Editing Timeline of nuclear fusion (section)

==1950s==
* '''1950'''
** In January, [[Klaus Fuchs]] admits to passing nuclear secrets to the [[Soviet Union]]. Almost all nuclear research in the UK, including the fledgling fusion program, is immediately classified. Thomson, until this time working at Imperial University, is moved to the [[Atomic Weapons Research Establishment]].
** The [[tokamak]], a type of [[magnetic confinement fusion]] device, was proposed by Soviet scientists [[Andrei Sakharov]] and [[Igor Tamm]].[[File:GreenHouseGeorge2.gif|thumb|The United States test [[Greenhouse George]], the first use of artificial thermonuclear fusion, in 1951]]
* '''1951'''
** [[Edward Teller]] and [[Stanislaw Ulam]] at [[Los Alamos National Laboratory]] (LANL) develop the [[Teller-Ulam design]] for the [[thermonuclear weapon]], allowing for the development of multi-megaton weapons.
** A press release from [[Argentina]] claims that their [[Huemul Project]] had produced controlled nuclear fusion. This prompted a wave of responses in other countries, especially the U.S.
*** [[Lyman Spitzer]] dismisses the Argentinian claims, but while thinking about it comes up with the [[stellarator]] concept. Funding is arranged under Project Matterhorn and develops into the [[Princeton Plasma Physics Laboratory]].
*** Tuck introduces the British pinch work to LANL. He develops the [[Perhapsatron]] under the codename [[Project Sherwood]]. The project name is a play on his name via Friar Tuck.<ref>...the first money to be allocated [to controlled nuclear research] happened to be for Tuck, and was diverted from Project Lincoln, in the Hood Laboratory. The coincidence of names prompted the well-known cover name "Project Sherwood". James L. Tuck, [http://bayesrules.net/JamesTuckVitaeAndBiography.pdf "Curriculum Vita and Autobiography"], declassified document from Los Alamos National Laboratory (1974), reproduced with permission. [https://web.archive.org/web/20120209082757/http://bayesrules.net/JamesTuckVitaeAndBiography.pdf Archived] 9 February 2012.</ref>
*** [[Richard F. Post]] presents his [[magnetic mirror]] concept and also receives initial funding, eventually moving to [[Lawrence Livermore National Laboratory]] (LLNL).
*** In the UK, repeated requests for more funding that had previously been turned down are suddenly approved. Within a short time, three separate efforts are started, one at Harwell and two at [[Atomic Weapons Establishment]] (Aldermaston). Early planning for a much larger machine at Harwell begins.
*** Using the Huemul release as leverage, Soviet researchers find their funding proposals rapidly approved. Work on linear pinch machines begins that year.
**On May 9, the American nuclear test [[Greenhouse George]], the first of a [[boosted fission weapon]], yields 255 kilotons from an [[enriched uranium]] core and [[deuterium]]-[[tritium]] gas. '''This is the artificial thermonuclear fusion, and the first weaponization of fusion energy'''.<ref name="i189">{{cite journal |last=Goncharov |first=German A |date=1996-10-31 |title=American and Soviet H-bomb development programmes: historical background |journal=Physics-Uspekhi |volume=39 |issue=10 |pages=1033–1044 |doi=10.1070/PU1996v039n10ABEH000174 |issn=1063-7869}}</ref>
**Experimental research of toroidal magnetic confinement systems starts at the [[Kurchatov Institute]], [[Moscow]], led by a group of Soviet scientists led by [[Lev Artsimovich]]. Device chambers are constructed from glass, porcelain, or metal. Their largest device, TMP, uses a porcelain chamber with metal spirals. Data is collected from '''the first operational toroidal magnetic plasma devices'''.<ref name="d7422">{{cite journal |last=Smirnov |first=V.P. |date=2009-12-30 |title=Tokamak foundation in USSR/Russia 1950–1990 |journal=Nuclear Fusion |publisher=IOP Publishing |volume=50 |issue=1 |page=014003 |doi=10.1088/0029-5515/50/1/014003 |issn=0029-5515 |doi-access=free}}</ref>
[[Image:IvyMike2.jpg|thumb|The United States test [[Ivy Mike]], the first full [[thermonuclear weapon]], in 1952.]]
