Analysis of alpha inelastic scattering in the continuum

1973 ◽  
Vol 7 (17) ◽  
pp. 936-940
Author(s):  
A. Demeyer ◽  
A. Chevarier ◽  
N. Chevarier ◽  
G. Hollinger ◽  
P. Petrosa ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
The Continuum

scholarly journals Collective Reactions in the Continuum

2019 ◽  
Vol 7 ◽  
pp. 209
Author(s):  
P. Demetriou ◽  
A. Marcinkowski ◽  
P. E. Hodgson
Keyword(s):  
Experimental Data ◽  
Inelastic Scattering ◽  
Cross Sections ◽  
Absolute Magnitude ◽  
Collective Excitations ◽  
Scattering Data ◽  
Detailed Structure ◽  
Sum Rule ◽  
Neutron Inelastic Scattering ◽  
The Continuum

We show that pre-equlibrium inelastic scattering reactions to the continuum contain substantial collective components in addition to the multistep direct and multistep compound reactions. These collective reactions are investigated for the vibrational nuclei 56Fe, 58Ni, 90Zr, 93Nb, 208Pb and 209Bi , and the strongly-deformed, rotational W nucleus. The collective cross-sections are calculated using the experimental data for low-lying collective excitations supplemented where necessary by the giant multipole resonances evaluated using the energy-weight ed sum rule. The MSC and MSD cross-sections are evaluated by the Feshbach-Kerman-Koonin theory using a consistent set of parameters determined by analyses of (p, xn) reactions, that have practically no collective components. The results are compared with high-resolution neutron inelastic scattering data and prove able to account for the absolute magnitude of the cross-sections and also their detailed structure.

Orbiting effects in the inelastic scattering of protons to the continuum

1982 ◽  
Vol 112 (4-5) ◽  
pp. 299-302 ◽  
Author(s):  
H.C. Bhang ◽  
I. Halpern ◽  
T.A. Trainor
Keyword(s):  
Inelastic Scattering ◽  
The Continuum

scholarly journals Spin alignment following inelastic scattering of Ne17 , lifetime of F16 , and its constraint on the continuum coupling strength

2018 ◽  
Vol 97 (5) ◽  
Author(s):  
R. J. Charity ◽  
K. W. Brown ◽  
J. Okołowicz ◽  
M. Płoszajczak ◽  
J. M. Elson ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
Coupling Strength ◽  
Spin Alignment ◽  
The Continuum

scholarly journals Inelastic Scattering of Neutrons. II. Comparison of QCN Theory with Experiment

1969 ◽  
Vol 22 (2) ◽  
pp. 145
Author(s):  
WK Bertram
Keyword(s):  
Inelastic Scattering ◽  
Cross Section ◽  
Compound Nucleus ◽  
The Other ◽  
Heavy Target ◽  
Other Hand ◽  
Good For ◽  
Theory And Experiment ◽  
Large Spin ◽  
The Continuum

The cross section for inelastic scattering of neutrons by medium and heavy target nuclei is derived using the quasi-compound nucleus theory. Calculations are carried out for 56Fe and 60NL The results of these calculations are compared with experiment. Agreement between theory and experiment is quite good for scattering to the continuum of high levels and to discrete levels with small spins. On the other hand the theory underestimates the scattering to levels with large spin values.

Low energyπ+inelastic scattering from nuclei to the continuum

1986 ◽  
Vol 33 (1) ◽  
pp. 208-233 ◽  
Author(s):  
K. A. Aniol ◽  
D. T. Chiang ◽  
K. G. R. Doss ◽  
I. Halpern ◽  
M. Khandaker ◽  
...  
Keyword(s):  
Inelastic Scattering ◽  
The Continuum

C. The Continuous Spectrum of Pulsating Variable Stars

1967 ◽  
Vol 28 ◽  
pp. 177-206
Author(s):  
J. B. Oke ◽  
C. A. Whitney
Keyword(s):  
Continuous Spectrum ◽  
Variable Stars ◽  
Velocity Fields ◽  
The Other ◽  
Line Spectrum ◽  
Direct Information ◽  
Thermodynamic Structure ◽  
Diagnostic Interpretation ◽  
Pulsating Variable Stars ◽  
The Continuum

