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"Everything should be as simple as it is, but not simpler", Albert Einstein
Browsing All Posts filed under »NUCLEAR PHYSICS«
Τhe Shrinking Proton: Particle Is Smaller Than Thought
How many protons can dance on the head of a pin? The answer is nowhere near as straightforward as one may think — and it might offer new insights into one of the most well-tested theories in physics. An international team of scientists recently tried to find out the actual size of a proton, one […]
Feb, 11, 1939: Lise Meitner, ‘Our Madame Curie’
February 11, 2013
1939: Austrian-born physicist Lise Meitner publishes her discovery that atomic nuclei split during some uranium reactions. Her research will be overlooked by the Nobel committee when it awards a prize for the work. Meitner is a prominent example of a woman whose gender put her in the back seat when the top prize was given. […]
Carbon’s Hoyle state calculated at long last
January 3, 2013
By calculating the behaviour of protons and neutrons inside carbon nuclei from first principles, physicists in Germany and the US have identified the shape of carbon’s Hoyle state – which is an important step in the production of heavy elements inside stars. The researchers found the state to have an unusual bent structure, a finding […]
Causes of an ad 774–775 14C increase
November 29, 2012
Adrian L. Melott & Brian C. Thomas Atmospheric 14C production is a potential window into the energy of solar proton and other cosmic ray events. It was previously concluded that 14C results from AD 774–775 would require solar events that were orders of magnitude greater than known past events1. We find that the coronal mass ejection energy based on 14C […]
Particle Decays Point to an Arrow of Time
November 19, 2012
An experiment studying B meson decays makes a direct observation of time-reversal violation without relying on assumed relationships with other fundamental symmetries Time moves irrevocably in one direction. Things get old, decay, and fall apart, but they rarely ever reassemble and grow young. But at the particle level, time’s arrow is not so clearly defined. […]
Tritium as an Anthropic Probe
July 11, 2012
Andrew Gould (Ohio State) I show that if tritium were just 20 keV lighter relative to helium-3, then the current deuterium burning phase of pre-main-sequence stellar evolution would be replaced by deuterium+tritium burning. This phase would take place at the same temperature but would last a minimum of 4 times longer and a maximum of […]
How Many Neutrons and Protons Can Get Along?
June 28, 2012
Maybe 7,000 The finding could be put to use at a new facility opening in 2020 that might create new elements—that is, nuclei with more than 118 protons—in addition to new isotopes of the known elements Scientists have long wondered whether there is a limit to the number of protons and neutrons that can be […]
Plutonium signature captured after 50 years of trying
May 17, 2012
by Jacob Aron Devoted fans can wait hours on the red carpet to get their favourite movie star’s autograph, but that’s nothing compared to acquiring the signature of plutonium-239. After 50 years of trying, physicists have finally managed to analyse the fissile isotope using nuclear magnetic resonance (NMR) spectroscopy. This could potentially allow them to […]
Scientists propose a solution to a critical barrier to producing fusion
April 23, 2012
By John Greenwald Physicists have discovered a possible solution to a mystery that has long baffled researchers working to harness fusion. If confirmed by experiment, the finding could help scientists eliminate a major impediment to the development of fusion as a clean and abundant source of energy for producing electric power. An in-depth analysis by […]
New detector design improves gamma-ray measurements
April 6, 2012
In the pursuit of precision measurements, nothing is simple, even when the apparatus employed appears to be utterly uncomplicated. An instructive case in point is the new ionization chamber used to determine the U.S. primary standard for radiation dose in air — or, strictly speaking, air kerma, the amount of kinetic energy released per unit […]
Physicists discover evidence of rare hypernucleus
February 17, 2012
…. a component of strange matter Physicists in Italy have discovered the first evidence of a rare nucleus that doesn’t exist in nature and lives for just 10-10 seconds before decaying. It’s a type of hypernucleus that, like all nuclei, contains an assortment of neutrons and protons. But unlike ordinary nuclei, hypernuclei also contain at […]
Rutherford, Radioactivity, and the Atomic Nucleus
February 7, 2012
