Measurements Of Background Radiation Research Articles

The Principles and Laws of Black Hole Universe

A new alternative cosmological model called black hole universe was recently developed by the author on the basis of the following three fundamentals: 1) the principle of spacetime black hole equivalence, 2) the cosmological principle of spacetime isotropy and homogeneity, and 3) the Einsteinian general theory of relativity that describes the effect of matter on spacetime. According to this black hole model of the universe, the author up-to-dately has self-consistently described the origin, structure, evolution, expansion, and acceleration of the universe, quantitatively explained the measurements of cosmic microwave background radiation, type Ia supernovae’s luminosity distance and redshift, and dynamic properties of star-like, massive, and supermassive black holes such as gamma-ray bursts, X-rays flares from galactic centers, and quasars, and fully overcome the difficulties of the conventional model of the universe such as the problems of horizon, flatness, monopole, inflation, dark matter, dark energy, and so on. In this paper, the author will examine and overview thoroughly this new cosmological model and completely describe its development from the three fundamentals and its creative explanations to the existing observations of the universe. From this comprehensive investigation of the new cosmological model, the author will further reveal the fundamental regularities and laws of the black hole universe with respect to the spacetime mass and radius, spacetime equilibrium, spacetime expansion and acceleration, spacetime radiation energy, and spacetime entropy variation. These efforts will help us to uncover various regularities and mysteries of the universe.

Inflationary cosmology and the scale-invariant spectrum

The claim of inflationary cosmology to explain certain observable facts, which the Friedmann-Roberston-Walker models of ‘Big-Bang’ cosmology were forced to assume, has already been the subject of significant philosophical analysis. However, the principal empirical claim of inflationary cosmology, that it can predict the scale-invariant power spectrum of density perturbations, as detected in measurements of the cosmic microwave background radiation, has hitherto been taken at face value by philosophers.The purpose of this paper is to expound the theory of density perturbations used by inflationary cosmology, to assess whether inflation really does predict a scale-invariant spectrum, and to identify the assumptions necessary for such a derivation.The first section of the paper explains what a scale-invariant power-spectrum is, and the requirements placed on a cosmological theory of such density perturbations. The second section explains and analyses the concept of the Hubble horizon, and its behaviour within an inflationary space-time. The third section expounds the inflationary derivation of scale-invariance, and scrutinises the assumptions within that derivation. The fourth section analyses the explanatory role of ‘horizon-crossing’ within the inflationary scenario.

An Experiment in Radiation Measurement Using the Depron Instrument

Most of the radiation measurements have been made onboard spacecraft flying along orbits with an inclination of up to 51.6 degrees. Due to the prospect of manned missions at orbits with larger inclinations, it is advisable to conduct preliminary detailed dosimetry measurements at a high-inclination orbit; due to its polar orbit, the Lomonosov satellite provides good opportunities for such study. We chose a method of cosmic radiation dosimetry based on semiconductor detectors. This method is widely used onboard spacecraft, including full-time radiation monitoring onboard the International Space Station (ISS). It should be noted that not only did the charged particles contribute significantly in the dose equivalent, but also did the neutrons. Semiconductor detectors have low sensitivity to neutron radiation and are not sufficient for detecting the expected flux of neutrons. We add a thermal neutron counter to the proposed device in order to provide an opportunity for estimation of neutron flux variations along the satellite trajectory. Thus, the design of the instrument DEPRON (Dosimeter of Electrons, PROtons and Neutrons) was determined. DEPRON is intended for registration of the absorbed doses and linear energy transfer spectra for high-energy electrons, protons and nuclei of space radiation, as well as registration of thermal neutrons. The present paper provides a brief description of the DEPRON instrument. Its calibration results and the first mission results of background radiation measurements are also presented.

On the Inverse Problem of Finding Cosmic Strings and Other Topological Defects

We consider how microlocal methods developed for tomographic problems can be used to detect singularities of the Lorentzian metric of the Universe using measurements of the Cosmic Microwave Background radiation. The physical model we study is mathematically rigorous but highly idealized.