Pecker:The topic to be considered today is the continuous spectrum of certain stars, whose variability we attribute to a pulsation of some part of their structure. Obviously, this continuous spectrum provides a test of the pulsation theory to the extent that the continuum is completely and accurately observed and that we can analyse it to infer the structure of the star producing it. The continuum is one of the two possible spectral observations; the other is the line spectrum. It is obvious that from studies of the continuum alone, we obtain no direct information on the velocity fields in the star. We obtain information only on the thermodynamic structure of the photospheric layers of these stars–the photospheric layers being defined as those from which the observed continuum directly arises. So the problems arising in a study of the continuum are of two general kinds: completeness of observation, and adequacy of diagnostic interpretation. I will make a few comments on these, then turn the meeting over to Oke and Whitney.

Photo-electric Hβ and uvby photometry

1966 ◽  
Vol 24 ◽  
pp. 170-180
Author(s):  
D. L. Crawford
Keyword(s):  
Narrow Band ◽  
Line Strength ◽  
Interference Filter ◽  
B Stars ◽  
Relative Line ◽  
The Mean ◽  
F Stars ◽  
Two Parameters ◽  
Filter Photometry ◽  
The Continuum

Early in the 1950's Strömgren (1, 2, 3, 4, 5) introduced medium to narrow-band interference filter photometry at the McDonald Observatory. He used six interference filters to obtain two parameters of astrophysical interest. These parameters he calledlandc, for line and continuum hydrogen absorption. The first measured empirically the absorption line strength of Hβby means of a filter of half width 35Å centered on Hβand compared to the mean of two filters situated in the continuum near Hβ. The second index measured empirically the Balmer discontinuity by means of a filter situated below the Balmer discontinuity and two above it. He showed that these two indices could accurately predict the spectral type and luminosity of both B stars and A and F stars. He later derived (6) an indexmfrom the same filters. This index was a measure of the relative line blanketing near 4100Å compared to two filters above 4500Å. These three indices confirmed earlier work by many people, including Lindblad and Becker. References to this earlier work and to the systems discussed today can be found in Strömgren's article inBasic Astronomical Data(7).

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

Analysis of STEM micrographs of thick objects

1978 ◽  
Vol 36 (2) ◽  
pp. 106-107
Author(s):  
S. Golladay
Keyword(s):  
Inelastic Scattering ◽  
Multiple Scattering ◽  
Mass Distribution ◽  
Cross Sections ◽  
Phase Contrast ◽  
Image Point ◽  
Contrast Effects ◽  
Total Cross Sections ◽  
Elastic And Inelastic Scattering

The theory of multiple scattering has been worked out by Groves and comparisons have been made between predicted and observed signals for thick specimens observed in a STEM under conditions where phase contrast effects are unimportant. Independent measurements of the collection efficiencies of the two STEM detectors, calculations of the ratio σe/σi = R, where σe, σi are the total cross sections for elastic and inelastic scattering respectively, and a model of the unknown mass distribution are needed for these comparisons. In this paper an extension of this work will be described which allows the determination of the required efficiencies, R, and the unknown mass distribution from the data without additional measurements or models. Essential to the analysis is the fact that in a STEM two or more signal measurements can be made simultaneously at each image point.

Temperature Dependence of the Critical Electron Dose for Fatty Acid Monolayers

1982 ◽  
Vol 40 ◽  
pp. 78-79
Author(s):  
Kenneth H. Downing ◽  
Robert M. Glaeser
Keyword(s):  
Electron Beam ◽  
Fatty Acid ◽  
Inelastic Scattering ◽  
Temperature Dependence ◽  
Structural Damage ◽  
Direct Result ◽  
Second Step ◽  
Strong Temperature Dependence ◽  
Electron Dose ◽  
Covalent Bonds

The structural damage of molecules irradiated by electrons is generally considered to occur in two steps. The direct result of inelastic scattering events is the disruption of covalent bonds. Following changes in bond structure, movement of the constituent atoms produces permanent distortions of the molecules. Since at least the second step should show a strong temperature dependence, it was to be expected that cooling a specimen should extend its lifetime in the electron beam. This result has been found in a large number of experiments, but the degree to which cooling the specimen enhances its resistance to radiation damage has been found to vary widely with specimen types.

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