Helge Kragh Modern atomic and nuclear physics took its start in the early part of the twentieth century, to a large extent based upon experimental investigations of radioactive phenomena. Foremost among the pioneers of the new kind of physics was Ernest Rutherford, who made fundamental contributions to the structure of matter for more than three […]
Carbon Dating with Lasers
January 3, 2012
Phys. Rev. Lett. 107, 270802 (2011) [4 pages] Molecular Gas Sensing Below Parts Per Trillion: Radiocarbon-Dioxide Optical Detection I. Galli, S. Bartalini, S. Borri, P. Cancio*, D. Mazzotti, P. De Natale, and G. Giusfredi Istituto Nazionale di Ottica-CNR (INO-CNR) and European Laboratory for Non-Linear Spectroscopy (LENS) Via N. Carrara 1, I-50019 Sesto Fiorentino, Italy Radiocarbon (14C) concentrations at a 43 parts-per-quadrillion […]
‘Lethal’ radiation doses can be treated with drugs
December 4, 2011
MICE can survive a dose of radiation that should have killed them when given a double-drug therapy – even if they get the drug cocktail 24 hours after exposure. Radiation damages rapidly dividing cells in the intestine, allowing harmful bacteria to leak into the bloodstream. Eva Guinan at Harvard Medical School found that boosting levels of a […]
Unusual levels of radioactivity (iodine-131) in France
November 15, 2011
Read also: Radioactivity in Europe (update17-11-2011) Selon l’Agence hongroise de l’énergie nucléaire, les très faibles concentrations d’iode 131 mesurées dans l’atmosphère de différents pays d’Europe, dont la France, proviennent d’un Institut spécialisé dans la production de produits radioactifs à usage médical ou industriel. L’AIEA qui vient de publier l’information rappelle que ces rejets ne présentent […]
Radiation Measurements at the Campus of Fukushima Medical University
November 14, 2011
….. through the 2011 off the Pacific Coast of Tohoku Earthquake and Subsequent Nuclear Power Plant crisis Tsuneo Kobayashi An earthquake, Tohoku region Pacific Coast earthquake, occurred on the 11th of March, 2011, and subsequent Fukushima nuclear power plant accidents have been stirring natural radiation around the author’s office in Fukushima Medical University (FMU). FMU […]
On the interaction between two point electric charges
November 13, 2011
Alexei M. Frolov The general formula for the interaction potential between two point electric charges is derived. This analytical formula has the correct asymtotic behaviour at large distances between two interacting charges. The derivation of this formula is based on the closed analytical expression for the Uehling potential obtained earlier (A.M. Frolov and D.M. Wardlaw, […]
Radioactivity in Europe
November 12, 2011
The UN atomic agency said Friday “very low levels” of radioactive iodine-131 had been detected in the air in the Czech Republic and in other countries, but presented no risk to human health. The Czech nuclear safety office said the source of the contamination was “most probably” outside the Czech Republic, and that its information […]
Super-Powerful X-Ray Beam Will Probe the Center of the Earth
November 10, 2011
It is much easier to get to Mars than to get deep inside this planet, so for all our knowledge about things like earthquakes and the magnetic field, Earth’s interior is actually very poorly understood. To study how metals interact at the prodigious pressures within, scientists squeeze small particles in the lab and heat them […]
Marie Curie’s birth celebrated by Google doodle
November 7, 2011
Search engine honours Nobel prize-winning scientist who was renowned for her pioneering work on radioactivity The birth of Nobel prize-winning scientist Marie Curie has being marked by Google with a picture of her at her work bench on the search engine’s home page. The Polish-born physicist and chemist is renowned for her pioneering work on […]
Double Beta Decay
October 30, 2011
Steven R. Elliott At least one neutrino has a mass of about 50 meV or larger. However, the absolute mass scale for the neutrino remains unknown. Furthermore, the critical question: Is the neutrino its own antiparticle? is unanswered. Studies of double beta decay offer hope for determining the absolute mass scale. In particular, zero-neutrino double […]
Inside the fusion furnace of California’s star chamber
October 21, 2011
Tiny stars are being created by the world’s largest and most energetic lasers in the hope of tapping what could be a relatively clean energy source – nuclear fusion. The National Ignition Facility at Lawrence Livermore National Laboratory in California is at the forefront of efforts to harness the power of fusion. It is also […]
Oscillations in the decay law: a possible quantum mechanical explanation of the GSI anomaly?
