Scientists at the Department of Physics of the University of Oulu have teamed up with scientists in France, Russia and Japan to propose a new experimental method for researching positively charged ions. The study, In the Finnish side carried out by postdoctoral researcher Saana-Maija Huttula and Professor Marko Huttula in Oulu, was published in Physical Review Letters on 12 March 2013. The study involved investigating the electronic structure of the argon ions using synchrotron radiation. The proposed theoretical simulations were done using methods developed by an electron spectroscopy research group based at the University of Oulu. The study was co-financed by the Academy of Finland.
Scientists propose alternative method for the study of ions
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Of grains and graphite: Simulating interstellar hydrogen formation
(Phys.org) —The process of molecular hydrogen formation is a key factor in astrophysics – specifically in the physics and chemistry of interstellar clouds. An electrically neutral atom containing a single positively charged proton and a single negatively charged electron bound to the nucleus by the Coulomb force, hydrogen is the lightest element and, in its monatomic (unbound single atom) form, known as H1, is the most abundant chemical substance, constituting roughly 75% of the universe's baryonic mass (that is, excluding so-called dark matter and dark energy). Hydrogen formed at an early stage of the universe during expansion, when the temperature dropped enough to reduce the rate of ionization processes and triggered the plasma-neutral phase transition of the primordial gas. This, in turn, decoupled matter from radiation and led to the appearance of the cosmic background radiation.
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Quantum dot commands light: A solid state ultrafast logic gate on a photon
(Phys.org) —If you could peek at the inner workings of a computer processor you would see billions of transistors switching back and forth between two states. In optical communications, information from the switches can be encoded onto light, which then travels long distances through glass fiber. Researchers at the Joint Quantum Institute and the Department of Electrical and Computer Engineering are working to harness the quantum nature of light and semiconductors to expand the capabilities of computers in remarkable ways.
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Green Pea galaxies could help astronomers understand early universe
The rare Green Pea galaxies discovered by the general public in 2007 could help confirm astronomers' understanding of reionization, a pivotal stage in the evolution of the early universe, say University of Michigan researchers.
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'Going negative' pays for nanotubes: Team finds possible keys to better nanofibers, films
(Phys.org) —A Rice University laboratory's cagey strategy turns negatively charged carbon nanotubes into liquid crystals that could enhance the creation of fibers and films.
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Five years of stereo imaging for NASA's TWINS
(Phys.org) —Surrounding Earth is a dynamic region called the magnetosphere. The region is governed by magnetic and electric forces, incoming energy and material from the sun, and a vast zoo of waves and processes unlike what is normally experienced in Earth-bound physics. Nestled inside this constantly changing magnetic bubble lies a donut of charged particles generally aligned with Earth's equator. Known as the ring current, its waxing and waning is a crucial part of the space weather surrounding our planet, able to induce magnetic fluctuations on the ground as well as to transmit disruptive surface charges onto spacecraft.
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New method to generate Laughlin states with atomic systems
In 1998, the Nobel Prize in Physics was conferred to the discovery of a new type of quantum fluid with fractional charge excitations, known as Laughlin state. The production of this quantum state, which explains the behaviour of electrons in two-dimensional metallic plaques when they are exposed to intense magnetic fields, has been one of the most popular research topics on ultracold and Bose-Einstein condensed atoms for one decade.
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Catalogs of distant, faint sources dark fields [rejected]
Over the past decade, the Hubble Space Telescope (HST) and other modern, giant telescopes have opened a new era in observational cosmology. By staring for long times at so-called "dark fields"—regions of the sky without much background emission from the solar system or the galaxy—astronomers have been able to detect very faint galaxies in the early universe, and to study their evolution from early stages to the present. More recently, deep multi-wavelength imaging surveys have been undertaken, and have revealed a complex interplay between galaxy mergers, star formation, and black holes over cosmic time, leading to new insights into the physical processes that drive galaxy formation and evolution.
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Writing the history of the 'Cosmic Dark Ages'
For millions of years after the Big Bang, there were no stars, or even galaxies to contain stars. During these "Cosmic Dark Ages," neutral hydrogen gas dominated the universe. When clouds of primordial hydrogen gas started to collapse from gravity, they became stars. The infant stars' nuclear reactions emitted ultraviolet radiation, stripping the surrounding hydrogen atoms of their lone electrons, making them ionized.
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Simulation sets atoms shivering
(Phys.org) —In "Harry Potter and the Sorcerer's Stone" (JK Rowling, 1997), Harry, Ron, and Hermione encounter a massive stone chessboard, one of many obstacles in their path. To advance, they must play, and win. Although the board and pieces are much larger than normal, and the circumstances a bit peculiar, one thing remains clear to them—this is a game of chess, with the same rules as always.
