Nobel prize in Physics

1992	GEORGES CHARPAK for his invention and development of particule detectors, in particular the multi_wire proportional chamber	Particle detectors Georges Charpak "invented" a method for electronically detecting particles. A charged particle tears electrons off gas molecules when passing through them. These electrons, once they have been collected, for example, by impinging metal wires, are transformed into electrical signals, which can be electronically processed. This breakthrough led to the development of fast and automatic data acquisition and analysis methods, using electronics and computer science. It has been the key to the design of modern nuclear and particle physics experiments. Electronic detectors derived from Georges Charpak's inventions are widely used at GANIL. They make it possible to reveal the trajectory of particles produced during nuclear reactions.
1983	WILLIAM A. FOWLER for his theoretical and experimental studies of the nuclear reactions of importance in the formation of the chemical elements in the universe	The nuclear reactions that form chemical elements in the Universe Chemical elements are synthesized within stars, from lighter elements that were created during the Big Bang. This nucleosynthesis involves numerous nuclear reactions, which must be quantified or modelled, in order to understand the origin of elements. Many reactions and nuclear properties, which are central to the understanding of nuclear synthesis, were studied at GANIL. With the advent of beams of exotic nuclei, in particular those rich in neutrons, it is now possible to carry out studies of astrophysical interest, because such nuclei, which are not or no longer found naturally on Earth, play an important role in the Universe, especially during nucleo-synthesis.
1975	AAGE BOHR, BEN MOTTELSON JAMES RAINWATER for the discovery of the connection between collective motion and particle motion in atomic nuclei and the development of the theory of the structure of the atomic nucleus based on this connection	The structure of nuclei The theoretical work of these three Nobel prize winners led to today's nuclear physics paradigm. However, recent studies of exotic nuclei, in particular those carried out at GANIL, challenge this unified vision of the nucleus, as many phenomena, such as halo nuclei, molecular nuclei, islands of deformation, magic-number disappearance, etc., had not been predicted before being observed.
1967	HANS ALBRECHT BETHE for his contributions to the theory of nuclear reactions, especially his discoveries concerning the energy production in stars	Nuclear reactions and the nuclear origin of stellar energy Bethe developed a theory of nuclear reactions. As a result, he was the first to understand that stars draw their energy from nuclear fusion. Nuclear reactions are one of the research topics at GANIL, and range from particle capture to fusion. Measurements, useful in the understanding of reaction cycles, which occur in stars, are carried out here.
1963	EUGENE P. WIGNER for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles MARIA GOEPPERT-MAYER J. HANS D. JENSEN for their discoveries concerning nuclear shell structure	Symmetry and layered structure of the atomic nucleus Certain numbers of protons or neutrons (2, 8, 20, 28, 50, 82 and 126) correspond to nuclei, which seem to have a strongly enhanced cohesion. This phenomenon, referred to as the "magic number", was interpreted by these three Nobel prize winners as being caused by a highly specific layout of nuclei. These would contain protons and neutrons arranged in layers. Each layer may only accommodate a maximum number of particles, so that, when one layer is full, additional particles must be placed into the next outer layer, that is one which is less strongly linked to the nucleus. The corresponding systems are thus more fragile. In return, nuclei with full layers are more robust than their neighbours. This layered structure is commonly found in nature. Ever since their discovery, magic nuclei have been one of the most commonly studied topics. Only recently, nuclei with magic numbers of protons and neutrons, such as tin-100 or nickel-48, which had been sought after for 50 years, have finally been synthesized at GANIL. More surprisingly, recent studies of exotic nuclei at the limit of nuclear cohesion seem to show that magic numbers do not have the generality predicted by Maria Goeppert-Mayer and her colleagues. Some appear, while others disappear. Understanding these mysteries is one of the goals of the studies carried out at GANIL on exotic nuclei, now using the SPIRAL facility and soon using the SPIRAL 2 facility.
1957	CHEN NING YANG TSUNG-DAO LEE for their penetrating investigation of the so-called parity laws which has led to important discoveries regarding the elementary particles	Parity violation in beta radioactivity These two physicists observed that beta radioactivity (the transformation of a neutron into a proton, along with the emission of an electron and a stranger particle called the anti-neutrino) was asymmetrical. Decay and its mirror image do not occur with the same probability. This asymmetry is used at GANIL to determine the orientation of nuclei before they decay. By studying the way they oscillate inside a strong magnetic field, this makes it possible, for example, to measure the magnetization of nuclei (their magnetic moment), since they behave like microscopic compasses.
