The rationale and experiences in implementing New Jersey's radon program

International Nuclear Information System (INIS)

Bynum, J.; Klotz, J.; Cahill, M.; Nicholls, G.

1988-01-01

The authors discuss how radon data from domestic modeling, mining studies, and animal studies provided a strong basis for New Jersey Department of Health (NJDOH) to support MJDEP's recommendation to establish a state radon program. The program, described in this report, focuses on promoting intensive testing by state residents followed by prompt remediation for residences with radon levels greater than or equal to four pico curies per liter. NJDOH believes a threshold for radiation carcinogens does not exist. Even at low levels, exposure to radiation is associated with some health risk. Hence, with consideration given to the length of exposure in the home prompt action is warranted until more definitive data suggest otherwise

Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs

International Nuclear Information System (INIS)

Yarmoshenko, I.; Malinovsky, G.; Vasilyev, A.; Zhukovsky, M.

2015-01-01

The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400 000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m"3. Average indoor radon concentration by region ranges from 12 to 207 Bq/m"3. The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m"3. - Highlights: • Reconstruction of indoor radon concentration distribution in Russia was carried out. • Data of official annual 4-DOZ reports were used. • All-Russian average indoor radon concentration is 48 Bq/m"3. • The 95-th percentile is 160 Bq/m"3.

6th International Microbeam Workshop

Energy Technology Data Exchange (ETDEWEB)

Dr Kevin M. Prise

2004-01-01

The extended abstracts which are submitted here present a summary of the proceedings of the 6th International Workshop/12th LH Gray Workshop: Microbeam Probes of Cellular Radiation Response, held at St. Catherine's College, University of Oxford, UK on March, 29th-31st, 2003. In 1993 the 4th LH Gray Workshop entitled ''Microbeam Probes of Cellular Radiation Response'' was held at the Gray Cancer Institute in Northwood. This was organized by Prof BD Michael, Dr M. Folkard and Dr KM Prise and brought together 40 participants interested in developing and applying new microbeam technology to problems in radiation biology (1). The workshop was an undoubted success and has spawned a series of subsequent workshops every two years. In the past, these workshops have been highly successful in bringing together groups interested in developing and applying micro-irradiation techniques to the study of cell and tissue damage by ionizing radiations. Following the first microbeam workshop, there has been a rapid growth in the number of centres developing radiobiology microbeams, or planning to do so and there are currently 15-20 worldwide. Much of the recent research using microbeams has used them to study low-dose effects and ''non-targeted'' responses such bystander effects, genomic instability and adaptive responses. The goal of the 6th workshop was to build on our knowledge of the development of microbeam approaches and the application to radiation biology in the future with the meeting stretching over a 3 day period. Over 80 participants reviewed the current state of radiobiology microbeam research worldwide and reported on new technological developments both in the fields of physics and biology.

Production and applications of positron microbeams

International Nuclear Information System (INIS)

Brandes, G.R.; Canter, K.F.; Horsky, T.N.; Lippel, P.H.; Mills, A.P. Jr.

1989-01-01

The production of a positron microbeam using the high-brightness beam developed at Brandeis University and possible applications of this microbeam to spatially resolved defect studies and positron microscopy are reviewed. The high-brightness beam consists of a W(110) primary moderator and two remoderation stages which provide a 500-fold increase in brightness. With this brightness increase and microbeam optics, we are able to form a 12 μm FWHM beam (48 mrad pencil half-angle) at 5 keV beam energy. The well characterised small-diameter beam is particularly adaptable for determining defect concentration and structure, both laterally and in a depth-profiling mode. In the case of a transmission positron microscope or a positron re-emission microscope operating in a high-magnification mode, efficient image formation requires the use of a microbeam to maximise the number of positrons in the area being imaged. Results of the scanning microbeam tests and the application of a microbeam to positron microscopy and defect studies are reviewed. (author)

Navy radon assessment and mitigation program: Final report

International Nuclear Information System (INIS)

1994-10-01

This final report encompasses the events from the beginning of the Navy Radon Assessment and Mitigation Program to the closure of the program on October 31, 1994. Included in the report are discussions of the phases of the program including screening, assessment, mitigation, and post-mitigation. The primary discussion involves screening and assessment. The report addresses recommendations made to the Naval Facilities Engineering Command by the Hazardous Waste Remedial Actions Program of Martin Marietta Energy Systems, Inc., and the final decisions that were made. Special emphasis is placed on quality assurance/quality control (QA/QC), since QA/QC was given top priority during the implementation of this program. Included in the discussion on QA/QC are ana overview of the measurement process, positive and negative controls, replicated measurements, and application of chamber exposures to data calibration. The report concludes with a discussion of testing considerations for naval facilities and radon mitigation considerations for the Department of the Navy

Comparative study of radon exposure in Canadian homes and uranium mines - a discussion on the importance of national radon program

International Nuclear Information System (INIS)

Chen, Jing

2017-01-01

The history of lung cancer in uranium miners is well known for over hundreds of years when the disease was referred to as 'miner's disease' or 'mountain sickness'. Radon levels in uranium mines have decreased significantly over the past 30 years as a result of effective radiation protection measures at workplaces. For the most recent 10-year period, the average radon concentrations to underground and surface workers in Canadian uranium mines were 111 and 11 Bq m -3 , respectively. Based on the recent radon survey carried out in roughly 14 000 homes in 121 health regions across Canada and the more recent radon and thoron survey in 33 Canadian cities and 4000 homes, the average radon concentration in Canadian homes is 77 Bq m -3 . This study demonstrates that, nowadays, workers are exposed to radon in underground mines at a comparable radon level to what Canadians are exposed to at home. Since exposure to indoor radon is the main source of natural radiation exposure to the population, it is important for the National Radon Program to further increase radon awareness, and to encourage more Canadians to take appropriate actions to reduce radon exposure. (authors)

Focus small to find big - the microbeam story.

Science.gov (United States)

Wu, Jinhua; Hei, Tom K

2017-08-29

Even though the first ultraviolet microbeam was described by S. Tschachotin back in 1912, the development of sophisticated micro-irradiation facilities only began to flourish in the late 1980s. In this article, we highlight significant microbeam experiments, describe the latest microbeam irradiator configurations and critical discoveries made by using the microbeam apparatus. Modern radiological microbeams facilities are capable of producing a beam size of a few micrometers, or even tens of nanometers in size, and can deposit radiation with high precision within a cellular target. In the past three decades, a variety of microbeams has been developed to deliver a range of radiations including charged particles, X-rays, and electrons. Despite the original intention for their development to measure the effects of a single radiation track, the ability to target radiation with microbeams at sub-cellular targets has been extensively used to investigate radiation-induced biological responses within cells. Studies conducted using microbeams to target specific cells in a tissue have elucidated bystander responses, and further studies have shown reactive oxygen species (ROS) and reactive nitrogen species (RNS) play critical roles in the process. The radiation-induced abscopal effect, which has a profound impact on cancer radiotherapy, further reaffirmed the importance of bystander effects. Finally, by targeting sub-cellular compartments with a microbeam, we have reported cytoplasmic-specific biological responses. Despite the common dogma that nuclear DNA is the primary target for radiation-induced cell death and carcinogenesis, studies conducted using microbeam suggested that targeted cytoplasmic irradiation induces mitochondrial dysfunction, cellular stress, and genomic instability. A more recent development in microbeam technology includes application of mouse models to visualize in vivo DNA double-strand breaks. Microbeams are making important contributions towards our

Active mems microbeam device for gas detection

KAUST Repository

Bouchaala, Adam M.

2017-10-05

Sensors and active switches for applications in gas detection and other fields are described. The devices are based on the softening and hardening nonlinear response behaviors of microelectromechanical systems (MEMS) clamped-clamped microbeams. In that context, embodiments of gas-triggered MEMS microbeam sensors and switches are described. The microbeam devices can be coated with a Metal-Organic Framework to achieve high sensitivity. For gas sensing, an amplitude-based tracking algorithm can be used to quantify an amount of gas captured by the devices according to frequency shift. Noise analysis is also conducted according to the embodiments, which shows that the microbeam devices have high stability against thermal noise. The microbeam devices are also suitable for the generation of binary sensing information for alarming, for example.

RECOMMENDED FOUNDATION FILL MATERIALS CONSTRUCTION STANDARD OF THE FLORIDA RADON RESEARCH PROGRAM

Science.gov (United States)

The report summarizes the technical basis for a recommended foundation fill materials standard for new construction houses in Florida. he radon-control construction standard was developed by the Florida Radon Research Program (FRRP). ill material standards are formulated for: (1)...

Radiological Programs- Ambient Radon at the Yucca Mountain Site (SCPB:NA)

International Nuclear Information System (INIS)

TRW

1999-01-01

This report summarizes the results of the ambient radon monitoring activities conducted by the Radiological/Environmental Field Programs Department of the Civilian Radioactive Waste Management and Operating Contractor (CRWMS M and O), Yucca Mountain Site Characterization Office. Overall, outdoor radon concentrations measured at the Yucca Mountain site were within the range of those reported for other areas in Nevada and the continental United States. Though there was some evidence of trends with time at some monitoring sites, regional atmospheric radon concentrations to date, do not appear to have changed significantly since the inception of site characterization activities. A preliminary dose assessment yielded an estimated annual effective dose equivalent of 134 mrem based on a continuous exposure to the average ambient radon concentration measured at the Yucca Mountain site. Concentrations were measured using two types of systems, passive electret ion chambers (EIC) and continuous radon monitors (CRM). The EICs produced time-averaged radon concentration data and the CRMs were used to study radon fluctuations over time. Between 1991 and 1995, the mean radon concentration at the site, as measured by EICs placed one meter above ground level, was 0.32 ± 0.15 pCi L -1 . Radon concentrations varied between monitoring locations and between years. Station NF38, located near the North Portal of the Exploratory Studies Facility (ESF), exhibited the highest overall average radon concentration at 0.55 pCi L -1 (1992 to 1995). Concentrations appear to cycle diurnally, generally peaking in the early morning hours and being lowest in the afternoon. The data also suggested that radon concentrations may fluctuate seasonally. The work accomplished between 1991 and 1995, established radon levels in the general area surrounding Yucca Mountain. It is recommended that further work focus directly on those locations that have the greatest potential for influencing ambient radon levels

Dynamics of Microbeams under Multi-Frequency Excitations

KAUST Repository

Ibrahim, Alwathiqbellah

2017-01-24

This paper presents an investigation of the dynamics of microbeams under multiple harmonic electrostatic excitation frequencies. First, the response of a cantilever microbeam to two alternating current (AC) source excitation is examined. We show by simulations the response of the microbeam at primary resonance (near the fundamental natural frequency) and at secondary resonances (near half, superharmonic, and twice, subharmonic, the fundamental natural frequency). A multimode Galerkin method combined with the Euler-Bernoulli beam equation, accounting for the nonlinear electrostatic force, has been used to develop a reduced order model. The response of the cantilever microbeam to three AC source excitation is also investigated and shown as a promising technique to enhance the bandwidth of resonators. Finally, an experimental study of a clamped-clamped microbeam is conducted, demonstrating the multi-frequency excitation resonances using two, three, and four AC sources.

Dynamics of Microbeams under Multi-Frequency Excitations

KAUST Repository

Ibrahim, Alwathiqbellah; Jaber, Nizar; Chandran, Akhil; Thirupathi, Maloth; Younis, Mohammad I.

2017-01-01

This paper presents an investigation of the dynamics of microbeams under multiple harmonic electrostatic excitation frequencies. First, the response of a cantilever microbeam to two alternating current (AC) source excitation is examined. We show by simulations the response of the microbeam at primary resonance (near the fundamental natural frequency) and at secondary resonances (near half, superharmonic, and twice, subharmonic, the fundamental natural frequency). A multimode Galerkin method combined with the Euler-Bernoulli beam equation, accounting for the nonlinear electrostatic force, has been used to develop a reduced order model. The response of the cantilever microbeam to three AC source excitation is also investigated and shown as a promising technique to enhance the bandwidth of resonators. Finally, an experimental study of a clamped-clamped microbeam is conducted, demonstrating the multi-frequency excitation resonances using two, three, and four AC sources.

Microbeam evolution: From single cell irradiation to preclinical studies

DEFF Research Database (Denmark)

Ghita, Mihaela; Fernandez-Palomo, Cristian; Fukunaga, Hisanori

2018-01-01

Purpose: This review follows the development of microbeam technology from the early days of single cell irradiations, to investigations of specific cellular mechanisms and to the development of new treatment modalities in vivo. A number of microbeam applications are discussed with a focus on prec...... to deliver radiotherapy using plane parallel microbeams, in Microbeam Radiotherapy (MRT)....

The Amsterdam proton microbeam

International Nuclear Information System (INIS)

Bos, A.J.J.

1984-01-01

The aim of the work presented in this thesis is to develop a microbeam setup such that small beam spot sizes can be produced routinely, and to investigate the capabilities of the setup for micro-PIXE analysis. The development and performance of the Amsterdam proton microbeam setup are described. The capabilities of the setup for micro-PIXE are shown with an investigation into the presence of trace elements in human hair. (Auth.)

Overview of current radon and radon daughter research at LBL

International Nuclear Information System (INIS)

1983-01-01

This report provides a brief summary of radon and radon daughter research at Lawrence Berkeley Laboratory. The radon and radon daughter research program has two broad goals: (1) the study of sources of radon and its subsequent transport into houses, and (2) research on the behavior of radon daughters in indoor environments. Additional research effort is directed to several auxiliary areas, including development of instrumentation and monitoring techniques, studies of indoor air movement, and measurement and control of indoor particulate concentrations

Proceedings of 6th International Microbeam Workshop/12th L.H. Gray Workshop Microbeam Probes of Cellular Radiation Response

International Nuclear Information System (INIS)

Prise, Kevin M.

2004-01-01

The extended abstracts which are submitted here present a summary of the proceedings of the 6th International Workshop/12th LH Gray Workshop: Microbeam Probes of Cellular Radiation Response, held at St. Catherine's College, University of Oxford, UK on March, 29th-31st, 2003. In 1993 the 4th LH Gray Workshop entitled ''Microbeam Probes of Cellular Radiation Response'' was held at the Gray Cancer Institute in Northwood. This was organized by Prof BD Michael, Dr M. Folkard and Dr KM Prise and brought together 40 participants interested in developing and applying new microbeam technology to problems in radiation biology (1). The workshop was an undoubted success and has spawned a series of subsequent workshops every two years. In the past, these workshops have been highly successful in bringing together groups interested in developing and applying micro-irradiation techniques to the study of cell and tissue damage by ionizing radiations. Following the first microbeam workshop, there has been a rapid growth in the number of centres developing radiobiology microbeams, or planning to do so and there are currently 15-20 worldwide. Much of the recent research using microbeams has used them to study low-dose effects and ''non-targeted'' responses such bystander effects, genomic instability and adaptive responses. The goal of the 6th workshop was to build on our knowledge of the development of microbeam approaches and the application to radiation biology in the future with the meeting stretching over a 3 day period. Over 80 participants reviewed the current state of radiobiology microbeam research worldwide and reported on new technological developments both in the fields of physics and biology

Navy Radon Assessment and Mitigation Program: Work/quality assurance project plan screening phase

International Nuclear Information System (INIS)

1991-03-01

In 1987, the military services of the United States were tasked to take appropriate action to establish an indoor radon assessment and mitigation program. As a result, the Naval Facilities Engineering Command (NAVFACENGCOM) was assigned the responsibility of identifying potential hazards to personnel from exposure to naturally occurring radon gas and prioritizing corrective actions and to coordinating these actions with the major claimants. NAVRAMP is based upon current US Environmental Protection Agency (EPA) guidelines. The program has been separated into four phases. The screening phase will concentrate on evaluating radon levels, based on statistical samples, in those buildings that have been determined to be at most at risk to elevated levels of radon, such as base housing, schools, day-care centers, hospitals, brigs, Base Officer Quarters, and Base Enlisted Quarters. During the assessment phase, every building that contains personnel for over 4 h/day will be evaluated. Mitigation work will be accomplished by Navy or Navy-contracted personnel. HAZWRAP services during the mitigation phase will consist of determining the extent of reduction in radon levels after the mitigation effort. 7 refs., 11 figs

Wide area scanning system and carbon microbeams at the external microbeam facility of the INFN LABEC laboratory in Florence

International Nuclear Information System (INIS)

Giuntini, L.; Massi, M.; Calusi, S.; Castelli, L.; Carraresi, L.; Fedi, M.E.; Gelli, N.; Liccioli, L.; Mandò, P.A.; Mazzinghi, A.; Palla, L.; Romano, F.P.

2015-01-01

Recently, developments have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence. A new system for mechanical sample scanning was implemented. This system allows us to acquire large maps (up to 20 × 20 cm 2 ), of great interest in the Cultural Heritage field. In parallel, the possibility of using carbon microbeams for experiments, such as, for example, ion beam modification of materials and MeV Secondary Ion Mass Spectrometry, has been investigated. As a test application, Particle Induced X-ray Emission with carbon microbeams has been performed on a lapis lazuli stone. First results for both wide area imaging and external carbon microbeams are briefly reported

Genome-wide transcription responses to synchrotron microbeam radiotherapy.

