Total Absorption Cross Sections of H_2, N_2, and O_2 in the Region 550–200 Å

1965 ◽  
Vol 55 (8) ◽  
pp. 1035 ◽  
Author(s):  
James A. R. Samson ◽  
R. B. Cairns
Keyword(s):  
Cross Sections ◽  
Total Absorption ◽  
Absorption Cross

Photoelectric cross sections derived from the total absorption cross sections in the energy range 5–130 keV

1979 ◽  
Vol 57 (1) ◽  
pp. 92-98 ◽  
Author(s):  
K. S. Puttaswamy ◽  
Ramakrishna Gowda ◽  
B. Sanjeevaiah
Keyword(s):  
Energy Range ◽  
Cross Sections ◽  
Proportional Counter ◽  
Atomic Data ◽  
Total Absorption ◽  
Absorption Cross ◽  
Total Cross Sections ◽  
Scattering Cross ◽  
Data Tables ◽  
Scattering Cross Sections

Total absorption cross sections in the elements C, Al, S, Cu, Zr, Ag, Sn, Ta, Au, and Pb for photons of energies 5.0, 5.9, 6.4, 8.1, 10.6, 14.4, 24.7, 32.9, 36.9, 66.6, and 129 keV are measured using a krypton-filled proportional counter in the energy range 5 to 25 keV and a thin NaI(Tl) detector in the energy range 30 to 130 keV. The measured total absorption cross sections are compared with those of Miller and Greening and McCrary, Plassman, Paekett, Conner, and Zimmermann. The scattering cross sections obtained by interpolation using the Atomic Data Tables are subtracted from the total cross sections to obtain the photoelectric cross sections and these are further compared with the recent theoretical values of Scofield.

Photoelectric cross sections derived from the measured total absorption cross sections at 52.2 and 84.3 keV in Al, Cu, Zr, Ag, Sn, Ta, Au, and Pb

1976 ◽  
Vol 54 (21) ◽  
pp. 2170-2172 ◽  
Author(s):  
Ramakrishna Gowda ◽  
K. S. Puttaswamy ◽  
B. Sanjeevaiah
Keyword(s):  
Cross Sections ◽  
Total Absorption ◽  
Absorption Cross ◽  
Total Scattering ◽  
Scattering Cross ◽  
Scattering Cross Sections ◽  
Theoretical Results

Photoelectric cross sections for 52.2 and 84.3 keV photons in Al, Cu, Zr, Ag, Sn, Ta, Au, and Pb are obtained by subtracting the total scattering cross sections from the measured total absorption cross sections. The scattering cross sections are taken from the recent tabulated values of Veigele, for subtracting purpose. The results are compared with the values interpolated from the theoretical results of (1) Schmickley and Pratt and (2) Scofield.

scholarly journals On the total absorption cross-section of galaxies - II: The case of λ cosmologies and covering factor variation

1998 ◽  
pp. 3-7
Author(s):  
M.M. Cirkovic ◽  
S. Samurovic
Keyword(s):  
Cosmological Constant ◽  
Cross Section ◽  
Cross Sections ◽  
Absorption Cross Section ◽  
Observational Cosmology ◽  
Total Absorption ◽  
Absorption Cross ◽  
Normal Galaxies ◽  
Previous Discussion ◽  
Inner Parts

In this work we expand the previous discussion of the plausibility of hypothesis of origin of the Ly? forest absorption systems in haloes of normal galaxies in connection with the HubbleDeepField (HDF) data. It is shown that simplistic approach to absorption cross-sections of galaxies with no luminosity scaling is in strong violation of empirical statistics up to redshift of z ? 3.5. Realistic variation of the covering factor in order to account for its increase in the inner parts of observed haloes leads to even bigger discrepancy. Cosmologies with finite cosmological constant are briefly discussed and compared to ? = 0 case. Ways to improve agreement with observational data are indicated. This problem is highly illustrative of the basic tenets of modern observational cosmology.

Sign in / Sign up

Export Citation Format

Share Document