 |
|
欧洲粒子物理研究所(European Organization for Nuclear Research ,简称CERN)成立于1954年,是世界最大的粒子物理研究中心。CERN是欧洲第一个联合研究机构,由20个成员国提供资金,其卓越成绩已经成为国际合作的典范。CERN位于法国和瑞士的交界处,就在日内瓦的郊区。CERN主要研究物质是怎样构成的,以及是什么把它们结合起来的。CERN建有世界上最大的正负电子对撞机LEP(Large Electron-Positron collider)和超级质子同步加速器SPS(Super Proton Synchrotron),如图所示,大圆是LEP,周长达到27公里,粒子能够加速到每秒运动11000周,接近光速。小圆是SPS。与加速器配套的是四层楼高的粒子检测器,用于对粒子性质进行分析。
来自全世界80多个国家、500多所大学及研究机构的6500多名科学家(占全球粒子物理学家的一半)在CERN进行各种各样的实验。CERN自身拥有各种各样的技术支持人员,包括物理学家、工程师、程序员、技术人员、管理人员、工人等,他们负责建立各种复杂的设施并保障其正常运转。在CERN完成的实验也是前所未有的,通常需要数百名科学家在巨大的设备上共同完成,一个实验昼夜不停,持续数月乃至数年。
顺便说一句,CERN同时也是万维网WWW(World Wide Web)的发源地。1990年,CERN的计算机科学家Tim Berners-Lee,为了方便分布于世界各地的高能物理学家之间的协作,设想和开发了WWW客户端和服务器端,还定义了URL、HTTP、HTML等。正是由于Tim等人的贡献,Internet才变成了大家今天所习惯的模样。
CERN光辉的历史(英文原版,欢迎网友一起来翻译):
1949
To redress the balance and restore European science to its former prestige, at the European Cultural Conference at Lausanne, the French physicist and Nobel prize-winner Louis de Broglie proposes the creation of a European science laboratory.
1950
At the 5th General Conference of UNESCO in Florence, the American physicist and Nobel prize-winner Isidore Rabi puts forward a resolution, unanimously adopted, authorizing UNESCO, "to assist and encourage the formation and organization of regional centres and laboratories in order to increase and make more fruitful the international collaboration of scientists ...".
1952
After two UNESCO Conferences, 11 European governments agree to set up a provisional "Conseil Européen pour la Recherche Nucléaire" (CERN). At a meeting of the new CERN Council in Amsterdam, a site near Geneva is selected for the planned laboratory.
1954
After initial ratification of the Convention by its Member States, the European Organization for Nuclear Research formally comes in to being on 29 September. Although the "provisional" CERN is dissolved, the handy acronym is retained. The twelve founding Member States are: Federal Republic of Germany, Belgium, Denmark, France, Greece, Italy, Norway, The Netherlands, United Kingdom, Sweden, Switzerland and Yugoslavia. Yugoslavia leaves in 1961. Austria and Spain join in 1959 and 1961 respectively - Spain leaves in 1969 but rejoins in 1983. Portugal joins in 1985, Finland and Poland in 1991, Hungary in 1992, the Czech and Slovak Republics in 1993 and Bulgaria in 1999, bringing the number of Member States to 20.
1955-02-24
First meeting of the CERN Council
1955-06-10
Felix Bloch, first Director-General of CERN, addresses the audience at the foundation stone ceremony.
1955-09,1960-04
Professor Cornelis Jan Bakker, Director-General of CERN from September 1955 to April 1960.
1957
CERN's first accelerator, a 600 MeV proton Synchro-Cyclotron begins operation. One of the first experimental achievements is the long-awaited observation of the decay of a pion into an electron and a neutrino.
1959
First operation of CERN's first major machine, the 28 GeV Proton Synchrotron (PS), for a time the world's highest energy accelerator.
1960-02-05
Inauguration of the PS : F. De Rose (left) and J. Adams
1961,1965
Professor V. Weisskopf, CERN Director General (1961-1965)
1961-07-27
J.B. Adams' departure ceremony (in front of the Main Building).
1962-05-24
Visit of Baudoin, King of Belgium
1962-09-20
Visit to CERN of Queen Frederica of Greece and of her daughter, Princess Irene
1963
First CERN bubble chamber pictures of neutrino interactions. Neutrino physics benefits greatly from fast ejection of protons from the synchrotron.
1965
Agreement with French authorities extends the CERN site into France. CERN's Council approves the construction of the Intersecting Storage Rings (ISR), the world's first proton collider, on this extension of the site in France, commissioned in 1971.
1967
CERN commissions the ISOLDE Isotope Separator On-line for the study of very short-lived nuclei. This world-class facility greatly extends the range of CERN's research. Under a special agreement between CERN and France, work begins on the Gargamelle heavy liquid bubble chamber. An agreement between CERN, France and Germany covers the construction of a 3.7 metre hydrogen bubble chamber equipped with the largest superconducting magnet in the world.
1968
The invention of multiwire proportional chambers and drift chambers revolutionizes the domain of electronic particle detectors. Georges Charpak is eventually awarded the Nobel Prize for Physics in 1992 for this work.
1971
Approval for the construction of a second laboratory, adjoining the existing site, with a 7-kilometre Super Proton Synchrotron (SPS) initially planned for an energy of 300 GeV. Although at first administratively separate, the two CERN laboratories are united in 1976.
