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Topic: Cosmic ray spallation

	Spallation - Wikipedia, the free encyclopedia
		In planetary physics, spallation describes meteoritic impacts on a planetary surface and the effects of a stellar wind on a planetary atmosphere.
		Nuclear spallation occurs naturally in earth's atmosphere owing to the impacts of cosmic rays, and also on the surfaces of bodies in space such as meteorites and the moon.
		Evidence of cosmic ray spallation is evidence that the material in question has been exposed on the surface of the body of which it is part, and gives a means of measuring the length of time of exposure.
	en.wikipedia.org /wiki/Spallation (452 words)

	Solar cosmic ray - Wikipedia, the free encyclopedia
		High energy (Mev and above) cosmic rays come mainly from outside the solar system, while the particles in the solar case are energized near the Sun's surface by the action of magnetic fields.
		Later, it was found that the solar cosmic rays vary widely in their intensity and spectrum, increasing in strength after some solar events such as solar flares.
		Further, an increase in the intensity of solar cosmic rays is followed by a decrease in the galactic cosmic rays, called the Forbush decrease after their discoverer, the physicist Scott Forbush.
	en.wikipedia.org /wiki/Solar_cosmic_ray (381 words)

	access.html
		Since charged cosmic rays are deflected in the magnetic fields of the galaxy their arrival directions cannot generally be used to directly infer their origins.
		The average behavior of cosmic rays in our galaxy is known from measurements of the fraction of secondary nuclei and the surviving fraction of Be clock nuclei at low energies.
		A clearer understanding of cosmic rays at present and some idea of earlier epochs is needed to interpret galactic chemical evolution for the rarer light elements since these are predominantly produced by cosmic ray spallation.
	access.uchicago.edu (909 words)

	A Model of Galactic Cosmic Ray Propagation in the Interstellar Medium (Site not responding. Last check: 2007-10-31)
		Cosmic rays are fully ionized nuclei with energies that follow a power law spectrum.
		Their work covers many aspects of cosmic rays from measurements of their flux at the top of the atmosphere to computer models of their transit through the galaxy.
		Nuclear spallation in particular is difficult to incorporate since it depends on a multitude of energy dependent and channel specific cross sections.
	www-meg.phys.cmu.edu /~clark/cosmic_rays.html (878 words)

	3 Spallation of cosmic ray nuclei
		For the proposal as to the origin of cosmic rays it is a necessary ingredient, that these stars have fairly substantial magnetic fields (Thum and Morris 1999; Seemann and Biermann 1997).
		This then means that the local spectrum of primary cosmic rays is steeper by this much, and so all secondaries are produced with a spectrum which is steeper by this much from the start.
		The cosmic rays observed are the sum of the various CR-populations arising from explosions of stars in the three mass ranges considered here separately.
	aanda.u-strasbg.fr:2002 /papers/aa/full/2001/13/aah2380/node3.html (2384 words)

	CR&LiBeB -- The Formation of LiBeB
		The new theory suggests that cosmic ray particles are accelerated directly from the material ejected by the supernova.
		These clouds have a different cosmic ray flux than in our galaxy, and so, provided cosmic ray spallation is a producer of B, they should have a lower concentration of B than in other areas of that galaxy.
		Spallation reactions between cosmic rays and the interstellar medium accurately predict the local abundances of 6Li, 9Be, and 10B, but underproduce 7Li and 11B.
	www.macalester.edu /astronomy/people/mattc/formation.htm (620 words)

	The Cosmic Ray Isotope Spectrometer
		Galactic cosmic rays (GCRs) consist of energetic electrons and nuclei which are a direct sample of material from far beyond the solar system.
		Many of the isotopes that will be collected by CRIS provide other information about the mechanisms of cosmic ray propagation (the study of the processes cosmic rays undergo between the time they are produced and the time of their arrival in the heliosphere).
		In CRIS, energy information about the cosmic ray particles is collected by the 4 stacks of thick silicon detectors (shown as A-D), while the trajectory of the particles are determined by the Scintillating Optical Fiber Trajectory (SOFT) system.
	www.srl.caltech.edu /ACE/CRIS_SIS/cris.html (790 words)

	Implications of Early Galactic Be and B on Cosmic Ray Origin (Site not responding. Last check: 2007-10-31)
		A major source of all the light elements (Li, Be and B) is cosmic ray spallation, with Be almost certainly being produced solely by cosmic rays.
		If the cosmic rays were accelerated only out of the ISM, then their composition would evolve proportionally to that of the ISM, and the Be yield per supernova would increase with metallicity because of the increase in the C and O abundances of both the ISM and the cosmic rays.
		Thus, the acceleration of all the cosmic rays in the early Galaxy out of the ISM is inconsistent with the Be data, implying that the cosmic rays (or at least the C and O) are accelerated out of freshly synthesized matter before it mixes into the ISM.
	www.aas.org /publications/baas/v30n2/aas192/abs/S072003.html (367 words)