* '''1952'''
** On November 1, the United States conducts the [[Ivy Mike]] shot of [[Operation Ivy]], '''the first detonation of a [[thermonuclear weapon|hydrogen bomb]]''', yields 10.4 megatons of TNT out of a fusion fuel of liquid deuterium.
** Cousins and Ware build a larger toroidal [[Pinch (plasma physics)|pinch]] device in England and demonstrated that the plasma in pinch devices is inherently unstable.
* '''1953'''
** The first Soviet fusion bomb test, [[RDS-6s]], American codename "[[Joe 4]]", demonstrated the first fission/fusion/fission "layercake" design, limited below the megaton range, with less than 20% of the yield coming directly from fusion. It was quickly superseded by the [[Teller-Ulam|Teller-Ulam design]]. This was '''the first aerial drop of a fusion weapon'''.
** [[Z-pinch|Linear pinch devices]] in the US and USSR report detections of [[neutron]]s, an indication of fusion reactions. Both are later explained as coming from instabilities in the fuel, and are non-fusion in nature.
** Scientists at the [[Princeton Plasma Physics Laboratory]] construct Model A, '''the first operational stellarator'''.<ref name="d742">{{cite journal |last=Smirnov |first=V.P. |date=2009-12-30 |title=Tokamak foundation in USSR/Russia 1950–1990 |journal=Nuclear Fusion |publisher=IOP Publishing |volume=50 |issue=1 |page=014003 |doi=10.1088/0029-5515/50/1/014003 |issn=0029-5515 |doi-access=free}}</ref>
* '''1954'''
** Early planning for the large [[ZETA (fusion reactor)|ZETA]] device at Harwell begins. The name is a take-off on [[research reactor|small experimental fission reactors]] which often had "zero energy" in their name, [[ZEEP]] being an example.
** [[Edward Teller]] gives a now-famous speech on plasma stability in magnetic bottles at the Princeton Gun Club. His work suggests that most magnetic bottles are inherently unstable, outlining what is today known as the [[interchange instability]].
* '''1955'''
** At the first [[Atoms for Peace]] meeting in Geneva, [[Homi J. Bhabha]] predicts that fusion will be in commercial use within two decades. This prompts a number of countries to begin fusion research; [[Japan]], [[France]] and [[Sweden]] all start programs this year or the next.
** Scientists in the Soviet Union achieve '''the first fusion via a purely chemical explosive-driven implosion''', using spherical shock waves to compress a <chem>UD2T</chem> target.<ref name="u898">{{cite journal |last=KOZYREV |first=A. S. |last2=ALEKSANDROV |first2=V. A. |last3=POPOV |first3=N. A. |year=1978 |title=Fusion first for USSR |journal=Nature |publisher=Springer Science and Business Media LLC |volume=275 |issue=5680 |pages=476–476 |doi=10.1038/275476a0 |issn=0028-0836 |doi-access=free}}</ref>
* '''1956'''
** Construction of ZETA begins at Harwell.
** [[Igor Kurchatov]] gives a talk at Harwell on pinch devices,<ref>[http://www.efda.org/2010/04/lecture-of-i-v-kurchatov-at-harwell/ "Lecture of I.V. Kurchatov at Harwell"], from the address of I.V. Kurchatov: "On the possibility of producing thermonuclear reactions in a gas discharge" at Harwell on 25 April 1956. [https://web.archive.org/web/20150720180242/https://www.euro-fusion.org/2010/04/lecture-of-i-v-kurchatov-at-harwell/ Archived] 20 July 2015.</ref> revealing for the first time that the USSR is also working on fusion. He details the problems they are seeing, mirroring those in the US and UK.
