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Topic: Proton emission


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  Proton emission - Wikipedia, the free encyclopedia
Proton emission (also known as proton radioactivity) is a type of radioactive decay in which a proton is ejected from a nucleus.
Proton emission can occur from high-lying excited states in a nucleus following a beta decay, in which case the process is known as beta-delayed proton emission, or can occur from the ground state (or a low-lying isomer) of very proton-rich nuclei, in which case the process is very similar to alpha decay.
The study of proton emission has aided the understanding of nuclear deformation, masses and structure, and is a wonderfully pure example of quantum tunneling.
en.wikipedia.org /wiki/Proton_emission   (294 words)

  
 Info and facts on 'Proton emission'   (Site not responding. Last check: 2007-10-13)
Proton emission (also known as proton radioactivity) is a type of radioactive decay in which a proton (A stable particle with positive charge equal to the negative charge of an electron) is ejected from a nucleus (A part of the cell containing DNA and RNA and responsible for growth and reproduction).
Proton emission is not seen in naturally-occurring isotopes; proton emitters can be produced via nuclear reaction ((physics) a process that alters the energy or structure or composition of atomic nuclei) s, usually utilising some kind of particle accelerator (A scientific instrument that increases the kinetic energy of charged particles).
The study of proton emission has aided the understanding of nuclear deformation, masses and structure, and is a wonderfully pure example of quantum tunneling (additional info and facts about quantum tunneling).
www.absoluteastronomy.com /encyclopedia/p/pr/proton_emission.htm   (246 words)

  
 Encyclopedia: Proton   (Site not responding. Last check: 2007-10-13)
The number of protons in the nucleus determines the chemical properties of the atom and which chemical element it is. A stylized representation of a lithium atom.
Protons are classified as baryons and are composed of two up quarks and one down quark, which are also held together by the strong nuclear force, mediated by gluons.
The antiproton (aka pbar) is the antiparticle of the proton.
www.nationmaster.com /encyclopedia/Proton   (1221 words)

  
 Encyclopedia: Proton emission   (Site not responding. Last check: 2007-10-13)
Neutron emission is a type of radioactive decay in which an atom contains excess neutrons and a neutron is simply ejected from the nucleus.
In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta plus particle (a positron) and a neutrino are emitted.
In beta minus decay, a neutron is converted to a proton via the weak nuclear force and a beta particle (an electron) and a neutrino are emitted.
www.nationmaster.com /encyclopedia/Proton-emission   (1318 words)

  
 Read about Proton emission at WorldVillage Encyclopedia. Research Proton emission and learn about Proton emission here!   (Site not responding. Last check: 2007-10-13)
Proton emission (also known as proton radioactivity) is a type of radioactive decay in which a
not beta-delayed) proton emission was observed from an isomer in
The study of proton emission has aided the understanding of nuclear deformation, masses and structure, and is a wonderfully pure example of
encyclopedia.worldvillage.com /s/b/Proton_emission   (239 words)

  
 Elemental Analysis of Renal Slices by Proton-induced X-ray Emission
The PIXE technique involves bombarding a sample with protons which eject inner-shell electrons of the elements in the sample; the subsequent decay of the induced electronic states results in the emission of X-rays whose energies are characteristic of the elements present in the sample and whose intensities are proportional to the concentrations of these elements.
The energies of the X-ray emissions are characteristic of the elements, and the intensities of the emissions are proportional to the concentrations of the elements in the sample.
The shape of the X-ray emission peaks in the spectrum is primarily Gaussian; the width of the peak is defined by the statistical distribution of the electrical pulses generated by X-ray photons in the Si(Li) detector and noise in the pulse-processing electronics.
ehis.niehs.nih.gov /members/1993/101-4/lowe-full.html   (4849 words)

  
 Glossary Item - Proton Emission   (Site not responding. Last check: 2007-10-13)
Proton emission is one process that unstable atoms can use to become more stable.
During proton emission, a proton is ejected from an atom's nucleus.
For example, after undergoing proton emission, an atom of nitrogen (with 7 protons) becomes an atom of carbon (with 6 protons).
education.jlab.org /glossary/proton_emission.html   (62 words)

