response of the device rather than how the device may be fabricated. Various combinations of photocathode and window materials were assigned "S-numbers" (spectral numbers) ranging from S-1 through S-40, which are still in use today. For example, S-11 uses the caesium-antimony photocathode with a lime glass window, S-13 uses the same photocathode with a fused silica window, and S-25 uses a so-called "multialkali" photocathode (Na-K-Sb-Cs, or [[sodium]]-[[potassium]]-[[antimony]]-[[caesium]]) that provides extended response in the red portion of the visible light spectrum. No suitable photoemissive surfaces have yet been reported to detect wavelengths longer than approximately 1700 nanometers, which can be approached by a special (InP/InGaAs(Cs)) photocathode.<ref name="Hamamatsu handbook">{{cite web |title = Hamamatsu PMT Handbook |access-date = 2009-04-21 |url = http://www.hamamatsu.com/resources/pdf/etd/PMT_handbook_v3aE.pdf |url-status = live |archive-url = https://web.archive.org/web/20140504001530/http://www.hamamatsu.com/resources/pdf/etd/PMT_handbook_v3aE.pdf |archive-date = 2014-05-04 }} p. 34, Table 4-1: Typical Spectral Response Characteristics, Transmission Mode Photocathodes</ref> ===RCA Corporation=== For decades, RCA was responsible for performing the most important work in developing and refining photomultipliers. RCA was also largely responsible for the commercialization of photomultipliers. The company compiled and published an authoritative and widely used ''Photomultiplier Handbook''.<ref>{{cite book|last=RCA Corporation|title=RCA Photomultiplier Manual|date=1970|url=https://archive.org/details/RcaPhotomultiplierManual|url-status=live|archive-url=https://web.archive.org/web/20160612174929/https://archive.org/details/RcaPhotomultiplierManual|archive-date=2016-06-12}}</ref> RCA provided printed copies free upon request. The handbook, which continues to be made available online at no cost by the successors to RCA, is considered to be an essential reference. Following a corporate break-up in the late 1980s involving the acquisition of RCA by [[General Electric]] and disposition of the divisions of RCA to numerous third parties, [[RCA]]'s photomultiplier business became an independent company. ===Lancaster, Pennsylvania facility=== The [[Lancaster, Pennsylvania]] facility was opened by the [[U.S. Navy]] in 1942 and operated by RCA for the manufacture of [[radio tube|radio]] and [[microwave tube]]s. Following [[World War II]], the naval facility was acquired by RCA. ''RCA Lancaster,'' as it became known, was the base for the development and the production of commercial [[television]] products. In subsequent years other products were added, such as [[cathode-ray tube]]s, photomultiplier tubes, [[motion detection|motion-sensing]] light control switches, and [[closed-circuit television]] systems. ===Burle Industries=== Burle Industries, as a successor to the RCA Corporation, carried the RCA photomultiplier business forward after 1986, based in the Lancaster, Pennsylvania facility. The 1986 acquisition of RCA by [[General Electric]] resulted in the [[divestiture]] of the RCA Lancaster New Products Division. Hence, 45 years after being founded by the U.S. Navy, its management team, led by Erich Burlefinger, purchased the division and in 1987 founded Burle Industries. In 2005, after eighteen years as an independent enterprise, Burle Industries and a key subsidiary were acquired by Photonis, a European holding company [[Photonis Group]]. Following the acquisition, Photonis was composed of Photonis Netherlands, Photonis France, Photonis USA, and Burle Industries. Photonis USA operates the former Galileo Corporation Scientific Detector Products Group ([[Sturbridge, Massachusetts]]), which had been purchased by Burle Industries in 1999. The group is known for [[microchannel plate detector]] (MCP) electron multipliers—an integrated micro-vacuum tube version of photomultipliers. MCPs are used for imaging and scientific applications, including [[night vision device]]s. On 9 March 2009, Photonis announced that it would cease all production of photomultipliers at both the Lancaster, Pennsylvania and the Brive, France plants.<ref>[https://web.archive.org/web/20090625052831/http://www.photonis.com/holding/news/press_release_photonis_is_announcing_the_halt_of_its_photomultiplier_activity PHOTONIS will stop its Photomultiplier activity]</ref> ===Hamamatsu=== The [[Japan]]-based company [[Hamamatsu Photonics]] (also known as Hamamatsu) has emerged since the 1950s as a leader in the photomultiplier industry. Hamamatsu, in the tradition of RCA, has published its own handbook, which is available without cost on the company's website.