Direct collection of some metal ions in an electromagnetic isotope separator and related surface effects

1969 ◽  
Vol 47 (21) ◽  
pp. 2405-2414 ◽  
Author(s):  
A. Fontell ◽  
E. Arminen
Keyword(s):  
Energy Range ◽  
Metal Ions ◽  
Metal Atom ◽  
The Self ◽  
Isotope Separator ◽  
Graphite Block ◽  
High Energies ◽  
Metal Atoms ◽  
Saturation Region ◽  
Low Energies

The direct collection of Fe, Co, Ni, Cu, Zn, and Sn ions has been investigated in the energy range from about 10 eV to 110 keV in an electromagnetic isotope separator. At low energies the ions build up a layer on the surface of the graphite block used as a backing, while at high energies only a certain saturation value can be collected. For these ions the highest energies at which the building-up of a layer was observed were 1.5 keV, 1.0 keV, 0.8 keV, 0.3 keV, 0.3 keV, and 0.45 keV, respectively. In the building-up region the efficiency of the collection process and the sticking probability of ions as a function of energy have been measured. From these the self-sputtering ratios have been calculated. In the saturation region the amounts of material collected have been measured and the ranges of ions in graphite backings saturated with metal atoms have been calculated theoretically. This calculation gives an estimate of the metal atom concentrations in the graphite, which in turn determines the sputtering ratio of carbon.

scholarly journals Evolution of sub-spaces at high and low energies

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Arkady A. Popov ◽  
Sergey G. Rubin
Keyword(s):  
Energy Range ◽  
Crucial Role ◽  
Numerical Solutions ◽  
Initial Conditions ◽  
Quantum Corrections ◽  
Extra Space ◽  
High Energies ◽  
Low Energies ◽  
Higher Derivatives ◽  
Shed Light

Abstract The evolution of sub-spaces in the framework of gravity with higher derivatives is studied. Numerical solutions to exact differential equations are found. It is shown that the initial conditions play crucial role in the space dynamic. Appropriate metrics describing an expanding and a stationary sub-space shed light on the well-known question: why our 3-dim space is large but an extra space is small and stable (if exists)? It is assumed that the values of parameters at high energies strongly depend on uncontrolled quantum corrections and, hence, are not equal to their values at low energies. Therefore, there is no way to trace solutions throughout the energy range, and we restrict ourselves to the sub-Planckian and the inflationary energies.

Electron Energy Dependence of Amorphization in Zr3Fe

1993 ◽  
Vol 316 ◽  
Author(s):  
A.T. Motta ◽  
L.M. Howe ◽  
P.R. Okamoto
Keyword(s):  
Electron Energy ◽  
Cross Section ◽  
Sharp Increase ◽  
Low Dose ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
High Energies ◽  
Intermediate Energies ◽  
Low Energies ◽  
Order Of Magnitude

ABSTRACTThis paper reports the results from a study conducted to determine the effect of electron energy on the dose-to-amorphization of Zr3Fe at 23-30 K. Zr3Fe samples were irradiated in the HVEM at Argonne National Laboratory, at energies ranging from 200 to 900 keV. Amorphization occurred at electron energies from 900 keV down to 250 keV. Three distinct regions were observed: between 900 and 700 keV amorphization occurred at a constant low dose of ~ 4 × 1021 e cm-2; a higher plateau at 1022 was observed between 600 and 400 keV, and finally there was a sharp increase in the dose-to-amorphization below 400 keV, so that at 250 keV the necessary dose was an order of magnitude higher than that at 900 keV. In the region below 400 keV there was evidence of a dependence of the dose-to-amorphization on the orientation of the sample with respect to the electron beam. The results can be analyzed in terms of a composite displacement cross section dominated at high energies by displacements of Zr and Fe atoms, by displacements of Fe atoms at intermediate energies and of secondary displacements of lattice atoms by recoil impurities at low energies.

Hexaruthenium and octaruthenium carbonyl cluster complexes derived from 2-amino-6-methylpyridine — Novel coordination modes for 2-imidopyridines

2006 ◽  
Vol 84 (2) ◽  
pp. 105-110 ◽  
Author(s):  
Javier A Cabeza ◽  
Ignacio del Río ◽  
Pablo García-Álvarez ◽  
Daniel Miguel
Keyword(s):  
Metal Atom ◽  
Cluster Compounds ◽  
Carbonyl Cluster ◽  
Amido Ligands ◽  
Ruthenium Cluster ◽  
Coordination Type ◽  
Metal Atoms ◽  
Pyridine Nitrogen ◽  
Cluster 2 ◽  
Reflux Temperature