October 12, 2011
Francesco Giacosa, Giuseppe Pagliara We study the deviations from the usual exponential decay law for quantum mechanical systems. We show that simple and physically motivated deviations from the Breit-Wigner energy distribution of the unstable state are sufficient to generate peculiar deviations from the exponential decay law. Denoting with p(t) the survival probability, its derivative h(t) […]
Time reversal: A simple particle could reveal new physics
October 11, 2011
A simple atomic nucleus could reveal properties associated with the mysterious phenomenon known as time reversal and lead to an explanation for one of the greatest mysteries of physics: the imbalance of matter and antimatter in the universe. The physics world was rocked recently by the news that a class of subatomic particles known as […]
Stellar Nucleosynthesis Nuclear Data Mining
October 6, 2011
Boris Pritychenko Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presently observed chemical elements and isotope abundances. It is also one of the corner stone hypotheses that provides basis for our understanding of Nature. Its theoretical predictions are often verified through the astrophysical observation and comparison of calculated isotopic abundances with […]
UK joins laser nuclear fusion project
September 9, 2011
By Jason Palmer The UK has formally joined forces with a US laser lab in a bid to develop clean energy from nuclear fusion. Unlike fission plants, the process uses lasers to compress atomic nuclei until they join, releasing energy. The National Ignition Facility (Nif) in the US is drawing closer to producing a surplus […]
Νuclear cars
September 7, 2011
Thorium lasers: The thoroughly plausible idea for nuclear cars Some proposed technological innovations seem so far out that they are easy to reject out of hand. But sometimes, a new idea has a kernel of plausibility. Such is the case with a new project to develop a thorium laser power generation system that its creator […]
Teaching Radioactivity: Ions produced by radiation carry a current
August 31, 2011
This demonstartes that a radioactive source produces radiation that will ionise the air. The conducting air completes a circuit to charge an electroscope. Use the circuit to show the ionising effect of the radiation and present it as a means of detecting ionising radiation.
Samuel A. Goudsmit Papers available online
August 20, 2011
The Niels Bohr Library and Archives is pleased to announce that it has digitized the complete Samuel A. Goudsmit Papers (1921–1979, 30 linear feet, approximately 67,000 images). The Goudsmit Papers are a major international collection of correspondence, research notebooks, reports, World War II science documents, and other material of Goudsmit, a Dutch physicist who spent most of […]
Fukushima Radiation In California
August 17, 2011
We all remember the earthquake and ensuing tsunami that hit Japan (see figure 1) and caused major troubles in the Fukushima nuclear power plant, which was severely damaged. Problems with containing radiation followed, leading to the pumping of huge amounts of seawater into the reactor, in an attempt to cool it down. The question on […]
Star power: Small fusion start-ups aim for break-even
August 16, 2011
Nuclear fusion will cost a fortune – or will it? A new wave of upstart companies think they’ve found cheaper, quicker ways to build a second sun A VAST earth platform looms into view above the treetops of Cadarache in France’s sultry south-east. It measures 1 kilometre long by 400 metres wide, and excavators dotted […]
Neutrons Become Cubes Inside Neutron Stars
August 11, 2011
Intense pressure can force neutrons into cubes rather than spheres, say physicists Inside atomic nuclei, protons and neutrons fill space with a packing density of 0.74, meaning that only 26 percent of the volume of the nucleus in is empty. That’s pretty efficient packing. Neutrons achieve a similar density inside neutron stars, where the force […]
100-year-old model of the atom to be celebrated
August 5, 2011
A series of public lectures taking place next week will look at the legacy of Rutherford’s discovery and give citizens of Manchester the chance to join nuclear physicists from around the world in celebrating his 100-year-old model of the atom. The lectures will explain how fundamental physics has moved on from Rutherford’s discovery to the […]
Antiproton Radiation Belt Discovered Around Earth
August 4, 2011
Physicists have long suspected that antiprotons must become trapped in a belt around Earth. Now they’ve found it The Earth is constantly bombarded by high energy particles called cosmic rays. These are generated by the Sun and by other sources further afield. (The source of the highest energy cosmic rays is still a mystery). The […]