Science.gov (United States)

Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

2012-10-01

The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

Wide area scanning system and carbon microbeams at the external microbeam facility of the INFN LABEC laboratory in Florence

Energy Technology Data Exchange (ETDEWEB)

Giuntini, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Massi, M. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Calusi, S. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Castelli, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Carraresi, L. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Fedi, M.E.; Gelli, N. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Liccioli, L.; Mandò, P.A.; Mazzinghi, A. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Firenze (Italy); Palla, L. [INFN, Sezione di Pisa and Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy); Romano, F.P. [Consiglio Nazionale delle Ricerche (CNR), Istituto per i Beni Archeologici e Monumentali (IBAM), Via Biblioteca, 4, 95124 Catania (Italy); Istituto Nazionale di Fisica Nucleare (INFN), LNS, Via S.Sofia 62, 95125 Catania (Italy); and others

2015-04-01

Recently, developments have been made to the external scanning microbeam of INFN-LABEC laboratory in Florence. A new system for mechanical sample scanning was implemented. This system allows us to acquire large maps (up to 20 × 20 cm{sup 2}), of great interest in the Cultural Heritage field. In parallel, the possibility of using carbon microbeams for experiments, such as, for example, ion beam modification of materials and MeV Secondary Ion Mass Spectrometry, has been investigated. As a test application, Particle Induced X-ray Emission with carbon microbeams has been performed on a lapis lazuli stone. First results for both wide area imaging and external carbon microbeams are briefly reported.

A horizontal multi-purpose microbeam system

Science.gov (United States)

Xu, Y.; Randers-Pehrson, G.; Marino, S. A.; Garty, G.; Harken, A.; Brenner, D. J.

2018-04-01

A horizontal multi-purpose microbeam system with a single electrostatic quadruplet focusing lens has been developed at the Columbia University Radiological Research Accelerator Facility (RARAF). It is coupled with the RARAF 5.5 MV Singleton accelerator (High Voltage Engineering Europa, the Netherlands) and provides micrometer-size beam for single cell irradiation experiments. It is also used as the primary beam for a neutron microbeam and microPIXE (particle induced x-ray emission) experiment because of its high particle fluence. The optimization of this microbeam has been investigated with ray tracing simulations and the beam spot size has been verified by different measurements.

The Department of Energy's radon testing program

International Nuclear Information System (INIS)

Scott, H.L.; Dudney, C.S.; Wilson, D.L.; Gammage, R.B.

1993-01-01

The US Department of Energy recently completed an initial survey of indoor radon in its buildings in response to Public Law 100--551, the Indoor Radon Abatement Act of 1988. Other federal agencies have also conducted radon surveys. This paper presents an overview of the results from radon testing of several thousand buildings ranging from 100 m 2 to over 10,000 M 2 in size. In addition, we have examined results from groups of buildings, classified according to ventilation and usage characteristics. So far, there is no apparent difference among building classes. The paper also discusses our proposal for phased radon surveys. We suggest that first-phase results can be used to identify facilities with radon problems. In the second phase, we suggest measurements be made at a much higher sampling density at facilities with radon problems. The results of the second phase are expected to identify all buildings in need of mitigation

Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

Science.gov (United States)

Bigelow, A W; Randers-Pehrson, G; Garty, G; Geard, C R; Xu, Y; Harken, A D; Johnson, G W; Brenner, D J

2010-08-08

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the (7)Li(p, n)(7)Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator - based on multiphoton excitation - is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF.

Radon house doctor

International Nuclear Information System (INIS)

Nitschke, I.A.; Brennan, T.; Wadach, J.B.; O'Neil, R.

1986-01-01

The term house doctor may be generalized to include persons skilled in the use of instruments and procedures necessary to identify, diagnose, and correct indoor air quality problems as well as energy, infiltration, and structural problems in houses. A radon house doctor would then be a specialist in radon house problems. Valuable experience in the skills necessary to be developed by radon house doctors has recently been gained in an extensive radon monitoring and mitigation program in upstate New York sponsored by Niagara Mohawk Power Corporation and the New York State Energy Research and Development Authority. These skills, to be described in detail in this paper, include: (i) the use of appropriate instruments, (ii) the evaluation of the symptoms of a radon-sick house, (iii) the diagnostic procedures required to characterize radon sources in houses, (iv) the prescription procedures needed to specify treatment of the problem, (v) the supervision of the implementation of the treatment program, (vi) the check-up procedures required to insure the house cured of radon problems. 31 references, 3 tables

Computations of concentration of radon and its decay products against time. Computer program; Obliczanie koncentracji radonu i jego produktow rozpadu w funkcji czasu. Program komputerowy

Energy Technology Data Exchange (ETDEWEB)

Machaj, B. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

1996-12-31

This research is aimed to develop a device for continuous monitoring of radon in the air, by measuring alpha activity of radon and its short lived decay products. The influence of alpha activity variation of radon and its daughters on the measured results is of importance and requires a knowledge of this variation with time. Employing the measurement of alpha radiation of radon and of its short lived decay products, require knowledge of radon concentration variation and its decay products against the time. A computer program in Turbo Pascal language was therefore developed performing the computations employing the known relations involved, the program being adapted for IBM PC computers. The presented program enables computation of activity of {sup 222}Rn and its daughter products: {sup 218}Po, {sup 214}Pb, {sup 214}Bi and {sup 214}Po every 1 min within the period of 0-255 min for any state of radiation equilibrium between the radon and its daughter products. The program permits also to compute alpha activity of {sup 222}Rn + {sup 218}Po + {sup 214}Po against time and the total alpha activity at selected interval of time. The results of computations are stored on the computer hard disk in ASCII format and are used a graphic program e.g. by DrawPerfect program to make diagrams. Equations employed for computation of the alpha activity of radon and its decay products as well as the description of program functions are given. (author). 2 refs, 4 figs.

The new Sandia light ion microbeam

Energy Technology Data Exchange (ETDEWEB)

Vizkelethy, G., E-mail: gvizkel@sandia.gov [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); Doyle, B.L. [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); McDaniel, F.L. [Sandia National Laboratories, P.O. Box 5800, MS 1056, Albuquerque, NM 87185 (United States); University of North Texas, Denton, TX 76203 (United States)

2012-02-15

The Ion Beam Laboratory of Sandia National Laboratories (SNL) was recently relocated into a brand new building. The 6 MV High Voltage Engineering (HVE) tandem accelerator (hosting the heavy ion microbeam and several analytical beam lines) and the 350 kV HVE implanter with a nanobeam were moved to the new building. There were several new pieces of equipment acquired associated with the move, among them a new high brightness 3 MV Pelletron accelerator, a high resolution light ion microbeam, a nanoimplanter, and a transmission electron microscope (TEM) connected to the tandem accelerator. In this paper this new facility will be described, and initial results of the new microbeam will be presented.

Managing Radon in Schools

Science.gov (United States)

EPA recommends testing all schools for radon. As part of an effective IAQ management program, schools can take simple steps to test for radon and reduce risks to occupants if high radon levels are found.

High resolution 3D imaging of synchrotron generated microbeams

Energy Technology Data Exchange (ETDEWEB)

Gagliardi, Frank M., E-mail: frank.gagliardi@wbrc.org.au [Alfred Health Radiation Oncology, The Alfred, Melbourne, Victoria 3004, Australia and School of Medical Sciences, RMIT University, Bundoora, Victoria 3083 (Australia); Cornelius, Iwan [Imaging and Medical Beamline, Australian Synchrotron, Clayton, Victoria 3168, Australia and Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales 2500 (Australia); Blencowe, Anton [Division of Health Sciences, School of Pharmacy and Medical Sciences, The University of South Australia, Adelaide, South Australia 5000, Australia and Division of Information Technology, Engineering and the Environment, Mawson Institute, University of South Australia, Mawson Lakes, South Australia 5095 (Australia); Franich, Rick D. [School of Applied Sciences and Health Innovations Research Institute, RMIT University, Melbourne, Victoria 3000 (Australia); Geso, Moshi [School of Medical Sciences, RMIT University, Bundoora, Victoria 3083 (Australia)

2015-12-15

Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200 or 400 μm peak-to-peak spacing were delivered as single, cross-fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using a NIKON A1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak-to-valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery.

High resolution 3D imaging of synchrotron generated microbeams

International Nuclear Information System (INIS)

Gagliardi, Frank M.; Cornelius, Iwan; Blencowe, Anton; Franich, Rick D.; Geso, Moshi

2015-01-01

Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200 or 400 μm peak-to-peak spacing were delivered as single, cross-fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using a NIKON A1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak-to-valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery

Air pollution. Actions to promote radon testing

International Nuclear Information System (INIS)

Guerrero, Peter F.; Adams, Charles M.; McGee, William F.; Goldsmith, Larry A.; Feldesman, Alice G.; Grissinger, Charles R.; Updegraff, William D.; Langdon, Robin S.; Bartholomew, Philip L.

1992-12-01

To promote radon testing, EPA initiated public information and awareness programs and provided grants to states to develop programs aimed at encouraging homeowners to test for radon. Nationwide telephone surveys, according to EPA, indicate that these efforts have raised the public awareness of radon to as high as 78 percent but that about only 9 percent of those surveyed have tested their homes for radon. Concerned about improving risk reduction through its radon program, EPA convened a review panel. The panel not only recommended in May 1992 that the current voluntary approach be continued but also called for program changes to encourage more testing. These changes include targeting public information and other resources to areas where radon levels are predicted to be high and promoting testing and mitigation at the time of real estate transactions. To support state radon efforts, the Congress authorized a grant program for yearly grants of $10 million for 3 years. Funds for this program were recently extended for a fourth year through fiscal year 1993. Information to measure states' success in promoting testing by homeowners was generally not available because (1) much of the grant funding has been used to identify the extent of the radon problem; (2) federally funded public information projects were often directed to large audiences, making it difficult to measure testing rates; and (3) EPA's evaluation process for the grant program did not contain a component to measure increases in testing. We did, however, identify some state projects that have increased radon testing by targeting program efforts to homes in areas with potentially high levels of radon. The results of the state projects would seem to support the EPA review panel's recommendations on promoting radon testing through targeting program resources. In two states we surveyed, the voluntary use of disclosure statements as part of a real estate sales contract was a frequent occurrence, and in one state

Development of economic MeV-ion microbeam technology at Chiang Mai University

Science.gov (United States)

Singkarat, S.; Puttaraksa, N.; Unai, S.; Yu, L. D.; Singkarat, K.; Pussadee, N.; Whitlow, H. J.; Natyanum, S.; Tippawan, U.

2017-08-01

Developing high technologies but in economic manners is necessary and also feasible for developing countries. At Chiang Mai University, Thailand, we have developed MeV-ion microbeam technology based on a 1.7-MV Tandetron tandem accelerator with our limited resources in a cost-effective manner. Instead of using expensive and technically complex electrostatic or magnetic quadrupole focusing lens systems, we have developed cheap MeV-ion microbeams using programmed L-shaped blade aperture and capillary techniques for MeV ion beam lithography or writing and mapping. The programmed L-shaped blade micro-aperture system consists of a pair of L-shaped movable aperture pieces which are controlled by computer to cut off the ion beam for controlling the beam size down to the micrometer order. The capillary technique utilizes our home-fabricated tapered glass capillaries to realize microbeams. Either system can be installed inside the endstation of the MeV ion beam line of the accelerator. Both systems have been applied to MeV-ion beam lithography or writing of micro-patterns for microfluidics applications to fabricate lab-on-chip devices. The capillary technique is being developed for MeV-ion beam mapping of biological samples. The paper reports details of the techniques and introduces some applications.

Radon risk communication research: Practical lessons

International Nuclear Information System (INIS)

Fisher, A.; Johnson, F.R.

1990-01-01

Those responsible for state and local radon programs often express frustration about the small share of homes that have been tested for radon, and the small share of those with high readings that have been mitigated. There are now a number of completed studies that have examined how well alternative ways of communicating about radon risk have accomplished the goals of motivating appropriate testing and mitigation. This paper summarizes the research results that are most crucial for planning and implementing effective radon risk communication programs. We identify six reasons why people do not respond to radon as a serious threat and provide some remedies suggested by radon studies

Human perception of radon risk and radon mitigation: Some remarks

International Nuclear Information System (INIS)

Neznal, M.; Neznal, M.

2008-01-01

The Radon program in the Czech Republic has a relatively long and rich history. Procedures, which enable to evaluate the risk of radon penetration from the ground, to protect new buildings, to find existing buildings with elevated indoor radon levels and to realise remedial measures in such buildings, have been developed, published and tested. In some cases, the whole system may fail due to psychological or sociological reasons. Three types of problems (conflicts) will be presented: human behaviour affecting measurement results, conflict between individual and 'all-society' points of view, interpretation of radon risk itself. (authors)

7th International Workshop on Microbeam Probes of Cellular Radiation Response

Energy Technology Data Exchange (ETDEWEB)

Brenner, David J.

2009-07-21

The extended abstracts that follow present a summary of the Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, held at Columbia University’s Kellogg Center in New York City on March 15–17, 2006. These International Workshops on Microbeam Probes of Cellular Radiation Response have been held regularly since 1993 (1–5). Since the first workshop, there has been a rapid growth (see Fig. 1) in the number of centers developing microbeams for radiobiological research, and worldwide there are currently about 30 microbeams in operation or under development. Single-cell/single-particle microbeam systems can deliver beams of different ionizing radiations with a spatial resolution of a few micrometers down to a few tenths of a micrometer. Microbeams can be used to addressquestions relating to the effects of low doses of radiation (a single radiation track traversing a cell or group of cells), to probe subcellular targets (e.g. nucleus or cytoplasm), and to address questions regarding the propagation of information about DNA damage (for example, the radiation-induced bystander effect). Much of the recent research using microbeams has been to study low-dose effects and ‘‘non-targeted’’ responses such as bystander effects, genomic instability and adaptive responses. This Workshop provided a forum to assess the current state of microbeam technology and current biological applications and to discuss future directions for development, both technological and biological. Over 100 participants reviewed the current state of microbeam research worldwide and reported on new technological developments in the fields of both physics and biology.

Radon: Residential attitudes toward the risk

International Nuclear Information System (INIS)

Fort, R.; Hinman, G.; Rosenman, R.; Wandschneider, P.

1990-01-01

Veradale, Washington (east of Spokane) is a region of high residential radon concentrations. Three hundred eighty residents of Veradale recently responded to a mail survey designed to elicit (1) their knowledge of and attitudes toward the risks of radon in their homes, (2) the actions they have taken or intend to take to identify and reduce those risks, and (3) policy preferences toward radon. Results reveal that these residents know that they live in an area with high radon levels, that radon causes lung cancer, and that radon will affect their health. However only 11% of respondents have had their homes tested for radon. This especially is puzzling because a large number of respondents claimed that (1) radon was important in home buying decisions, (2) they would test their own homes, (3) they would take action if such tests revealed problems, and (4) their willingness to pay for tests and improvements was well within the current costs of these actions. It remains a mystery why testing is at such a low level. Three other results are of note. First, subsidies for radon tests and home improvements may be having the unintended consequences of unneeded improvements and (potentially) moves without improvements. Second, individuals want radon testing required and results made known during home purchase decisions. Third, at present, weatherization programs that concentrate radon are acceptable to individuals. Of course, the future may hold different results. Administrators of weatherization programs, who are trusted by respondents according to this survey, would do well to institute weatherization programs with reduced radon concentrations in mind

U.S. Postal Service radon assessment and mitigation program. Progress report, September 1993--November 1994

Energy Technology Data Exchange (ETDEWEB)

Velazquez, L.E.; Petty, J.L. Jr.

1994-12-31

In 1992, the US Postal Service (USPS) entered into an Interagency Agreement with the Department of Energy (DOE) whereby DOE would provide technical assistance in support of the USPS Radon Assessment and Mitigation Program. To aid in this effort, DOE tasked the Hazardous Waste Remedial Actions Program (HAZWRAP), which is managed by Martin Marietta Energy Systems, Inc., for DOE under contract AC05-84OR21400. Since that time, HAZWRAP has developed and finalized the sampling protocol, mitigation diagnostic protocol, and the quality assurance and quality control procedures. These procedures were validated during the Protocol Validation (1992-1993) and Pilot Study (1993-1994) phases of the program. To date, HAZWRAP has performed approximately 16,000 radon measurements in 250 USPS buildings. Mitigation diagnostics have been performed in 27 buildings. Thus far, 13% of the measurements have been above the Environmental Protection Agency action level of 4 pCi/L. This report summarizes the pilot program radon testing data and mitigation diagnostic data for 22 sites and contains recommendations for mitigation diagnostics.

U.S. Postal Service radon assessment and mitigation program. Progress report, September 1993--November 1994

International Nuclear Information System (INIS)

Velazquez, L.E.; Petty, J.L. Jr.

1994-01-01

In 1992, the US Postal Service (USPS) entered into an Interagency Agreement with the Department of Energy (DOE) whereby DOE would provide technical assistance in support of the USPS Radon Assessment and Mitigation Program. To aid in this effort, DOE tasked the Hazardous Waste Remedial Actions Program (HAZWRAP), which is managed by Martin Marietta Energy Systems, Inc., for DOE under contract AC05-84OR21400. Since that time, HAZWRAP has developed and finalized the sampling protocol, mitigation diagnostic protocol, and the quality assurance and quality control procedures. These procedures were validated during the Protocol Validation (1992-1993) and Pilot Study (1993-1994) phases of the program. To date, HAZWRAP has performed approximately 16,000 radon measurements in 250 USPS buildings. Mitigation diagnostics have been performed in 27 buildings. Thus far, 13% of the measurements have been above the Environmental Protection Agency action level of 4 pCi/L. This report summarizes the pilot program radon testing data and mitigation diagnostic data for 22 sites and contains recommendations for mitigation diagnostics

Radon reduction

International Nuclear Information System (INIS)

Hamilton, M.A.

1990-01-01

During a radon gas screening program, elevated levels of radon gas were detected in homes on Mackinac Island, Mich. Six homes on foundations with crawl spaces were selected for a research project aimed at reducing radon gas concentrations, which ranged from 12.9 to 82.3 pCi/l. Using isolation and ventilation techniques, and variations thereof, radon concentrations were reduced to less than 1 pCi/l. This paper reports that these reductions were achieved using 3.5 mil cross laminated or 10 mil high density polyethylene plastic as a barrier without sealing to the foundation or support piers, solid and/or perforated plastic pipe and mechanical fans. Wind turbines were found to be ineffective at reducing concentrations to acceptable levels. Homeowners themselves installed all materials

Radon Measurements in Vojvodina

International Nuclear Information System (INIS)

Bikit, I.; Bikit, K.; Forkapic, S.; Mrda, D.; Nikolov, J.; Todorovic, N.; Veskovic, M.