1951	SIR JOHN DOUGLAS COCKCROFT ERNEST THOMAS SINTON WALTON for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles	Transmutation induced by accelerated particles The atomic nuclei accelerated by GANIL are used, on a daily basis, to transmute atomic nuclei. Collisions between target and projectile nuclei indeed modify their numbers of protons, or produce new nuclei. The atoms in the target beam are transformed into new elements. However, the amounts produced by GANIL are infinitesimal. If the facility had been used since it was put into operation, only to transmute the atoms of a lead target into gold, just a few milligrams of the latter would have been produced. The aim is in fact to synthesize a kind of matter which is far more noble than gold: exotic nuclei, matter which is not or no longer found on Earth in its natural state.
1949	HIDEKI YUKAWA for his prediction of the existence of mesons on the basis of theoretical work on nuclear forces	The theory of nuclear forces Still today, the forces exerted between nucleons within nuclei are not well understood. It is by observing the cohesion and structure of nuclei that nuclear forces are studied at GANIL.
1948	LORD PATRICK MAYNARD STUART BLACKETT for his development of the Wilson cloud chamber method, and his discoveries therewith in the fields of nuclear physics and cosmic radiation	The cloud chamber method: Nuclear physics and cosmic rays A charged particle rapidly passing through a vapour-saturated atmosphere causes condensation of a light mist. Just like the white trails left by aircraft flying at a high altitude, these mist tracks reveal the trajectories of particles. Today, cloud chambers are museum items. However, nuclear physics and the study of cosmic rays, initiated thanks to these "particle trackers", are still carried out using new technologies such as those developed by Georges Charpak.
1944 1943	ISIDOR ISAAC RABI for his resonance method for recording the magnetic properties of atomic nuclei OTTO STERN for his contribution to the development of the molecular ray method and his discovery of the magnetic moment of the proton	Magnetic moment of atomic nuclei Magnetic moment of protons Most particles are microscopic compasses. Thus, their state of magnetization, referred to as a magnetic moment, is one of their fundamental characteristics. This magnetization may be measured by studying the way particles behave within a strong magnetic field. The methods developed, and the measurements carried out for that purpose, earned these two authors the 1943 and 1944 Nobel prizes. Their measurement techniques are still used today, in particular at GANIL, to measure the still unknown magnetization of many synthesized nuclei (exotic nuclei).
1939	ERNEST ORLANDO LAWRENCE for the invention and development of the cyclotron and for results obtained with it, especially with regard to artificial radioactive elements	Cyclotrons and the synthesis of radioactive elements GANIL's activity is a direct continuation of the work of E.O. Lawrence. The GANIL uses 5 cyclotrons to create and accelerate radioactive nuclei (exotic nuclei).
1938	ENRICO FERMI for his demonstrations of the existence of new radioactive elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons	Nuclear reactions with neutrons and the synthesis of radioactive elements With the SPIRAL 2 project of transmuting Uranium into exotic nuclei, by means of neutron irradiation, GANIL will open up a new field of research into the properties of highly neutron-rich nuclei.
1935	SIR JAMES CHADWICK for the discovery of the neutron	The discovery of the neutron Experimental programs using GANIL’s facilities are designed to uncover multi-neutron systems such as the quadrineutron. This is one of the extreme cases in the study of the role played by neutrons in the structure of atomic nuclei (physics of exotic nuclei).
1927	CHARLES THOMSON REES WILSON for his method of making the paths of electrically charged particles visible by condensation of vapour	The cloud chamber A charged particle rapidly passing through a vapour-saturated atmosphere causes condensation of a light mist. Just like the white trails left by aircraft flying at a high altitude, these mist tracks reveal the trajectories of particles within the cloud chambers. After many years of good and loyal service, cloud chambers now are museum items. They have been replaced by electronic sensors, such as those developed by Georges Charpak.
1903	ANTOINE HENRI BECQUEREL in recognition of the extraordinary services he has rendered by his discovery of spontaneous radioactivity PIERRE CURIE and MARIE CURIE, née SKLODOWSKA in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel	The discovery of radioactivity In 2003, the simultaneous emission of 2 protons by a nucleus (2p radioactivity) was observed for the first time at GANIL.