<ref>{{cite book|last=Hamamatsu Photonics K. K.|title=PHOTOMULTIPLIER TUBES Basics and Applications|date=2017|url=https://www.hamamatsu.com/content/dam/hamamatsu-photonics/sites/documents/99_SALES_LIBRARY/etd/PMT_handbook_v4E.pdf}}</ref> Hamamatsu uses different designations for particular photocathode formulations and introduces modifications to these designations based on Hamamatsu's proprietary research and development. ===Photocathode materials=== The photocathodes can be made of a variety of materials, with different properties. Typically the materials have low [[work function]] and are therefore prone to [[thermionic emission]], causing noise and dark current, especially the materials sensitive in infrared; cooling the photocathode lowers this thermal noise. The most common photocathode materials are<ref name="pmt">[https://www.chem.uci.edu/~unicorn/243/handouts/pmt.pdf Photomultiplier Tubes. Construction and Operating Characteristics. Connections to External Circuits], Hamamatsu</ref> Ag-O-Cs (also called S1) transmission-mode, sensitive from 300–1200 nm. High dark current; used mainly in near-infrared, with the photocathode cooled; GaAs:Cs, [[caesium]]-[[Activator (phosphor)|activated]] [[gallium arsenide]], flat response from 300 to 850 nm, fading towards ultraviolet and to 930 nm; InGaAs:Cs, caesium-activated [[indium gallium arsenide]], higher infrared sensitivity than GaAs:Cs, between 900–1000 nm much higher [[signal-to-noise ratio]] than Ag-O-Cs; Sb-Cs, (also called S11) caesium-activated [[antimony]], used for reflective mode photocathodes; response range from ultraviolet to visible, widely used; bialkali (Sb-K-Cs, Sb-Rb-Cs), caesium-activated antimony-rubidium or antimony-potassium alloy, similar to Sb:Cs, with higher sensitivity and lower noise. can be used for transmission-mode; favorable response to a NaI:Tl [[scintillator]] flashes makes them widely used in [[gamma spectroscopy]] and radiation detection; high-temperature bialkali (Na-K-Sb), can operate up to 175 °C, used in [[well logging]], low dark current at room temperature; multialkali (Na-K-Sb-Cs), (also called S20), wide spectral response from ultraviolet to near-infrared, special cathode processing can extend range to 930 nm, used in broadband [[spectrophotometer]]s; [[Solar-blind technology|solar-blind]] (Cs-Te, Cs-I), sensitive to vacuum-UV and ultraviolet, insensitive to visible light and infrared (Cs-Te has cutoff at 320 nm, Cs-I at 200 nm). ===Window materials=== The windows of the photomultipliers act as wavelength filters; this may be irrelevant if the cutoff wavelengths are outside of the application range or outside of the photocathode sensitivity range, but special care has to be taken for uncommon wavelengths. [[Borosilicate glass]] is commonly used for near-infrared to about 300 nm. [[Borosilicate_glass#High-borate_borosilicate_glasses|High borate borosilicate glasses]] exist also in high UV transmission versions with high transmission also at 254 nm.<ref>{{cite web|url=http://www.schott.com/tubing/english/product_selector/#!/region--all/lang--english/product--8337B/propuvtransp|title=SCHOTT - Glass Tubing Explorer|website=www.schott.com|url-status=live|archive-url=https://web.archive.org/web/20160711121216/http://www.schott.com/tubing/english/product_selector/#!/region--all/lang--english/product--8337B/propuvtransp|archive-date=2016-07-11}}</ref> Glass with very low content of [[potassium]] can be used with bialkali photocathodes to lower the background radiation from the [[potassium-40]] isotope. Ultraviolet glass transmits visible and ultraviolet down to 185 nm. Used in spectroscopy. Synthetic [[fused quartz|silica]] transmits down to 160 nm, absorbs less UV than fused silica. Different thermal expansion than [[kovar]] (and than borosilicate glass that's [[Glass-to-metal_seal|expansion-matched]] to kovar), a graded seal needed between the window and the rest of the tube. The seal is vulnerable to mechanical shocks. [[Magnesium fluoride]] transmits ultraviolet down to 115 nm. [[Hygroscopic]], though less than other alkali halides usable for UV windows.
Summary:
Please note that all contributions to Niidae Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Encyclopedia:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Search
Search
Editing
Photomultiplier tube
(section)
Add topic