A BaF2 detector system for (n,γ) cross section measurements at ORELA

1997 ◽  
Vol 621 (1-2) ◽  
pp. 254-257 ◽  
Author(s):  
K.H. Guber ◽  
R.R. Spencer ◽  
P.E. Koehler ◽  
R.R. Winters
2021 ◽  
Vol 62 (4) ◽  
Author(s):  
A. Wilczek ◽  
A. Szadziński ◽  
N. Kalantar-Nayestanaki ◽  
St. Kistryn ◽  
A. Kozela ◽  
...  

AbstractAnalysis of the data acquired with the BINA detector system in $$^1$$ 1 H(d, pp)n reaction at the beam energy of 80 MeV/nucleon makes a systematic analysis of the star configurations possible. This paper shows the preliminary cross section of the Forward-Plane Star (FPS) configuration with the neighbouring configurations.


2018 ◽  
Vol 181 ◽  
pp. 01010 ◽  
Author(s):  
Joana Wirth

Nuclear reactions, π−+A (A = C;W), at an incident beam momentum of 1:7 GeV/c were measured with the HADES setup at SIS18/GSI. Detailed investigations of the K+, K− and ϕ production off nuclei are connected to the study of hadron in-medium properties at nuclear saturation density. A contradictory role is played by the ϕ meson since the ϕN absorption cross-section is assumed to be small due to the OZI suppression which is in contrast to experimental observations. We present the analysis method to identify the ϕ meson exploiting the large K+K− branching ratio (≈ 50%). The correction for acceptance and effciency effects of the detector system will be discussed as well.


2020 ◽  
Vol 239 ◽  
pp. 17021
Author(s):  
Jie Ren ◽  
Xichao Ruan ◽  
Jie Bao ◽  
Guangyuan Luan ◽  
Hanxiong Huang ◽  
...  

Radiative neutron capture cross sections are very important in the field of basic physics research and nuclear device R&D. The Back-n white neutron beam line of China Spallation Neutron Source (CSNS) is the first spallation neutron beam line in China. On the purpose for radiative neutron capture cross section measurement, a C6D6 detector system was built in the Back-n experimental station. The pulse height weighting technique (PHWT) was used to make the system’s detective efficiency independent of the cascade path and the energy of cascade gamma rays. The neutron energy spectrum was measured for the energy between 1eV and 80keV with a 6Li loaded ZnS scintillation detector. Besides, a testing experiment with 197Au and 169Tm samples was carried out to examine this system. According to the preliminary results, this C6D6 detector system can be used to perform neutron capture cross section measurement.


1988 ◽  
Vol 102 ◽  
pp. 71-73
Author(s):  
E. Jannitti ◽  
P. Nicolosi ◽  
G. Tondello

AbstractThe photoabsorption spectra of the carbon ions have been obtained by using two laser-produced plasmas. The photoionization cross-section of the CV has been absolutely measured and the value at threshold, σ=(4.7±0.5) × 10−19cm2, as well as its behaviour at higher energies agrees quite well with the theoretical calculations.


Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.


Author(s):  
V. Mizuhira ◽  
Y. Futaesaku

Previously we reported that tannic acid is a very effective fixative for proteins including polypeptides. Especially, in the cross section of microtubules, thirteen submits in A-tubule and eleven in B-tubule could be observed very clearly. An elastic fiber could be demonstrated very clearly, as an electron opaque, homogeneous fiber. However, tannic acid did not penetrate into the deep portion of the tissue-block. So we tried Catechin. This shows almost the same chemical natures as that of proteins, as tannic acid. Moreover, we thought that catechin should have two active-reaction sites, one is phenol,and the other is catechole. Catechole site should react with osmium, to make Os- black. Phenol-site should react with peroxidase existing perhydroxide.


Author(s):  
J. P. Colson ◽  
D. H. Reneker

Polyoxymethylene (POM) crystals grow inside trioxane crystals which have been irradiated and heated to a temperature slightly below their melting point. Figure 1 shows a low magnification electron micrograph of a group of such POM crystals. Detailed examination at higher magnification showed that three distinct types of POM crystals grew in a typical sample. The three types of POM crystals were distinguished by the direction that the polymer chain axis in each crystal made with respect to the threefold axis of the trioxane crystal. These polyoxymethylene crystals were described previously.At low magnifications the three types of polymer crystals appeared as slender rods. One type had a hexagonal cross section and the other two types had rectangular cross sections, that is, they were ribbonlike.


Author(s):  
Thomas S. Leeson ◽  
C. Roland Leeson

Numerous previous studies of outer segments of retinal receptors have demonstrated a complex internal structure of a series of transversely orientated membranous lamellae, discs, or saccules. In cones, these lamellae probably are invaginations of the covering plasma membrane. In rods, however, they appear to be isolated and separate discs although some authors report interconnections and some continuities with the surface near the base of the outer segment, i.e. toward the inner segment. In some species, variations have been reported, such as longitudinally orientated lamellae and lamellar whorls. In cross section, the discs or saccules show one or more incisures. The saccules probably contain photolabile pigment, with resulting potentials after dipole formation during bleaching of pigment. Continuity between the lamina of rod saccules and extracellular space may be necessary for the detection of dipoles, although such continuity usually is not found by electron microscopy. Particles on the membranes have been found by low angle X-ray diffraction, by low temperature electron microscopy and by freeze-etching techniques.


Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as


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