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Touschek Effect
The Touschek effect describes the scattering and loss of charged particles in a storage ring. It was discovered by Bruno Touschek. It is determined by the average of the scattering rate around the ring : \frac = \frac\oint \frac(s) \, ds In fact, since the momentum acceptance for scattering with energy gain may be different from that for scattering with energy loss, the lifetime must be computed by taking into account the positive and negative momentum acceptances, i.e. : \frac = \frac\left(\frac + \frac\right) A formula for the local scattering rate, given by Bruck, is : \frac(s) = \fracF(\varepsilon_m). Here, r_0 is the classical particle radius, ''c'' is the speed of light, ''N'' is the number of particles, \gamma is the relativistic gamma factor, \delta_\mathrm is the momentum acceptance, \sigma_ are the RMS horizontal, vertical, and bunch sizes, respectively. : \varepsilon_m = \left(\frac\right)^2 where the function ''F'' is given by : F(\varepsilon)=\frac\in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Storage Ring
A storage ring is a type of circular particle accelerator in which a continuous or pulsed particle beam may be kept circulating typically for many hours. Storage of a particular particle depends upon the mass, momentum and usually the charge of the particle to be stored. Storage rings most commonly store electrons, positrons, or protons. Storage rings are most often used to store electrons that radiate synchrotron radiation. Over 50 facilities based on electron storage rings exist and are used for a variety of studies in chemistry and biology. Storage rings can also be used to produce polarized high-energy electron beams through the Sokolov-Ternov effect. The best-known application of storage rings is their use in particle accelerators and in particle colliders, where two counter-rotating beams of stored particles are brought into collision at discrete locations. The resulting subatomic interactions are then studied in a surrounding particle detector. Examples of such facilities ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruno Touschek
Bruno Touschek (3 February 1921 – 25 May 1978) was an Austrian physicist, a survivor of the Holocaust, and initiator of research on electron-positron colliders. Biography Touschek was born and attended school in Vienna. In 1937, he was not allowed to finish high school since his mother was Jewish. He passed the final year exam in a different school as an external pupil. Shortly after he started studying physics and mathematics at the University in Vienna, he again had to quit for racial reasons. Thanks to a couple of friends, he could keep on studying in Hamburg, where nobody knew of his origins. In order to make a living, he took up several jobs at the same time. During this period, he worked at the Studiengesellschaft für Elektronengeräte, a company affiliated to Philips, where "drift tubes" - the forerunners of the klystron - were being developed at that time. In 1943, he asked Rolf Widerøe to cooperate with him in building a betatron, critically studying an article o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classical Electron Radius
The classical electron radius is a combination of fundamental physical quantities that define a length scale for problems involving an electron interacting with electromagnetic radiation. It links the classical electrostatic self-interaction energy of a homogeneous charge distribution to the electron's relativistic mass–energy. According to modern understanding, the electron is a point particle with a point charge and no spatial extent. Nevertheless, it is useful to define a length that characterizes electron interactions in atomic-scale problems. The classical electron radius is given as :r_\text = \frac\frac = 2.817 940 3227(19) \times 10^ \text = 2.817 940 3227(19) \text , where e is the elementary charge, m_ is the electron mass, c is the speed of light, and \varepsilon_0 is the permittivity of free space. This numerical value is several times larger than the radius of the proton. In cgs units, the permittivity factor and \frac do not enter, but the classical electron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Of Light
The speed of light in vacuum, commonly denoted , is a universal physical constant that is important in many areas of physics. The speed of light is exactly equal to ). According to the special theory of relativity, is the upper limit for the speed at which conventional matter or energy (and thus any signal carrying information) can travel through space. All forms of electromagnetic radiation, including visible light, travel at the speed of light. For many practical purposes, light and other electromagnetic waves will appear to propagate instantaneously, but for long distances and very sensitive measurements, their finite speed has noticeable effects. Starlight viewed on Earth left the stars many years ago, allowing humans to study the history of the universe by viewing distant objects. When communicating with distant space probes, it can take minutes to hours for signals to travel from Earth to the spacecraft and vice versa. In computing, the speed of light fixes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorentz Factor
The Lorentz factor or Lorentz term is a quantity expressing how much the measurements of time, length, and other physical properties change for an object while that object is moving. The expression appears in several equations in special relativity, and it arises in derivations of the Lorentz transformations. The name originates from its earlier appearance in Lorentzian electrodynamics – named after the Dutch physicist Hendrik Lorentz. It is generally denoted (the Greek lowercase letter gamma). Sometimes (especially in discussion of superluminal motion) the factor is written as (Greek uppercase-gamma) rather than . Definition The Lorentz factor is defined as :\gamma = \frac = \frac = \frac , where: *''v'' is the relative velocity between inertial reference frames, *''c'' is the ''speed of light in a vacuum'', * is the ratio of ''v'' to ''c'', *''t'' is coordinate time, * is the proper time for an observer (measuring time intervals in the observer's own frame). This is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SOLEIL
SOLEIL ("Sun" in French) is a synchrotron facility near Paris, France. It performed its first acceleration of electrons on May 14, 2006. The name ''SOLEIL'' is a backronym for ''Source optimisée de lumière d’énergie intermédiaire du LURE'' (LURE optimised intermediary energy light source), LURE meaning ''Laboratoire pour l'utilisation du rayonnement électromagnétique''. The facility is run by a civil corporation held by the French National Centre for Scientific Research (CNRS) and the French Alternative Energies and Atomic Energy Commission (CEA), two French national research agencies. It is located in Saint-Aubin in the Essonne département, a south-western suburb of Paris, near Gif-sur-Yvette and Saclay, which host other facilities for nuclear and particle physics. The facility is an associate member of the University of Paris-Saclay. SOLEIL also hostIPANEMA, the European research platform on ancient materials (archaeology, palaeontology, past environments and cultu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
