On the invalidity of Bragg's rule in stopping cross sections of molecules for swift Li ions

Neuwirth, Wolfgang; Pietsch, W.; Richter, Karl; Hauser, U.

doi:10.1007/bf01409287

Cited by 30 publications

(2 citation statements)

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“…Comparison of Dpir and DLSS gave excellent agreement for gaseous BF3 and elementary boron, while some disagreement was found for water. Neuwirth et al pointed out that the discrepancy occurring in the chemical Compounds should be put down to chemical bonding effects [9][10][11][12][13][14]. They have argued that Equation (14) be not strictly valid for chemical Compounds.…”

Section: Analysis Of Line Shapesmentioning

confidence: 95%

Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction

et al. 1996

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Line shape of prompt y ray / Doppler broadening / '°B(n,a)^*Li reaction / Range oflA / Boron neutroncapture therapy AbstractThe ranges of 'Li and '*Li produced via the "'B(n,a)'*Li reaction in elementary boron and water were determined by analysis of the Doppler broadened line-shapes of the 478 IceV prompt yray from the shortlived '*Li (T = 1.05X10"" s). The spectral line-shapes of the prompt y rays were measured with a low background using neutron beams guided outside the reactor at JRR-3M. The ränge of 3.9 um estimated for 'Li in water is compared with that (4.8 um) used in boron neutron-capture therapy as an appropriate value.'"B(n,a)^*Li reaction. That of 'Li in water which has been regarded as an appropriate value in BNCT was obtained semi-experimentally [3]. The hne shapes of the prompt y ray of 478 keV from were investigated by Neuwirth et al. [4,5], relating the Doppler broadened line-shapes to the slowing-down processes of in matter. The present authors also measured and analyzed the prompt y ray using the neutron beam and the prompt y-ray analysis system [6,7] at the newly constructed JRR-3M reactor, Japan Atomic Energy Research Institute. In our analysis procedure, a parameter called "velocity degradation constant" D of was introduced. The ranges of ''*Li and 'Li were estimated using the D values determined experimentally.

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Section: Analysis Of Line Shapesmentioning

confidence: 95%

Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction

et al. 1996

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“…However, this rule may lead to impora e-mail: jose@ecm.ub.edu 1 A comprehensive overview of methods employed to measure stopping powers can be consulted in chapter 9 of reference [11]. tant uncertainties, in particular for organic compounds, oxides and nitrides [13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Stopping cross sections of TiO2 for H and He ions

et al. 2014

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Stopping cross sections of TiO2 films were measured for H and He ions in the energy intervals 200−1500 keV and 250−3000 keV, respectively, using the Rutherford backscattering technique. Theoretical calculations were performed by means of two versions of the dielectric formalism and a non-linear model. Good agreement is found between the present experimental data and the theoretical results at intermediate and high energies, and also with the very limited experimental information available in the literature.

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The effect of atomic chemical bonding under fast ion stopping in solids

Burenkov

Komarov

1977

Physica Status Solidi (b)

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The calculation of ion stopping cross-sections in compounds was carried out by applying Bragg and Kleeman's rule /1/ However, in a series of experimental papers / 2 , 3/ (and in those quoted in /3/) the inadequacy of this rule for a variety of binary compounds has been shown.Earlier Brandt /4, 5/ considered the effect of atomic chemical bonding on the mean ionization potential comprised in the Bethe-Bloch equation for fast ion energy loss.In the present paper an atomic chemical bonding effect both on heavy ion stopping cross-sections and on the deviations from the above rule is shown for ionic crystals.Indeed, at an ionic velocity lower than that of outer electrons, the electrons of the outermost shell of target atoms provide the main contribution to the electronic energy loss cross-sections, S . The spatial distribution and the bonding energy of these electrons accounts for the oscillatory dependence of S both on the projectile atomic number Z compounds the character of the outer electron distribution essentially depend6 on the bond type between compound constituents. One can define the additivity rule of stopping cross-sections with the account of chemical bonding in compouods as e e and that of the monoatomic target Z2 /6, 7/. In the case of 1'where AS can acquire any sign. 0bIn monoatomic solid and gas targets inelastic ion stopping croes-sections a r e well described by the modified Firsov theory /7/, where it i s assumed that free atoms a r e localized in regular lattice sites. The electron configuration wave functions were used in the form of Slater orbitals / 8 / .

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On the invalidity of Bragg's rule in stopping cross sections of molecules for swift Li ions

Cited by 30 publications

References 27 publications

Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction

Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction

Stopping cross sections of TiO2 for H and He ions

The effect of atomic chemical bonding under fast ion stopping in solids

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On the invalidity of Bragg's rule in stopping cross sections of molecules for swift Li ions

Cited by 30 publications

References 27 publications

Ranges of 7Li Produced in 10B(n,α)7*Li Reaction

Ranges of 7Li Produced in 10B(n,α)7*Li Reaction

Stopping cross sections of TiO2 for H and He ions

The effect of atomic chemical bonding under fast ion stopping in solids

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Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction

Ranges of ⁷Li Produced in ¹⁰B(n,α)⁷*Li Reaction