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Spinning atoms in light crystals
(Phys.org) —After more than 40 years of intense research, experimental physicists still seek to explore the rich behaviour of electrons confined to a two-dimensional crystalline structure exposed to large magnetic fields. Now a team of scientists around Prof. Immanuel Bloch (Chair for Experimental Physics at the Ludwig-Maximilians-Universität Munich and Director at MPQ) in collaboration with the theoretical physicist Dr. Belén Paredes (CSIC/UAM Madrid) developed a new experimental method to simulate these systems using a crystal made of neutral atoms and laser light. In such artificial quantum matter, the atoms could be exposed to a uniform effective magnetic field several thousand times stronger than in typical condensed matter systems.
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River of hydrogen flowing through space seen with Green Bank Telescope
(Phys.org) —Using the National Science Foundation's Robert C. Byrd Green Bank Telescope (GBT), astronomer D.J. Pisano from West Virginia University has discovered what could be a never-before-seen river of hydrogen flowing through space. This very faint, very tenuous filament of gas is streaming into the nearby galaxy NGC 6946 and may help explain how certain spiral galaxies keep up their steady pace of star formation.
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Quantum chaos in ultracold gas discovered
A team of University of Innsbruck researchers discovered that even simple systems, such as neutral atoms, can possess chaotic behavior, which can be revealed using the tools of quantum mechanics. The ground-breaking research, published in the journal Nature, opens up new avenues to observe the interaction between quantum particles.
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Ultra-cold atom transport made simple
Techniques for controlling ultra-cold atoms travelling in ring traps currently represent an important research area in physics. A new study gives a proof of principle, confirmed by numerical simulations, of the applicability to ultra-cold atoms of a very efficient and robust transport technique called spatial adiabatic passage (SAP). Yu Loiko from the University of Barcelona, Spain, and colleagues have, for the first time, applied SAP to inject, extract, and filter the velocity of neutral atoms from and into a ring trap. Such traps are key to improving our understanding of phenomena involving ultra-cold atoms, which are relevant to high-precision applications such as atom optics, quantum metrology, quantum computation, and quantum simulation.
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NASA-funded X-ray instrument settles interstellar debate
New findings from a NASA-funded instrument have resolved a decades-old puzzle about a fog of low-energy X-rays observed over the entire sky. Thanks to refurbished detectors first flown on a NASA sounding rocket in the 1970s, astronomers have now confirmed the long-held suspicion that much of this glow stems from a region of million-degree interstellar plasma known as the local hot bubble, or LHB.
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Research team creates a superfluid in a record-high magnetic field
MIT physicists have created a superfluid gas, the so-called Bose-Einstein condensate, for the first time in an extremely high magnetic field. The magnetic field is a synthetic magnetic field, generated using laser beams, and is 100 times stronger than that of the world's strongest magnets. Within this magnetic field, the researchers could keep a gas superfluid for a tenth of a second—just long enough for the team to observe it. The researchers report their results this week in the journal Nature Physics.
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Quantum computing advance locates neutral atoms
For any computer, being able to manipulate information is essential, but for quantum computing, singling out one data location without influencing any of the surrounding locations is difficult. Now, a team of Penn State physicists has a method for addressing individual neutral atoms without changing surrounding atoms.
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Astronomers detect the farthest galaxy yet with Keck telescope
A team of Caltech researchers that has spent years searching for the earliest objects in the universe now reports the detection of what may be the most distant galaxy ever found. In an article published August 28, 2015 in Astrophysical Journal Letters, Adi Zitrin, a NASA Hubble postdoctoral scholar in astronomy, and Richard Ellis—who recently retired after 15 years on the Caltech faculty and is now a professor of astrophysics at University College, London—describe evidence for a galaxy called EGS8p7 that is more than 13.2 billion years old. The universe itself is about 13.8 billion years old.
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Entering the strange world of ultra-cold chemistry
Researchers at the Georgia Institute of Technology have received a $900,000 grant from the U.S. Air Force Office of Scientific Research (AFOSR) to study the unusual chemical and physical properties of atoms and molecules at ultra-cold temperatures approaching absolute zero - the temperature at which all thermal activity stops.
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NASA plans twin sounding rocket launches over Norway this winter
This winter, two sounding rockets will launch through the aurora borealis over Norway to study how particles move in a region near the North Pole where Earth's magnetic field is directly connected to the solar wind. After the launch window opens on Nov. 27, 2015, the CAPER and RENU 2 rockets will have to wait for low winds and a daytime aurora before they can send their instrument payloads soaring through the Northern Lights.