Estimation of outdoor and indoor effective dose and ex-cess lifetime cancer risk from Gamma dose rates in Gonabad, Iran

Humans' background gamma irradiation in the indoor and outdoor environments is a major concern in the world. The study area was Gonabad city. Four stations and buildings for background radiation measurement of outdoor and indoor were randomly selected and the G.M detector (X5C plus) was used. All dose rates on display of survey meter were recorded and mean of all data in each station and buildings was computed and taken as measured dose rate of that particular station. The average dose rates of background radiation were 84.2 nSv/h for outdoor and 108.6 nSv/h for indoor, maximum and minimum dose rates were 88.9 nSv/h and 77.7 nSv/h for outdoor measurements and 125.4 nSv/h and 94.1 nSv/h for indoor measurements, respectively. Results show that the annual effective dose is 0.64 mSv, which compare to global level of the annual effective dose 0.48 mSv is high. Estimated excess lifetime cancer risk was 2.24×10 -3 , indicated that it is large as compared to the world average value of 0.25×10 -3 .

Citizen-based environmental radiation monitoring network

This paper discusses a Citizen Radiation Monitoring project designed and implemented by the Natural Resources Defense Council . The goal of the project was to implement a radiation monitoring system that provides radiation data accessible to the public. The monitoring system consisted of usage of a radiation detector integrated with near real-time data collection and visualization. The monitoring systems were installed at five different locations and background radiation measurements were taken. The developed monitoring system demonstrated that citizen-based monitoring system could provide accessible radiation data to the general public and relevant to the area where they live.

Design of a portable dose rate detector based on a double Geiger–Mueller counter

A portable dose rate detector was designed to monitor radioactive pollution and radioactive environments. The portable dose detector can measure background radiation levels (0.1 μSv/h) to nuclear accident radiation levels (>10 Sv/h). Both automatic switch technology of a double Geiger–Mueller counter and time-to-count technology were adopted to broaden the measurement range of the instrument. Global positioning systems and the 3G telecommunication protocol were installed to prevent radiation damage to the human body. In addition, the Monte Carlo N-Particle code was used to design the thin layer of metal for energy compensation, which was used to flatten energy response The portable dose rate detector has been calibrated by the standard radiation field method, and it can be used alone or in combination with additional radiation detectors.

Association of Radon Background and Total Background Ionizing Radiation with Alzheimer’s Disease Deaths in U.S. States

Exposure of the brain to ionizing radiation might promote the development of Alzheimer's disease (AD). Analysis of AD death rates versus radon background radiation and total background radiation in U.S. states. Total background, radon background, cosmic and terrestrial background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States and Report No. 160 - Ionizing Radiation Exposure of the Population of the United States. 2013 AD death rates by U.S. state are from the Alzheimer's Association. Radon background ionizing radiation was significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.467, p = 0.001). Total background ionizing radiation was also significantly correlated with AD death rate in 50 states and the District of Columbia (r = 0.452, p = 0.001). Multivariate linear regression weighted by state population demonstrated that AD death rate was significantly correlated with radon background (β= 0.169, p < 0.001), age (β= 0.231, p < 0.001), hypertension (β= 0.155, p < 0.001), and diabetes (β= 0.353, p < 0.001). Our findings, like other studies, suggest that ionizing radiation is a risk factor for AD. Intranasal inhalation of radon gas could subject the rhinencephalon and hippocampus to damaging radiation that initiates AD. The damage would accumulate over time, causing age to be a powerful risk factor.

Background radiation dose of dumpsites in Ota and Environs

In-situ measurement of background radiation dose from selected dumpsites in Ota and its environs was done using Radialert Nuclear Radiation Monitor (Digilert 200). Ten measurements were taken from each dumpsite. The measured background radiation range between 0.015 mRhr-1 for AOD and 0.028 mRhr-1 for SUS dumpsites. The calculated annual equivalent doses vary between 1.31 mSvyr-1 for AOD and 2.28 mSv/yr for SUS dumpsites. The air absorbed dose calculated ranged from 150 nGyhr-1 to 280 nGy/hr for AOD and SUS dumpsites respectively with an average value of 217 nGyhr-1 for all the locations. All the estimated parameters were higher than permissible limit set for background radiation for the general public. Conclusively, the associated challenge and radiation burden posed by the wastes on the studied locations and scavengers is high. Therefore, there is need by the regulatory authorities to look into the way and how waste can be properly managed so as to alleviate the effects on the populace leaving and working in the dumpsites vicinity.