1972
A four-ring 800 MeV Booster is completed to increase the injection energy of the PS. With the booster and a new Linac, which starts operation in 1978, the PS machine goes on to exceed its design intensity by more than a thousand times. CERN's unique interlinked system of accelerators, with the PS as the central hub, provides an unparalleled variety of particle beams and research possibilities.
1973
First important discoveries from the experiments at the ISR show that protons grow in size as their energy is increased; and particles emerging at wide angles reveal scattering between the constituent particles deep inside the protons. The Gargamelle bubble chamber in a neutrino beam at the PS provides one of CERN's greatest physics discoveries: neutrinos can interact with another particle and remain as neutrinos. This "neutral current interaction" breaks new ground, giving strong support to a theory which attempts to unite our understanding of the weak force - governing such phenomena as radioactivity - with the familiar electromagnetic force.
1976
Start of operation of the Super Proton Synchrotron (SPS). As with the ISR, machine construction is completed ahead of schedule and within the authorised budget. The accelerator performance improves rapidly so that the design intensity is exceeded and at the end of 1978, the peak energy is taken to 500 GeV.
1978
Experiments at CERN show how beam quality and intensity can be improved using the "stochastic cooling technique", proposed by Simon van der Meer at CERN in 1968. The possibility of accelerating and storing intense beams of particles opens the door to a bold new proposal to convert the SPS into a proton-antiproton collider, using a Antiproton Accumulator ring (AA) to apply stochastic cooling to antiprotons.
1979-06
CERN?s 25th anniversary.
1981
With the SPS adapted as a proton-antiproton collider and with two experiments, UA1 and UA2, to study the collisions, the first proton-antiproton collisions, at an energy of 270 GeV per beam, are seen in July 1981
1981
Council approves construction of the 27-kilometre Large Electron-Positron collider (LEP) ring, the largest scientific instrument ever constructed, for an initial operating energy of 50 GeV per beam.
1983
Historic discovery of the W-bosons (January) and the Z-boson (May) - the long-sought carriers of the weak nuclear force - thus confirming the 'electroweak' theory unifying weak and electromagnetic forces
1983-09-13
In September, the ground-breaking ceremony for LEP takes place with French and Swiss Presidents, Fran?ois Mitterrand and Pierre Aubert, as guests of honour.
1984
Carlo Rubbia and Simon van der Meer receive the Nobel Prize for Physics for their work which culminated in the discovery of the W boson and Z boson at CERN in 1983.
1989
In August, LEP starts up. In October, only two months after the first collisions in LEP, extremely accurate measurements of the Z particle show that the fundamental building blocks of matter consist of three, and only three, families of particles.
1989-11-13
On the 13th of November, LEP is officially inaugurated by Heads of State and Science Ministers.
1990
Tim Berners-Lee, working with Robert Cailliau at CERN, proposes a distributed information system, based on 'hypertext', a way of linking related pieces of information stored on computers. By hiding network addresses behind highlighted items on the screen, information can be linked between several computers. The name "World-Wide Web" is chosen.
1991-12
In December, CERN Council delegates agree unanimously that the Large Hadron Collider (LHC) in the LEP tunnel is the 'right machine' for the future.
1992
Georges Charpak of CERN is awarded the Nobel Prize for Physics for his invention of the multiwire proportional chamber. As well as revolutionizing the tracking of particles, this instrumentation is used in many medical applications.
1994
The years from 1989 are marked by the success of LEP experiments. The outstanding result is the precision measurement of the Z resonance parameters: from 1989 to 1993 the four LEP detectors - ALEPH, DELPHI, L3 and OPAL - reconstructed more than 10 million Z decays.
1994
CERN's 40th anniversary.
1994
Council approves construction of the LHC.
1995
In September 1995, an international team led by Walter Oelert succeeded in synthesizing atoms of antimatter from their constituent antiparticles. The creation of atoms of antimatter at CERN has opened the door to the systematic exploration of the antiworld.
1995
After making significant financial contributions to the LHC, Japan becomes a CERN Observer state.
1996
LEP energy is increased to allow production of pairs of W particles.
1997
After agreeing to provide significant financial contributions to the LHC, the USA becomes a CERN Observer State.
2000
Experiments at CERN present compelling evidence for the existence of a new state of matter 20 times denser than nuclear matter, in which quarks, instead of being bound up into more complex particles such as protons and neutrons, are able to roam freely. Such a state, the “quark-gluon plasma”, must have existed just a few microseconds after the Big Bang, before the formation of particles of matter.
2000-11
The LEP accelerator closes in November. During its eleven years of running, precision measurements made by the four LEP experiments confirmed the Standard Model to an extraordinary degree of precision.
2001-05
In May CERN announces its final results on direct Charge Parity (CP)-violation, the subtle effect that explains nature's preference for matter over antimatter. The results demonstrate beyond doubt that direct CP-violation exists.
2002
At CERN’s Antiproton Decelerator (AD) facility, the ATHENA collaboration announced the first controlled production of large quantities of antihydrogen atoms at low energies. The trapping technology had been pioneered by CERN’s ATRAP collaboration.
2003
The first component of the Palais de l’Equilibre arrives at CERN. Renamed the Globe of Innovation, this elegant wooden sphere was offered by Switzerland during the inauguration of the gigantic experimental cavern which is to house the ALAS detector in 2007.
2004
Scientists, heads of state, and representatives from many countries attended CERN's official 50th anniversary ceremony.
2005
The first of the 1232 superconducting dipole magnets is lowered into the LHC tunnel. This achievement marks the start of LHC installation.
CERN官方网站地址:http://public.web.cern.ch/Public/Welcome.html
|
|
|
|