** In August, a number of articles on plasma physics appear in various Soviet journals.
** In the wake of the Kurchatov's speech, the US and UK begin to consider releasing their own data. Eventually, they settle on a release prior to the 2nd [[Atoms for Peace]] conference in [[Geneva]] in 1958.
** On May 27, the United States conducts the Zuni test of [[Operation Redwing]] with a [[B41 nuclear bomb|Mk-41 bomb]], '''the first test of a three-stage hydrogen bomb'''.[[File:Scylla I in 1958.jpg|thumb|Scylla I, the first device to achieve controlled thermonuclear fusion, in 1958. It was a [[theta pinch]] design built by [[Los Alamos National Laboratory]].]]
* '''1957'''
** In the US, at [[Los Alamos National Laboratory|LANL]], [[Scylla I (thermonuclear fusion device)|Scylla I]]<ref>[http://www.lanl.gov/about/history-innovation/now-then-los-alamos.php In 1957, Los Alamos achieved the first controlled thermonuclear plasma.], Now and Then at Los Alamos.</ref> begins operation using the θ-pinch design.
** ZETA is completed in the summer, it will be the largest fusion machine for a decade.
** In August, initial results on ZETA appear to suggest the machine has successfully reached basic fusion temperatures. UK researchers start pressing for public release, while the US demurs.
** Scientists at the AEI Research laboratory in Harwell reported that the [[Sceptre (fusion reactor)|Sceptre III]] plasma column remained stable for 300 to 400 microseconds, a dramatic improvement on previous efforts. Working backward, the team calculated that the plasma had an electrical resistivity around 100 times that of copper, and was able to carry 200 kA of current for 500 microseconds in total.[[File:Tokamak T-1.jpg|thumb|T-1, the first operational [[tokamak]], built by the [[Kurchatov Institute]] in 1958.]]
* '''1958'''
** In January, the US and UK release large amounts of data, with the ZETA team claiming fusion. Other researchers, notably Artsimovich and Spitzer, are sceptical.
** In May, a series of new tests demonstrate the measurements on ZETA were erroneous, and the claims of fusion have to be retracted.
** American, British and [[USSR|Soviet]] scientists began to share previously classified controlled fusion research as part of the [[Atoms for Peace]] conference in [[Geneva]] in September. It is the largest international scientific meeting to date. It becomes clear that basic pinch concepts are not successful and that no device has yet created fusion at any level.
** Scylla demonstrates '''the first controlled thermonuclear fusion in any laboratory''',<ref>[https://fas.org/sgp/othergov/doe/lanl/lib-www/la-pubs/00403632.pdf Reviewing next the thermonuclear plasma achievements at Los Alamos, we have achieved:(1) The first controlled thermonuclear reaction.], Review of Controlled Thermonuclear Research at Los Alamos 1965, J. L. Tuck</ref><ref>[https://fas.org/sgp/othergov/doe/lanl/pubs/00285870.pdf The first experiment in which thermonuclear fusion was achieved in any laboratory was done in 1958 with the Scylla I machine. ], Winter/Spring 1983 [[Los Alamos Science]].</ref> although confirmation came too late to be announced at Geneva. This [[theta pinch|θ-pinch]] approach will ultimately be abandoned as calculations show it cannot scale up to produce a reactor.
** The [[Kurchatov Institute]] constructs its first toroidal device with an all-metal chamber, T-1, considered to be '''the first operational tokamak'''.<ref name="d7423">{{cite journal |last=Smirnov |first=V.P. |date=2009-12-30 |title=Tokamak foundation in USSR/Russia 1950–1990 |journal=Nuclear Fusion |publisher=IOP Publishing |volume=50 |issue=1 |page=014003 |doi=10.1088/0029-5515/50/1/014003 |issn=0029-5515 |doi-access=free}}</ref>