  
 Beta decay - LearnThis.Info Enclyclopedia   (Site not responding. Last check: 2007-10-13)
In nuclear physics, beta decay (sometimes called neutron decay) is a type of radioactive decay in which a beta particle (an electron or a positron) is emitted.
decay, a proton is converted into a neutron, a positron and a neutrino:
If the proton and neutron are part of an atomic nucleus, these decay processes transmute one chemical element into another.
encyclopedia.learnthis.info /b/be/beta_decay.html   (231 words)

  
 Electron capture - RecipeFacts   (Site not responding. Last check: 2007-10-13)
Electron capture is a decay mode for chemical elements that will occur when there are too many protons in the nucleus of an atom, and there isn't enough energy to emit a positron; however, it continues to be a viable decay mode for radioactive elements that can decay by positron emission.
In this case, one of the orbital electrons is captured by a proton in the nucleus, forming a neutron and a neutrino.
Since the proton is changed to a neutron, the number of neutrons increases by 1, the number of protons decreases by 1, and the atomic mass remains unchanged.
www.recipeland.com /encyclopaedia/index.php/Electron_capture   (291 words)

  
 CERN Courier - Researchers observe two-prot - IOP Publishing - article
An atomic nucleus is an ensemble of nucleons - protons and neutrons.
The situation is similar for the very-light, even-Z, proton drip-line nuclei beryllium-6 and oxygen-12, studied during the 1990s (a drip line is the boundary beyond which nuclei decay by proton or neutron emission).
Although for these light nuclei, the intermediate one-proton daughter state may lie higher in energy than the two-proton emitting state, the sequential branch is always found open, because all the states involved are very broad, a consequence of the small Coulomb barrier for these light nuclei.
www.cerncourier.com /main/article/42/10/16   (1356 words)

  
 The Time Dependent Spectral Emission of Proton Bombarded Aerogels - Storming Media
The spectroscopic emission characteristics of proton bombarded aerogels 1.68 mm - 5.50 mm thick were studied, particularly the emission as a function of bombardment time.
It was discovered that the intensities of proton bombarded aerogel emissions depend on proton beam current, emitted wavelength, aerogel thickness, observation position inside of the gel, the time the aerogel is bombarded in a particular experiment, the time the aerogel had been bombarded prior to an experiment, and the time elapsed between experiments.
In general, proton bombarded aerogel emission decreases with time bombarded prior to an experiment and increases with the time elapsed between experiments.
www.stormingmedia.us /20/2024/A202453.html   (305 words)

  
 Elemental Analysis Incorporated - Proton Induced X-ray Emission - PIXE   (Site not responding. Last check: 2007-10-13)
Proton induced x-ray emission (PIXE) was first introduced at the Lund Institute of Technology in 1970.
It involves both the excitation of the atoms in the sample to produce characteristic X-rays and a means of detection, in order that their intensities may be identified and quantified.
When samples are bombarded with the beam, the protons interact with the electrons in the atoms of the sample, creating inner shell vacancies.
www.elementalanalysis.com /pixe   (303 words)

  
 Proton emission Info - Bored Net - Boredom   (Site not responding. Last check: 2007-10-13)
Proton emission Info - Bored Net - Boredom
Proton emission is a type of radioactive decay in which a proton is simply ejected from the nucleus.
Example isotopes which emit protons are Li-5 and N-11.
www.borednet.com /e/n/encyclopedia/p/pr/proton_emission.html   (45 words)

  
 Nuclear Proton Emission Predictions   (Site not responding. Last check: 2007-10-13)
Decay widths of nuclear proton emission from neutron-deficient odd-Z nuclei, 51=
Including the ss half-lives, calculated from the Gross theory of nuclear ss emission, reasonable agreement with the experimentally determined half-lives of 147-Tm and 151-Lu is achieved.
Predictions of possible new candidates for nuclear proton emission are given.
smallsystems.isn-oldenburg.de /publications/metadocs/ebs.nuclear.proton.html   (73 words)

  
 e-Prints Soton - IMF Control of Cusp Proton Emission Intensity and Dayside Convection: Implications for component and ...   (Site not responding. Last check: 2007-10-13)
We study a brightening of the Lyman-a emission in the cusp which occurred in response to a short-lived south-ward turning of the interplanetary magnetic field (IMF) during a period of strongly enhanced solar wind plasma concentration.
The cusp proton emission is detected using the SI-12 channel of the FUV imager on the IMAGE spacecraft.
Application of the derived propagation delays reveals that the intensity of the cusp emission varied systematically with the IMF clock angle, the relationship being particularly striking when the intensity is normalised to allow for the variation in the upstream solar wind proton concentration.
eprints.soton.ac.uk /9128   (468 words)

