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ATRAP
__FORCETOC__ The Antihydrogen Trap (ATRAP) collaboration at the Antiproton Decelerator facility at CERN, Geneva, is responsible for the AD-2 experiment. It is a continuation of the TRAP collaboration, which started taking data for the PS196 experiment in 1985. The TRAP experiment (PS196) pioneered cold antiprotons, cold positrons, and first made the ingredients of cold antihydrogen to interact. Later ATRAP members pioneered accurate hydrogen spectroscopy and observed the first hot antihydrogen atoms. Experimental setup ATRAP is a collaboration between physicists around the world with the goal of creating and experimenting with antihydrogen. ATRAP accumulates positrons emitted from a radioactive 22Na source. There are two effective ways to slow down the fast positrons by inelastic processes. The ATRAP collaboration initially chose a different method to ATHENA (AD-1). Slowing down and trapping positron The positrons which were emitted by the 22Na were first slowed down wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atrap2
__FORCETOC__ The Antihydrogen Trap (ATRAP) collaboration at the Antiproton Decelerator facility at CERN, Geneva, is responsible for the AD-2 experiment. It is a continuation of the TRAP experiment, TRAP collaboration, which started taking data for the PS196 experiment in 1985. The TRAP experiment (PS196) pioneered cold antiprotons, cold positrons, and first made the ingredients of cold antihydrogen to interact. Later ATRAP members pioneered accurate hydrogen spectroscopy and observed the first hot antihydrogen atoms. Experimental setup ATRAP is a collaboration between physicists around the world with the goal of creating and experimenting with antihydrogen. ATRAP accumulates positrons emitted from a radioactive Sodium, 22Na source. There are two effective ways to slow down the fast positrons by inelastic processes. The ATRAP collaboration initially chose a different method to ATHENA experiment, ATHENA (AD-1). Slowing down and trapping positron The positrons which were emitted ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antiproton Decelerator
The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory near Geneva. It was built from the Antiproton Collector (AC) to be a successor to the Low Energy Antiproton Ring (LEAR) and started operation in the year 2000. Antiprotons are created by impinging a proton beam from the Proton Synchrotron on a metal target. The AD decelerates the resultant antiprotons to an energy of 5.3 MeV, which are then ejected to one of several connected experiments. The major goals of experiments at AD are to spectroscopically observe the antihydrogen and to study the effects of gravity on antimatter. Though each experiment at AD has varied aims ranging from testing antimatter for cancer therapy to CPT symmetry and antigravity research. History From 1982 to 1996, CERN operated the Low Energy Antiproton Ring (LEAR), through which several experiments with slow-moving antiprotons were carried out. During the end stages of LEAR, the physics community involved in those antimatt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antihydrogen
Antihydrogen () is the antimatter counterpart of hydrogen. Whereas the common hydrogen atom is composed of an electron and proton, the antihydrogen atom is made up of a positron and antiproton. Scientists hope that studying antihydrogen may shed light on the question of why there is more matter than antimatter in the observable universe, known as the baryon asymmetry problem. Antihydrogen is produced artificially in particle accelerators. Experimental history Accelerators first detected hot antihydrogen in the 1990s. ATHENA studied cold in 2002. It was first trapped by the Antihydrogen Laser Physics Apparatus (ALPHA Collaboration, ALPHA) team at CERN in 2010, who then measured the structure and other important properties. ALPHA, AEGIS, and GBAR plan to further cool and study atoms. 1s–2s transition measurement In 2016, the ALPHA experiment measured the atomic electron transition between the two lowest energy levels of antihydrogen, 1s–2s. The results, which are identical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TRAP Experiment
The TRAP experiment, also known as PS196, operated at the Proton Synchrotron facility of the Low Energy Antiproton Ring (LEAR) at CERN, Geneva, from 1985 to 1996. Its main goal was to compare the mass of an antiproton and a proton by trapping these particles in the penning traps. The TRAP collaboration also measured and compared the charge-to-mass ratios of antiproton and proton. Although the data-taking period ended in 1996, the analysis of datasets continued until 2006. __FORCETOC__ Experimental setup In the first step, the antiprotons obtained from the LEAR entered the TRAP apparatus. They were immediately slowed down using the degrader foils. The first penning trap was used to the accumulate the entering antiprotons. While the second trap, located very close to the first one was used for the precision measurements. The number of antiprotons entering the degrader foils were counted using a scintillating device. A number of antiprotons coming out from the degrader foils we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Particle Experiments
In the physical sciences, a particle (or corpuscule in older texts) is a small localized object which can be described by several physical or chemical properties, such as volume, density, or mass. They vary greatly in size or quantity, from subatomic particles like the electron, to microscopic particles like atoms and molecules, to macroscopic particles like powders and other granular materials. Particles can also be used to create scientific models of even larger objects depending on their density, such as humans moving in a crowd or celestial bodies in motion. The term ''particle'' is rather general in meaning, and is refined as needed by various scientific fields. Anything that is composed of particles may be referred to as being particulate. However, the noun '' particulate'' is most frequently used to refer to pollutants in the Earth's atmosphere, which are a suspension of unconnected particles, rather than a connected particle aggregation. Conceptual properties Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
