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	Muonium - Wikipedia, the free encyclopedia
		A muonium particle is an exotic atom made up of a positive muon and an electron, and is given the symbol Mu or μ
		Due to the mass difference between the muon and the electron, muonium is more similar to atomic hydrogen than positronium.
		It's Bohr radius and ionization energy are within 0.5% of H, D. and T. Physical chemists consider muonium to be an isotope of hydrogen and though it is short-lived, use it in a modified form of electron spin resonance (which is not surprisingly called muon spin resonance) spectroscopy for the analysis of chemical transformations.
	en.wikipedia.org /wiki/Muonium (239 words)

	4.4 Delayed Muonium Formation
		Muonium formation involving electrons originating in the radiolysis track depends on the transport of these electrons to the muon under the influence of their mutual Coulomb attraction and any external fields.
		The conversion of coherent muon polarization to partially dephased muonium polarization results in a measureable loss of asymmetry whenever the formation time is comparable to or larger than the muonium precession period.
		After all muonium formation is complete, the resulting muonium precesses at the same frequency and undergoes spin relaxation according to the same function as the prompt muonium fraction.
	musr.physics.ubc.ca /theses/Morris/node26.html (808 words)

	4.2.2 Muonium in Neon (Site not responding. Last check: 2007-08-20)
		Muonium was found to be abundant in solid Ne as a long-lived species, amounting to 80% of the total asymmetry.
		The complete absence of muonium in Ne gas was once considered a key argument that the crucial factor to muonium formation was the relative size of the ionization potential of the stopping medium compared to that of muonium.
		Formation of muonium while the muon is still energetic ought to be unaffected by the phase of the material, at least in the condensed phases.
	musr.physics.ubc.ca /theses/Morris/node22.html (283 words)

	[No title]
		In track-end competition between muonium formation and cation-electron recombination, the muon is found to react with electrons from a significant part of the track end, corresponding to an energy attenuation of several tens of keV and a length of several microns.
		Delayed muonium formation leads to a much smaller amplitude of the muonium asymmetry than for prompt muonium formation during slowing down of the muon, and in this way may account for the missing polarization in transverse magnetic field experiments.
		If reaction of muons with electrons from their radiolysis tracks contributes to the experimentally observed muonium yield, the muon must thermalize between 60 and 150 nm from the last ionization of the track to reproduce the amplitudes of the muon and muonium asymmetries.
	allen.rad.nd.edu /new_pubs/ndrl4129.doc (216 words)

	4.2.1 Muonium in Solid Nitrogen
		phase a large muonium signal and a smaller diamagnetic muon signal together account for virtually all the muon polarization.
		Since only half of the muonium asymmetry is experimentally observable, (the other half oscillating too fast to be resolved - see Appendix A) loss of some of the diamagnetic species to muonium formation results in an increase in the muonium asymmetry half as large.
		like the muonium fraction, this strongly suggests that transport of electrons through the lattice is involved in muonium formation in solid nitrogen.
	musr.org /theses/Morris/node21.html (261 words)

	Modern atomic physics
		In collaboration with the University of Heidelberg, we are conducting experiments to measure the 1S-2S transition in muonium, in an attempt to determine the Lamb shift of the transition (1S and 2S shifts together).
		The muonium is produced using a pulsed muon source (50 Hz) at the ISIS facility at the Rutherford Appleton Laboratory (RAL).
		However, the muonium atom has a lifetime of only a few microseconds (the decay time of the positive muon), so there is a fundamental limit on the accuracy of the shift.
	www-alphys.physics.ox.ac.uk /research/groups/baird/muonium.htm (817 words)

	4.5 Implications of Delayed Muonium Formation for (Site not responding. Last check: 2007-08-20)
		First, there is the question of how much the muon and muonium signals in various (insulating) materials are affected by direct interaction with the stray electrons.
		For both muons and muonium, the most obvious affect would be a contribution to the relaxation rate of the polarization function.
		Second, the bulk properties of the sample in the vicinity of these stray electrons may also be affected, and have an indirect influence on the muon or muonium signals.
	musr.org /theses/Morris/node27.html (238 words)

	A listing of my muon-related publications
		Muonium adduct of benzaldehyde: a novel probe of cation-molecule interactions in zeolite catalysis and of solvation and electronic substituent effects.
		Muonium addition to vinylaromatics and to diacetylenes: formation and stability of arylethyl/vinylcyclohexadienyl and alkylvinyl radicals.
		Radiolabelling studies of free radical reactions using muonium (the second hydrogen radioisotope): evidence of a direct antioxidant role for vitamin K in repair of oxidative damage to lipids.
	people.brunel.ac.uk /~eesridr/mupubs.html (1982 words)