2013-01-01

Recent analyses of epidemiological studies of lung cancer risk from residential exposures demonstrate a statistically significant increase per unit of exposure below average annual concentrations of about 200 Bq/m 3 . Indoor radon measurements performed in Novi Sad in about 400 houses and flats are presented and discussed in this paper. By measuring gamma-activity of radon daughters, radon activity concentration was determined to be 50 Bq/m 3 . In Vojvodina region indoor radon levels were measured by alpha track detectors CR-39 on about 3000 locations during the winter seasons in the period of three years (2003-2005). The main aim of the present study was to explore the critical group of population for radon exposure and to estimate maximal annual doses. Existing radon maps which identify regions with elevated radon levels will improve data collection and analysis for the future radon campaigns. Collaboration on the JRC program of European indoor radon map and implementation of grid system are also discussed.(author)

Response of avian embryonic brain to spatially segmented x-ray microbeams.

Science.gov (United States)

Dilmanian, F A; Morris, G M; Le Duc, G; Huang, X; Ren, B; Bacarian, T; Allen, J C; Kalef-Ezra, J; Orion, I; Rosen, E M; Sandhu, T; Sathé, P; Wu, X Y; Zhong, Z; Shivaprasad, H L

2001-05-01

Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam

High energy ion hit technique to local area using microbeam

Energy Technology Data Exchange (ETDEWEB)

Tanaka, Ryuichi; Kamiya, Tomihiro; Suda, Tamotsu; Sakai, Takuro; Hirao, Toshio; Kobayashi, Yasuhiko; Watanabe, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

Single energetic ion hit technique has been developed as an application of ion microbeam technique, in order to study the effect of local damage or injury to materials and living organisms. The overall performance is basically defined by those of separate techniques: microbeam formation, microbeam positioning, single ion detection, detection signal processing, hit timing control, and hit verification. Recent progress on the developments of these techniques at JAERI-TIARA facility are reviewed. (author)

Synchrotron microbeam radiation therapy for rat brain tumor palliation-influence of the microbeam width at constant valley dose

International Nuclear Information System (INIS)

Serduc, Raphael; Fonta, Caroline; Renaud, Luc; Bouchet, Audrey; Braeuer-Krisch, Elke; Sarun, Sukhena; Bravin, Alberto; Le Duc, Geraldine; Laissue, Jean A; Spiga, Jenny; Boutonnat, Jean; Siegbahn, Erik Albert; Esteve, Francois

2009-01-01

To analyze the effects of the microbeam width (25, 50 and 75 μm) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 μm wide microbeams, all spaced 211 μm on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 μm wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of ∼50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 μm width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 μm or 25 μm widths when used with a 211 μm on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are kept constant in all groups. The use

Synchrotron microbeam radiation therapy for rat brain tumor palliation-influence of the microbeam width at constant valley dose

Energy Technology Data Exchange (ETDEWEB)

Serduc, Raphael; Fonta, Caroline; Renaud, Luc [Universite de Toulouse, UPS, Centre de Recherche Cerveau et Cognition (France); Bouchet, Audrey; Braeuer-Krisch, Elke; Sarun, Sukhena; Bravin, Alberto; Le Duc, Geraldine [European Synchrotron Radiation Facility, F38043 Grenoble (France); Laissue, Jean A [Institute of Pathology, University of Bern (Switzerland); Spiga, Jenny [Department of Physics, University of Cagliari, s.p. Monserrato-Sestu, Monserrato (Canada) 09042 (Italy); Boutonnat, Jean [TIMC lab, UMR CNRS 5525, Univ Joseph Fourier, CHU, Grenoble (France); Siegbahn, Erik Albert [Department of Medical Physics, Karolinska Universitetssjukhuset, 17176 Stockholm (Sweden); Esteve, Francois [INSERM U836, Equipe 6, Institut des Neurosciences de Grenoble, 38043 Grenoble Cedex (France)], E-mail: raph.serduc@gmail.com

2009-11-07

To analyze the effects of the microbeam width (25, 50 and 75 {mu}m) on the survival of 9L gliosarcoma tumor-bearing rats and on toxicity in normal tissues in normal rats after microbeam radiation therapy (MRT), 9L gliosarcomas implanted in rat brains, as well as in normal rat brains, were irradiated in the MRT mode. Three configurations (MRT25, MRT50, MRT75), each using two orthogonally intersecting arrays of either 25, 50 or 75 {mu}m wide microbeams, all spaced 211 {mu}m on center, were tested. For each configuration, peak entrance doses of 860, 480 and 320 Gy, respectively, were calculated to produce an identical valley dose of 18 Gy per individual array at the center of the tumor. Two, 7 and 14 days after radiation treatment, 42 rats were killed to evaluate histopathologically the extent of tumor necrosis, and the presence of proliferating tumors cells and tumor vessels. The median survival times of the normal rats were 4.5, 68 and 48 days for MRT25, 50 and 75, respectively. The combination of the highest entrance doses (860 Gy per array) with 25 {mu}m wide beams (MRT25) resulted in a cumulative valley dose of 36 Gy and was excessively toxic, as it led to early death of all normal rats and of {approx}50% of tumor-bearing rats. The short survival times, particularly of rats in the MRT25 group, restricted adequate observance of the therapeutic effect of the method on tumor-bearing rats. However, microbeams of 50 {mu}m width led to the best median survival time after 9L gliosarcoma MRT treatment and appeared as the better compromise between tumor control and normal brain toxicity compared with 75 {mu}m or 25 {mu}m widths when used with a 211 {mu}m on-center distance. Despite very high radiation doses, the tumors were not sterilized; viable proliferating tumor cells remained present at the tumor margin. This study shows that microbeam width and peak entrance doses strongly influence tumor responses and normal brain toxicity, even if valley doses are kept constant in

Cost-effectiveness analysis of public education and incentive programs for controlling radon in the home. Final report

International Nuclear Information System (INIS)

Bierma, T.J.; Swartzman, D.

1988-12-01

The objective of this study was to evaluate the cost-effectiveness in Illinois of five radon public education and incentive program options. Programs evaluated included (1) no program, (2) a toll-free hotline and information packet, (3) free short-term monitors, (4) free confirmatory monitors, and (5) low-interest loans. Existing literature and expert opinion were used to estimate program costs and public responses under the various programs. Computer simulation, with Monte Carlo sampling, was used for uncertainty and sensitivity analysis. The cost-effectiveness model was analyzed based on assumed radon exposures to Illinois citizens. Results for standard conditions indicate that budget levels under approximately $30,000 do not warrant a radon education and incentive program. For budget levels of approximately $30,000 to $1 million, Program 2 was most effective, and Program 3 was most effective above this level. Sensitivity analyses indicate the results are relatively insensitive to input variable assumptions with the exception of public-response estimates. Study results suggest that all of the programs evaluated are likely to be relatively ineffective. Considerable improvement may be possible using more innovative approaches to public education

Techniques and multi-disciplinary applications of ion microbeam

International Nuclear Information System (INIS)

Du Guanghua

2012-01-01

Beam of MeV ions form particle accelerators can be confined by collimators or focused by electrical/magnetic quadruples into micrometer size, and this microbeam can be used to obtain spatial information or radiation effect in solids and biological samples. This paper reviews the technical developments and the multi-disciplinary applications of microbeam, including ion beam analysis, single event effect in semiconductor devices, proton beam writing and cellular response to targeted particle irradiations. Finally, the high-energy heavy-ion microbeam facility at the Institute of Modern Physics of Chinese Academy of Sciences is introduced, which has successfully focused 1 GeV Carbon ions into a beam spot of 1 μm × 2 μm in air. (authors)

Conceptual design for real time monitoring of electron microbeam

International Nuclear Information System (INIS)

Kim, Ji Seok; Kim, Hyun Ki; Jang, Mee; Choi, Chang Woon; Sun, Gwang Min; Lee, Jai Ki

2008-01-01

It is recognized that the microbeam is powerful system to understand the interaction of ionizing radiation with cells. Especially, electron microbeam system is useful to investigate the effect of low-LET radiation for cells. Electron microbeam has been developed in KIRAMS. It can irradiate the small volume in cell level by collimator and electromagnetic field and give local dose to individual cell by controlling the number of electrons. When the electron microbeam irradiates the individual cell, however, there is a possibility to change the current and intended trajectory of electron beam. Because this possibility introduces the uncertainty of dose, it is necessary to monitor the trajectory and current of electron beam. This study deals with development of real time monitoring device to confirm beam quality and to control if necessary during experiment. Consequently we designed dual monitoring device to solve various factors. And we optimize the design by simulation. (author)

Attempts of local irradiation of cells by microbeam. From ultraviolet to heavy particles

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Yasuhiko [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2002-03-01

This review describes the history of attempts of local irradiation of cells by microbeam and present status of the study. Local irradiation of cells was attempted as early as in 1912 with use of short {alpha}-particle range and of focused UV beams. After the war, laser microbeams were then developed for microsurgery in embryology. In addition, microbeams of electron generated from the gun and of X-ray collimated were developed. In 1950s, the electron microbeam was generated from Van de Graaff accelerator in Chicago University and proton, deuteron and He-ion microbeams from the cyclotron, in BNL. In 1980s, Gesellschaft fuer Schwerionenforshung (Germany) used heavy ion microbeams from C to U generated from the linear accelerator and PNL, proton to {sup 4}He-ion microbeams from the tandem-electrostatic accelerator. At present in 2002, the equipments for microbeam for cell irradiation are the Van de Graaff accelerators in Gray Cancer Institute (England) and in Columbia University, and the cyclotron in TIARA in Japan. The purpose of the study in TIARA is to develop a system to generate heavy particle microbeams for cell irradiation for analysis of the biological effect of ultra-low fluence, high LET heavy particles like the galactic cosmic ray. Recently, the CHO-KI cell nucleus is irradiated by {sup 40}Ar and {sup 20}Ne ions. (K.H.)

Attempts of local irradiation of cells by microbeam. From ultraviolet to heavy particles

International Nuclear Information System (INIS)

Kobayashi, Yasuhiko

2002-01-01

This review describes the history of attempts of local irradiation of cells by microbeam and present status of the study. Local irradiation of cells was attempted as early as in 1912 with use of short α-particle range and of focused UV beams. After the war, laser microbeams were then developed for microsurgery in embryology. In addition, microbeams of electron generated from the gun and of X-ray collimated were developed. In 1950s, the electron microbeam was generated from Van de Graaff accelerator in Chicago University and proton, deuteron and He-ion microbeams from the cyclotron, in BNL. In 1980s, Gesellschaft fuer Schwerionenforshung (Germany) used heavy ion microbeams from C to U generated from the linear accelerator and PNL, proton to 4 He-ion microbeams from the tandem-electrostatic accelerator. At present in 2002, the equipments for microbeam for cell irradiation are the Van de Graaff accelerators in Gray Cancer Institute (England) and in Columbia University, and the cyclotron in TIARA in Japan. The purpose of the study in TIARA is to develop a system to generate heavy particle microbeams for cell irradiation for analysis of the biological effect of ultra-low fluence, high LET heavy particles like the galactic cosmic ray. Recently, the CHO-KI cell nucleus is irradiated by 40 Ar and 20 Ne ions. (K.H.)

Proton microbeam irradiation effects on PtBA polymer

Indian Academy of Sciences (India)

Microbeam irradiation effects on poly-tert-butyl-acrylate (PtBA) polymer using 2.0 MeV proton microbeam are reported. Preliminary results on pattern formation on PtBA are carried out as a function of fluence. After writing the pattern, a thin layer of Ge is deposited. Distribution of Ge in pristine and ion beam patterned surface ...

Nonlinear analysis of thermally and electrically actuated functionally graded material microbeam.

Science.gov (United States)

Li, Yingli; Meguid, S A; Fu, Yiming; Xu, Daolin

2014-02-08

In this paper, we provide a unified and self-consistent treatment of a functionally graded material (FGM) microbeam with varying thermal conductivity subjected to non-uniform or uniform temperature field. Specifically, it is our objective to determine the effect of the microscopic size of the beam, the electrostatic gap, the temperature field and material property on the pull-in voltage of the microbeam under different boundary conditions. The non-uniform temperature field is obtained by integrating the steady-state heat conduction equation. The governing equations account for the microbeam size by introducing an internal material length-scale parameter that is based on the modified couple stress theory. Furthermore, it takes into account Casimir and van der Waals forces, and the associated electrostatic force with the first-order fringing field effects. The resulting nonlinear differential equations were converted to a coupled system of algebraic equations using the differential quadrature method. The outcome of our work shows the dramatic effect and dependence of the pull-in voltage of the FGM microbeam upon the temperature field, its gradient for a given boundary condition. Specifically, both uniform and non-uniform thermal loading can actuate the FGM microbeam even without an applied voltage. Our work also reveals that the non-uniform temperature field is more effective than the uniform temperature field in actuating a FGM cantilever-type microbeam. For the clamped-clamped case, care must be taken to account for the effective use of thermal loading in the design of microbeams. It is also observed that uniform thermal loading will lead to a reduction in the pull-in voltage of a FGM microbeam for all the three boundary conditions considered.

EML indoor radon workshop, 1982

International Nuclear Information System (INIS)

George, A.C.; Lowder, W.; Fisenne, I.; Knutson, E.O.; Hinchliffe, L.

1983-07-01

A workshop on indoor radon, held at the Environmental Measurements Laboratory (EML) on November 30 and December 1, 1982, covered recent developments in radon daughter research and development. Thirty papers were presented dealing with standardization and quality assurance measurement methods, surveys, measurements strategy, physical mechanisms of radon and radon daughter transport and development of guidance standards for indoor exposures. The workshop concluded with a planning session that identified the following needs: (1) national and international intercomparisons of techniques for measuring radon and radon daughter concentrations, working level and radon exhalation flux density; (2) development and refinement of practical measurement techniques for thoron and its daughter products; (3) quantitative definition of the sources of indoor radon and the mechanisms of transport into structures; (4) better knowledge of the physical properties of radon daughters; (5) more complete and accurate data on the population exposure to radon, which can only be met by broadly based surveys; and (6) more international cooperation and information exchange among countries with major research programs

MOSFET dosimetry of the radiation therapy microbeams at the European synchrotron radiation facility

International Nuclear Information System (INIS)

Rozenfeld, A.; Lerch, M.

2002-01-01

Full text: We have developed an innovative on-line MOSFET readout system for use in the quality assurance of radiation treatment beams. Recently the system has found application in areas where excellent spatial resolution is also a requirement in the quality assurance process, for example IMRT, and microbeam radiation therapy. The excellent spatial resolution is achieved by using a quadruple RADFET TM chip in 'edge on' mode. In developing this approach we have found that the system can be utilised to determine any error in the beam profile measurements due to misalignment of RADFET with respect to the radiation beam or microbeam. Using this approach will ensure that the excellent spatial resolution of the RADFET used in 'edge-on' mode is fully utilised. In this work we report on dosimetry measurements performed at the microbeam radiation therapy beamline located at the European Synchrotron Radiation Facility. The synchrotron planar array microbeam with size 10-30 μm and pitch ∼200 μm has found an important application in microbeam radiation therapy (MRT) of brain tumours in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. The radiation damage from an array of parallel microbeams correlates strongly with the range of peak-valley dose ratios (PVDR), ie, the range of the ratio of the absorbed dose to tissue directly in line with the mid-plane of the microbeam to that in the mid-plane between adjacent microbeams. Novel physical dosimetry of the microbeams using the online MOSFET reader system will be presented. Comparison of the experimental results with both GaF film measurements and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue phantom

Heavy Ion Microbeam- and Broadbeam-Induced Current Transients in SiGe HBTs

Science.gov (United States)

Pellish, Jonathan A.; Reed, R. A.; McMorrow, D.; Vizkelethy, G.; Ferlet-Cavrois, V.; Baggio, J.; Duhamel, O.; Moen, K. A.; Phillips, S. D.; Diestelhorst, R. M.;

Radon mapping - Santa Barbara and Ventura counties

International Nuclear Information System (INIS)

Churchill, R.

1997-01-01

Since 1990, the Department of Conservation''s Division of Mines and Geology (DMG) has provided geologic information and conducted several research projects on geology and radon for the California Department of Health Services (DHS) Radon Program. This article provides a brief overview of radon''s occurrence and impact on human health, and summarizes a recent DMG project for DHS that used geologic, geochemical, and indoor radon measurement data to produce detailed radon potential zone maps for Santa Barbara and Ventura counties

Dynamic Characteristics of Electrostatically Actuated Microbeams with Slant Crack

Directory of Open Access Journals (Sweden)

Han Zhou

2015-01-01

Full Text Available An improved model of the slant crack on a microbeam is presented. Based on fracture mechanics, the rotation coefficient for the slant crack is derived as a massless rotational spring accounting for the additional stress intensity factors generated by the orientation of the crack compared to the transverse crack. Comparisons between microbeams with a slant crack of different geometry parameters (slant angle, depth ratio, and crack position are investigated with regard to the dynamic mechanical behaviors and nonlinear response. By presenting a mathematical modeling, the effects of the slant crack and the electric actuation of an electrostatically actuated fixed-fixed microbeam on the dynamic characteristics are examined in detail. It is shown that the crack position has more significant influence on the pull-in voltage value than the slant angle or the depth ratio. Approaching the slant crack to the fixed end or enlarging the external incentives amplifies the nonlinearity of the microbeam system, while the effects of depth ratio and slant angle are dependent on the crack position. The resonance frequency and the resonance amplitude are affected as well.

Evaluation of the performance characteristics of radon and radon-daughter concentration measurement devices under controlled environmental conditions

International Nuclear Information System (INIS)

Pearson, M.D.