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Scientists launch NASA rocket into auroral "speed bumps" above Norway
A team of scientists led by Marc Lessard of the University of New Hampshire Space Science Center launched an instrument-laden, four-stage sounding rocket from Norway's Andøya Space Center about 280 miles above Earth to study how particles move in a region near the North Pole where Earth's magnetic field is directly connected to the solar wind. The launch occurred Sunday, Dec. 13, at 2:34 a.m. EST.
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Measuring the magnetization of wandering spins
The swirling field of a magnet—rendered visible by a sprinkling of iron filings—emerges from the microscopic behavior of atoms and their electrons. In permanent magnets, neighboring atoms align and lock into place to create inseparable north and south poles. For other materials, magnetism can be induced by a field strong enough to coax atoms into alignment.
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Chandra observations of comets C/2012 S1 (ISON) and C/2011 L4 (PanSTARRS)
For millennia, people on Earth have watched comets in the sky. Many ancient cultures saw comets as the harbingers of doom, but today scientists know that comets are really frozen balls of dust, gas, and rock and may have been responsible for delivering water to planets like Earth billions of years ago.
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Giant hydrogen cloud spotted around the Triangulum Galaxy
(Phys.org)—While peering into the nearby Triangulum Galaxy known as M33, astronomers have detected what appears to be a giant cloud of hydrogen around it. According to research published online on May 5 on the arXiv pre-print server, the cloud is extremely large, even bigger than the galaxy itself. The discovery could improve our knowledge about the distribution of gas in and around galaxies.
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Scientists set traps for atoms with single-particle precision
Atoms, photons, and other quantum particles are often capricious and finicky by nature; very rarely at a standstill, they often collide with others of their kind. But if such particles can be individually corralled and controlled in large numbers, they may be harnessed as quantum bits, or qubits—tiny units of information whose state or orientation can be used to carry out calculations at rates significantly faster than today's semiconductor-based computer chips.
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Diagnostics for super-hot plasmas in fusion reactors
In the sun and other fusion plasmas, atoms of hydrogen and its isotopes are the fuel. Plasmas are gases that are so hot that electrons are knocked free of the atom, making the atoms electrically charged ions. The un-ionized atoms are called neutrals. On earth, accurately measuring neutral hydrogen concentration in plasmas could offer insights into future fusion experiments and impact the design of a future fusion-based energy source. To measure the hydrogen density, scientists need to use a calibrated measurement method. They used krypton gas, which absorbs two chunks of light energy at the same time (photons) and in turn emits another photon. The problem is the light emitted is not at the right wavelength for accurate hydrogen density measurements. In this study, scientists discovered that xenon atoms emit light at a wavelength that calibrates well with hydrogen and improves the measurements of neutral hydrogen density.
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Cassini, Voyager missions suggest new picture of Sun's interaction with galaxy
New data from NASA's Cassini mission, combined with measurements from the two Voyager spacecraft and NASA's Interstellar Boundary Explorer, or IBEX, suggests that our sun and planets are surrounded by a giant, rounded system of magnetic field from the sun—calling into question the alternate view of the solar magnetic fields trailing behind the sun in the shape of a long comet tail.
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Researchers perform first basic-physics simulation of the impact of recycled atoms on plasma turbulence
Turbulence, the violently unruly disturbance of plasma, can prevent plasma from growing hot enough to fuel fusion reactions. Long a puzzling concern of researchers has been the impact on turbulence of atoms recycled from the walls of tokamaks that confine the plasma. These atoms are neutral, meaning that they have no charge and are thus unaffected by the tokamak's magnetic field or plasma turbulence, unlike the electrons and ions—or atomic nuclei—in the plasma. Yet, experiments have suggested that the neutral atoms may be significantly enhancing the edge plasma turbulence, hence the theoretical interest in their effects.
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Properties of a massive galaxy 800 million years after the Big Bang
Searches for the most distant galaxies have now probed earlier than the first billion years in the history of the universe, early enough to start seeing the primary effects of the first stars: the reionization of neutral atoms.
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Ions in the spotlight
The results of a research group from the Institute of Physics at the University of Freiburg has been given a special place in Nature Photonics. An accompanying "News & Views" article in the print version of the science journal highlights the work of the team led by Alexander Lambrecht, Julian Schmidt, Dr. Leon Karpa and Prof. Dr. Tobias Schätz. In their article "Long lifetimes and effective isolation of ions in optical and electrostatic traps," the work group describes the method they used to prevent the previously unavoidable driven motion of trapped charged atoms.
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