INSPIRE-HEP
INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1970s. History SPIRES was (in addition to the CERN Document Server (CDS), arXiv and parts of Astrophysics Data System) one of the main Particle Information Resources. A survey conducted in 2007 found that SPIRES database users wanted the portal to provide more services than the, at that time, already 30-year-old system could provide. On the second annual Summit of Information Specialists in Particle Physics and Astrophysics in May 2008, the physics laboratories CERN, DESY, SLAC and Fermilab therefore announced that they would work together to create a new Scientific Information System for high energy physics called INSPIRE. It interacts with other HEP service providers like arXiv.org, Particle Data Group, NASA's Astrophysics Data Syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forschungszentrum Jülich
Forschungszentrum Jülich (FZJ here for short) is a national research institution that pursues interdisciplinary research in the fields of energy, information, and bioeconomy. It operates research infrastructures with a focus on supercomputers. Current research priorities include the structural change in the Rhineland lignite-mining region, hydrogen, and quantum technologies. As a member of the Helmholtz Association with roughly 6,800 employees in ten institutes and 80 subinstitutes, Jülich is one of the largest research institutions in Europe. Forschungszentrum Jülich’s headquarters are located between the cities of Aachen, Cologne, and Düsseldorf on the outskirts of the North Rhine-Westphalian town of Jülich. FZJ has 15 branch offices in Germany and abroad, including eight sites at European and international neutron and synchrotron radiation sources, two joint institutes with the University of Münster, Friedrich-Alexander Universität Erlangen-Nürnberg (FAU), and He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Mainz
The Johannes Gutenberg University Mainz (german: Johannes Gutenberg-Universität Mainz) is a public research university in Mainz, Rhineland Palatinate, Germany, named after the printer Johannes Gutenberg since 1946. With approximately 32,000 students (2018) in about 100 schools and clinics, it is among the largest universities in Germany. Starting on 1 January 2005 the university was reorganized into 11 faculties of study. The university is a member of the German U15, a coalition of fifteen major research-intensive and leading medical universities in Germany. The Johannes Gutenberg University is considered one of the most prestigious universities in Germany. The university is part of the IT-Cluster Rhine-Main-Neckar. The Johannes Gutenberg University Mainz, the Goethe University Frankfurt and the Technische Universität Darmstadt together form the Rhine-Main-Universities (RMU). History The first University of Mainz goes back to the Archbishop of Mainz, Prince-elector and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
York University
York University (french: Université York), also known as YorkU or simply YU, is a public university, public research university in Toronto, Ontario, Canada. It is Canada's fourth-largest university, and it has approximately 55,700 students, 7,000 faculty and staff, and over 325,000 alumni worldwide. It has 11 faculties, including the Faculty of Liberal Arts and Professional Studies, Faculty of Science, Lassonde School of Engineering, Schulich School of Business, Osgoode Hall Law School, Glendon College, Faculty of Education, Faculty of Health, Faculty of Environmental and Urban Change, Faculty of Graduate Studies, School of the Arts, Media, Performance and Design, and 28 research centres. York University was established in 1959 as a non-denominational institution by the ''York University Act'', which received royal assent in the Legislative Assembly of Ontario on 26 March of that year. Its first class was held in September 1960 in Falconer Hall on the University of Toronto campu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harvard University
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher learning in the United States and one of the most prestigious and highly ranked universities in the world. The university is composed of ten academic faculties plus Harvard Radcliffe Institute. The Faculty of Arts and Sciences offers study in a wide range of undergraduate and graduate academic disciplines, and other faculties offer only graduate degrees, including professional degrees. Harvard has three main campuses: the Cambridge campus centered on Harvard Yard; an adjoining campus immediately across Charles River in the Allston neighborhood of Boston; and the medical campus in Boston's Longwood Medical Area. Harvard's endowment is valued at $50.9 billion, making it the wealthiest academic institution in the world. Endow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO) In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quadrupole
A quadrupole or quadrapole is one of a sequence of configurations of things like electric charge or current, or gravitational mass that can exist in ideal form, but it is usually just part of a multipole expansion of a more complex structure reflecting various orders of complexity. Mathematical definition The quadrupole moment tensor ''Q'' is a rank-two tensor—3×3 matrix. There are several definitions, but it is normally stated in the traceless form (i.e. Q_ + Q_ + Q_ = 0). The quadrupole moment tensor has thus nine components, but because of transposition symmetry and zero-trace property, in this form only five of these are independent. For a discrete system of \ell point charges or masses in the case of a gravitational quadrupole, each with charge q_\ell, or mass m_\ell, and position \vec_\ell = \left(r_, r_, r_\right) relative to the coordinate system origin, the components of the ''Q'' matrix are defined by: : Q_ = \sum_\ell q_\ell\left(3r_ r_ - \left\, \vec_\ell \rig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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