1989-04-01

The Technical Measurements Center (TMC) conducted a study to expose 10 radon and 7 radon-daughter concentration measurement devices in the DOE/GJPO Radon/Radon-Daughter Environmental Chamber for a series of 24 controlled-environment tests. The tests evaluated the devices' response to temperature, relative humidity, dew point, condensation-nuclei concentration, radon-daughter/radon equilibrium ratio, and non-uniform radon and radon-daughter concentration. Devices were evaluated for linear response as a function of concentration. In addition to response to environmental parameters, the evaluation included determining the utility of the devices in providing reasonable assurance of compliance with the radon and radon-daughter concentration standards for DOE remedial action programs. This reasonable assurance criterion is based on a coefficient of variation of 25 percent for devices deployed for year-long measurements and a coefficient of variation of 18 percent for devices deployed for intermittent sampling. 39 refs., 65 figs., 33 tabs

NORM and radon in Austria. Status and strategy; Norm und Radon in Oesterreich. Status und Strategie

Energy Technology Data Exchange (ETDEWEB)

Maringer, F.J. [Bundesamt fuer Eich- und Vermessungswesen, Wien (Austria)

2013-07-01

The author reviews the actual radiation protection practice in Austria for NORM and radon, including possible strategies and developments. Specific topics are radiation protection technologies, metrological resources for NORM in Austria, civil engineering standards (OeNORM) for radon measurement, radon prevention for new buildings and radon cleansing for existing buildings, future assessment and legal regulation of radioactivity in construction materials. The strategic development in Austria considers the current European standard projects (EU standards) and European and international research programs.

Lessons from radon

International Nuclear Information System (INIS)

Nichols, M.

1993-01-01

At EPA there is a public outreach program that the Office of Air and Radiation (OAR) has developed for radon. To meet the difficult challenge radon presented, OAR's Radon Division developed working relationships with national nonprofit groups who share a mission. These groups have well-established communication networks with their memberships for advancing their goals. Such diverse groups as the American Lung Association, the Advertising Council, the National Association of Counties (NACo), the Consumer Federation of America, the National Association of Homebuilders, and the National Safety Council have joined with EPA to reduce radon health risks. Through this alliance, EPA has been able to take advantage of communication channels that it could never replicate on tis own. Every group working with EPA disseminates the radon message through its own established channels to reach its constituency. These partners wield authority in their fields and are ideal for addressing the concerns of their audiences

The future of the radon program in the Czech Republic : the problems and challenges from the regulatory point of view

International Nuclear Information System (INIS)

Petrova, Karla

2008-01-01

Recently the radon program in the Czech Republic is running under the governmental resolution adopted in 1999 for 10 years. During the 2008 year a new national strategy for the further long term management of the radon issue should be proposed to the government. Taking into account the experience from the preceding years and particularly the effectiveness of the running radon program the proposal which is now in preparation is more focused to the prevention in new houses and to the more qualified, understandable information distribution within the population. The current initiatives of E U concerning the natural exposure regulation within the recast process of the European legislation related to the radiation protection are also reflected as far as possible at the moment. The principal points of the decision making process and the highlights of the proposal for a new national radon program in the Czech Republic are given in the paper. (author)

EPA'S strategy to reduce risk of radon

International Nuclear Information System (INIS)

Page, S.

1993-01-01

The Indoor Radon Abatement Act of 1988 (IRAA) directed EPA to undertake a variety of activities to address the growing public concern over dangers posed by exposure to indoor radon. Among other requirements, the law directed the Agency to study radon levels, evaluate mitigation methods, establish proficiency programs, assist states with program development, develop training centers, and provide public information. EPA has developed and implemented programs to address each of the key provisions of this statute. This paper presents EPA's broad national strategy to reduce radon risks. It combines and reinforces EPA's basic foundation, including its guiding policies and cooperative partnerships, with an overall management approach and focus for the future. The paper starts with an overview that introduces the strategy's four key elements: underlying policies and scientific principles, a decentralized system of states and other partners for targeting the public, multiple strategies for achieving radon risk reduction, and a strong focus on five key program priorities. This paper then discusses each of these elements in more detail and describes how they interact to guide future efforts and directions of the Agency

A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection

Science.gov (United States)

2015-09-01

ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for...ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for Chemical...TITLE AND SUBTITLE A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER

Human Lung Cancer Risks from Radon – Part I - Influence from Bystander Effects - A Microdose Analysis

Science.gov (United States)

Leonard, Bobby E.; Thompson, Richard E.; Beecher, Georgia C.

2010-01-01

Since the publication of the BEIR VI report in 1999 on health risks from radon, a significant amount of new data has been published showing various mechanisms that may affect the ultimate assessment of radon as a carcinogen, at low domestic and workplace radon levels, in particular the Bystander Effect (BE) and the Adaptive Response radio-protection (AR). We analyzed the microbeam and broadbeam alpha particle data of Miller et al. (1995, 1999), Zhou et al. (2001, 2003, 2004), Nagasawa and Little (1999, 2002), Hei et al. (1999), Sawant et al. (2001a) and found that the shape of the cellular response to alphas is relatively independent of cell species and LET of the alphas. The same alpha particle traversal dose response behavior should be true for human lung tissue exposure to radon progeny alpha particles. In the Bystander Damage Region of the alpha particle response, there is a variation of RBE from about 10 to 35. There is a transition region between the Bystander Damage Region and Direct Damage Region of between one and two microdose alpha particle traversals indicating that perhaps two alpha particle “hits” are necessary to produce the direct damage. Extrapolation of underground miners lung cancer risks to human risks at domestic and workplace levels may not be valid. PMID:21731539

Consequences of cytoplasmic irradiation. Studies from microbeam

International Nuclear Information System (INIS)

Zhou, Hongning; Hong, Mei; Chai, Yunfei; Hei, Tom K.

2009-01-01

The prevailing dogma for radiation biology is that genotoxic effects of ionizing radiation such as mutations and carcinogenesis are attributed mainly to direct damage to the nucleus. However, with the development of microbeam that can target precise positions inside the cells, accumulating evidences have shown that energy deposit by radiation in nuclear DNA is not required to trigger the damage, extra-nuclear or extra-cellular radiation could induce the similar biological effects as well. This review will summarize the biological responses after cytoplasm irradiated by microbeam, and the possible mechanisms involved in cytoplasmic irradiation. (author)

Radon survey in Metropolitan Toronto schools

International Nuclear Information System (INIS)

Becker, E.; Moridi, R.

1992-01-01

The radon testing survey in Metropolitan Toronto public schools was the most intensive project of its kind ever undertaken in Canadian schools. It also included an extensive public education program on radiation and radon-in-schools. The radon levels at 632 schools were measured using the CAIRS Radon Monitors. Ninety percent of the locations measured were found to have a radon level equal to or less than 2 mWL. Two locations in two different schools were found to have a radon level at or above the Action Level (20 mWL). The remaining results were between the two extremes. Follow-up testing in those schools where more than 10 mWL of radon was found is in progress. (author)

Microbeam facility at NIRS

International Nuclear Information System (INIS)

Sato, Yukio; Yamaguchi, Hiroshi

2000-01-01

Radiation biophysics or microdosimetry has suggested radiation effect mechanism. Full understanding of it has not yet been obtained. There are vast variety of events in physical, chemical and biological processes from at the time of irradiation to biological endpoints. Analysis of RBE-LET relation for biological endpoints like survival, mutation and transformation in cultured mammalian cells is still the leading subject to study the physical processes. The biological and repair processes have been studied phenomenologically through dose rate effect or fractionation experiment. Human genome project has accelerated biological sciences as a whole taking methodology of the molecular biology, where the mechanism is explained by molecules involved. We have thus to know entity and its (biological) function in every single process. Molecular biological approach in radiation biology has started and revealed several proteins being involved in the repair processes. Quantitative relation between phenomenological data like cell survivals and molecular processes, however, has been little known yet. A promising approach to fill this gap should be the study by microbeam, which enables us to see, for example, a deletion in chromosomal level by a single particle traverse of cell nucleus and may suggest possible molecular processes. Under this motivation we started feasibility study on installation of a microbeam port in our Tandem accelerator (5.1 MeV 4 He 2+ ). We have planned to adopt a lens focusing and a scanning system developed (by the Oxford microbeam Ltd) for the existing micro PIXE system in NIRS, which has basically achieved irradiation to a cell within a position resolution of 2 micrometer. There are two practical requirements, i.e. precise positioning and faster irradiation. These are described including research subjects planned. (author)

Light ion microbeam analysis / processing system and its improvement

International Nuclear Information System (INIS)

Koka, Masashi; Ishii, Yasuyuki; Yamada, Naoto; Ohkubo, Takeru; Kamiya, Tomihiro; Satoh, Takahiro; Kada, Wataru; Kitamura, Akane; Iwata, Yoshihiro

2016-03-01

A MeV-class light ion microbeam system has been developed for micro-analysis and micro-fabrication with high spatial resolution at 3-MV single-ended accelerator in Takasaki Ion Accelerators for Advanced Radiation Application of Takasaki Advanced Radiation Research Institute, Sector of Nuclear Science Research, Japan Atomic Energy Agency. This report describes the technical improvements for the main apparatus (the accelerator, beam-transport lines, and microbeam system), and auxiliary equipments/ parts for ion beam applications such as Particle Induced X-ray/Gamma-ray Emission (PIXE/PIGE) analysis, 3-D element distribution analysis using PIXE Computed Tomography (CT), Ion Beam Induced Luminescence (IBIL) analysis, and Proton Beam Writing with the microbeam scanning, with functional outline of these apparatus and equipments/parts. (author)

Measurement of radon in Spanish houses: characterization of its sources

International Nuclear Information System (INIS)

1998-01-01

The determination of radon concentrations in-house are analyzed by different universities. The programs of Cantabria, Valencia, Barcelona and La Laguna Universities are presented. These programs study the environmental impact of radon in Barcelona and Madrid and characterize the radon sources

Indoor radon II

International Nuclear Information System (INIS)

Anon.

1987-01-01

Because of the growing interest in and public concern about indoor radon, APCA, in April 1987, sponsored the Second International Specialty Conference on Indoor Radon. This book is the proceedings of this conference and includes discussions on: A current assessment of the nature of the problem; Issues related to health effects and risk assessment; The development of public and private sector initiatives; Research into methods of control and prevention; International perspectives; and Measurement methods and programs. The material is intended for the technically oriented and for those responsible for developing programs and initiatives to address this important public health issue. Contributors include federal, state, and provincial program officials and members of the academic and private sectors

Standardization of radon measurements

International Nuclear Information System (INIS)

Matuszek, J.M.; Hutchinson, J.A.; Lance, B.H.; Virgil, M.G.; Mahoney, R.J.

1988-01-01

Radon escaping from soil into homes appears to present the single greatest source of radiation exposure that most people will ever face. Measurement protocols for the relatively inert gas inextricably link the method of collection with the counting of the specimen. The most commonly used methods depend on the measurement of dislocation sites on plastic α-track detectors or on the adsorption of radon onto activated charcoal for subsequent counting of the γ-rays produced by decay of the radon progeny. The uncertainties inherent to the radon-measurement methods used commercially in the United States are far greater than those for measurements of other environmental radionuclides. The results of this preliminary study raise doubts as to whether existing proficiency-testing programs can provide assurance that radon-measurement methods are representative of actual conditions in any dwelling. 17 refs., 1 figs., 4 tabs

Radon: Chemical and physical states of radon progeny. Final technical report

International Nuclear Information System (INIS)

Castleman, A.W. Jr.

1996-01-01

The evolving chemical and physical form of radon progeny influence their transport to the bioreceptor and the extent to which that receptor can take up these species into various tissues. When first born following radioactive decay processes, the potentially deleterious radon progeny undergo various physical and chemical transformations as they transcend from a highly charged to a neutral state, and interact with various constituents of the environment. These transformations impact on the extent to which the radon progeny become associated with aerosol particles on the one hand, and their ultimate chemical form that is available for uptake in the biosystem, on the other. The program, which originally commenced in 1987, dealt with the basic chemistry and physics of radon progeny and hence impacted on several themes of importance to the DOE/OHER radon program. One of these is dose response, which is governed by the physical forms of the radon progeny, their transport to the bioreceptor and the chemical forms that govern their uptake. The second theme had to do with cellular responses, one of the major issues motivating the work. It is well known that various sizes of ions and molecules are selectively transported across cell membrane to differing degrees. This ultimately has to do with their chemical and physical forms, charge and size. The overall objective of the work was threefold: (1) quantifying the mechanisms and rates of the chemical and physical transformation; (2) ascertaining the ultimate chemical forms, and (3) determining the potential interactions of these chemical species with biological functional groups to ascertain their ultimate transport and incorporation within cells

Swiss radon programme 'RAPROS'

International Nuclear Information System (INIS)

Zeller, W.

1992-03-01

The results of the five-year radon research program RAPROS presented in this report, allow for scientifically valid statements on the origin of elevated levels of indoor radon in Switzerland. These results form a basis for recommendations and for actions to be taken. Indoor radon concentrations have been measured in more than 4000 living-rooms and 2000 basements; a sampling density of about 0.2% of the Swiss housing stock. According to these measurements radon leads to an estimated average annual effective dose of 2 milli-Sievert, although in some regions the annual dose may be much higher. Extrapolation of the existing data shows that in about 10'000 Swiss houses radon may exceed 1000 Bq/m 3 . For these houses remedial actions are recommended. There seems to be no radon problem in the large cities in the Swiss Plateau. High indoor radon concentrations in Switzerland are due to the soil beneath the buildings. Data from the study indicated that the most important soil characteristic influencing indoor radon concentrations was its gas permeability. Because natural ventilation in a heated house creates a slight underpressure in the lower levels with respect to surrounding soils, radon is driven from the soil into the building. Weatherization of the houses to reduce energy consumption had in most cases no effect on the indoor radon concentrations. Radon from tap water or from building materials does not contribute significantly to indoor radon levels in Switzerland. The high levels in the Jura Mountains are thought to be associated with karstic limestone bedrock. Several houses within Switzerland have now been modified to reduce radon levels. The most successful mitigation technique combined forced-air ventilation with tightening of the basement to decrease or prevent air infiltration from the soil. (author) figs., tabs., refs

World Health Organization's International Radon Project 2005-2008

International Nuclear Information System (INIS)

Carr, Zhanat; Shannoun, Ferid; Zielinski, Jan M.

2008-01-01

Recent epidemiological studies of people exposed to indoor radon have confirmed that radon in homes is a serious health hazard that can be easily mitigated. To address the issue at an international level, the World Health Organization (WHO) established the International Radon Project (IRP). The project was launched in January 2005 with its first meeting attended by 36 experts representing 17 countries. The project's scope and the key objectives were outlined at this meeting and later refined: 1-) To identify effective strategies for reducing the health impact of radon; 2-) To promote sound policy options, prevention and mitigation programs (including monitoring and evaluation of programs; 3-) To raise public, political and economical awareness about the consequences of exposure to radon (including financial institutions as target group); 4-) To estimate the global health impact of exposure to residential radon using available data on radon worldwide. WHO and its member states strive through the WHO-IRP to succeed in putting indoor radon on the environmental health agenda in countries with lower awareness of radon as a health problem and in strengthening local and national radon-related activities in countries with ongoing radon programs. Two subsequent working meetings were held: in March, 2006 in Geneva with 63 participants from 25 countries, along with representatives of the International Atomic Energy Agency (IAEA), the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), the International Commission on Radiological Protection (ICRP), and European Commission (EC); and in March 2007 in Munich with 61 participants from 27 countries. Both meetings reviewed the IRP progress and focused on the two main outputs: 'The WHO Report on the Global Burden of Disease (GBD) due to Radon' and 'The WHO Radon Handbook'. The former applies the WHO methodology for GBD assessment and considers ways to graphically map residential radon concentrations

Ambient Radon-222 Monitoring in Amargosa Valley, Nevada

International Nuclear Information System (INIS)

L.H. Karr; J.J. Tappen; D. Shafer; K.J. Gray

2008-01-01

As part of a program to characterize and baseline selected environmental parameters in the region around the proposed repository at Yucca Mountain, Nevada, ambient radon-222 monitoring was conducted in the rural community of Amargosa Valley, the community closest to the proposed repository site. Passive integrating radon monitors and a continuous radon monitoring instrument were deployed adjacent to the Community Environmental Monitoring Program (CEMP) (http://www.cemp.dri.edu/index.html) station located in the Amargosa Valley Community Center near the library. The CEMP station provided real-time ambient gamma exposure and meteorological data used to correct the integrated radon measurements as well as verify meteorological data collected by the continuous radon monitoring instrument. Additionally, different types of environmental enclosures that housed the monitors and instrument were used to determine if particular designs influenced the ambient radon measurements

Weanling piglet cerebellum: a surrogate for tolerance to MRT (microbeam radiation therapy) in pediatric neuro-oncology

Science.gov (United States)

Laissue, Jean A.; Blattmann, Hans; Di Michiel, Marco; Slatkin, Daniel N.; Lyubimova, Nadia; Guzman, Raphael; Zimmermann, Werner; Birrer, Stephan; Bley, Tim; Kircher, Patrick; Stettler, Regina; Fatzer, Rosmarie; Jaggy, Andre; Smilowitz, Henry; Brauer, Elke; Bravin, Alberto; Le Duc, Geraldine; Nemoz, Christian; Renier, Michel; Thomlinson, William C.; Stepanek, Jiri; Wagner, Hans-Peter

2001-12-01

The cerebellum of the weanling piglet (Yorkshire) was used as a surrogate for the radiosensitive human infant cerebellum in a Swiss-led program of experimental microbeam radiation therapy (MRT) at the ESRF. Five weanlings in a 47 day old litter of seven, and eight weanlings in a 40 day old litter of eleven were irradiated in November, 1999 and June, 2000, respectively. A 1.5 cm-wide x 1.5 xm-high array of equally space approximately equals 20-30 micrometers wide, upright microbeams spaced at 210 micrometers intervals was propagated horizontally, left to right, through the cerebella of the prone, anesthetized piglets. Skin-entrance intra-microbeam peak adsorbed doses were uniform, either 150, 300, 425, or 600 gray (Gy). Peak and inter-microbeam (valley) absorbed doses in the cerebellum were computed with the PSI version of the Monte Carlo code GEANT and benchmarked using Gafchromic and radiochromic film microdosimetry. For approximately equals 66 weeks [first litter; until euthanasia], or approximately equals 57 weeks [second litter; until July 30, 2001] after irradiation, the littermates were developmentally, behaviorally, neurologically and radiologically normal as observed and tested by experienced farmers and veterinary scientists unaware of which piglets were irradiated or sham-irradiated. Morever, MRT implemented at the ESRF with a similar array of microbeams and a uniform skin-entrance peak dose of 625 Gy, followed by immunoprophylaxis, was shown to be palliative or curative in young adult rats bearing intracerebral gliosarcomas. These observations give further credence to MRT's potential as an adjunct therapy for brain tumors in infancy, when seamless therapeutic irradiation of the brain is hazardous.