Measurement of Background Radiation

The publication by Sulekha Rao et al . entails the measurement of radiation in three areas, i.e. Gopalpur, Chhatrapur and Rushikulya along the southern coast of Odisha by deploying TLD badges in different houses and later converting the data into annual dose equivalent in terms of mSv yr -1 . The attempt by the authors to measure background radiation of certain areas and then discuss various aspects of radiation and its health effects is quite informative and appreciable. However, certain statements made in the publication, as noted below, may be incorrect and amount to misleading the readers and the public at large.

Analysis of energetic radiation associated with thunderstorms in the Ebro delta region in Spain

AbstractThe analysis of high‐energy background radiation (0.1–2 MeV) enhancements during eight winter thunderstorms and five summer storms in the Ebro delta region in the northeast of Spain is presented. For the first time, high‐energy radiation counts, precipitation, radar reflectivity, and very high frequency lightning detections to infer charge regions altitude have been analyzed in order to find out what produces the measured background radiation increments associated with storms. The good agreement between radar reflectivity and precipitation with increases in background radiation counts coupled with the spectrum analysis comparing rain/no rain periods suggests that radon‐ion daughters play a major role in the radiation increments reported. No evidence has been found supporting that measured background radiation enhancements can be produced by storm electric fields. Finally, a single case of a high‐energy radiation increase was prior to a cloud‐to‐ground lightning stroke, which reinforces the theory that a lower positive charge layer's existence is important for the production of Terrestrial Ground Enhancements.

Bone Mineral Densitometry (BMD) Precision and Scattered Radiation Level of Dual Energy X-ray Absorptiometry (DXA) Installed in Mymensingh Nuclear Medicine Unit, Bangladesh

Dual Energy X-ray Absorptiometry (DXA) has long been and remains the most widely used technique for Bone Mineral Densitometry (BMD) measurement. Several manufacturers developed their performance of DXA with various types of measurement software but still not a unique data processing system which can ensure the unique measurement for the patients. The aim of this article is to show the precision level of BMD in DXA machine GE (Model: DPX Lunar) installed at INMAS, Mymensingh and to measure background radiation consistency during acquisition. A rectangular shape QA phantom of variable density for precision measurement and survey meter (Austral Rad Mini 8 in 1) for radiation monitoring were used. Coefficient of Variation for BMD values was 0.37% and always ranges from 0.32% to 0.38%. Radiation survey meter reading always showed the values ranges from 0-3 µSv/hr. It can be concluded that these good QC are not the conformity of exact measurement because there some reference values involved in T-score or Z-score measurement. These reference values were taken from healthy adult Caucasian women which are different from Bangladeshi population.

Background Radiation Measurements at High Power Research Reactors

Background Radiation Measurements at High Power Research Reactors

Background radiation measurements at high power research reactors

Research reactors host a wide range of activities that make use of the intense neutron fluxes generated at these facilities. Recent interest in performing measurements with relatively low event rates, e.g. reactor antineutrino detection, at these facilities necessitates a detailed understanding of background radiation fields. Both reactor-correlated and naturally occurring background sources are potentially important, even at levels well below those of importance for typical activities. Here we describe a comprehensive series of background assessments at three high-power research reactors, including γ-ray, neutron, and muon measurements. For each facility we describe the characteristics and identify the sources of the background fields encountered. The general understanding gained of background production mechanisms and their relationship to facility features will prove valuable for the planning of any sensitive measurement conducted therein.

Development of environmental radiation monitoring system using inspector+ and FPGA board

In this report, we present the development of an environmental radiation monitoring system. The system includes Inspector+ dose meter, FPGA board, and LabVIEW interface. In the electronic board using FPGA, the embedded VHDL program is developed for FPGA board. Its functions are to accumulate pulse signals from the Inspector+, transmit data to the computer. Computer interface is written on LabVIEW platform. Its functions are to receive data from FPGA board, plot data, store data, as well as control the FPGA board. We evaluate the response of the system by using a standard pulse generator. With this system, we carry out the measurement of environmental background radiation in two experimental rooms and outside at Nuclear physics Department, University of Science, VNU-HCMC.