The hexanuclear ruthenium cluster [Ru6(µ3-H)2(µ-H)2(µ4-κ2-ampy)2(CO)14] (1) and the octanuclear one [Ru8(µ-H)(µ4-κ2-ampy)3(µ3-κ2-Hampy)(µ-CO)2(CO)15] (2) have been prepared by treating [Ru6(µ3-H)2(µ5-κ2-ampy)(µ-CO)2(CO)14] with 2-amino-6-methylpyridine (H2ampy) in decane at reflux temperature. Their metal atoms are supported by ligands that derive from the activation of one (complex 2) or both N—H bonds (complexes 1 and 2) of the H2ampy amino fragment. Both contain at least one ampy ligand featuring an unprecedented coordination type: the imido N atom caps a triangle of metal atoms while the pyridine nitrogen is attached to an additional metal atom. One of the ampy ligands of cluster 2 also displays another unprecedented coordination type: it caps a distorted square of metal atoms through the imido N atom while the pyridine nitrogen is attached to one of the atoms included in that square.Key words: ruthenium, cluster compounds, amido ligands, imido ligands.

scholarly journals Self-similarity of hadron production in pp and AA collisions at high energies

2015 ◽  
Vol 30 (21) ◽  
pp. 1550127 ◽  
Author(s):  
D. A. Artemenkov ◽  
G. I. Lykasov ◽  
A. I. Malakhov
Keyword(s):  
Hadron Production ◽  
The Self ◽  
Pp Collisions ◽  
Self Similarity ◽  
High Energies ◽  
Wide Range ◽  
Aa Collisions

We analyze the self-similarity approach applied to study the hadron production in pp and AA collisions. This approach allows us to describe rather well the ratio of the proton to antiproton yields in AA collisions as a function of the energy at a wide range from a few GeV to a few TeV. We suggest a modification of this approach to describe rather well the inclusive spectra of hadrons produced in pp collisions at different initial energies from the AGS to LHC.

Construction of homochiral alkaline–lanthanide heteronuclear helicates with Na+-selective bonding in the self-assembly process

2019 ◽  
Vol 48 (39) ◽  
pp. 14595-14599 ◽  
Author(s):  
Ge Li ◽  
Li Wang ◽  
Qingxin Han ◽  
Weisheng Liu
Keyword(s):  
Metal Ions ◽  
Self Assembly ◽  
The Self ◽  
Assembly Process

A supramolecular approach to distinguish Na+ from other biologically important metal ions.

Pd1/BN as a promising single atom catalyst of CO oxidation: a dispersion-corrected density functional theory study

RSC Advances ◽  
2015 ◽  
Vol 5 (103) ◽  
pp. 84381-84388 ◽  
Author(s):  
Zhansheng Lu ◽  
Peng Lv ◽  
Jie Xue ◽  
Huanhuan Wang ◽  
Yizhe Wang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Co Oxidation ◽  
Metal Atom ◽  
Density Functional ◽  
Single Atom ◽  
Two Dimensional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Metal Atoms ◽  
Two Dimensional Materials

Single metal atom catalysts exhibit extraordinary activity in a large number of reactions, and some two-dimensional materials (such as graphene and h-BN) are found to be prominent supports to stabilize single metal atoms.

AP-FIM INVESTIGATION OF THE INITIAL STAGE OF OXIDATION ON THE SURFACE OF ALLOYS

1995 ◽  
Vol 02 (02) ◽  
pp. 177-181 ◽  
Author(s):  
D.G. REN
Keyword(s):  
Binding Energy ◽  
Field Strength ◽  
Metal Atom ◽  
Exposure Period ◽  
Atom Probe ◽  
Field Evaporation ◽  
Residual Oxygen ◽  
Metal Atoms ◽  
Initial Stage ◽  
The Difference

This paper reports a study of the initial stage of oxidation on the surface of alloys by field-ion microscopy and atom probe (AP-FIM). The samples used in this investigation contained Ni, Ni-Cr, Ni-Al, Ti-Al , and Pt-Rh metals and alloys. A clean-tip surface, after atom-probe analysis, was exposed in the atmosphere of residual oxygen (vacuum 10−4 torr) for a few hours. AP analysis found that a small quantity of oxygen was adsorbed on the surface of the alloys. The clusters of a combination of a metal atom with an oxygen, i.e., PtO +2, NiO +2, and TiO +2 were determined by AP. The experiment found that the binding energy between metal atom on the surface of alloys was reduced when oxygen was adsorbed on the surface. The binding energy of surface atoms was determined according to the field strength of the tip surface. The reduction of the binding energy was about 0.5–2.0 eV, which changed following the exposure period in the atmosphere and depending on the kind of alloys used. The difference in field-ion image due to adsorption of oxygen was observed as compared to without the oxygen. The results of the experiment show that oxygen was absorbed on the “clean surface” of alloys. First the oxygen molecule was dissociated to oxygen atoms by the reaction with metal atoms and then formed the metal-oxygen bonding (M+O→MO) . This is an initial stage of oxidation on the surface of alloys. The clusters of combining oxygen did not dissociate during the field-evaporation process with 4.5 V/Å field strength.

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