Improvement of the Energy Stability of the Single Ion Microbeam

International Nuclear Information System (INIS)

Zhan Furu; Qi Xuehong; Xu Mingliang; Chen Lianyun; Yu Zengliang

2008-01-01

Energy instability strongly affects the state and the beam size of the single ion microbeam. A facility based on the Generating Voltmeter was developed to improve the energy stability of the CAS-LIBB (Chinese Academy of Sciences, key laboratory of ion beam bioengineering) single ion microbeam. This paper presents the analysis of the energy instability of the single ion microbeam. A simplified theoretical model is set up to calculate the relationship between the energy instability and the beam spot size. By using this technique, the energy instability is adjusted to about 1%. Stable run-time is over 6 hours. The radius of the single ion beam is reduced by 10% compared to the previous one.

Design of the IMP microbeam irradiation system for 100 MeV/u heavy ions

International Nuclear Information System (INIS)

Sheng Lina; Song Mingtao; Zhang Xiaoqi; Yang Xiaotian; Gao Daqing; He Yuan; Zhang Bin; Liu Jie; Sun Youmei; Dang Bingrong; Lwenjian; Su Hong; Man Kaidi; Guo Yizhen; Wang Zhiguang; Zhan Wenlong

2009-01-01

A state-of-the-art high energy heavy ion microbeam irradiation system is constructed at the Institute of Modern Physics of the Chinese Academy of Sciences. This microbeam system operates in both full current intensity mode and single ion mode. It delivers a predefined number of ions to pre-selected targets for research in biology and material science. The characteristic of this microbeam system is high energy and vertical irradiation. A quadrupole focusing system, in combination with a series of slits, has been designed to optimize the spatial resolution. A symmetrically achromatic system leads the beam downwards and serves simultaneously as an energy analyzer. A high gradient quadrupole triplet finally focuses a C 6+ ion beam to 1 μm in the vacuum chamber within the energy range from 10 MeV/u to 100 MeV/u. In this paper, the IMP microbeam system is described in detail. A systematic investigation of the ion beam optics of this microbeam system is presented together with the associated aberrations. Comparison is made between the IMP microbeam system and the other existing systems to further discuss the performance of this microbeam. Then the optimized initial beam parameters are given for high resolution and high hitting efficiency. At last, the experiment platform is briefly introduced. (authors)

Vibration Characteristics of Piezoelectric Microbeams Based on the Modified Couple Stress Theory

Directory of Open Access Journals (Sweden)

R. Ansari

2014-01-01

Full Text Available The vibration behavior of piezoelectric microbeams is studied on the basis of the modified couple stress theory. The governing equations of motion and boundary conditions for the Euler-Bernoulli and Timoshenko beam models are derived using Hamilton’s principle. By the exact solution of the governing equations, an expression for natural frequencies of microbeams with simply supported boundary conditions is obtained. Numerical results for both beam models are presented and the effects of piezoelectricity and length scale parameter are illustrated. It is found that the influences of piezoelectricity and size effects are more prominent when the length of microbeams decreases. A comparison between two beam models also reveals that the Euler-Bernoulli beam model tends to overestimate the natural frequencies of microbeams as compared to its Timoshenko counterpart.

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

Science.gov (United States)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-08-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

International Nuclear Information System (INIS)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-01-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed

From insulation contracting to radon mitigation

International Nuclear Information System (INIS)

West, D.R.

1990-01-01

As the definition of house doctor has evolved over the past ten years and the field of energy services has grown more sophisticated, many contractors have expanded the services they offer their clients. This paper presents the story of one insulation contractor who has found a niche in radon testing and mitigation. The EPA now has a national program for the radon mitigator called the Radon Contractor Proficiency Program. The requirements include attending the Radon Technology for Mitigators course, passing an exam, and taking continuing education. In the Midwest, the most popular mitigation technique is the subslab depressurization system. To draw suction from under the slab, the system can take advantage of an existing sump crock or can penetrate the slab. Interior drain tiles collect water to empty into the crock, providing an excellent pathway to draw from. This mitigation process is explained

Find a Radon Test Kit or Measurement and Mitigation Professional

Science.gov (United States)

Find a qualified radon service professional to fix or mitigate your home. If you have questions about a radon, you should contact your state radon contact and/or contact one or both of the two privately-run National Radon Proficiency Programs

Indoor Radon Concentration Related to Different Radon Areas and Indoor Radon Prediction

Science.gov (United States)

Juhásová Šenitková, Ingrid; Šál, Jiří

2017-12-01

Indoor radon has been observed in the buildings at areas with different radon risk potential. Preventive measures are based on control of main potential radon sources (soil gas, building material and supplied water) to avoid building of new houses above recommended indoor radon level 200 Bq/m3. Radon risk (index) estimation of individual building site bedrock in case of new house siting and building protection according technical building code are obligatory. Remedial actions in buildings built at high radon risk areas were carried out principally by unforced ventilation and anti-radon insulation. Significant differences were found in the level of radon concentration between rooms where radon reduction techniques were designed and those where it was not designed. The mathematical model based on radon exhalation from soil has been developed to describe the physical processes determining indoor radon concentration. The model is focused on combined radon diffusion through the slab and advection through the gap from sub-slab soil. In this model, radon emanated from building materials is considered not having a significant contribution to indoor radon concentration. Dimensional analysis and Gauss-Newton nonlinear least squares parametric regression were used to simplify the problem, identify essential input variables and find parameter values. The presented verification case study is introduced for real buildings with respect to various underground construction types. Presented paper gives picture of possible mathematical approach to indoor radon concentration prediction.

Alignment of dipole magnet in micro-beam line of HIRFL

International Nuclear Information System (INIS)

Wang Shaoming; Chen Wenjun; Yang Shengli; Cai Guozhu; Guo Yizhen; Zhou Guangming; Man Kaidi; Song Mingtao

2010-01-01

Microbeam irradiation facility is an experiment platform, which can reduce the beam-spot on the irradiated sample to micrometer level, and can accurately locate and count the radioactive particles. It is a powerful research tool for the irradiation material science, irradiation biology, irradiation biomedicine and micro mechanical machining. The microbeam irradiation facility requires the precise work for installation and alignment. These conditions make magnet's change for directions and positions because the location space of dipole magnets in micro-beam line of HIRFL (Heavy Ion Research Facility in Lanzhou) is very small. It is a challenge for the installation and alignment work of magnets. It was solved by transforming coordinates of benchmarks of magnets, which controlled the error of magnet setup within error tolerance range. (authors)

Procedure manual for the estimation of average indoor radon-daughter concentrations using the radon grab-sampling method

International Nuclear Information System (INIS)

George, J.L.

1986-04-01

The US Department of Energy (DOE) Office of Remedial Action and Waste Technology established the Technical Measurements Center to provide standardization, calibration, comparability, verification of data, quality assurance, and cost-effectiveness for the measurement requirements of DOE remedial action programs. One of the remedial-action measurement needs is the estimation of average indoor radon-daughter concentration. One method for accomplishing such estimations in support of DOE remedial action programs is the radon grab-sampling method. This manual describes procedures for radon grab sampling, with the application specifically directed to the estimation of average indoor radon-daughter concentration (RDC) in highly ventilated structures. This particular application of the measurement method is for cases where RDC estimates derived from long-term integrated measurements under occupied conditions are below the standard and where the structure being evaluated is considered to be highly ventilated. The radon grab-sampling method requires that sampling be conducted under standard maximized conditions. Briefly, the procedure for radon grab sampling involves the following steps: selection of sampling and counting equipment; sample acquisition and processing, including data reduction; calibration of equipment, including provisions to correct for pressure effects when sampling at various elevations; and incorporation of quality-control and assurance measures. This manual describes each of the above steps in detail and presents an example of a step-by-step radon grab-sampling procedure using a scintillation cell

Electrothermally Actuated Microbeams With Varying Stiffness

KAUST Repository

Tella, Sherif Adekunle

2017-11-03

We present axially loaded clamped-guided microbeams that can be used as resonators and actuators of variable stiffness, actuation, and anchor conditions. The applied axial load is implemented by U-shaped electrothermal actuators stacked at one of the beams edges. These can be configured and wired in various ways, which serve as mechanical stiffness elements that control the operating resonance frequency of the structures and their static displacement. The experimental results have shown considerable increase in the resonance frequency and mid-point deflection of the microbeam upon changing the end conditions of the beam. These results can be promising for applications requiring large deflection and high frequency tunability, such as filters, memory devices, and switches. The experimental results are compared to multi-physics finite-element simulations showing good agreement among them.

The radon service industry in selected Northeastern states

International Nuclear Information System (INIS)

Watson, M.R.; Reese, J.P.; Adams, A.R.

1988-01-01

In 1986 the EPA initiated an expedited program of technical assistance in response to the discovery of extremely elevated levels of indoor radon in Pennsylvania homes. A vital component of this project was a training program which addressed the variety of techniques used to reduce human exposure to radon gas and its decay products. The New York State Energy Office was selected as the most suitable organization to assist in this project because of its relevant experience in training programs, especially the building for energy efficiency workshop series with its indoor radon gas component. This paper reports on the project

Ground-truthing predicted indoor radon concentrations by using soil-gas radon measurements

International Nuclear Information System (INIS)

Reimer, G.M.

2001-01-01

Predicting indoor radon potential has gained in importance even as the national radon programs began to wane. A cooperative study to produce radon potential maps was conducted by the Environmental Protection Agency (EPA), U.S. Geological Survey (USGS), Department of Energy (DOE), and Lawrence Berkeley Laboratory (LBL) with the latter taking the lead role. A county-wide predictive model based dominantly on the National Uranium Resource Evaluation (NURE) aerorad data and secondly on geology, both small-scale data bases was developed. However, that model breaks down in counties of complex geology and does not provide a means to evaluate the potential of an individual home or building site. Soil-gas radon measurements on a large scale are currently shown to provide information for estimating radon potential at individual sites sort out the complex geology so that the small-scale prediction index can be validated. An example from Frederick County, Maryland indicates a positive correlation between indoor measurements and soil-gas data. The method does not rely on a single measurement, but a series that incorporate seasonal and meteorological considerations. (author)

Static Response of Microbeams due to Capillary and Electrostatic Forces

KAUST Repository

Bataineh, Ahmad M.

2016-03-07

Micro-sensors or micro-switches usually operate under the effect of electrostatic force and could face some environmental effects like humidity, which may lead to condensation underneath the beams and create strong capillary forces. Those tiny structures are principally made of microbeams that can undergo instabilities under the effect of those created huge capillary forces. In fact, during the fabrication of microbeams, there is an important step to separate the beam from its substrate (wet etching). After this step, the microstructure is dried, which may causes the onset of some droplets of water trapped underneath the beam that could bring about a huge capillary force pulling it toward its substrate. If this force is bigger than the microbeam\\'s restoring force, it will become stuck to the substrate. This paper investigates the instability scenarios of both clamped-clamped (straight and curved) and cantilever (straight and curled) microbeams under the effect of capillary and/or electrostatic forces. The reduced order modeling (ROM) based on the Galerkin procedure is used to solve the nonlinear beam equations. The non-ideal boundaries are modeled by adding springs. The volume of the fluid between the beam and the substrate underneath it is varied and the relation between the volume of the water and the stability of the beam is shown. An analysis for the factors of which should be taken in to consideration in the fabrication processes to overcome the instability due to huge capillary forces is done. Also the size of the electrode for the electrostatic force is varied to show the effect on the micro-switch stability. A variation of the pull-in voltage with some specific beam parameters and with more than one case of electrode size is shown. It is found that capillary forces have a pronounced effect on the stability of microbeams. It is also found that the pull-in length decreases as the electrode size increases. It is also shown that the pull-in voltage decreases

Origin of Knudsen forces on heated microbeams

KAUST Repository

Zhu, Taishan

2010-09-09

The presented work probes the fundamentals of Knudsen forces. Using the direct simulation Monte Carlo (DSMC) method, the flows induced by temperature inhomogeneity within a representative configuration and the Knudsen force acting on a heated microbeam are captured as functions of Knudsen number in the entire flow regime. Both flow strength and Knudsen force peak in the transition regime and negative Knudsen force absent in experimental data is observed. The mechanisms of the thermally induced flows and Knudsen forces are studied. It has been found that thermal edge flow is the main driven source for the formation of the Knudsen force on microbeams and domain configuration plays an important role in the process.

High energy ion microbeams and their applications

International Nuclear Information System (INIS)

Bakhru, H.; Nickles, E.; Haberl, A.; Morris, W.G.

1992-01-01

In recent years there has been rapid growth for the development of equipment for forming a focussed beam (0.5 - 2μm) with high energy ions. The State University of New York at Albany ion scanning microprobe has been used for several applications especially in the fields of materials and biological studies. Rutherford backscattering spectroscopy (RBS) and particle-induced x-ray emission (PIXE) analysis have been performed on microelectronic circuits with a spatial resolution of approximately 2 μm. Studies on films of superconductors (YBa CuO) will be presented. Applications of microbeams for the biological studies and analytical techniques will be presented. Current and future role of microbeams and their limitations will be discussed. (author)

Physiologically gated microbeam radiation using a field emission x-ray source array

Energy Technology Data Exchange (ETDEWEB)

Chtcheprov, Pavel, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Biomedical Engineering, University of North Carolina, 152 MacNider Hall, Campus Box 7575, Chapel Hill, North Carolina 27599 (United States); Burk, Laurel; Inscoe, Christina; Ger, Rachel; Hadsell, Michael; Lu, Jianping [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 (United States); Yuan, Hong [Department of Radiology, University of North Carolina, 2006 Old Clinic, CB #7510, Chapel Hill, North Carolina 27599 (United States); Zhang, Lei [Department of Applied Physical Sciences, University of North Carolina, Chapman Hall, CB#3216, Chapel Hill, North Carolina 27599 (United States); Chang, Sha [Department of Radiation Oncology, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States); Zhou, Otto, E-mail: PavelC@unc.edu, E-mail: zhou@email.unc.edu [Department of Physics and Astronomy, University of North Carolina, Phillips Hall, CB #3255, 120 East Cameron Avenue, Chapel Hill, North Carolina 27599 and UNC Lineberger Comprehensive Cancer Center, University of North Carolina, 101 Manning Drive, Chapel Hill, North Carolina 27514 (United States)

2014-08-15

Purpose: Microbeam radiation therapy (MRT) uses narrow planes of high dose radiation beams to treat cancerous tumors. This experimental therapy method based on synchrotron radiation has been shown to spare normal tissue at up to 1000 Gy of peak entrance dose while still being effective in tumor eradication and extending the lifetime of tumor-bearing small animal models. Motion during treatment can lead to significant movement of microbeam positions resulting in broader beam width and lower peak to valley dose ratio (PVDR), which reduces the effectiveness of MRT. Recently, the authors have demonstrated the feasibility of generating microbeam radiation for small animal treatment using a carbon nanotube (CNT) x-ray source array. The purpose of this study is to incorporate physiological gating to the CNT microbeam irradiator to minimize motion-induced microbeam blurring. Methods: The CNT field emission x-ray source array with a narrow line focal track was operated at 160 kVp. The x-ray radiation was collimated to a single 280 μm wide microbeam at entrance. The microbeam beam pattern was recorded using EBT2 Gafchromic{sup ©} films. For the feasibility study, a strip of EBT2 film was attached to an oscillating mechanical phantom mimicking mouse chest respiratory motion. The servo arm was put against a pressure sensor to monitor the motion. The film was irradiated with three microbeams under gated and nongated conditions and the full width at half maximums and PVDRs were compared. An in vivo study was also performed with adult male athymic mice. The liver was chosen as the target organ for proof of concept due to its large motion during respiration compared to other organs. The mouse was immobilized in a specialized mouse bed and anesthetized using isoflurane. A pressure sensor was attached to a mouse's chest to monitor its respiration. The output signal triggered the electron extraction voltage of the field emission source such that x-ray was generated only

Contribution of radon in natural gas to the dose from aiborne radon-daughters in homes

International Nuclear Information System (INIS)

Barton, C.J.; Moore, R.E.; Rohwer, P.S.

