Reduction of the radiation in radioactive substances

2020 ◽  
Vol 34 (04) ◽  
pp. 2050001
Author(s):  
Gianni Albertini ◽  
Fabio Cardone ◽  
Giovanni Cherubini ◽  
Ettore Guerriero ◽  
Alberto Rosada

The radioactivity reduction of a system containing Ni-63 radioactive nuclei after an appropriate ultrasound treatment in an apparatus designed on purpose is reported. The application of ultrasounds for 200 s resulted in the partial disappearance of about 13% of the radioactive Ni-63 nuclei and the appearance of nonradioactive elements. The formation of new elements, not belonging to the decay chain of Nickel-63, is a strong issue where strong nuclear reactions transform Nickel into different elements rather than the usual weak interaction, responsible for the decay, which is accelerated. This way, the time necessary to halve the intensity is shortened by about 20 years, without altering the Ni-63 decay constant, which is [Formula: see text] years. Two cases producing similar effects in other radioactive systems after ultrasound treatment are described in the literature and support this finding, which is not forecast by the commonly accepted theories. A theory able to explain these and other results is also reported.

2019 ◽  
Vol 22 (2) ◽  
pp. 213-218
Author(s):  
Ngoc Duy Nguyen ◽  
Thi To Vy Vo ◽  
Kim Uyen Nguyen

The critical concentration plays an important role in the consideration of the analysts, such as gamma or alpha analyzers, for the isotopic analysis. Since the 232Th isotope and its a-decay daughters are abundant in the environments of soils, rocks and water, it is necessary to investigate the content of these isotopes to reduce the risks of health. In this work, the critical concentrations of the mentioned radioactive nuclei were estimated based on their radioactivities for the alpha analysts. The a-decay half-lives of the nuclei in the decay chain of the 232Th isotope were re-examined for the radioactivities. The semi-empirical formulae proposed by Viola-Seaberg, Royer and Poenaru were applied to the estimation. The predicted half-lives were normalized by their average values and compared to the data (NuDat) of the National Nuclear Data Center, Brookhaven National Laboratory. The results show that there exist a large uncertainty, 15% - 95% dispersed from the average values (in decimal logarithmic scale), of the half-lives evaluated by each models. Most of average half-lives are close to the NuDat data except the multi-decay-mode isotopes. The relationships between the estimated half-lives and the NuDat data are deduced as linear functions. The decay-constant deviations due to the half-life uncertainty are in the range of 1% - 120% from the average values. The large radioactivity uncertainty due to the half-lives estimated by the three models should be paid an attention for considering the environmental samples for the analysis of the natural exotic isotopes using alpha spectrometers. By assuming an efficiency of 100%, the critical concentration for the alpha analyst of the 232Th nucleus is found to be in the range 1.5 – 2.5 microgram/(l or kg).


2011 ◽  
Vol 2 ◽  
pp. 61-64
Author(s):  
Arbind Kumar Mallik

Nucleus is composed of uncharged neutrons and charged protons, chiefly given the fact that the electrostatic repulsion of the protons tends to disrupt the nucleus? What is the nature of forces that ensure stability between charged and uncharged particles in the nucleus? Attempts have been made to solve this problem both on the experimental and theoretical sides. In this article, a brief statement of these investigations is described. Search for the causes of stability of nuclei have been made in the following four directions, Relative abundance of elements as well as of isotopes that occur in nature, the binding energy per nucleon curve, Decay constant of natural radioactive substances, Magic numbers.Keywords: Uncharged neutrons; Charged and uncharged particles; NucleiThe Himalayan PhysicsVol.2, No.2, May, 2011Page: 61-64Uploaded Date: 1 August, 2011


1976 ◽  
Vol 32 ◽  
pp. 169-182
Author(s):  
B. Kuchowicz

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.


Author(s):  
D.M. Vanderwalker

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.


Author(s):  
R. Gotthardt ◽  
A. Horsewell ◽  
F. Paschoud ◽  
S. Proennecke ◽  
M. Victoria

Fusion reactor materials will be damaged by an intense field of energetic neutrons. There is no neutron source of sufficient intensity at these energies available at present, so the material properties are being correlated with those obtained in irradiation with other irradiation sorces. Irradiation with 600 MeV protons produces both displacement damage and impurities due to nuclear reactions. Helium and hydrogen are produced as gaseous impurities. Other metallic impurities are also created . The main elements of the microstructure observed after irradiation in the PIREX facility, are described in the following paragraphs.A. Defect clusters at low irradiation doses: In specimens irradiated to very low doses (1021-1024 protons.m-2), so that there is no superimposition of contrast, small defect clusters have been observed by the weak beam technique. Detailed analysis of the visible contrast (>0.5 nm diameter) revealed the presence of stacking fault tetrahedra, dislocation loops and a certain number of unidentified clusters . Typical results in Cu and Au are shown in Fig. 1.


1968 ◽  
Vol 111 (1) ◽  
pp. 392-416 ◽  
Author(s):  
K DIETRICH ◽  
K HARA

1971 ◽  
Vol 32 (1) ◽  
pp. 7-9 ◽  
Author(s):  
J. Galin ◽  
D. Guerreau ◽  
M. Lefort ◽  
X. Tarrago

1961 ◽  
Vol 1 (03) ◽  
pp. 246-257
Author(s):  
M. O. Roxo-Nobre ◽  
D. M. Vizeu

SummaryA technique of mouldage, employing fluid radioactive substances is adopted, to replace the radium-moulding in the treatment of large surfaces. The technique is explained in detail, proving its greater safety by remote control and an adjustment of adequate means of protection. Distribution is obtained by means of a serpentine attached to the mould in question, which follows the Paterson-Parker system. The authors believe the distribution of radiation on curved anatomical areas to be much more uniform by mould system than any other process of application of the same radiation of rectilineal propagation, transmitted at greater focus-skin distances. The isotopes used up to now were the La140 and others of reduced half-life, in order to prevent the danger of eventual contaminations. Although the application of the process still has very little clinical practice, the technique is presented with a view to experimentation in extensive superficial tumours, or those of little depth, such as tumours of the skin, breast, penis, thyrreoid and lymph nodes.


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