Antiprotons pass latest symmetry test
July 28, 2011
By Hamish Johnston For something that is rare in the universe, antimatter has certainly been in the news a lot lately. The latest breakthrough involves antiprotonic helium and is published in Nature today. This exotic “atom” is formed when one electron in a helium atom is replaced with an antiproton, which is negatively charged. For two decades […]
New laser technique makes cold positronium
July 25, 2011
Physicists in the US have shown that positronium – a short-lived bound state of a positron and an electron – can be produced by firing a laser beam onto a silicon surface. Because the technique is highly controllable and operates over a wide range of temperatures, it could prove extremely useful in low-temperature experiments designed […]
Inside the Innards of a Nuclear Reactor: Tiny Robots May Monitor Underground Pipes for Radioactive Leaks
July 23, 2011
As workers continue to grapple with the damaged Fukushima Daiichi nuclear powerplant in Japan, the crisis has shone a spotlight on nuclear reactors around the world. In June, The Associated Press released results from a yearlong investigation, revealing evidence of “unrelenting wear” in many of the oldest-running facilities in the United States. That study found […]
Best ever measurement of Earth’s radioactivity
July 19, 2011
Ghostly subatomic particles streaming from Earth’s interior have enabled the most precise measurement yet of our planet’s radioactivity. These particles, called antineutrinos, suggest that about half of Earth’s heat comes from the radioactive decay of uranium and thorium – and give clues to the location of geological stashes of these elements. Heat is needed to […]
Quantum quirk makes carbon dating possible
July 15, 2011
RADIOCARBON dating relies on carbon-14 to decode an object’s age, but the isotope has steadfastly refused to divulge the key to its own unusual longevity. The answer, it seems, lies in the bizarre rules of quantum physics. Carbon-14 decays with a half-life of 5730 years, so it is often used to date objects up to about 50,000 […]
My favourite particle: the neutron
July 15, 2011
A guest post by Jim Grozier on particles you can store in a beryllium bottle without a lid on I’m not really one for favourites, but I do have a soft spot for the neutron; and after all, it would be a shame to leave it out, wouldn’t it? There are two things I really […]
Periodic Table gets new elements (but no one knows what they do)
June 8, 2011
They have existed for less than a second each, but two new elements have been added to the Periodic Table Evidence for the existence of the two elements, the heaviest yet to be included, has been mounting for several years. A number of research teams had claimed to have produced the heavy elements by smashing […]
Antimatter in a bottle: Scientists stabilise the staple of science fiction disasters for 16 whole minutes
June 6, 2011
Scientists have successfully stored anti-matter – the mysterious substance used as a weapon of mass destruction in the novels of Da Vinci Code author Dan Brown. Researchers at CERN, home of the Large Hadron Collider, had bottled antimatter back in 2010, keeping hold of the atoms for a fraction of a second. But CERN have now […]
New Synchrotron Technique Could See Hidden Building Blocks of Life
May 30, 2011
Scientists from Finland and France have developed a new synchrotron X-ray technique that may revolutionize the chemical analysis of rare materials like meteoric rock samples or fossils. The results have been published on 29 May 2011 in Nature Materials as an advance online publication Life, as we know it, is based on the chemistry of […]
NMR spectroscopy without the ‘M’
May 29, 2011
Nuclear magnetic resonance (NMR) spectroscopy is perhaps the most useful technique in the organic chemist’s toolkit. But conventional NMR requires the sample to be placed in a very high magnetic field, which needs large and expensive superconducting magnets cooled by liquid helium. Now, an interdisciplinary group in the US has managed to accomplish NMR spectroscopy […]
Chain Reactions Reignited At Fukushima After Tsunami
May 9, 2011
Radioactive byproducts indicate that nuclear chain reactions must have been burning at the damaged nuclear reactors long after the disaster unfolded Nuclear reactors produce radioactive by-products that decay at different rates. One common by-product is iodine-131 which has a half life of about 8 days while another is cesium-137 with a half life of about […]
Inside Japanese nuclear plant
May 4, 2011
April 14, 2013
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