1973-01-01

Data have been obtained on the radon concentration in natural gas supplied to several metropolitan areas in the United States. The average value of 20 pCi/l was selected to estimate the contribution of this source of natural radioactivity to doses from radon-daughters received by individuals in homes. Radon-daughter concentrations in the home atmosphere were calculated by use of computer programs for an 8000 ft 3 house in which 27 ft 3 of gas per day was used for cooking in an unvented kitchen range. The total estimated dose to the bronchial epithelium included contributions from radon plus daughters in the outside ventilation air, each of which was assumed to be present at a concentration of 0.13 pCi/l, and from the radon plus daughters in the natural gas. The latter contribution averaged approximately 3 percent of the total dose. There was a 3.5 percent decrease in the estimated total dose when the air change rate increased from 0.25 to 2.0 per hour. We conclude that radon and radon-daughters entering the home with natural gas produce a negligible fraction of the total dose to the respiratory system of home occupants from airborne radon-daughters

Ion microbeam irradiation for radiobiology and radical chemistry: status and prospect

Energy Technology Data Exchange (ETDEWEB)

Khodja, H, E-mail: hicham.khodja@cea.fr [CEA, IRAMIS, SIS2M, LEEL, 91191 Gif-sur-Yvette (France); CNRS, UMR 3299, SIS2M, LEEL, 91191 Gif-sur-Yvette (France)

2011-01-01

Ion microbeams are commonly used to study local irradiation effects in living cells, as it has been established that ion beam irradiations can lead to deleterious changes in cells that are not struck directly by the microbeam. Such changes, which take place over distances long compared to the size of the irradiation spot and for times long compared to the time of irradiation, are collectively termed radiation-induced bystander effect or RIBE. Free-radical chemistry is frequently invoked to explain the RIBE but no unified model is available at present. Ion microbeams when coupled with advanced methods for observing free radicals are the tools of choice for investigating the chemistry and biological processes governing RIBE.

Nanoscale and submicron fatigue crack growth in nickel microbeams

International Nuclear Information System (INIS)

Yang, Y.; Yao, N.; Imasogie, B.; Soboyejo, W.O.

2007-01-01

This paper presents a novel edge-notched microbeam technique for the study of short fatigue crack growth. The technique is used to study submicron and nanoscale fatigue in LIGA Ni thin films with columnar microstructures. The edge-notched microbeams were fabricated within LIGA Ni thin films, using focused ion beam (FIB) techniques. The microbeams were then cyclically deformed to failure at a stress ratio of 0.1. Different slip-band structures were observed below the nanoscale notches. Cyclic deformation resulted in the formation of primary slip bands below the notch. Subsequent crack growth then occurred by the unzipping of fatigue cracks along intersecting slip bands. The effects of the primary slip bands were idealized using dislocation-based models. These were used to estimate the intrinsic fatigue threshold and the fatigue endurance limit. The estimates from the model are shown to be consistent with experimental data from prior stress-life experiments and current/prior fatigue threshold estimates

Communicating the risk from radon

International Nuclear Information System (INIS)

Fisher, A.; McClelland, G.H.; Schulze, W.D.; Doyle, J.K.

1991-01-01

A prominent television station developed a special series of newscasts and public service announcements about radon. This was combined with their advertising of the availability of reduced-price radon test kits in a local supermarket chain. The large number of test kits sold was a success from a marketing perspective, but not from a public health perspective - especially because of the very small share of high readings that were mitigated. In contrast, a study of housing sales showed a much higher testing rate and corresponding mitigation when risk communication accompanied the housing transaction, rather than being directed toward the general public. This paper examined the relative effectiveness of these alternative approaches to radon risk communication, emphasizing the implications for developing and implementing radon programs

Live cell imaging at the Munich ion microbeam SNAKE - a status report.

Science.gov (United States)

Drexler, Guido A; Siebenwirth, Christian; Drexler, Sophie E; Girst, Stefanie; Greubel, Christoph; Dollinger, Günther; Friedl, Anna A

2015-02-18

Ion microbeams are important tools in radiobiological research. Still, the worldwide number of ion microbeam facilities where biological experiments can be performed is limited. Even fewer facilities combine ion microirradiation with live-cell imaging to allow microscopic observation of cellular response reactions starting very fast after irradiation and continuing for many hours. At SNAKE, the ion microbeam facility at the Munich 14 MV tandem accelerator, a large variety of biological experiments are performed on a regular basis. Here, recent developments and ongoing research projects at the ion microbeam SNAKE are presented with specific emphasis on live-cell imaging experiments. An overview of the technical details of the setup is given, including examples of suitable biological samples. By ion beam focusing to submicrometer beam spot size and single ion detection it is possible to target subcellular structures with defined numbers of ions. Focusing of high numbers of ions to single spots allows studying the influence of high local damage density on recruitment of damage response proteins.

Heavy ion microbeam system for study of single event effects

International Nuclear Information System (INIS)

Kamiya, Tomihiro; Utsunomiya, Nobuhiro; Minehara, Eiichi; Tanaka, Ryuichi; Ohmura, Miyoshi; Kohno, Kazuhiro; Iwamoto, Eiji.

1992-01-01

A high-energy heavy ion microbeam system has been developed and installed on a beam line of a 3 MV tandem electrostatic accelerator mainly for analysis of basic mechanism of single event upset (SEU) of semiconductor devices in spacecraft. The SEU is now the most serious problem for highly reliable spacecraft electronics system with long space mission. However, the mechanism has not been understood on the basis of microscopic process of SEU. The SEU phenomena depends not only upon hitting particles, but also upon the hit position on the microcircuit. To observe the transient charge pulse from a SEU, a single ion particle must hit exactly the desired position of the microcircuit. Such an experiment requires the microbeam spot size within 1 μm, the beam positioning accuracy within ±1 μm, and single ion hitting. The microbeam system has been designed to meet the above technical requirements. The system is equipped with two lens systems: one to control the target beam current in a wide range down to extremely low current without any change of the beam optics, and the other to focus heavy ion beams within a spot size of 1 μm. The final goal is to hit a microscopic target area with a single 15 MeV nickel ion. The beam spot size has been evaluated by Gaussian fitting of secondary electron profiles with microbeam scanning across the fine Cu mesh. The single ion detection has been also tested to generate a trigger signal for closing beam shutter to prevent further hits. This paper outlines the new microbeam system and describes methods to realize these techniques. (author)

The first interdisciplinary experiments at the IMP high energy microbeam

Energy Technology Data Exchange (ETDEWEB)

Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Guo, Na; Liu, Wenjing; Ye, Fei; Sheng, Lina; Li, Qiang [Institute of Modern Physics (IMP), Chinese Academy of Sciences, Lanzhou (China); Li, Huiyun [Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen (China)

2015-04-01

The high energy beam of tens to hundred MeV/u ions possesses mm-to-cm penetration depth in materials and can be easily extracted into air without significant energy loss and beam scattering. Combination of high energy ions and microbeam technology facilitates the microprobe application to many practical studies in large scale samples. The IMP heavy ion microbeam facility has recently been integrated with microscopic positioning and targeting irradiation system. This paper introduced the first interdisciplinary experiments performed at the IMP microbeam facility using the beam of 80.5 MeV/u carbon ions. Bystander effect induction via medium transferring was not found in the micro-irradiation study using HeLa cells. The mouse irradiation experiment demonstrated that carbon irradiation of 10 Gy dose to its tuberomammillary nucleus did not impair the sleep nerve system. The fault injection attack on RSA (Rivest–Shamir–Adleman) decryption proved that the commercial field-programmable gate array chip is vulnerable in single event effect to low linear-energy-transfer carbon irradiation, and the attack can cause the leakage of RSA private key. This work demonstrates the potential of high energy microbeam in its application to biology, biomedical, radiation hardness, and information security studies.

Coordinated indoor radon surveys in some Arab countries

International Nuclear Information System (INIS)

Al-Azmi, D.; Al-Abed, T.; Alnasari, M.S.; Borham, E.E.; Chekir, Z.; Khalifa, M.S.; Shweikani, R.

2012-01-01

Indoor radon surveys were carried out in some of the Arab countries through a Coordination Research Program (CRP) organized by the Arab Atomic Energy Agency (AAEA). The objectives of the program aim at establishing a database on indoor radon concentration levels in the region and investigating any anomalies, where they exist. The approach adopted by the survey teams to achieve public participation in accepting the radon detectors in dwellings is presented and discussed. Most of the participants in the CRP used the passive method (CR-39 plastic detectors) for long-term radon measurements, while others used charcoal detectors and E-Perm systems for short-term measurements. The results of the surveys showed that radon concentration levels in most of the dwellings were low, whilst in some old cities and in an area close to a phosphate mine the levels were found to be relatively high. (authors)

Negative Knudsen force on heated microbeams

KAUST Repository

Zhu, Taishan; Ye, Wenjing; Zhang, Jun

2011-01-01

Knudsen force acting on a heated microbeam adjacent to a cold substrate in a rarefied gas is a mechanical force created by unbalanced thermal gradients. The measured force has its direction pointing towards the side with a lower thermal gradient

National Radon Contractor Proficiency Program. Proficiency report: Supplement

International Nuclear Information System (INIS)

1991-02-01

The report, a supplement to the RCP Proficiency Report, will further assist governmental officials in providing advice to the public on the selection of proficient radon mitigation contractors. These reports list 1,123 contractors who have met the requirements of the RCP Program as of December 15, 1990. The Proficiency Report provides information on each contractor's name, RCP identification number, company name, address, phone number, and geographic service area. The report provides two additional tables, indexed by company name and by RCP identification number. The report is intended to help users quickly identify a proficient contractor if only the company name is known, or to verify which contractor is associated with a particular ID number

Electron microbeam specifications for use in cell irradiation experiments

International Nuclear Information System (INIS)

Kim, E.-H.; Choi, M.-C.; Lee, D.-H.; Chang, M.; Kang, C.-S.

2003-01-01

The microbeam irradiation system was devised originally to identify the hit and unhit cells by confining the beam within the target cell. The major achievement through the microbeam experiment studies has turned out to be the discovery of the 'bystander effect'. Microbeam experiments have been performed with alpha and proton beams in major and with soft x-rays in minor. The study with electron microbeam has been deferred mainly due to the difficulty in confining the electron tracks within a single target cell. In this paper, the electron microbeam irradiation system under development in Korea is introduced in terms of the beam specifications. The KIRAMS electron microbeam irradiation system consists of an electron gun, a vacuum chamber for beam collimation into 5 μm in diameter and a biology stage. The beam characteristics in terms of current and energy spectrum of the electrons entering a target cell and its neighbor cells were investigated by Monte Carlo simulation for the electron source energies of 25, 50, 75 and 100 keV. Energy depositions in the target cell and the neighbor cells were also calculated. The beam attenuation in current and energy occurs while electrons pass through the 2 μm-thick Mylar vacuum window, 100 μm-thick air gap and the 2 μm-thick Mylar bottom of cell dish. With 25 keV electron source, 80 % of decrease in current and 30 % of decrease in average energy were estimated before entering the target cell. With 75 keV electron source, on the other hand, 55 % of decrease in current and less than 1 % of decrease in average energy were estimated. Average dose per single collimated electron emission was 0.067 cGy to the target cell nucleus of 5 μm in diameter and 0.030 cGy to the cytoplasm of 2.5 μm in thickness with 25 keV electron source while they were 0.15 cGy and 0.019 cGy, respectively, with 75 keV electron source. The multiple scattering of electrons resulted in energy deposition in the neighbor cells as well. Dose to the first

Radon legislation and national guidelines

Energy Technology Data Exchange (ETDEWEB)

Aakerblom, G

1999-07-01

50-500 Bq/l for public waters and 200-1000 Bq/l for private water supplies. 4 EU member states and 11 non-EU European countries have reference levels for the concentration of radioactive elements in building materials. 8 European countries have guidelines regarding radon at city planning and 13 have mapped the radon risk in their countries. It is essential to the work against radon and to future reduction of radon concentrations in dwellings and workplaces that the national states issue recommendations, regulations, directives or laws on radon limits and building practices. In order to have a significant effect on the radon situation, the questionnaire responses show that radon reference levels and regulations must be enforced or very little progress is achieved. Extensive measurement and research programs have been carried out in many in countries. Heretofore, only those countries with enforced regulations have had successful programs, resulting in remedial actions in more than 10,000 buildings. The only exception is USA, which concentrated on extensive information media campaigns on radon and the training of large numbers of contractors to perform measurements and remedial measures.

Radon legislation and national guidelines

International Nuclear Information System (INIS)

Aakerblom, G.

1999-07-01

-500 Bq/l for public waters and 200-1000 Bq/l for private water supplies. 4 EU member states and 11 non-EU European countries have reference levels for the concentration of radioactive elements in building materials. 8 European countries have guidelines regarding radon at city planning and 13 have mapped the radon risk in their countries. It is essential to the work against radon and to future reduction of radon concentrations in dwellings and workplaces that the national states issue recommendations, regulations, directives or laws on radon limits and building practices. In order to have a significant effect on the radon situation, the questionnaire responses show that radon reference levels and regulations must be enforced or very little progress is achieved. Extensive measurement and research programs have been carried out in many in countries. Heretofore, only those countries with enforced regulations have had successful programs, resulting in remedial actions in more than 10,000 buildings. The only exception is USA, which concentrated on extensive information media campaigns on radon and the training of large numbers of contractors to perform measurements and remedial measures

Plastic-bag radon gas monitor and survey results

International Nuclear Information System (INIS)

Torri, G.

1990-01-01

The Plastic-bag radon monitor used in the Italian National Survey is described. The choice of this radon gas sampler has been determined by the peculiarity of the italian environmental monitoring program, which is carried out by several different regional laboratories. Results obtained in the past using this radon monitoring device are also reported. (author). 8 refs, 7 figs

Radon in Estonian dwellings - Results from a National Radon Survey

Energy Technology Data Exchange (ETDEWEB)

Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo [Estonian Radiation Protection Centre (Kiirguskeskus), Tallinn (Spain); Aakerblom, Gustav [Swedish Radiation Protection Authority, Stockholm (Sweden)

2003-10-01

A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m{sup 3}, in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m{sup 3}. In 1% of the dwellings the radon concentration exceeded 400 Bq/m{sup 3}. The highest radon concentration found in the study was 1040 Bq/m{sup 3}. Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m{sup 3}, and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m{sup 3}. The mean value for all Estonia dwellings is calculated

Radon in Estonian dwellings - Results from a National Radon Survey

International Nuclear Information System (INIS)

Pahapill, Lia; Rulkov, Anne; Rajamaee, Raivo; Aakerblom, Gustav

2003-10-01

A countrywide survey of radon concentrations in Estonian dwellings was carried out during the period 1998-2001. The survey formed a part of the cooperation program on radiation protection between the Estonian Radiation Protection (Kiirguskeskus) Centre and the Swedish Radiation Protection Authority (SSI). The survey included measurements in a number of dwellings representative for Estonia in detached houses and multifamily buildings (only dwellings on the bottom floor were included in the survey). Altogether, radon concentrations were measured in 515 dwellings, a number large enough to be statistically significant. All measurements were made with alphatrack film detectors of the same type that SSI uses in Sweden. The measurements were made during a 2-3 month period during the winter half-year. Two detectors were used in each dwelling. In Estonia there are 0.17 million dwellings in detached houses and 0.45 million in multi apartment buildings. Of the 1.26 million inhabitants in Estonia. 0.36 million live in detached houses and 0.90 million in multi apartment buildings. Most of the latter were built during the Soviet occupation. Of the dwellings in multifamily buildings 30 % are assumed to be situated on the first floor. The mean radon concentration in dwellings in detached hoses, according to the survey results, is 103 Bq/m 3 , in dwellings on the bottom floor in multi apartment buildings it is 78 Bq/m 3 . In 1% of the dwellings the radon concentration exceeded 400 Bq/m 3 . The highest radon concentration found in the study was 1040 Bq/m 3 . Based on the assumption that the average radon concentration in the dwellings in multi-apartment buildings that are not situated on the bottom floor is 30 Bq/m 3 , and that these dwellings constitute 70% of all dwellings in multi apartment buildings, the mean radon concentration in dwellings in multi apartment buildings is calculated to be 44 Bq/m 3 . The mean value for all Estonia dwellings is calculated to be 60 Bq/m 3 . Using

Control of indoor radon and radon progeny concentrations

International Nuclear Information System (INIS)

Sextro, R.G.

1985-05-01

There are three general categories of techniques for the control of radon and radon progeny concentrations in indoor air - restriction of radon entry, reduction of indoor radon concentrations by ventilation or air cleaning, and removal of airborne radon progeny. The predominant radon entry process in most residences appears to be pressure driven flow of soil gas through cracks or other openings in the basement, slab, or subfloor. Sealing these openings or ventilation of the subslab or subfloor space are methods of reducing radon entry rates. Indoor radon concentrations may be reduced by increased ventilation. The use of charcoal filters for removal of radon gas in the indoor air by adsorption has also been proposed. Concentrations of radon progeny, which are responsible for most of the health risks associated with radon exposures, can be controlled by use of electrostatic or mechanical filtration. Air circulation can also reduce radon progeny concentrations in certain cases. This paper reviews the application and limitations of each of these control measures and discusses recent experimental results

Uranium mill tailings and radon

International Nuclear Information System (INIS)

Hanchey, L.A.

1981-01-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100

Uranium mill tailings and radon

Energy Technology Data Exchange (ETDEWEB)

Hanchey, L A

1981-04-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the United States may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Uranium mill tailings and radon

Energy Technology Data Exchange (ETDEWEB)

Hanchey, L A

1981-01-01

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Quality assurance for environmental radon measurements by LR115 nuclear track detectors

Energy Technology Data Exchange (ETDEWEB)

Gomaa, M A [National Network of Radiation Physics, Atomic Energy Authority, Cairo (Egypt); Hafez, A F [Physics Department, Faculty of Science, Alexandria Univercity, Alexandria (Egypt); Hussein, A S [Radiation Protection Department, Nuclear Power Plants Authority, Cairo (Egypt)

2007-06-15

Passive radon dosimeters based on LR115 nuclear track detectors are very attractive for assessment of radon exposure. For developing countries wishing to undertake national radon survey the most appropriate techniques are those making use of LR115 detectors. These detectors are small, cheap, simple, and non-hazardous and provide an entirely adequate tool for large scale use in assessing levels of radon over several months because of the short - term fluctuations in radon concentrations. In this paper, the principles and philosophy in order to improve the quality and reliability of radon exposure under a quality assurance (QA) program are presented . Also examples of how a QA program of radon measurements by LR115 detectors using the can-techniques are well defined and applied.

