Laboratory of the linear accelerator

The Laboratoire of the linear accelerator (in summary LAL) is a laboratory of the Université Paris XI associated, as a mixed unit of research, with the National institute of nuclear physics and physics of the particles of CNRS.

It is located on the campus of Orsay and occupies buildings 200 to 209, located in the valley at the south of the Yvette. The main part of the research activities of the Laboratory of the linear accelerator is centered on the Physique particles, but for a few years certain researchers have also directed themselves towards the Astrophysique and more particularly towards the Cosmologie.

It employs at January 1st, 2007: 111 researchers and 219 technical personnel divided into:

178 engineers, technicians, administrative established officials of CNRS,
21 technicians and engineers of nuclear physics, established officials of CNRS,
5 ITA of the University contractual Paris XI
16

The technical activities are distributed between various services:

accelerating
administrative
electronic
data-processing
mechanical infrastructure and purchases

History

Under the impulse of his director the professor Yves Rocard, the physics laboratory of the National university to Paris started in 1955 the construction of the Laboratory of the linear accelerator with Orsay to give to the scientists an accelerating of electrons.

Construction was completed in 1958 and the first experiments took place in 1959.

The personnel was composed of the researchers and the technical personnel of the National university too to narrow in his Parisian buildings. The first section of energy of 1,3 GeV (1 Giga électonvolt = 10⁹eV) was completed in 1962, as well as the ring of collision electron-positrons ACO (Ring of collision of Orsay) which was a circular accelerator where annihilation matter-antimatter was studied.

Of 1965 with 1968 construction of the last section which carried energy to 2,3 GeV. At that time, the Laboratory of the linear accelerator was one of the largest laboratories in the world in the field of the high-energy physics. But, little by little, from the more powerful tools to CERN or to DESY (Hamburg) will move away the physicists this tool from proximity.

In 1973 a new laboratory was created to use the beam of the accelerator, it acted of the Laboratory for the use of the electromagnetic radiation (in summary ERUL).

The year 1976 saw the startup of the ring of stokage and collision DCI for the Physique of the particles and as a source of X-rays for the Laboratory for the use of the electromagnetic radiation.

In 1985 the Laboratory of the linear accelerator and the Laboratory for the use of the electromagnetic radiation became two distinct entities. The Laboratory for the use of the electromagnetic radiation continuing to exploit the accelerator, ACO and DCI, while the personnel of the Laboratory of the linear accelerator took part more and more in large international experiments.

Starting from 1987 part of the activity of the Laboratory of the linear accelerator will be directed towards experiments of physics without accelerator and towards the Astrophysique.

In 2001 an civil society called Sun began again by developing them the experiments of the ERUL.

In December 2003, the Laboratory for the use of the electromagnetic radiation ceased the exploitation of its two synchrotrons (DCI and SuperACO) and of its accelerator of electrons, it (Linac).

In 2004 began the dismantling of the linear accelerator God has his heart! ) -->qui will last between five and ten years.

The technical activities and of research continue at the Laboratory of the linear accelerator while taking part in the various international experiments in which the teams are implied since many years.

During these fifty years of existence, eleven directors followed one another the head of the Laboratory of the linear accelerator:

1955 Foundation per M Yves Rocard
1956 - 1961 Mr. Henri Halban
1961 - 1969 Mr. André White-Lapierre
1969 - 1975 Mr. André Lagarrigue
from January to March 1975 Mr. Pierre Lehmann, following the sudden death of Andre Lagarrigue.
1975 - 1985 Mr. Jean Perez there Jorba
1985 - 1994 Mr. Michel Forceps
1994 - 1998 Mr. Jacques Lefrançois
1998 - 2002 Mr. François Richard
2002 August -31 2005 Mr. Bernard d' Almagne.
September 1st 2005…: Mr. Guy Wormser

In June 2006 the laboratory celebrated its fiftieth anniversary in the presence of scientific personalities.