	SAHRA - Isotopes & Hydrology
		Be (half-life of 53 days) are continuously produced in the atmosphere by the high-energy proton component in cosmic radiation, causing spallation of atmospheric oxygen and nitrogen atoms.
		Be is also produced at the surface of the earth by direct cosmic ray irradiation of target atoms in geologic materials.
		Be is produced by spallation from the interaction of cosmic rays with oxygen and silicon and by negative mu-meson capture of
	www.sahra.arizona.edu /programs/isotopes/beryllium.html (855 words)

	Astron. Astrophys. 348, 211-221 (1999)
		Hence, observed beryllium abundances may be used to calibrate the yields of cosmic ray spallation.
		Li contribution from spallation by galactic high-energy cosmic rays is rather well constrained by the observed Be abundance, there are no comparable constraints on the contributions of the fusion reactions and of spallation by low energy cosmic rays.
		The cosmic ray flux was assumed to increase with decreasing metallicity.
	aa.springer.de /papers/9348001/2300211/sc5.htm (2335 words)

	[No title] (Site not responding. Last check: 2007-10-31)
		Above 7 MeV, the dominant remaining background is due to cosmic ray spallation events which motivitates improvements to the spallation cut.
		Beyond an improved spallation cut for events where the parent cosmic ray muon deposits less energy than a minimum ionizing muon and a tightened gamma ray cut against external events below 6.5 MeV, there are three new cuts:
		The dominating background below 6.5 MeV are external events (possibly gamma rays from the rocks surrounding the Super-Kamiokande tank), most of which are removed before events are written to tape by a cut on the fiducial volume utilizing on-line event vertex fitters.
	www.ps.uci.edu /~smy/sle.html (435 words)

	SPACE.com -- Astronomers Study Interstellar Lithium to Discover Origin of Light Elements
		Now, a team of astronomers in this weeks issue of Nature is reporting that many of the light elements in the Milky Way may have formed relatively recently, by a special kind of reaction called "spallation," in which cosmic rays split larger atomic elements into smaller ones.
		Cosmic spallation reactions occur when rays of "mainly protons traveling near the speed of light" break apart nuclei of larger elements like carbon that are present in interstellar space, explained Federman.
		Their most recent findings show that a significant amount of lithium continues to form today as a result of cosmic-ray spallation.
	www.space.com /scienceastronomy/astronomy/light_elements_000608.html (474 words)

	Astron. Astrophys. 337, 714-720 (1998)
		In the 70's and 80's the problem of Li, Be and B (hereafter LiBeB) nucleosynthesis has been considered essentially solved by Galactic Cosmic Ray (GCR) spallation (Meneguzzi, Audouze and Reeves 1971, Reeves 1994).
		First, as we noted above, if the cosmic rays are accelerated out of the ISM and interact in the ISM, the rising CNO/H abundance in the ISM leads to cumulative Be and B abundances which depend quadratically on the ISM metallicity, and thus is in disagreement with the observations.
		If the Be in the early Galaxy is indeed produced by particles whose acceleration is related to short-lived very massive stars, then the difference in the lifetimes of the progenitors of Be and Fe and the relative number of stars implied in each case, could also affect the evolution of Be/Fe.
	aa.springer.de /papers/8337003/2300714/sc1.htm (1405 words)

	USGS -- Isotope Tracers -- Resources
		Cosmogenic Be is produced in the atmosphere by cosmic ray spallation of oxygen and nitrogen (Arnold and Al-Salih, 1955; Peters, 1955, 1959).
		Because beryllium tends to exist in solution at pH levels less than about 5.5 (and most rainwater has a pH less than 5), it will enter into solution and be transported to the Earth's surface bia rainwater.
		Arnold, J. R., and Al-Salih, H. "Beryllium-7 produced by cosmic rays".
	wwwrcamnl.wr.usgs.gov /isoig/period/be_iig.html (643 words)

	Noble Gas Research (Site not responding. Last check: 2007-10-31)
		Sub-surface lunar material is initially shielded from cosmic ray spallation reactions but, once brought to the surface by an impact, production of stable krypton isotopes and radioactive Krypton-81 begins.
		With production rates monitored by radioactive Krypton-81 and the integrated effects determined by the stable spallation products, surface exposure ages can be obtained without prior knowledge of specific production rates.
		This method established the age of lunar craters North Ray and South Ray as 50 and 2 million years, respectively, and Tycho as 100 million years (Drozd, et al., 1974a).
	presolar.wustl.edu /work/noblegas.html (846 words)