Quality assurance for environmental radon measurements by LR115 nuclear track detectors

International Nuclear Information System (INIS)

Gomaa, M.A.; Hafez, A.F.; Hussein, A.S.

2007-01-01

Passive radon dosimeters based on LR115 nuclear track detectors are very attractive for assessment of radon exposure. For developing countries wishing to undertake national radon survey the most appropriate techniques are those making use of LR115 detectors. These detectors are small, cheap, simple, and non-hazardous and provide an entirely adequate tool for large scale use in assessing levels of radon over several months because of the short - term fluctuations in radon concentrations. In this paper, the principles and philosophy in order to improve the quality and reliability of radon exposure under a quality assurance (QA) program are presented . Also examples of how a QA program of radon measurements by LR115 detectors using the can-techniques are well defined and applied

Active mems microbeam device for gas detection

KAUST Repository

Bouchaala, Adam M.; Jaber, Nizar; Younis, Mohammad I.

2017-01-01

Sensors and active switches for applications in gas detection and other fields are described. The devices are based on the softening and hardening nonlinear response behaviors of microelectromechanical systems (MEMS) clamped-clamped microbeams

Radon: a bibliography

Energy Technology Data Exchange (ETDEWEB)

Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

1981-01-01

The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given.

Radon: a bibliography

International Nuclear Information System (INIS)

Lepman, S.R.; Boegel, M.L.; Hollowell, C.D.

1981-01-01

The Lawrence Berkeley Laboratory, with the support of the Department of Energy, has developed a computerized database to manage research information in the area of building ventilation and indoor air quality. This literature survey contains references pertaining to the physical properties of radon and its daughters, instrumentation for their measurement, health effects, surveys and measurements, and regulatory information. The references in the bibliography are sequenced in alphabetical order and abstracts are included when supplied by the author. The objective of this report is to disseminate the bibliographic references compiled at the laboratory relating to radon research portion of the program. Interested database users are encouraged to contact the laboratory to receive instructions for direct database acess. A flyer describing the database is supplied at the end of the bibliography and a brief overview of the Radon Research porgram is given

Radon/radium detection increases uranium drilling effectiveness

International Nuclear Information System (INIS)

Morse, R.H.; Cook, L.M.

1979-01-01

The use of portable radon detectors has become routine in reconnaissance uranium surveys where water and sediment samples are analyzed in field labs for radon and radium, and in detailed work where drill hole locations are pinpointed by field determinations of radon in soil gas from shallow holes. During the drilling program itself, however, very few operators are taking advantage of radon and radium analyses to decide whether a barren drill hole was a near miss or whether the immediate area can be written off. The technique, which is outlined here, is effective both above and below the water table

Radon

Energy Technology Data Exchange (ETDEWEB)

Weigel, F [Muenchen Univ. (Germany, F.R.). Inst. fuer Anorganische Chemie

1978-09-01

The noble gas radon, formerly called emanation, was discovered a few years after radium. /sup 222/Rn, the longest-lived isotope, has a half-life of 3,82 days. This half life is so short that the experimental techniques available at present (1978) are not sufficient for a characterization of defined radon compounds, even though there are definite indications for the existence of such compounds, and one may expect such radon compounds to be even more stable than the numerous known xenon compounds. - The radon isotopes /sup 219/Rn (Actinon), /sup 220/Rn (Thoron), and /sup 222/Rn (Radon) occur in nature despite their rather short half-lives, because they are continously generated from their mothers /sup 223/Ra, /sup 224/Ra, and /sup 226/Ra, which are in secular equilibrium with long-lived isotopes /sup 235/U, /sup 238/U, and /sup 232/Th, and are in turn continously formed from these long-lived isotopes. Since the radon isotopes are gases, they enter the atmosphere and are carried for long distances with air currents. - Because radon is so short-lived, its practical applications are rather limited. For medical applications, small sealed glass tubes filled with radon are used as radiation sources after the radon has decayed, because the whole series of Po-, Bi-, and Pb-isotopes of the radium decay chain are formed, whose penetrating radiation is useful for therapy. When solids are spiked with Ra isotopes, radon is evolved at a constant rate. On heating such solids, phase transitions show up by sudden increased radon evolution (Hahn's emanation method). - On the basis of nuclear theoretical calculations, there is hardly a chance for the discovery of a long-lived radon species. Therefore, major progress in radon chemistry is hardly to be expected in the near future.

Operating instructions for LBL radon measurement facilities

International Nuclear Information System (INIS)

Ingersoll, J.G.

1980-06-01

This manual is intended for users of the radon-measuring facilities of the Radon Project of the Building Ventilation and Indoor Air Quality Program at Lawrence Berkeley Laboratory. The manual comprises three parts. Part 1 sets out the steps involved in collecting, transferring, and counting radon. Part 2 describes the calibration of the transfer system and of the Lucas cells in the counting system. Part 3 outlines the maintenance procedures for the facility

Semiconductor analysis with a channeled helium microbeam

International Nuclear Information System (INIS)

Ingarfield, S.A.; McKenzie, C.D.; Short, K.T.; Williams, J.S.

1981-01-01

This paper describes the use of a channeled helium microbeam for analysis of damage and dopant distributions in semiconductors. Practical difficulties and potential problems associated with the channeling of microbeams in semiconductors have been examined. In particular, the following factors have been characterised: i) the effect of both convergence of focused beam and beam scanning on the quality of channeling; ii) damage produced by the probe ions; and iii) local beam heating effects arising from high current densities. Acceptable channeling has been obtained (minimum yield approaching 4%) under a variety of focusing and scanning conditions which are suitable for analysis of device structures. The capabilities of the technique are demonstrated by monitoring variations in local damage and impurity depth distributions across a narrow (<2mm) region of an ion implanted silicon wafer

Radon gas as a tracer for volcanic processes

International Nuclear Information System (INIS)

Thomas, D.M.

1990-01-01

Radon emissions from volcanic systems have been under investigation for several decades. Soil gas and groundwater radon activities have been used to map faults and to characterize geothermal systems, and measurements of atmospheric radon and radon daughter concentrations have been used to estimate the volume of magma chambers feeding active eruptions. Several studies have also shown that temporal variations in radon concentration have been associated with the onset of volcanic eruptions or changes in the rates or character of an eruption. Some of these studies have been able to clearly define the cause of the radon anomalies but others have proposed models of radon emission and transport that are not well supported by the known physical and chemical processes that occur in a volcanic system. In order to better characterize the processes that control radon activities in volcanic systems, it is recommended that future radon monitoring programs attempt to maintain continuous recording of radon activities; individual radon measurements should be made over the shortest time intervals possible that are consistent with acceptable counting statistics and geophysical, meteorological, and hydrological parameters should be measured in order to better define the physical processes that affect radon activities in volcanic systems. (author). 63 refs

Realisation of a calibration chamber for radon in the air and establishment of a system for measuring radon in water

International Nuclear Information System (INIS)

Sassi, Nedra

2011-01-01

Radon is a radioactive gas that is naturally produced from the decay of radium. The main source of radon found in the earth's crust caused by the presence of a series of uranium (222 isotope of radon) and a series of thorium (220 isotope of radon) therein. We have optimized a new radon calibration chamber by developing an electronic system controlled by a PIC 16F877 microcontroller type to manage the various functions of the room. Several electronic circuits were developed to manage multiple functions such as pressure, temperature and controls motors and solenoids. This system can also be interfaced with a computer through programs such as LabView or Matlab.

Social marketing and the reduction of indoor radon

International Nuclear Information System (INIS)

Bierma, T.J.; Swartzman, D.

1990-01-01

Indoor radon monitoring and mitigation has apparently been conducted by only a small percentage of private homeowners despite extensive media coverage of the radon issue and public information programs at the federal, state, and local levels. Whether public education programs should be informative or persuasive is an ethical decision. Arguments on each side of the issue are presented. A framework for the development of a persuasive campaign is then presented, suing the concepts of social marketing and the limited empirical evidence available on radon-related behavior. In this paper a four-step process is proposed: identify problem dimensions using focus groups and other methods, confirm dimension for market segmentation using probability samples and factor analysis, implement program and evaluate and revise

X-ray microbeams: Tumor therapy and central nervous system research

International Nuclear Information System (INIS)

Dilmanian, F.A.; Qu, Y.; Liu, S.; Cool, C.D.; Gilbert, J.; Hainfeld, J.F.; Kruse, C.A.; Laterra, J.; Lenihan, D.; Nawrocky, M.M.; Pappas, G.; Sze, C.-I.; Yuasa, T.; Zhong, N.; Zhong, Z.; McDonald, J.W.

2005-01-01

Irradiation with parallel arrays of thin, planar slices of X-ray beams (microplanar beams, or microbeams) spares normal tissue, including the central nervous system (CNS), and preferentially damages tumors. The effects are mediated, at least in part, by the tissue's microvasculature that seems to effectively repair itself in normal tissue but fails to do so in tumors. Consequently, the therapeutic index of single-fraction unidirectional microbeam irradiations has been shown to be larger than that of single-fraction unidirectional unsegmented beams in treating the intracranial rat 9L gliosarcoma tumor model (9LGS) and the subcutaneous murine mammary carcinoma EMT-6. This paper presents results demonstrating that individual microbeams, or arrays of parallel ones, can also be used for targeted, selective cell ablation in the CNS, and also to induce demyelination. The results highlight the value of the method as a powerful tool for studying the CNS through selective cell ablation, besides its potential as a treatment modality in clinical oncology

Personal radon daughter dosimetry

International Nuclear Information System (INIS)

Stocker, H.

1979-12-01

The conventional means of radon daughter exposure estimatikn for uranium miners in Canada is by grab sampling and time weighting. Personal dosimetry is a possible alternative method with its own advantages and limitations. The author poses basic questions with regard to two methods of radon daughter detection, thermoluminescent chips and track-etch film. An historical review of previous and current research and development programs in Canada and in other countries is presented, as are brief results and conclusions of each dosimeter evaluation

Other applications of ion microbeams

International Nuclear Information System (INIS)

Cookson, J.A.

1987-01-01

The paper concerns the analytical and non-analytical applications of ion microbeams. The analytical applications considered include:-fusion research, environmental studies, ion implantations and criminology, and each is briefly discussed. Non-analytical applications in which nuclear microprobes have been used include:-thickness and uniformity measurements, energy loss radiography, channelling contrast, tomography, topography, ion implantation, and detector testing, and these are also discussed. (UK)

Elemental analysis techniques using proton microbeam

International Nuclear Information System (INIS)

Sakai, Takuro; Oikawa, Masakazu; Sato, Takahiro

2005-01-01

Proton microbeam is a powerful tool for two-dimensional elemental analysis. The analysis is based on Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE) techniques. The paper outlines the principles and instruments, and describes the dental application has been done in JAERI Takasaki. (author)

Study of transient current induced by heavy-ion microbeams in Si and GaAs

Energy Technology Data Exchange (ETDEWEB)

Hirao, Toshio; Nashiyama, Isamu; Kamiya, Tomihiro; Suda, Tamotu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

1997-03-01

Heavy-ion microbeams were applied to the study of mechanism of single event upset (SEU). Transient current induced in p{sup +}n junction diodes by strike of heavy ion microbeam were measured by using a high-speed digitizing sampling system. (author)

Retrofit and preoccupancy radon mitigation program for homes

International Nuclear Information System (INIS)

Ibach, M.T.; Gallagher, J.H. Jr.

1987-01-01

A requirement was levied on a Maryland builder by the FHA to demonstrate acceptable radon levels in his homes before they would be approved for loans. This paper describes the use of products shown by appropriate tests to be effective radon barriers to meet this requirement. The sheet goods can be used in exterior and interior applications on foundation walls. The other is applied to the interior floors and/or walls of the basement area. Product installation procedures are straightforward and relatively simple. Problems encountered were routine and concerned primarily the complete sealing of floor and wall penetrations, window openings, sealing the top of the wall under the sill plate, and the location and mounting of permanent fixtures on walls and floors. Also discussed are methods of repairing ruptures of the seal, warranties to protect the homeowner, support systems and costs. Conclusions are that effective reductions in radon levels can be achieved by the application of sealants during the construction of new homes or as a retrofit to existing structures

Indoor radon and decay products: Concentrations, causes, and control strategies

Energy Technology Data Exchange (ETDEWEB)

Nero, A.V.; Gadgil, A.J.; Nazaroff, W.W.; Revzan, K.L.

1990-11-01

This report is another in the on going technical report series that addresses various aspects of the DOE Radon Research Program. It provides an overview of what is known about the behavior of radon and its decay products in the indoor environment and examines the manner in which several important classes of factors -- structural, geological, and meteorological -- affect indoor radon concentrations. Information on US indoor radon concentrations, currently available monitoring methods and novel radon control strategies are also explored. 238 refs., 22 figs., 9 tabs.

Multifrequency Excitation of a Clamped-Clamped Microbeam

KAUST Repository

Jaber, Nizar; Ramini, Abdallah; Younis, Mohammad I.

2016-01-01

. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency

Origin of Knudsen forces on heated microbeams

KAUST Repository

Zhu, Taishan; Ye, Wenjing

2010-01-01

microbeam are captured as functions of Knudsen number in the entire flow regime. Both flow strength and Knudsen force peak in the transition regime and negative Knudsen force absent in experimental data is observed. The mechanisms of the thermally induced

Radon

Science.gov (United States)

... radon-resistant features. These features include gravel and plastic sheeting below the foundation, along with proper sealing ... lower the radon level. Detailed information about radon reduction in your home or building can be found ...

Radon in service and industrial premises (rooms) of Tashkent

International Nuclear Information System (INIS)

Mirahmedova, N.M.; Akimov, V.A.; Mullagalieva, F.G.

2004-01-01

Full text: The radon map of the Tashkent is received in some approach on the basis of 800 surveyed inhabited and industrial premises, are designed average for one year radiating doze come on the average city dweller. Is paid attention to huge medical-biological danger natural and technogenesis of radon emanations, the question on acceptance of the special state program 'Radon' is put

Multifrequency excitation of a clamped–clamped microbeam: Analytical and experimental investigation

KAUST Repository

Jaber, Nizar

2016-03-14

Using partial electrodes and a multifrequency electrical source, we present a large-bandwidth, large-amplitude clamped–clamped microbeam resonator excited near the higher order modes of vibration. We analytically and experimentally investigate the nonlinear dynamics of the microbeam under a two-source harmonic excitation. The first-frequency source is swept around the first three modes of vibration, whereas the second source frequency remains fixed. New additive and subtractive resonances are demonstrated. We illustrated that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled. The microbeam is fabricated using polyimide as a structural layer coated with nickel from the top and chromium and gold layers from the bottom. Using the Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device. A good agreement between the theoretical and experimental data are reported.

Multifrequency excitation of a clamped–clamped microbeam: Analytical and experimental investigation

KAUST Repository

Jaber, Nizar; Ramini, Abdallah; Younis, Mohammad I.

2016-01-01

Using partial electrodes and a multifrequency electrical source, we present a large-bandwidth, large-amplitude clamped–clamped microbeam resonator excited near the higher order modes of vibration. We analytically and experimentally investigate the nonlinear dynamics of the microbeam under a two-source harmonic excitation. The first-frequency source is swept around the first three modes of vibration, whereas the second source frequency remains fixed. New additive and subtractive resonances are demonstrated. We illustrated that by properly tuning the frequency and amplitude of the excitation force, the frequency bandwidth of the resonator is controlled. The microbeam is fabricated using polyimide as a structural layer coated with nickel from the top and chromium and gold layers from the bottom. Using the Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device. A good agreement between the theoretical and experimental data are reported.

The radon

International Nuclear Information System (INIS)

1998-01-01

This booklet is intended to answer briefly the most important questions about the nature and sources of radon, its pathways from environment to organism, as well as the ways to minimize its concentration in the habitat's atmosphere. The radon is a naturally appearing radioactive gas, produced through the decay of uranium and radium present in the terrestrial crust. It can be found everywhere on the planet's surface and it is emitted particularly from the granite and volcanic underground rocks as well as from certain construction materials. It is one of the agents producing pulmonary cancer, although not so dangerous as the tobacco is. The following items are elaborated in this booklet: - the place of radon in the average exposure to ionizing radiations of the French population; - the risk; - the radon in the environment (the meteorological conditions, the nature of the rocks); - radon in dwellings (radon measurements in the French dwellings, the entrance pathways of radon, the dependence of radon concentration on the profession and way of life of the inhabitants); - radon measurements; - how to reduce the radon concentration in dwellings

Draft of „National Radon Programme” 2013-2017

International Nuclear Information System (INIS)

Ivanova, K.; Badulin, V.; Georgieva, R.

2013-01-01

The World Health Organization defines radon as the second most important causal factor for lung cancer after smoking and the number one factor for people who have never smoked. The draft of the new European Directive takes accounts the latest ICRP Recommendations for reducing radon exposure in buildings. The Directive requires Member States to bring into force the laws, regulations and administrative provisions. The main goal of „National Radon Programme” is establishment and implementation of long-term policy to reduce and prevent risks of public health resulting from exposure to high concentrations of indoor radon in buildings. To achieve this are required: – to establish an appropriate system; – to carry out national survey and mapping of areas with radon background; – to establish radon prevention strategies in newly constructed buildings and radon mitigation strategies in existing buildings; – to improve public awareness; – to lay down a system for protection against radon in workplaces. The implementation of the program will contribute to reducing the public exposure due to indoors due to radon. Along with the reduction of smoking, it will directly and indirectly improve the prevention of lung cancer risks. (author)

Development of a portable radon detection system

International Nuclear Information System (INIS)

Allen, J.W.