First world

In 1962, the ring of collision AdA (anello di accumulazione) built with Frascati close to Rome, in Italy was transported in Orsay at the Laboratory of the linear accelerator to observe there collisions between electron S and Positron S. This transport gave place to some adventures, a customs officer at the border wanting " voir" the vacuum which was maintained inside the ring during transport. The collisions e⁺/e^- were observed there for the first time in the world in December 1963. This experiment opened the way for construction in the whole world of colliders electron-positrons.

Fields of research

The fields of research of the physicists of the Laboratory of the linear accelerator are the following:

Physical of the particles

Near the accelerating

With CERN with Geneva near LEP until in 2003 and near LHC to parir of 2007:

Experiments ALEPH and DELPHI : these two experiments were installed near the Collider electron Positron (LEP). Their construction lasted nearly ten years, the data acquisition too. That made it possible to seek in particular the Boson of Higgs , they are now finished.

Experiment Atlas : this experiment is an enormous international collaboration since, for ten years, 1.700 people (physicists and engineers) have been in this project. It will be installed near the LHC which is a collider proton-proton which will provide an energy of several TeV (Tera électronvolt=10¹² eV) and a rate of collision hundred times superior to that of the older colliders. The Atlas detector is composed of three subsystems. The LAL is implied in one of its units: the electromagnetic calorimeter.

Experiment Lhcb (Broad high-energy particle collider beauty experiment): As its name indicates it this experiment will be installed near LHC, she will study the violation of symmetry particle-antiparticle during the disintegration of Méson S “beautiful” (meson B). The ten billion particles generated daily at the point of interaction will allow the measurement of the various demonstrations of this dissymmetry. One will find perhaps there the explanation of the absence of antimatter in nature. It is also an international collaboration within which the LAL has in load electronics associated with the calorimeters.

Near the accelerator HERA with Hamburg: H1 experiment with DESY

With Fermilab with Chicago:

Experiment D0 : In June 2007, a new particle there was discovered: the Baryon xi-b whose mass is 6 times that of the Proton. It is composed of three quark different: a quark " beautiful, a quark " down" and a quark " étrange".

In Stanford the United States: Babar experiment

Physique of the Neutrino

Experiment NEMO : to be with the shelter of the cosmic radiation, detector NEMO 3 is installed in the underground laboratory of Modane (LSM), cave located perpendicular to the road tunnel in the Tunnel of Frejus approximately with equal distance of the Italy and the France. The goal of the experiment and to determine the nature of the Neutrino S. NEMO means Neutrino Ettore Majorana Observatory. With this experiment one seeks to answer two questions:

the is Neutrino a particle different or identical to its Antiparticule?
the does Neutrino have a mass? and, if so, why this mass is so weak?

The LAL was implied from a technical point of view in the mechanical engineering of the detector and the electronics of aquisisition of the data.

Expérience Operated (Oscillation project whith emulsion alignment apparatus): a beam of Neutrino S produced with CERN with Geneva will traverse 732 km through the earth's crust to arrive in the laboratory of Gran Sasso close to Aquila in Italy. There, two large detectors of a few thousands of tons each one await these neutrinos. It is an international collaboration of thirty laboratories.

Astrophysical

Experiment Planck launching of the probe in space in 2007:
EROS Experiment in Silla in the Andes cordillera to the Chile:
Argentinian Auger Experiment in Malargüe in :
Experiment Virgo in Cascina, beside Pisa in Italy: it is an interferometric detector of gravitational waves. The project was initiated in 1993 and the installation of the arms finished in 2002. The principle is that of a interferometer of Michelson but whose arms are 3 km long, which is enormous, and technically very difficult to realize, because one needs inside the arms a vacuum better than 10^-8mb. Eight physicists of the LAL work on this experiment as well as an engineering team for the study and the follow-up in manufacturing plant of the tubes forming the arms, and for the control of the source of light (a laser of power).

In project

ILC (International linear collider) in the past Future FLC for linear collider : it is a collider electron S Positron S of very high energies (1 TeV) and strong luminosity which could see the day after 2015, within the framework of a world collaboration. It could make progress research by measurements of precision: bosons of Higgs, Quark signal, particles supersymmetric, couplings of the Boson S Z and W

External bonds

Site of the LAL

A little more on the experiment Operated

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