  
 Proton aurora [Oulu]   (Site not responding. Last check: 2007-10-13)
As typical for diffuse aurora, the proton precipitation is confined to be most often on the equatorward part of the oval.
When proton aurora occurs at the same local time sector as pulsating (electron) aurora, they are typically located northward from pulsations (e.g., Creutzberg et al., 1981).
The proton emission show no pulsation themselves (e.g., Eather, 1968; Miller and Zeitz, 1970), although in one case rocket measurements have shown weak modulation in the precipitating flux (Smith et al., 1980).
www.oulu.fi /~spaceweb/textbook/aurora/proton_aurora.html   (481 words)

  
 Cancer Cell International | Full text | Proton-Induced X-ray Emission (PIXE) Analysis and DNA-chain Break study in rat ...
Combined effect of vanadium and beta-carotene on rat liver DNA-chain break and Proton induced X-ray emission (PIXE) analysis was studied during a necrogenic dose (200 mg/kg of body weight) of Diethyl Nitrosamine (DENA) induced rat liver carcinogenesis.
The technique of PIXE (Proton induced X-ray emission), since its introduction has been successfully used by various groups throughout the world for trace elemental analysis of biomedical samples due to high sensitivity, multielemental capability and its non-destructive nature [3].
Proton induced X-ray emission analysis and assessment was made by author 2 SM and author 4 VV and author 5 MD. Author 6 NBK, a senior medical specialist has done the expert consultant for the pathological aspects of the work.
www.cancerci.com /content/5/1/16   (4088 words)

  
 Beta decay
In the case of electron emission, it is referred to as "beta minus"(β
In beta minus decay, a neutron is converted to a proton via the weak nuclear force and a beta particle (an electron) and an anti-neutrino are emitted.
In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta minus particle (a positron) and a neutrino are emitted.
news-server.org /b/be/beta_decay.html   (250 words)

  
 lallena
If, in addition, one chooses two-proton emission, MEC involving charged mesons do not contribute and the situation is, at least in principle, rather clean to investigate SRC effects.
The geometry of the two-proton emission process produced by electron scattering from nuclei is shown in Fig.
These kind of experiments are not the unique tool to extract the characteristics of the SRC correlations, but another procedure allowing, together with elastic, inclusive and one-nucleon emission experiments, to obtain the information we are looking for.
www.pv.infn.it /~2hconf/CDpavia/lallena/lallena.html   (1590 words)

  
 Environmental Studies   (Site not responding. Last check: 2007-10-13)
Conservation and management of fish stocks hinges on an accurate assessment of the life histories of fish, environmental factors affecting their behaviour and growth, and population stock structure.
Scanning proton microprobe can be used to establish the correspondence between Sr variation and optically resolved annuli in arctic charr otoliths.
Halden, N.M., Babaluk, J.A., Campbell, J.L., Teesdale, W.J. Scanning proton microprobe analysis of strontium in Arctic char : implications for the           interpretation of anadromy.
www.umanitoba.ca /geoscience/faculty/halden/enviro.html   (897 words)

  
 Brosius
We present theoretical calculations of temporal variations in the nonthermal redshifted Ly-alpha emission due to time-invariant proton beams injected into a stellar atmosphere during the impulsive phase of a flare.
The computations are performed for a power law spectrum of nonthermal proton energies injected into a model stellar atmosphere consisting of pure hydrogen in local thermodynamic equilibrium; beam-induced variations in temperature and particle densities at all depths and for all times are calculated with the Saha equation.
Based upon trends evident in the resulting emission, proton beam properties can be deduced from sufficiently high quality observations of the nonthermal redshifted Ly-alpha profile.
lheawww.gsfc.nasa.gov /users/ramaty/hessiabstracts/brosius.html   (237 words)