CERN@school: demonstrating physics with the Timepix detector

This article shows how the Timepix hybrid silicon pixel detector, developed by the Medipix2 Collaboration, can be used by students and teachers alike to demonstrate some key aspects of any well-rounded physics curriculum with CERN@school. After an overview of the programme, the detector’s capabilities for measuring and visualising ionising radiation are examined. The classification of clusters – groups of adjacent pixels – is discussed with respect to identifying the different types of particles. Three demonstration experiments – background radiation measurements, radiation profiles and the attenuation of radiation – are described; these can used as part of lessons or as inspiration for independent research projects. Results for exemplar data-sets are presented for reference, as well as details of ongoing research projects inspired by these experiments. Interested readers are encouraged to join the CERN@school Collaboration and so contribute to achieving the programme’s aim of inspiring the next generation of scientists and engineers.

Directional dependence of the local estimation of H0 and the nonperturbative effects of primordial curvature perturbations

Recent measurements of the cosmic microwave background (CMB) radiation have shown an apparent tension with the present value of the Hubble parameter inferred from local observations of supernovae, which look closer, i.e. brighter, than what is expected in a homogeneous model with a value of H0 equal to the one estimated from CMB observations. We examine the possibility that such a discrepancy is the consequence of the presence of a local inhomogeneity seeded by primordial curvature perturbations, finding that a negative peak of the order of less than two standard deviations could allow to fit low-redshift supernovae observations without the need of using a value of the Hubble parameter different from H0CMB. The type of inhomogeneity we consider does not modify the distance to the last scattering, making it compatible with the constraints of the PLANCK mission data. The effect on the luminosity distance is in fact localized around the region in space where the transition between different values of the curvature perturbations occurs, producing a local decrease, while the distance outside the inhomogeneity is not affected. Our calculation is fully relativistic and nonperturbative, and for this reason shows important effects which were missed in the previous investigations using relativistic perturbations or Newtonian approximations, because the structures seeded by primordial curvature perturbations can be today highly nonlinear, and relativist Doppler terms cannot be neglected. Because of these effects the correction to the luminosity distance necessary to explain observations is associated to a compensated structure which involves both an underdense central region and an overdense outer shell, ensuring that the distance to the last scattering surface is unaffected. Comparison with studies of local structure based on galaxy surveys analysis reveals that the density profile we find could in fact be compatible with the one obtained for the same region of sky where most of the supernovae used for the local H0 estimation are located, suggesting a possible directional dependence which could be partially attributed to the presence of the Sloan Great Wall and hinting to the need of a more careful investigation, including a wider set of low-redshift supernovae in different regions of the sky.

Lung Cancer Hormesis in High Impact States Where Nuclear Testing Occurred

BackgroundHormesis is a favorable biological response to low toxin exposure. In the case of radiation, large doses are carcinogenic, but low doses might be protective. In the current study, we analyzed lung cancer incidence in high-impact radiation states where nuclear testing occurred and compared it with lung cancer incidence in the remaining normal-impact radiation states and the District of Columbia. Materials and MethodsLung cancer incidence data were from the American Cancer Society. Tobacco use 2012 data were from the Centers for Disease Control and Prevention. The distribution of states grouped according to lung cancer incidence interval was from the Centers for Disease Control and Prevention. Total background radiation measurements (terrestrial + cosmic + radon) were from Assessment of Variations in Radiation Exposure in the United States (2005). Data on high- and normal-impact states were from the National Radiation Exposure Screening & Education Program (RESEP). Congress passed the Radiation Exposure Compensation Act Amendments of 2000, creating RESEP, to help thousands of people diagnosed with cancer and other diseases caused by exposure to nuclear fallout or radioactive materials such as uranium. These people live in 12 high-impact states where nuclear testing had occurred. High-impact states were not designated according to measurements of background radiation. ResultsLung cancer incidence is significantly lower in high-impact states in men (t = 5.4 for unequal variance; P < .001) and women (t = 3.0; P < .001). The clustering of the 12 high-impact states in the 2 lowest lung cancer incidence intervals (26.8-56.9 and 57.0-63.2) is statistically significant (P < .001, Fisher exact test, 2-tailed). Because cigarette smoking is ordinarily the most powerful risk factor for lung cancer, multivariate linear regression analysis of the effect of U.S. state group (normal-impact, high-impact, or extra high-impact for Nevada, Utah, and Arizona) on lung cancer incidence in men and women was performed. (In Nevada, Utah, and Arizona, men and women would have been downwind.) The U.S. state group impact was significant (P < .001 for men; P = .015 for women). The effect of percentage of smokers in the population was significant (P < .001 for men; P < .001 for women). The effect of total background radiation was significant (P = .029 for men; P < .029 for women); like the state group impact, more background radiation exposure was associated with less lung cancer. ConclusionHormesis is still mired in controversy. Yet, it is of vital medical importance because of the continuing debate over whether the low-level radiation doses from diagnostic x-ray procedures, such as computed tomography scans, are harmful. Our analysis adds to the body of evidence suggesting that the linear no threshold model of radiation carcinogenicity in lung cancer might not be correct. Low-level radiation exposure might protect against lung cancer rather than cause it.

