Radioactive Emanations Research Articles

Contribution of the Photonic Component to the Ionization of the Atmosphere by Earth Crust Radionuclides and Radioactive Emanations

Contribution of the Photonic Component to the Ionization of the Atmosphere by Earth Crust Radionuclides and Radioactive Emanations

Contribution of the Photonic Component to the Ionization of the Atmosphere by Earth Crust Nuclides and Radioactive Emanations

Abstract—We investigate the contribution of gamma radiation of natural radionuclides constituting the Earth crust, radioactive emanations, and their decay product in the ground to the intensity of production of ion pairs in the atmosphere against the background of ionization of the atmosphere by radioactive gases flowing to the atmosphere from the ground and propagating together with their short-lived daughter products. The density of the radon flux to the atmosphere is estimated by three methods: the reservoir method, the integration of altitude profiles of volume activity of radon, based on gamma spectroscopic observation and diffusion model. The distribution of the gamma dose rate dose from the earth radionuclides in the soil and in the atmosphere is calculated using Gleant4 software. The propagation of the radon isotopes and their decay products in the atmosphere is calculated using large eddy simulations supplemented with kinematic simulations of the subgrid transport of a passive scalar. It is shown that depending on the specific activity of nuclides in the ground and the turbulent regime of the atmosphere, the total contribution of the γ-radiation to the ion pair production rate in the atmospheric boundary layer is approximately from 1% to 20% and increases upon a decrease in the penetrability of the upper ground layer for radioactive emanations.

Can Radioactive Emanations in a Seismically Active Region Affect Atmospheric Electricity and the Ionosphere?

—Anomalous variations in radon emissions from the soil are sometimes observed before and after strong earthquakes. In this paper, we theoretically analyze the known hypothesis that these variations in radioactive emanations in the surface layer of the atmosphere cause variations in the vertical background current in the atmosphere with subsequent changes in the electron density {{n}_{e}} in the lower ionosphere. For this purpose, we will first assess the relation between radon emission variations and the vertical atmospheric current flowing into the ionosphere. Then we will solve a model problem concerning the spatial distribution of plasma density and electric field perturbations occurring in the E-layer of the ionosphere caused by an inflowing vertical current. It was believed that the current flowing into this layer contains only an electron component and is attenuated only by the recombination of electrons. The estimate of the maximum variation {{n}_{e}} is at least 3–5 orders of magnitude smaller than the observed anomalous variations, which allows us to conclude that this hypothesis is not plausible.

Conduction current density profile transformation near the earth’s surface, in connection with atmospheric stratification change

The paper considers physical conditions that influence the formation of vertical profiles of the conduction current density in the surface atmosphere. The proximity of the earth’s surface, which is a source of radioactive emanations and aerosols, determines the significant variability of atmospheric-electrical characteristics in height. The results obtained made it possible to identify the features of the conduction current density vertical profiles transformation with regard to the atmosphere stratification. The study of the weather conditions dynamics at the observation point, as well as the study of the conduction current density profile variability makes it possible to determine the nature of the influence of meteorological parameters on the process of charge transfer and accumulation in the studied layer.

Imprints of nonlinearity in radioactive gas Radon-222 expelled out of Bakreswar hot spring, India

Nonlinear time series analysis of data related to the radioactivity profile of a hot spring area can explore the dynamics of the geothermal activities along with other different nonlinear features of the Earth system. However, not much work in this field has been done so far in India. In this paper nonlinear time series analysis of the radioactive gas Radon-222 ( 222 Rn) (time series) data recorded at Bakreswar hot spring area of West Bengal, India during the period 2005-2010 was carried out to investigate the dynamics of the radioactive gas emanation process and its relation with the Earth’s tide. Power spectral density and the Hurst exponents were obtained for the above said time series signal using the nonlinear techniques of Fast Fourier Transform (FFT) and power law scaling relationship. An attempt was also made to understand the system dynamics using the surrogate and truncated data of the original time series as well. The result shows that the seasonal variations of the 222 Rn emission from the hot spring is highly influenced by the Earth’s tidal effects, and the same has been confirmed by the power spectral density plot. The estimated Hurst exponent from log p-log f plot reflects the anti-persistent Brownian motion nature of the whole five years recorded data set.

Earth electric field negative anomalies as earthquake precursors

In fair weather conditions, electric field potential gradient in the near-ground air takes positive values. Negative anomalies occur under the influence of different ionizing processes such as galactic cosmic ray flux and radioactive gas emanation from the ground. In the conditions of calm geomagnetic state and fair weather, anomalies can be used for earthquake forecast. In the paper, the efficiency of earthquake forecast based on negative anomalies is under the study. It was obtained that the efficiency of such a forecast during any weather conditions is 10%.