  
 Determination of the Chemical Composition of Martian Soil and Rocks:   (Site not responding. Last check: 2007-10-13)
The APXS needs for its operation in alpha, proton and X-ray modes a beam of alpha particles with high intensity and low energy spread: Intensity of the beam determines the total measurement time needed to obtain data with the necessary statistical accuracy; its energy spread directly determines the resolving capability of the alpha mode.
This signal remains unchanged until the circuit is reset by the microcontroler: The CMOS switch IH-5141 serves to disconnect input from output during analysis and to discharge the hold capacitor after analysis and during normal acquisition.
The approach taken is therefore an iterative one: In a first step data from the alpha and proton spectra are combined and the complex sample spectrum is decomposed into its individual components, using a least square fitting procedure with a library of standard spectra, and applying appropriate corrections for matrix effects.
astro.uchicago.edu /home/web/papers/economou/pathfinder/apxs.html   (9704 words)

  
 NMP Ion Beam Techniques
These qualities permit the in situ, non-destructive analysis and imaging of buried structures such as solid and fluid inclusions in minerals.
In low energy encounters between ions and atoms, the Coulomb repulsion between the charged ion and the nucleus of the atom prevent any close interaction between the ion and the nucleus.
Cl are determined using (p,p'gamma) reactions (PIGE) at proton energies from less than 2 MeV up to 3.5 MeV, suitable for simultaneous PIXE analysis of heavier elements.
www.nmp.csiro.au /ion-PIGE.html   (505 words)

  
 Decay mode - RecipeFacts   (Site not responding. Last check: 2007-10-13)
For radioactive decay (the decay of nuclides) the decay modes are:
decay (emission of a positron and a neutrino)
Typically one decay mode predominates for a particular nuclide.
www.recipeland.com /encyclopaedia/index.php/Decay_mode   (142 words)

  
 PROTON INDUCED X-RAY EMISSION (PIXE)   (Site not responding. Last check: 2007-10-13)
Proton induced X-ray emission (PIXE) technique [1, 2] relies on the analysis of the energy spectra of characteristic X-rays emitted from a sample bombarded with 1-3 MeV protons.
Since the proton limited range and the absorption of the X-ray photons in the sample material, only several micrometer thick outer layer is analysed and the total amount of the analysed material commonly varies from micrograms to miligrams.
In our PIXE facility the samples kept in a vacuum chamber are irradiated with 2.5 MeV proton beam and the characteristic X-ray spectra are registered with a Si(Li) semiconductor detector coupled to standard electronics and a PC based multichannel analyser.
omega.ujf.cas.cz /CFANR/pixe.html   (230 words)

  
 New isotope doubles up (May 2005) - News - PhysicsWeb
However, some nuclei that contain more protons than neutrons can also decay by emitting a proton -- a process that was first observed about 20 years ago.
Single-proton emission is observed in nuclei with an odd number of protons.
The iron-45 nuclei were created by firing a beam of nickel-58 ions onto a nickel or beryllium target.
physicsweb.org /articles/news/9/5/13/1   (409 words)

  
 Non-invasive MRI Technique Distinguishes Between Alzheimer's And Frontotemporal Dementia   (Site not responding. Last check: 2007-10-13)
In arterial spin labeling, a technique invented by researchers at the University of Pennsylvania, protons in arterial blood are magnetically aligned in the opposite direction from the rest of the protons in blood and brain tissue.
By measuring the intensity of the magnetic signal from these so-called inversely polarized protons when they reach the brain, researchers can calculate the amount of blood flow, and thus neuron activity, in a particular section of the brain.
Additional authors of the study are G.-H. Jahng, PhD, and Bruce Miller, MD, of UCSF; Sataru Hayasaka, PhD, of SFVAMC; Joel Kramer, MD, of UCSF; and Michael Weiner, MD, Director of the Magnetic Resonance Spectroscopy Unit at SFVAMC and professor of radiology, medicine, psychiatry, and neurology at UCSF.
www.sciencedaily.com /releases/2005/06/050618160238.htm   (1141 words)

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