Detection of ultra-high-energy neutrinos by IceCube: sterile neutrino scenario

The short-baseline neutrino oscillation experiments, the excess of radiation from the measurement of the cosmic microwave background radiation, the necessity of the nonbaryonic dark matter candidate and the depletion of the neutrino flux in IceCube all seem to hint at new physics beyond the standard model. An economical way to address these issues is to invoke the existence of sterile neutrinos. We present simple extensions of the standard model with additional three sterile neutrinos and discuss the corresponding PMNS like neutrino flavor mixing matrix. The noteworthy features of the sterile neutrino scenario advocated here is that the lightest one is almost degenerate with one of the active neutrinos, the second sterile has mass of order eV and the heaviest one is in the keV range. In the present scenario, the short baseline anomaly is explained through $\Delta m^2\sim 1\, {\rm eV^2}$, the depletion of muon neutrino flux in IceCube is explained through $\Delta m^2\sim 4.0\times 10^{-16}\, {\rm eV^2}$ and the dark matter problem is addressed through $\Delta m^2\sim 1\, {\rm keV^2}$. Our proposed mixing matrix is also compatible with the observed neutrino oscillation data. We show that the high energy muon and the tau neutrino fluxes from Gamma Ray Bursts can be depleted in IceCube by as much as 38% and 43% respectively. These substantial depletion in both muon and tau neutrino fluxes is due to their small but sizable mixing with the sterile neutrinos.

Evaluation of the natural gamma radiation level in residential zones and determination of annual effective exposure dose in the residents of Hamadan province, Iran, 2012

Background and Aim: Human is always exposed to natural background ionizing radiation which may have harmful effects; therefore, measurement of the natural background radiation is important. In this study, was measured the dose of effective natural background gamma radiation in indoor residential zones of Hamadan Province. Material and Methods: In this cross-sectional study, we selected four stations along the main geographic directions and one in the center of city for measurement of the indoor dose rate in each of the cities in Hamadan Province. Based on the household numbers, some houses were selected randomly in every station and natural background indoor dose was measured by using RDS-110 survey meter. Then, using the results of our previous study about measuring the level of outdoor natural gamma radiation in this province, we determined the level of annual effective exposure dose from natural gamma radiation in Hamadan residents. Results: In Hamadan province cities, maximum and minimum indoor natural background radiation (gamma ray) belonged to Razan City (1.41±0.079 mSv) and Asadabad City (0.955±0.044 mSv), respectively. Mean annual equivalent indoor dose in Hamadan Province was 1.20±0.070 mSv. Also the maximum indoor natural background radiation dose (gamma ray) in the buildings with the age of more and less than 25 years were 1.42±0.219 mSv and 1.44±0.149 mSv, respectively. According to the results of this study and our previous study about outdoor gamma natural background radiation, the annual effective dose in Hamadan Province residents was 0.83 mSv. Conclusion: According to the results of this study, it seems that annual effective equivalent dose due to indoor gamma radiation in Hamadan Province exceeded the mean external exposure amount reported by UNSCEAR (0.5 mSv). Also the annual effective dose due to gamma background radiation in Hamadan Province residents is 0.83 mSv, which is higher than the global average (0.48 mSv) reported by UNSCEAR - 2000. Therefore epidemiological studies to assess the prevalence of chronic diseases associated with natural radiation exposure among Hamadan Province residents are recommended.