Exposure to Radioactive Emanations of Medical Personnel in Percutaneous Nephrolithotomy.

The use of radioactive emanations has been of great importance for the performance of endourology procedures, such as percutaneous nephrolithotomy (NLP). The damage to health caused by radiation has been a sensitive issue. The objective of this work was to determine the dose received by the surgeon during NLP and the total dose generated by the fluoroscope. A cross-sectional study was conducted with data from a cohort study with a duration of 18 months that included 101 patients. Radiation was measured with dosimeter during the last 6 months. During the last 6 months of the study, 34 patients were submitted to surgery. The average age was 47 years. Average fluoroscopy time was 58.3 second (24-122 seconds) in both male and female groups, with 57.16 seconds and 58.95 seconds per case, respectively (P = .6). Radiation emitted during 6 months for the 34 patients was 330.5 mGy. The total radiation measured by the dosimeter was 1 mSv, which is equivalent to 0.3% of the total radiation applied during the procedures. Doses measured by the dosimeter on the surgeon were within the recommended annual doses although dose received by the hands exceeds the authorized limits (500 mSv/y).

Statistical analysis of the atmospheric ion concentrations and mobility distributions at a tropical station, Pune

Measurements of ion mobility spectra in the range of 0.00133–3.16 cm2 s−1 volt−1 were made at a tropical station, Pune, India from March 2010 to December 2012. A total of 12 004 hourly averaged ion mobility spectra were obtained over the entire period. The average mobility spectrum shows three distinct peaks for the traditional categories of small, intermediate and large ions. However, to understand the seasonal variability and statistical characteristics of ions that justify their further division into five different categories, we have divided our data into five mobility ranges of small cluster, big cluster, intermediate, light large and heavy large ions. Our results show that small ions in atmospheric conditions at Pune can be further divided into two classes with the boundary at a mobility of 1.78 cm2 s−1 volt−1 (diameter 0.66 nm) where relative standard deviation of ion concentrations starts increasing instead of decreasing with mobility. Some but not all small cluster ions of negative polarity are likely to grow to the intermediate ion size. Further, the growth from small to big cluster ions is faster for negative than positive ions. In contrast to the observations of higher mean values of ion concentration in warm season than in winter at a midlatitude station, our observations show higher mean values of ion concentration in winter than in the warm season at this tropical station. This contrast in observations at the two sites is explained by trapping of radioactive emanations by snow at the ground during winter at the midlatitude site.Our observations indicate that intermediate ions are generated by two independent processes, probably by growth of big cluster ions and by direct nucleation from trace gases. Further, the results indicate that the sources for light and heavy large ions are different.

Estimating granite roughness using systematic random sampling for the evaluation of radon gas emanation from ornamental granite rocks

Author Summary: There are three natural radioactive families according to their decay, which are: the uranium series (238U decreasing to stable 206Pb), the actinium series (235U decreasing to stable 207Pb) and the thorium series (236U → 232Th decreasing to stable 208Pb). The three series all have radon gas as an intermediary element, but each with a different atomic mass (222Rn, 219Rn and 220Rn). The three isotopes are inert gases at ambient conditions and all are alpha particles emitters. Soils naturally emanate these radioactive gases in variable concentrations depending on composition and location. The radon radioactive emanation is a mass flow composed of radionuclides emitted to the atmosphere from the surface of the material, or transported to it. Emanation depends on the amount of radon atoms formed from the decay of radium and on the surface roughness of the material. Treatment such as polishing can be used to decrease radon gas emanation by closing open surface pores and reducing the specific surface area. This study aims at evaluating granite roughness of experimental plates of ornamental rocks using a systematic random sampling approach in order to minimise analysis time. To validate the systematic minimum area sampling results these were compared to measurements made over the whole reference area. It is concluded that measurements can be conducted in just a few locations using systematic random sampling, significantly reducing the time for obtaining estimates of the granite’s roughness by factors 150–200.

