scholarly journals ESTIMATION OF GROSS-STRUCTURE PARAMETERS OF GIANT DIPOLE RESONANCE: 2. EXPERIMENTAL TESTING

2021 ◽  
pp. 3-7
Author(s):  
N.P. Dikiy ◽  
A.A. Zakharchenko ◽  
Yu.V. Lyashko ◽  
V.L. Uvarov ◽  
V.A. Shevchenko ◽  
...  
Keyword(s):  
Giant Dipole Resonance ◽  
Experimental Testing ◽  
Reaction Yield ◽  
X Rays ◽  
Bremsstrahlung Radiation ◽  
Natural Isotopic Composition ◽  
Novel Technique ◽  
Dipole Resonance ◽  
Good Agreement

Experimental testing of a novel technique for determination of width and maximum of excitation function of a photonuclear reaction with dominant giant dipole resonance is conducted. The method is based on measurement of normalized reaction yield in a thin target, overlapping entirely a flux of X-rays and on processing of data obtained with the use of a developed analytical model. For the checking of method, the nickel and molybdenum foils of natural isotopic composition were activated by bremsstrahlung radiation at four energies of the electron beam in the range 40…95 MeV. The obtained parameters of cross-section of the reference reactions 58Ni(γ,n)57Ni and 100Mo(γ,n)99Mo are in good agreement with those presented in the available databases.

DETERMINATION OF PHYSICAL QUANTITIES FOR PIXE BY MEANS OF PIXE 1: ABSORPTION CURVE

1994 ◽  
Vol 04 (02n03) ◽  
pp. 165-179 ◽  
Author(s):  
K. SERA ◽  
S. FUTATSUGAWA ◽  
S. HATAKEYAMA ◽  
S. SAITOU
Keyword(s):  
Background Subtraction ◽  
New Method ◽  
Absorption Curve ◽  
X Rays ◽  
Pixe Analysis ◽  
Peak Areas ◽  
Physical Quantities ◽  
Different Thickness ◽  
Good Agreement

A new method has been developed to determine absorption curves which are needed to derive quantitative values in PIXE analysis. In this method two spectra obtained with absorbers of different thickness are divided by each other after background subtraction and the absorption curve can be obtained immediately. Absorption curves for a 50 and a 200 µm-thick Mylar films and that for a Cr foil of 2500 µg/cm2 were determined experimentally. These curves are in good agreement with the absorption values derived from peak areas of characteristic x-rays. This method enables one to obtain absorption curves for any kind of absorber accurately and quickly.

Quantitative Determination of Carbon in Solid Hydrocarbons Using the Intensity Ratio of Incoherent to Coherent Scattering of X-Rays

1964 ◽  
Vol 18 (6) ◽  
pp. 171-174 ◽  
Author(s):  
C. J. Toussaint ◽  
G. Vos
Keyword(s):  
Intensity Ratio ◽  
Coherent Scattering ◽  
X Rays ◽  
Ray Method ◽  
Sample Weight ◽  
X Ray ◽  
Carbon Determination ◽  
Solid Hydrocarbons ◽  
Good Agreement

A method is presented for the determination of carbon in solid hydrocarbons using the intensity ratio of incoherent to coherent scattering of x-rays. The method is very rapid with precision at the 95% confidence level of about ±0.3%. The minimum sample weight necessary is 0 2 g. Analysis of samples by the x-ray method shows good agreement with values obtained by microcombustion. Finally a general comparison between different methods for carbon determination in solid hydrocarbons is discussed.

scholarly journals Divergent-beam X-ray photography of crystals

1947 ◽  
Vol 240 (817) ◽  
pp. 219-250 ◽  
Keyword(s):  
Wave Length ◽  
Impurity Content ◽  
Type I ◽  
X Rays ◽  
Divergent Beam ◽  
X Ray ◽  
Air Temperatures ◽  
High Degree ◽  
Good Agreement

Divergent-beam X-ray photography of single crystals by transmission can be used to study the ‘extinction’, that is, the diminution of the transmitted radiation that takes place at the Bragg reflexion angles. The intensity and geometry of the absorption lines observed give useful information about the texture of the crystal. Divergent beam photographs have shown that many crystals of organic compounds are unexpectedly perfect, and that sudden cooling to liquid-air temperatures will increase the mosaic character of their structure by an important factor and make them more suitable for structural analysis by the usual methods. Type I diamonds, and natural ice even near to its melting-point, are also found to possess a high degree of perfection, which cannot be removed by liquid-air treatment. The divergent beam method may be used for the determination of orientation, but it is important that the wave-length of X-rays employed should be correctly related to the size and nature of the crystal. In certain favourable cases it is possible to make precision measurements of lattice constant or of wave-length from divergent beam photographs, without the use of any kind of precision apparatus. By such means it has been shown that the C—C distance in individual diamonds varies from 1541.53(± 0-02) to 1541.27X, (1.54465-1-54440A), a difference presumably due to varying impurity content. Using diamond and a brass anticathode, the Zn Ka 1 wave-length, relative to Cu K Ka 1 as 1537.40X, is found to be 1432.21 ( ± 0-04) X. Temperature control would improve the accuracy of this measurement, which is, however, in good agreement with the latest value obtained by orthodox precision methods.

Determination of the isotensor symmetry energy for the giant dipole resonance

1994 ◽  
Vol 49 (6) ◽  
pp. 3338-3341
Author(s):  
H. T. Fortune ◽  
J. M. O’Donnell
Keyword(s):  
Symmetry Energy ◽  
Giant Dipole Resonance ◽  
Dipole Resonance

Experimental determination of the proton escape width in the giant dipole resonance ofY89

1981 ◽  
Vol 24 (6) ◽  
pp. 2499-2506 ◽  
Author(s):  
E. Van Camp ◽  
R. Van de Vyver ◽  
E. Kerkhove ◽  
D. Ryckbosch ◽  
H. Ferdinande ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Giant Dipole Resonance ◽  
Dipole Resonance

The barium giant dipole resonance in barite: a study of soft X-ray absorption edges using hard X-rays

2008 ◽  
Vol 23 (6) ◽  
pp. 807 ◽  
Author(s):  
Christian Sternemann ◽  
Henning Sternemann ◽  
Simo Huotari ◽  
Felix Lehmkühler ◽  
Metin Tolan ◽  
...  
Keyword(s):  
Giant Dipole Resonance ◽  
X Rays ◽  
X Ray ◽  
Dipole Resonance ◽  
X Ray Absorption ◽  
Absorption Edges

Problems in Thin-Film X-ray Quantification

1990 ◽  
Vol 48 (2) ◽  
pp. 458-459
Author(s):  
J N Chapman ◽  
W A P Nicholson
Keyword(s):  
Thin Film ◽  
Specimen Thickness ◽  
X Rays ◽  
Characteristic Peak ◽  
Local Composition ◽  
X Ray ◽  
Measured Ratio ◽  
Path Lengths ◽  
Composition Changes

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.

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