THE EMISSION OF γ-RAYS IN NUCLEAR REACTIONS

1934 ◽  
Vol 56 (12) ◽  
pp. 2786-2787
Author(s):  
William D. Harkins ◽  
David M. Gans
Keyword(s):  
Nuclear Reactions ◽  
Γ Rays

ABSOLUTE STANDARDIZATION OF RADIOACTIVE NEUTRON SOURCES: II. THE USE OF THE F19(α, n)Na22 REACTION

1959 ◽  
Vol 37 (5) ◽  
pp. 550-556 ◽  
Author(s):  
K. W. Geiger
Keyword(s):  
Nuclear Reactions ◽  
Emission Rate ◽  
Neutron Emission ◽  
National Research Council ◽  
Neutron Output ◽  
Neutron Sources ◽  
Neutron Thermalization ◽  
Γ Rays ◽  
Absolute Standardization ◽  
Good Agreement

Fluorine has only one stable isotope, F19. If neutrons are produced by the F19(α, n)Na22 reaction the neutron output can be calculated from the yield of the resulting radioactive Na22. The growth of Na22 (half-life, 2.58 years) has been measured in a neutron source consisting originally of 1.6 curies Po210 mixed with CaF2 powder. Since Na22 is a positron emitter, discrimination against γ-rays from Po210 and from nuclear reactions could be achieved by detecting the two positron annihilation quanta in coincidence. The Na22 growth has been followed over 20 months and is in agreement with the theoretical growth curve. Comparison with a calibrated Na22 source yielded a neutron emission rate of (10.70 ± 0.25) × 104 sec−1. This resulted in a neutron emission rate of (3.16 ± 0.10) × 106 sec−1 for the Ra-α-Be source of the National Research Council, in good agreement with (3.22 ± 0.05) × 106 sec−1 obtained by a neutron thermalization method.

Intense proton beam current measurement via prompt γ rays from nuclear reactions

1978 ◽  
Vol 49 (10) ◽  
pp. 1384-1387 ◽  
Author(s):  
J. Golden ◽  
R. A. Mahaffey ◽  
J. A. Pasour ◽  
F. C. Young ◽  
C. A. Kapetanakos
Keyword(s):  
Proton Beam ◽  
Nuclear Reactions ◽  
Beam Current ◽  
Current Measurement ◽  
Γ Rays ◽  
Beam Current Measurement

NUCLEAR REACTIONS INDUCED IN TANTALUM BY PROTONS OF ENERGY UP TO 84 MEV

1963 ◽  
Vol 41 (10) ◽  
pp. 2516-2532 ◽  
Author(s):  
C. L. Rao ◽  
L. Yaffe
Keyword(s):  
Cross Sections ◽  
Half Life ◽  
Reasonable Agreement ◽  
Nuclear Reactions ◽  
Schematic Model ◽  
Radiation Characteristics ◽  
Excitation Functions ◽  
Γ Rays ◽  
The Cross

Nuclear reactions induced in tantalum by protons of energy up to 84 Mev have been studied and excitation functions obtained for products formed by (p,xn), (p,pxn), (p,2pxn), and (p,3pxn) reactions. Radiation characteristics of the products were redetermined. Previously unreported γ-rays with energies 90 to 1050 kev have been found for W176, and 113 kev for W177. A new half-life of 2.7 ± 0.1 hr for W176 is reported. The cross sections for the (p,xn) reactions were compared with the values predicted by Jackson's schematic model and found to be in reasonable agreement. More complex reactions are discussed in the light of current nuclear theories.

Excitation of isomeric 1h 11/2 states in nuclear reactions induced by γ rays and neutrons and in beta decay

2001 ◽  
Vol 64 (11) ◽  
pp. 1901-1908 ◽  
Author(s):  
A. G. Belov ◽  
Yu. P. Gangrsky ◽  
L. M. Melnikova ◽  
V. Yu. Ponomarev ◽  
N. Tsoneva ◽  
...  
Keyword(s):  
Beta Decay ◽  
Nuclear Reactions ◽  
Γ Rays

Nuclear Processes Related to the Ap Stars and the Heaviest Chemical Elements

1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz
Keyword(s):  
Nuclear Physics ◽  
Nuclear Reactions ◽  
Chemical Elements ◽  
Fission Products ◽  
Abundance Pattern ◽  
Isotopic Shifts ◽  
Processed Material ◽  
R Process ◽  
Ap Stars ◽  
Nuclear Processes

SummaryIsotopic shifts in the lines of the heavy elements in Ap stars, and the characteristic abundance pattern of these elements point to the fact that we are observing mainly the products of rapid neutron capture. The peculiar A stars may be treated as the show windows for the products of a recent r-process in their neighbourhood. This process can be located either in Supernovae exploding in a binary system in which the present Ap stars were secondaries, or in Supernovae exploding in young clusters. Secondary processes, e.g. spontaneous fission or nuclear reactions with highly abundant fission products, may occur further with the r-processed material in the surface of the Ap stars. The role of these stars to the theory of nucleosynthesis and to nuclear physics is emphasized.

The Fine Structure of Irradiated Mouse Heart

1976 ◽  
Vol 34 ◽  
pp. 184-185
Author(s):  
Vivian V. Yang ◽  
S. Phyllis Stearner
Keyword(s):  
Microscopic Level ◽  
Ultrastructural Changes ◽  
Mouse Heart ◽  
Blood Vessel Wall ◽  
Histopathological Changes ◽  
Light Microscopic Level ◽  
Γ Rays ◽  
Fission Neutrons ◽  
Total Body

The heart is generally considered a radioresistant organ, and has received relatively little study after total-body irradiation with doses below the acutely lethal range. Some late damage in the irradiated heart has been described at the light microscopic level. However, since the dimensions of many important structures of the blood vessel wall are submicroscopic, investigators have turned to the electron microscope for adequate visualization of histopathological changes. Our studies are designed to evaluate ultrastructural changes in the mouse heart, particularly in the capillaries and muscle fibers, for 18 months after total-body exposure, and to compare the effects of 240 rad fission neutrons and 788 rad 60Co γ-rays.Three animals from each irradiated group and three control mice were sacrificed by ether inhalation at 4 days, and at 1, 3, 6, 12, and 18 months after irradiation. The thorax was opened and the heart was fixed briefly in situwith Karnofsky's fixative.

Nuclear Reactions in Deuterium Titanium

1990 ◽  
Vol 48 (2) ◽  
pp. 134-135
Author(s):  
D.M. Vanderwalker
Keyword(s):  
Nuclear Reactions ◽  
Ion Beam ◽  
Exothermic Reaction ◽  
Pure Titanium ◽  
Fundamental Interest ◽  
Transmission Electron ◽  
Iodide Titanium ◽  
A Cell ◽  
After Hours ◽  
Quantity Of Heat

There is a fundamental interest in electrochemical fusion of deuterium in palladium and titanium since its supposed discovery by Fleischmann and Pons. Their calorimetric experiments reveal that a large quantity of heat is released by Pd after hours in a cell, suggesting fusion occurs. They cannot explain fusion by force arguments, nor can it be an exothermic reaction on the formation of deuterides because a smaller quantity of heat is released. This study examines reactions of deuterium in titanium.Both iodide titanium and 99% pure titanium samples were encapsulated in vacuum tubes, annealed for 2h at 800 °C. The Ti foils were charged with deuterium in a D2SO4 D2O solution at a potential of .45V with respect to a calomel reference junction. Samples were ion beam thinned for transmission electron microscopy. The TEM was performed on the JEOL 200CX.The structure of D charged titanium is α-Ti with hexagonal and fee deuterides.

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