Some features of fluid dynamics at platforms as illustrated by the example of variations in subsoil radon and seismic noises in the Moscow and Nizhni Novgorod regions

Huge areas of ancient platforms are traditionally ascribed to geodynamically passive structures of the Earth’s crust. This leads to some conservatism in the interpretation of diverse natural phenomena at platforms (landslide, karst‐suffosional processes, rock impacts and gas explosions in mines, breakups of pipelines, and others), which are typically related to the exogenous change in the geological environment of the sedimentary cover [1]. However, following Kropotkin [2], who pointed to a possible relation of global change in the strain-deformational state of the Earth’s crust with variations in the Earth’s rotation, we demonstrated [3] that these processes affect fluid dynamics in both geosynclinal (seismically active) and platformal regions, thus defining the evolution dynamics of exogenous processes in decompressed areas of sedimentary cover that are formed above faults in the crystalline basement. The processes determine the rhythmic evolution of diverse geodynamic phenomena at platforms, including weak seismic activity [4]. Our previous research in seismically active regions showed that changes in the fluid dynamics of faults caused by variations in the strain-deformed state of the rocks is adequately correlated with variations in the radioactive and hydrocarbon emanation [5] and seismic noises [6]. Temporal series of the measured parameters of the aforementioned fields reflects the entire spectrum of variations in the strain-deformational state of the Earth’s crust, from secular (60 to 70 years) to circadian tidals (12 h and less). This allows one to use the emanation and seismic emission methods as highly sensitive noise-proof technologies for monitoring the geological environment, especially suitable for urban agglomerations, where the level of electromagnetic and vibrational‐noise emanation rules out or constrains the application of many methods of geophysical monitoring.

Radioactive Origin of Emissions Observed from Uranium Compounds and Their Silica Cells.

Uranyl ion fluorescence at 520 nm has been recorded from solutions that were excited only by radioactive emanations from trace concentrations of a 232U impurity or added 225actinium nitrate. This fluorescence had also been observed by others from 233UO4·2H2O, but was attributed to a nuclear origin. Atomic oxygen emission was observed for a 233UO4·2H2O sample, as was a broad visible emission originating from the fused silica tube that contained the radioactive sample.

On the global atmospheric electrical circuit

A model of global atmospheric electric circuit has been developed, which incorporates the pollution due to aerosol particles of anthropogenic and volcanic origins and the ionization caused by the coronal discharges due to intense electric field beneath thunderclouds in the atmospheric layers close to the earth's surface. Also the effects of solar activity and of Stratospheric Aerosol Particles (SAP) on the parameters of the circuit have been studied. The global distribution of Aerosol Particles (AP) of man-made origin has been assumed on the basis of world population density and that of volcanic origin on the basis of global distribution of volcanic activities. The thunderstorms are assumed to be the current generators of the global circuit. The latitudinal, longitudinal and height variations of atmospheric conductivity have been calculated from the known variations of ionization caused by cosmic rays, the radio-active emanations and intense electric fields beneath thunderclouds (over continents), along with the assumed variation of AP concentration. On increasing the AP concentration over the northern hemisphere by about 5 times that of the southern hemisphere, the ionospheric potential increases to about 6% and electric field increases in non-mountainous regions more than that in the high mountain regions. A large increase in SAP serves to increase the global resistance while both global current and ionospheric potential decrease. However, for low SAP concentration, the ionospheric potential increases. The SAP affect the electrical structure of the stratosphere without much influencing the troposphere except in the volcanically active regions, where conductivity is low due to high AP concentration. The major influence on the global atmospheric electric circuit occurs in response to solar activity. In the absence of local effects, the calculated variation of ionospheric potential is 14%. However, in real atmosphere (where both local and global processes act simultaneously), the ionospheric potential is found to vary by only about 3%. This has little effect on the ground electrical properties where more than 30% of the variations have been found to be caused by the local effect.

Geochemical controls on 99Tc transport and retention

Measurements of the isotopic abundance of 99Ru in rocks containing fossils of natural nuclear fission reactors show that 99Tc was geochemically active during nuclear criticality 2 Gyr. ago. The element is deficient in the reactor zones and enriched in the rocks peripheral to the zones of criticality. Theoretical consideration suggests that changes in the chemical environment produced by increased temperatures and/or high fluxes of radioactive emanations may have increased the element's solubility in a coexisting aqueous phase. The increased solubility allowed portions of the fission product to be transported away from the reactor zones by the mobile fluid.

Mesure de la masse superficielle d'un élément lourd consultant une cible mince, en présence d'éléments légers

Elastic scattering of α particles has been used to measure the quantity of a heavy element of given Z (⩾28) in a target the other components of which are light ( Z⪅17). The α particles are emitted by 212Po from a radioactive emanation source. Calibrations of the device can be made using a target of known thickness of any other heavy element. A precision of the order of ±10% can be reached.