	NASA Hubble Space Telescope Daily Report # 3647 \| SpaceRef Canada - Your Daily Source of Canadian Space News
		We propose to further investigate the origin of the light elements Li, Be, and B, by observing B in a group of galactic stars found to have similar O abundances but to differ significantly in their Be content.
		Contrary to Li, which is produced in the Big Bang and its abundance in halo stars constrains primordial nucleosynthesis and the baryonic density, Be and B are produced later by cosmic ray spallation as the galactic halo forms.
		The case for cosmic acceleration rests on the observation that SNe Ia at z = 0.5 are about 0.25 mag fainter than they would be in a universe without acceleration.
	www.spaceref.ca /news/viewsr.html?pid=13316 (6549 words)

	Atom Trap Trace Analysis @ ANL - Research (Site not responding. Last check: 2007-10-31)
		Kr atoms are selectively captured and detected with a laser-based atom trap.
		Kr is produced in the upper atmosphere by cosmic-ray induced spallation and neutron activation of stable krypton isotopes.
		It is the ideal tracer for dating ice and groundwater in the age range of 10
	www-mep.phy.anl.gov /atta/research.htm (471 words)

	Grad Student Knauth, David (Site not responding. Last check: 2007-10-31)
		Galactic cosmic ray (GCR) spallation and (-(fusion reactions account for the relative abundance of present day
		My observations lend support to the idea that Galactic cosmic ray spallation, associated with supernovae and the winds of massive stars in superbubbles surrounding OB associations, play an important role in the current production of lithium in our Galaxy.
		David is from upstate NY where he grew up in a family of 4 brothers and 6 sisters.
	www.physics.utoledo.edu /~webforce/_People/_Gradpages/gsKnaut.html (464 words)

	Guest Investigators' Abstracts
		The Cosmic Ray Path Length Distribution Expected from the Local Space and Time Dependent Supernova Distribution
		However, the standard leaky box model or other general Galactic models cannot provide the level of precision now required for analysing the ACE/CRIS measurements.
		We now need to investigate the local cosmic ray transport, spallation and reacceleration in the context of the local (~ kpc) interstellar medium and the local, relatively recent (
	www.srl.caltech.edu /ACE/GI/abstract_Higdon.html (109 words)

	Deep Ocean Exploration Institute - Educational Activities (Site not responding. Last check: 2007-10-31)
		She is using an isotope of beryllium (
		Be is generated from cosmic ray spallation reactions of oxygen and nitrogen in the atmosphere.
		Because it has a relatively short half-life, it is only found in significant concentrations in surficial oceanic sediments.
	www.whoi.edu /institutes/doei/research/education_grad.htm (957 words)

	Statement of research interests and plans
		In the future, I will continue to investigate the evolution of the light elements in the ISM.
		This combination of light elements, Li and B, on the same sight lines will place stringent constraints on current models of the production pathways of the light elements (i.e., whether GCR spallation or neutrino-induced spallation dominates light element production in OB associations).
		As a consequence of my research, I have become interested in light element evolution in metal poor stars, the winds and mass loss rates of AGB, RGB, and massive stars, and in the process of astration that either enhances or destroys interstellar material.
	fuse.pha.jhu.edu /~dknauth/research_interests.html (976 words)

	Energy Citations Database (ECD) - Energy and Energy-Related Bibliographic Citations
		Energy Citations Database (ECD) Document #6168244 - Solar wind gases, cosmic-ray spallation products and the irradiation history of Apollo II samples
		Availability information may be found in the Availability, Publisher, Research Organization, Resource Relation and/or Author (affiliation information) fields and/or via the "Full-text Availability" link.
		Solar wind gases, cosmic-ray spallation products and the irradiation history of Apollo II samples
	www.osti.gov /energycitations/product.biblio.jsp?osti_id=6168244 (139 words)

	QUATAVOLUTION SERIES (15 VOLUMES) -ALPHABETIC CONCORDANCE (Site not responding. Last check: 2007-10-31)
		Indeed, asserted the uniformitarians, the short span of time demanded by the catastrophists was absurdly incapable of bringing forth the great variety of nature;
		13536 COSMIC HERETICS: PART 3: - Chapter 11: CLOCKWORK -
		13705 COSMIC HERETICS: PART 3: - Chapter 11: CLOCKWORK -
	www.grazian-archive.com /quantavolution/QuantaHTML/alphabetic/c4145.htm (2062 words)

	[54.05] Boron in the Small Magellanic Cloud: A Novel Test of Light Element Formation (Site not responding. Last check: 2007-10-31)
		These results suggest that boron may scale quadratically with oxygen (B \alpha O
		) in the SMC, as is expected for a pure cosmic-ray spallation standard model.
		However, the results are also consistent with the scaling law B \alpha O
	www.aas.org /publications/baas/v33n4/aas199/508.htm (252 words)

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