	Polarized muon spins in pulsed magnetic fields
		The crossover between the sudden and adiabatic regimes was measured for both muonium and free muons.
		A largely debated question regards muonium and its radicals formation, which can take place with a negligible formation time, typically in an epithermal regime, or according to a given rate equation, with a long formation time, as it may happen in a thermal regime.
		The pulsed magnetic field is achieved by using a flat-loop device [8] in which spatially uniform pulsed currents flow in opposite directions in two parallel slabs with the sample sandwiched in between.
	www.fis.unipr.it /~derenzi/infm-highlight.html (1412 words)

	Abstract "Weird muonium diffusion in solid xenon" (Site not responding. Last check: 2007-08-20)
		Muon and muonium spin rotation and relaxation parameters are studied in liquid and solid xenon.
		The muonium hyperfine frequency was measured for the first time in liquid Xe and was found to be in agreement with the vacuum value.
		A nonmonotonic temperature dependence of the muonium relaxation rate probably indicates that muonium diffusion in solid Xe is of quantum nature.
	www.jinr.dubna.su /~duginov/publicat/weirdxe.html (95 words)

	Positronium and Muonium
		Improvements in accuracy can be expected with higher numbers of muonium atoms as they are expected to be available from future high flux muon sources such as the PRISM facility of the Japanese Hadron Facility, the Oak Ridge spallation neutron source or the front end of a muon collider
		We are analyzing our muonium data and expect to report results at the Hydrogen II Conference.
		The advantage, compared with muonium, is the absence of an additional free parameter like the muon mass.
	www.vniim.ru /sgk/psas/book/positronium.htm (2743 words)

	Muonium centres in semiconductors - a new approach
		Experiments in GaAs, GaP and CdS suggest that the electron is initially captured into a highly excited state, from which the cascade down to the muonium ground state goes through an intermediate weakly bound state determined by the electron effective mass and the dielectric constant of the host.
		The nature of the final (on the μSR timescale) muonium state depends on the energy releasing mechanisms in the cascade process.
		We suggest that muonium dynamics in semiconductors (including the effects of electric and magnetic fields and temperature) reflect the electron dynamics in weakly bound muonium state(s) in which the electron is delocalized over distances of about 100 Å.
	stacks.iop.org /0953-8984/16/S4761 (332 words)

	4 Muonium formation in Insulators
		It is quite likely that this is at least part of the answer to a long-standing puzzle regarding the differentiation of muons into diamagnetic and muonium fractions in so many (electrically) insulating materials - solids, liquids and gases.
		, and to show that the amount of muonium formed depends on the ability of radiolysis electrons, initially released by the muon much further from its final position than previously thought, to reach the stopped muon.
		Cryocrystals and cryoliquids have been instrumental in the discovery of this technique, so it is fitting that this be included in a thesis primarily concerned with muonium diffusion in cryocrystals.
	musr.physics.ubc.ca /theses/Morris/node18.html (309 words)

	Muonium Reactions with Oxalic Acid and Oxalate Ions in Water: Huge Kinetic Isotope Effects When Compared with H (Site not responding. Last check: 2007-08-20)
		Arrhenius plots for the muonium reactions at pH = 1, 3, and 8 show the unusually small activation energies of <17 kJ/mol for all three acid-base forms of oxalic acid.
		When the reaction rate of muonium is compared with published data on ordinary H atoms at pH = 1 (57% oxalic acid and 43% hydrogen oxalate ions), one obtains a kinetic isotope effect of 850 favoring muonium.
		The reaction is taken to be addition of muonium to one of the C=O groups, and the large isotope effect and small E
	pubs.acs.org /cgi-bin/abstract.cgi/jpcafh/1997/101/i13/abs/jp963392y.html (241 words)

	LMU : Seminar
		The ionization of muonium is resonantly enhanced by using a vacuum-ultraviolet radiation resonant with 2P state (122.09 nm).
		The high laser intensities required for efficient muonium ionization unfortunately limit the use of this method to only pulsed muon sources with pulse repetition rates not exceeding 25 Hz.
		The experimental setup that has been built over the past few years at RIKEN-RAL facility at ISIS (UK) will be described, as well as the results the low energy muon production obtained during March 2004.
	lmu.web.psi.ch /seminar/seminar_w22.html?forprint (242 words)

	Muonium Data Base
		There are also solutes for which reactions of muonium have been studied in aqueous micelles.
		In view of continuous interest in chemistry and radiation chemistry of supercritical water (SCW), however, some rate constants obtained for muonium reacting in aqueous solutions at very high temperatures and pressures have been included.
		Muonium, even more so than H, can undergo a remarkable variety of reactions (see ref 8 above) which is what makes its role in chemistry so significant.
	mbaza.mm.com.pl /data_base3.asp (786 words)

	Quantum Diffusion of Isotropic Muonium (MuT) in 13C Diamond studied by LF-mSR Spectroscopy
		It is, however, recognised that muonium and hydrogen are incorporated in two different ways in these samples.
		Hydrogen is usually introduced during the process of sample preparation and reaches thermal and chemical equilibrium before measurements begin, while muonium is observed within 2.2 microseconds after very dilute implantation of almost 100% spin polarized muons.
		C diamond and the external field is parallel to the initial muon spin polarization.
	www.src.wits.ac.za /groups/psi/diam-msr/abstract3.htm (619 words)