Electrode effect at a mountain station

Electric space charge densities have been computed from the measurements of atmospheric poterrtial made at 0.25 m, 0.50 m and 1 m above the ground. The potential was measured using Crozier's passive anterrna technique at Gulmarg (2700 m). The results indicate the presence of a considerable amount of net negative space charge at the 0.50 m level at the station throughout the day and night (in fair weather) under calm or light wind conditions and in the absence of snow at or around the station. At 0.25 m a greater magnitude of negative space charge was observed which disappeared soon after the sunrise and a considerable positive charge appeared which persisted during the main convective period. The results are seen to be in general agreement with Hoppel's (1969) theoretical prediction of charge stratification under stable conditions with the negative space charge in an upper region and the positive in the lower region next to the ground. A strong electrode effect was observed for a number of days after an unusually long spell of heavy rain. This has been explained in terms of the reduction of radioactive emanations from the soil due to excessive moisture. Further evidence of the electrode effect was found from the measurements of polar conductivities carried out close to a one metre thick snow surface.

Dynamics of the changes taking place in the content of radioactive emanations in the air of mining installations

Dynamics of the changes taking place in the content of radioactive emanations in the air of mining installations

Lead-212 in the urban boundary layer of New York City.

The radioactive emanation product lead-212 is useful in estimating rates of air exchange within the urban boundary layer. The concentration of lead-212 is negligible in air of oceanic origin as well as in air above continental areas under snow cover. On several days when conditions were such that one of these types of air mass approached New York City, measurements were made which show that the source strength of lead-212 within the city is relatively constant. On two such days vertical profiles of the concentration of lead-212 were measured from the Empire State Building, which served as a sampling tower. From the data of these profiles and a two-layer model of the urban boundary layer, we estimate the vertical eddy diffusivity to be of the order of tens of square meters per second and the residence time of air within the street layer to be of the order of S minutes. These results are consistent with the observed distribution of stable lead and with an independent estimate of the eddy viscosity from a wind profile. Under moderate wind conditions and with a mixing depth of hundreds of meters, virtually all the horizontal transport of lead-212 and other tracers with street-level sources takes place in the advective layer.

Measurements of radon 220 (thoron) in the atmosphere below 50 centimeters

Direct measurements of Rn220 (thoron) have been made from the ground surface to a height of 50 cm, using apparatus adapted from that of G. W. Israel. Activity profiles are similar to those calculated by Jacobi and Andre and by Wormell; this supports their assumption that in the 50-cm height range a linear increase of diffusivity with height property describes the turbulent diffusion of radioactive emanations from the soil surface, at least for turbulence of moderate intensity. The maximum activity at ground level, as expected, occurs at night during intervals of very low wind speed; it reaches values 75 to 150 times as high as the typical activities at 50 cm and 1 m. The Rn220 flux through the soil surface at our site is approximately 2.1×10−15 curie cm−2 sec−1, or 0.006 atom cm−2 sec−1. The activities of Rn220 plus Po216 observed under conditions of very low turbulent diffusion are capable of yielding an ion production rate of about 250 ion pairs cm−3 sec−1 in the lowest 10 cm of the atmosphere over appreciable time intervals; this seems adequate to explain the presence of the shallow stratum of relatively high space charge density previously reported to exist under these conditions.

The ionization state of the atmosphere as a function of the meteorological elements and of various sources of ions

The content of positive (N+) and negative (N−) medium ions in the atmosphere, was measured during five periods. The influence of wind velocity and direction, humidity, rainfall and various sources of natural ionization on the N+ and N− content and the relation N+/N− were investigated. Emphasis was placed on the influence of a special kind of weather called “chamsin” in Israel. The amount of N+ and N− and the relation N+/N− began to increase about 10 hours before the meteorological instruments indicated the specific features of this kind of weather — increase in temperature and decrease in humidity. As some laboratory tests have shown that N− has a beneficial physiological and biological influence, and N+ has the opposite effect, it is assumed that the above-mentioned changes in N+/N− are the cause for persons who are sensitive to this kind of weather, feeling ill. The increase in N+ and N− with the increase in radioactive emanation from the earth and the nuclear tests was established.

Production of the Joshi Effect under β- and γ-Rays

EXAMINATION of the literature having shown absence of information on the Joshi effect under radioactive emanations, a detailed investigation was made employing, in the first instance, a β-ray capsule with negligible γ-ray activity. Siemens ozonizer type tubes charged with various vapours and gases and excited by commercial-frequency potentials of kilovolts were used. In agreement with results obtained with visible1 and ultra-violet2 radiation and with X-rays3–6, and employing especially organic vapours, an exposure to β-rays caused an instantaneous and reversible positive effect + Δi at relatively low voltage; with slight increase of voltage, + Δi diminished sharply; and finally changed over to − Δi above Vm, the threshold for a ‘self-maintained’ discharge. Thus, for example, cyclohexane vapour showed under β-rays about 150 per cent positive Joshi effect at 4 kV.; + 9.5 per cent and − 5.8 per cent at 6 and 8 kV. respectively.