	Muonium Spectroscopy (ResearchIndex) (Site not responding. Last check: 2007-08-20)
		The muonium atom (M = + e \Gamma) is the hydrogen-like bound state of leptons from two different particle generations, an antimuon(+) and an electron(e \Gamma) [1,2].
		The dominant interaction within the M atom is electromagnetic and level energies can be calculated in bound state Quantum Electrodynamics (QED) to sufficiently high accuracy for...
		0.5: Spectroscopy of the Muonium Atom - Jungmann
	citeseer.ist.psu.edu /303202.html (253 words)

	Citebase - Muonium Decay
		Authors: Czarnecki, Andrzej; Lepage, G. Peter; Marciano, William J. Modifications of the mu+ lifetime in matter due to muonium (M = mu+ e-) formation and other medium effects are examined.
		Muonium and free mu+ decay spectra are found to differ at O(alpha m
		[30] The right-hand side of the normalization condition would be the electromagnetic form factor of muonium at zero momentum transfer if the electron had no electric charge, and provided that the potential is instantaneous (which is true up to O(3) corrections which we ignore).
	citebase.eprints.org /cgi-bin/citations?id=oai:arXiv.org:hep-ph/9908439 (1406 words)

	A Muonium Spin Polarization Function
		In this Appendix we derive from first principles the eigenvalues and states of muonium, in the simplest case of free muonium in vacuum with a static magnetic field applied.
		The polarization functions with the applied magnetic field oriented either transverse to or along the initial muon spin are calculated.
		In doing so we will obtain the muonium states and corresponding energies, which determine the precession frequencies observed in the muon spin polarization signal.
	musr.org /theses/Morris/node47.html (397 words)

	Effect of pH on Muonium Reactions in Aqueous Solutions of p-Aminobenzoic Acid
		The overall rate of reaction is barely affected by pH, but there is nearly a 2-fold switch in the site at which muonium adds to the ring.
		There is also a considerable switch in the magnetic field at which muon level crossing resonance occurs, the radical with muonium attached at C(2) moving upfield by 125 mT and the C(3) one moving downfield by a similar amount.
		If this compound is representative of aromatic systems, then the differences in pH which usually exist between hydrogen and muonium studies would account for only a small factor in most reported kinetic isotope effects.
	pubs.acs.org /cgi-bin/abstract.cgi/jpchax/1996/100/i09/abs/jp9518320.html (225 words)

	Muonium - TheBestLinks.com - Electron, Hydrogen, Particle physics, Portable Document Format, ... (Site not responding. Last check: 2007-08-20)
		Muonium - TheBestLinks.com - Electron, Hydrogen, Particle physics, Portable Document Format,...
		Muonium, Electron, Hydrogen, Muon, Particle physics, Portable Document Format...
		"Names for muonium and hydrogen atoms and their ions (http://www.iupac.org/publications/pac/2001/pdf/7302x0377.pdf)".
	www.thebestlinks.com /Muonium.html (173 words)

	Precise Measurement of the Muonium 1s-2s Interval (Site not responding. Last check: 2007-08-20)
		[WB16.06] Precise Measurement of the Muonium 1s-2s Interval
		The 1s-2s interval in the hydrogen-like muonium atom (\mu^+e^-) was determined by Doppler-free two-photon spectroscopy using pulsed laser excitation.
		The necessary UV light was generated by frequency tripling of the output of an alexandrite ring laser amplifier which was seeded from Ti::sapphire laser beam which was stabilized in frequency to a calibrated transition in molecular I_2.
	flux.aps.org /meetings/YR99/CENT99/abs/S8290006.html (151 words)

	UBC Chemistry Personnel - Donald G. Fleming
		This "µSR" (Muon Spin Rotation or Relaxation or Resonance) signal is analyzed to yield amplitudes, frequencies and relaxations characteristic of the interactions of the muon spin with its environment, as indicated in the diagram below, and similar in scope to related studies in magnetic resonance.
		Positive muons form the muonium atom (Mu=µ+e-), which is an extraordinary ultralight isotope of hydrogen: m
		As such, its study provides an exceptionally sensitive probe of quantum mass effects in chemical reaction dynamics.
	www.chem.ubc.ca /personnel/faculty/fleming/index.shtml (236 words)

	International Union of Pure and Applied Chemistry
		Although chemical reactions of muonium atoms have been studied for more than two decades, the nomenclature of muonium and related species has not been addressed by IUPAC.
		The name 'muon' is used in physics for the species that belong to the lepton family and that are designated with the symbols
		The positive muon can abstract an electron near the end of the radiation track, and the combination of positive muon and electron mimics the reactivity of the hydrogen atom.
	www.iupac.org /reports/provisional/abstract00/muonium_311200.html (210 words)

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