1976-09-01

The presence of radon-222 in soil gas and ground water can indicate the existence of nearby uranium deposits even when heavy overburdens completely absorb the associated gamma radiation. Techniques to detect and measure radon have evolved during the past several years to the point where radon prospecting is routinely employed in a number of countries. A program to develop and field test a prototype system for measuring radon from soil gas and water is described. A prototype system employing a flow through scintillation detector was designed and constructed, utilizing standard commercial components, to provide a fieldworthy unit for testing the system concepts. Laboratory and preliminary field tests of this unit indicate that it can detect anomalous radon levels of less than 10 picoCuries per liter (pCi/l) in soil gas and ground water

The application of microbeam in the research on radiation-induced bystander effects

International Nuclear Information System (INIS)

Xiong Jie; Han Ling

2002-01-01

There has been more and more attention to the phenomenon known as radiation-induced bystander effects, which will have a tremendous effect on the research in low -dose radiation biological effects. However, due to the stochastic nature of energy deposition and the random position of tracts, direct evidence for bystander effects and exact results of single particle interacts with a cell cannot be provided by using conventional broad-field irradiation. The availability of microbeam, especially the single particle microbeam in the world, whereby individual cells or precise location of cells can be irradiated with either a single or an exact number of particles provides a useful tool for the research on radiation-induced bystander effects. The author describes the radiation -induced bystander effect and the application of microbeam in the research on it

Radon dynamics in underwater thermal radon therapy

International Nuclear Information System (INIS)

Lettner, H.; Hofmann, W.; Winkler, R.; Rolle, R.; Foisner, W.

1998-01-01

At a facility for underwater thermal radon therapy in Bad Hofgastein, experiments were carried out with the aim of establishing radon in the air exhaled by the treated patients and of radon decay products on the skin of the patients. The time course of radon concentration in the exhaled air shows a maximum a few minutes after entering the bath, then the Rn concentration remains constant over the remaining time spent in the bath. Taking into account several simplifying assumptions, the average dose to the epidermis from radon daughters is about 50 μGy. (A.K.)

Radon in buildings: instrumentation of an experimental house

International Nuclear Information System (INIS)

Ameon, R.; Diez, O.; Dupuis, M.; Merle-Szeremeta, A.

2004-01-01

IRSN decided to develop a code called RADON 2 for conducting simple and methodical studies of indoor radon concentrations. Since a validity check must be performed of the phenomenological model on which the code is based, an experimental program was initiated in 2002, within which a house in Brittany, located on a well-characterized uranium-bearing geological formation, was fitted with special instruments. After characterizing the soil underlying the house, the instrumentation implemented on site continuously monitors a number of parameters to characterize: the radon source term in the building (exhalation rate of 222 Rn at the ground/building interface and at soil surface, radon concentration in the soil and in outdoor air); radon penetration by advection (differential pressure in the house basement); the driving mechanisms for natural ventilation in the house (weather conditions, indoor temperature and relative humidity); radon distribution throughout the house by air flow and radon diffusion (indoor radon concentration at each floor of the house). Using the experimental data acquired over the past two years, the phenomena governing radon penetration inside the house (wind and stack effect) and radon extraction (fresh air supply rate) have been characterized to lay down the bases for validating the newly developed code

Radon in Schools

Science.gov (United States)

... Search Search Radon Contact Us Share Radon in Schools Related Information Managing Radon in Schools Radon Measurement ... Radon Could Be a Serious Threat to Your School Chances are you've already heard of radon - ...

Development of an intermediate energy heavy-ion micro-beam irradiation system

International Nuclear Information System (INIS)

Song Mingtao; Wang Zhiguang; He Yuan; Gao Daqing; Yang Xiaotian; Liu Jie; Su Hong; Man Kaidi; Sheng Li'na

2008-01-01

The micro-beam irradiation system, which focuses the beam down the micron order and precisely delivers a predefined number of ions to a predefined spot of micron order, is a powerful tool for radio-biology, radio-biomedicine and micromachining. The Institute of Modern Physics of Chinese Academy of Sciences is developing a heavy-ion micro-beam irradiation system up to intermediate energy. Based on the intermediate and low energy beam provided by Heavy Ion Research Facility of Lanzhou, the micro-beam system takes the form of the magnetic focusing. The heavy-ion beam is conducted to the basement by a symmetrical achromatic system consisting of two vertical bending magnets and a quadrupole in between. Then a beam spot of micron order is formed by magnetic triplet quadrupole of very high gradient. The sample can be irradiated either in vacuum or in the air. This system will be the first opening platform capable of providing heavy ion micro-beam, ranging from low (10 MeV/u) to intermediate energy (100 MeV/u), for irradiation experiment with positioning and counting accuracy. Target material may be biology cell, tissue or other non-biological materials. It will be a help for unveiling the essence of heavy-ion interaction with matter and also a new means for exploring the application of heavy-ion irradiation. (authors)

Dynamic response of an electrostatically actuated microbeam to drop-table test

International Nuclear Information System (INIS)

Ouakad, Hassen M; Younis, Mohammad I; Alsaleem, Fadi

2012-01-01

In this paper, we present a theoretical and experimental investigation into the dynamic response of an electrostatically actuated microbeam when subjected to drop-table test. For the theoretical part, a reduced-order model based on an Euler–Bernoulli beam model is utilized. The model accounts for the electrostatic bias on the microbeam and the shock pulse of the drop-table test. Simulation results are presented showing the combined effect of electrostatic force and mechanical shock in triggering early pull-in instability of the cantilever microbeams. The analytical simulation results are validated by finite-element results for the static response. Dynamic pull-in threshold as a function of the mechanical shock amplitude is shown over a wide range of shock spanning hundreds of thousands of g up to zero g. For the experimental part, a micromachined cantilever beam made of gold of length 50 µm is subjected to drop-table tests while being biased by electrostatic loads. Several experimental data are shown demonstrating the phenomenon of collapse due to the combined shock and electrostatic forces. It is also demonstrated that by biasing short and too stiff microbeams with electrostatic voltages, their stiffness is weakened. This lowers their threshold of collapse considerably to the range of acceleration that enables testing them with in-house shock testing equipments, such as drop-table tests. (paper)

Radon-technical design methods based on radon classification of the soil

International Nuclear Information System (INIS)

Kettunen, A.V.

1993-01-01

Radon-technical classification of the foundation soil divides the foundation soil into four classes: negligible, normal, high and very high. Separate radon-technical designing methods and radon-technical solutions have been developed for each class. On regions of negligible class, no specific radon-technical designing methods are needed. On regions of normal radon class, there is no need for actual radon-technical designing based on calculations, whereas existing radon-technical solutions can be used. On regions of high and very high radon class, a separate radon-technical designing should be performed in each case, where radon-technical solutions are designed so that expected value for indoor radon content is lower than the maximum allowable radon content. (orig.). (3 refs., 2 figs., 2 tabs.)

Multifrequency Excitation of a Clamped-Clamped Microbeam

KAUST Repository

Jaber, Nizar R.

2016-01-20

We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

Mineral dusts and radon in uranium mines

International Nuclear Information System (INIS)

Abelson, P.H.

1991-01-01

The Environmental Protection Agency (EPA) continues to assert that radon is a major cause of lung cancer in this country. EPA is fostering a radon program that could entail huge financial and emotional costs while yielding negligible benefits to public health. Justification for the program was the occurrence of lung cancer in men exposed to huge amounts of radon, mineral dusts, and other lung irritants in uranium mines on the Colorado Plateau. Lung cancer has been reported in about 356 cigarette smokers and in about 25 nonsmokers. During the era of high radon levels, monitoring was sporadic. Conditions in only a small fraction of the mines were measured, and that on a few separate occasions. Later, cumulative exposure to radon was calculated on the basis of measurements involving only a tiny fraction of the miners. Some were exposed to more than 15,000 pCi/liter of radon and its products. The level in the average home is about 1.5 pCi/liter. In making extrapolations from mine to home, the assumption is made that residents are in their dwellings most of the time and that miners spend only 170 hours a month in the mine. Two major questionable assumptions are involved in extrapolations from high doses of radon in the mines to low doses in homes. One is that no threshold is involved; that is, that humans have no remediation mechanism for α particle damages. There is evidence to the contrary. The most unrealistic assumption is that heavy exposure to silica has no effect on inducing lung cancer. Many studies have shown that silica dust causes lung cancer in animals. Exposure of human culture cells to silica has resulted in formation of neoplastic tissue. EPA has no solid evidence that exposures to 4 pCi/liter of radon causes lung cancer in either smokers or nonsmokers. Indeed, there is abundant evidence to the contrary in the fact that in states with high levels of radon, inhabitants have less lung cancer than those in states with low levels

Analysis of the X-ray microbeam test result of the flash memories

International Nuclear Information System (INIS)

Yan Yihua; Ding Lili; Chen Wei; Guo Hongxia; Guo Xiaoqiang; Lin Dongsheng; Zhang Keying; Zhang Fengqi; Deng Yuliang; Fan Ruyu

2013-01-01

Background: The failure phenomenon is difficult to analyze for the flash memories when the whole chip is exposed to irradiation since both the memory array and the peripheral circuits might be degraded. Purpose: In order to detect the radiation susceptibility and corresponding phenomenon of the related circuits that included in the flash memories, the X-ray microbeam is used as the radiation source instead of 60 Co. Methods: The failure phenomenon is studied respectively when the memory array, decoder circuits, the charge pump circuits as well as the I/O circuits are exposed to radiation. The errors are mapped according to the logical address and the failure mechanism is analyzed based on the circuits. Results: Irradiated on the memory .array win lead to regularly distributed 0→1 bit flips, while only 1→0 are found when the row decoder is under exposure. Degradation of the charge pump circuits would lead to the erase/program functional failure. Conclusions: The results suggest that the X-ray microbeam radiation test is a good method for detecting the radiation susceptibility of the integrated circuits that contains lots of circuit modules. (authors)

Radon in houses due to radon in potable water

International Nuclear Information System (INIS)

Hess, C.T.; Korsah, J.K.; Einloth, C.J.

1987-01-01

Radon concentration in the air of 10 houses has been measured as a function of water use and meterological parameters such as barometric pressure, wind velocity and direction, indoor and outdoor temperature, and rainfall. Results of calibrations and data collected in winter, spring, fall, and summer are given for selected houses. Average values of radon concentration in air are from 0.80 to 77 rhoCi/1. Water use average ranges from 70 to 240 gal/day. Average potential alpha energy concentrations in these houses range from 0.02 to 1.6 working levels. The radon level due to water use ranges from 0 to 36% of the house radon from soil and water combined. The radon level change due to use of a filter on the water supply shows a 60% reduction in radon in the house. Conclusions are that water radon can be a major fraction of the radon in houses. The ratio of airborne radon concentration due to water use to the radon concentration in water is 4.5 x 10/sup -5/ - 13 x 10/sup -5/

WE-AB-BRB-12: Nanoscintillator Fiber-Optic Detector System for Microbeam Radiation Therapy Dosimetry

Energy Technology Data Exchange (ETDEWEB)

Rivera, J [University of North Carolina and North Carolina State University, Chapel Hill, NC (United States); Dooley, J; Chang, S [University of North Carolina School of Medicine, Chapel Hill, NC (United States); Belley, M; Yoshizumi, T [Duke University Medical Center, Durham, NC (United States); Stanton, I; Langloss, B; Therien, M [Duke University, Durham, NC (United States)

2015-06-15

Purpose: Microbeam Radiation Therapy (MRT) is an experimental radiation therapy that has demonstrated a higher therapeutic ratio than conventional radiation therapy in animal studies. There are several roadblocks in translating the promising treatment technology to clinical application, one of which is the lack of a real-time, high-resolution dosimeter. Current clinical radiation detectors have poor spatial resolution and, as such, are unsuitable for measuring microbeams with submillimeter-scale widths. Although GafChromic film has high spatial resolution, it lacks the real-time dosimetry capability necessary for MRT preclinical research and potential clinical use. In this work we have demonstrated the feasibility of using a nanoscintillator fiber-optic detector (nanoFOD) system for real-time MRT dosimetry. Methods: A microplanar beam array is generated using a x-ray research irradiator and a custom-made, microbeam-forming collimator. The newest generation nanoFOD has an effective size of 70 µm in the measurement direction and was calibrated against a kV ion chamber (RadCal Accu-Pro) in open field geometry. We have written a computer script that performs automatic data collection with immediate background subtraction. A computer-controlled detector positioning stage is used to precisely measure the microbeam peak dose and beam profile by translating the stage during data collection. We test the new generation nanoFOD system, with increased active scintillation volume, against the previous generation system. Both raw and processed data are time-stamped and recorded to enable future post-processing. Results: The real-time microbeam dosimetry system worked as expected. The new generation dosimeter has approximately double the active volume compared to the previous generation resulting in over 900% increase in signal. The active volume of the dosimeter still provided the spatial resolution that meets the Nyquist criterion for our microbeam widths. Conclusion: We have

Ventilation measurements as an adjunct to radon measurements in buildings

International Nuclear Information System (INIS)

Knutson, E.O.; Franklin, H.

1977-01-01

The concentration of radon in a building is a function of the radon sources within the building and of the building's ventilation characteristics. To complement its radon measurement program, HASL is currently assessing apparatus and procedures for measuring building ventilation. Results are reported from ventilation measurements made in the laboratory and in a residential building

Radon risks: Attitudes, perceptions and actions. Risk communication series. Final report

Energy Technology Data Exchange (ETDEWEB)

Sjoeberg, L.

1989-08-01

As many as 8 million homes in the United States may have elevated radon levels, with accompanying lung cancer risks several orders of magnitude higher than for most other environmental risks. The U.S. Environmental Protection Program (EPA) does not have clear regulatory authority over radon, so has relied on an information program. Less than 5% of homes have been tested, which is disappointing from a public health stance. The report summarizes the available research on communicating about the risk from radon from the perspective of a psychologist. The research results are critiqued to draw practical conclusions for radon policy and suggest the most important topics for further risk communication research.

The role of the ventilation industry in addressing indoor radon

International Nuclear Information System (INIS)

Wellford, B.W.

1988-01-01

It is generally acknowledged that radon mitigation can only be accomplished on a national scale through a cooperative effort of government, industry and an informed public. The Environmental Protection Agency has developed, demonstrated and published acceptable procedures for testing and preventing the entry or radon into occupancies, as well as procedures for removal when it is not possible or economically viable to prevent radon from entering these occupancies. Various states have instituted programs for industry implementation of EPA procedures and public education programs are now underway. Industry effort will be required to mitigate existing housing stock, to insure new radon resistant housing and, equally important, to provide for radon monitoring and servicing of mitigation measures for centuries to come. What the nature of that industry can and should be and how government agencies can encourage the development of such industry is the subject of this paper

Contribution of radon and radon daughters to respiratory cancer

International Nuclear Information System (INIS)

Harley, N.; Samet, J.M.; Cross, F.T.; Hess, T.; Muller, J.; Thomas, D.

1986-01-01

This article reviews studies on the contribution of radon and radon daughters to respiratory cancer and proposes recommendations for further research, particularly a national radon survey. The steady-state outdoor radon concentration averages 200 pCi/m3, and indoor levels are about 4 times higher. The primary source of radon in homes is the underlying soil; entry depends on multiple variables and reduced ventilation for energy conservation increases indoor radon levels. Occupational exposures are expressed in units of radon daughter potential energy concentration or working level (WL). Cumulative exposure is the product of the working level and the time exposed. The unit for cumulative exposure is the working level month (WLM). The occupational standard for radon exposure is 4 WLM/year, and 2 WLM/year has been suggested as a guideline for remedial action in homes. Epidemiologic studies show that miners with cumulative radon daughter exposures somewhat below 100 WLM have excess lung cancer mortality. Some 3% to 8% of miners studied have developed lung cancer attributable to radon daughters. All of the underground mining studies show an increased risk of lung cancer with radon daughter exposure. All cell types of lung cancer increased with radon exposure. If radon and smoking act in a multiplicative manner, then the risk for smokers could be 10 times that for nonsmokers. The potential risk of lung cancer appears to be between 1 and 2 per 10,000/WLM, which yields a significant number of lung cancers as some 220 million persons in the United States are exposed on average to 10 to 20 WLM/lifetime

Parameter identification of an electrically actuated imperfect microbeam

KAUST Repository

Ruzziconi, Laura; Younis, Mohammad I.; Lenci, Stefano

2013-01-01

In this study we consider a microelectromechanical system (MEMS) and focus on extracting analytically the model parameters that describe its non-linear dynamic features accurately. The device consists of a clamped-clamped polysilicon microbeam

Residual stress measurement method in MEMS microbeams using frequency shift data

International Nuclear Information System (INIS)

Somà, Aurelio; Ballestra, Alberto

2009-01-01

The dynamical behaviour of a set of gold microbeams affected by residual stress has been studied. Experimental frequency shift curves were obtained by increasing the dc voltage applied to the specimens. Comparison with different analytical and numerical models has been carried out in order to identify both analytical and finite element models in the presence of residual stress. Residual strain and stress, due to the fabrication process, have been widely reported in the literature in both out-of-plane microcantilevers and clamped–clamped microbeams by using mainly the value of pull-in voltage and static deflection data. In the case of a microcantilever, an accurate modelling includes the effect of the initial curvature due to microfabrication. In double-clamped microbeams, a pre-load applied by tensile stress is considered. A good correspondence is pointed out between measurements and numerical models so that the residual stress effect can be evaluated for different geometrical configurations

Systematic measurements of the radon concentration indoor from Remetea, Harghita county

International Nuclear Information System (INIS)

Csegzi, Sandor

2000-01-01

Primary goal of the Remetea radon program was to carry out an indoor radon survey. The program can be applied too, in other places of the country. Remetea was built on volcanic rocks, where aligning of mineral water springs tells about the existence of geologic faulting. The 1992 census counted 2406 houses and 6550 residents of the village. The sample consisted of 120 houses chosen randomly from the entire stock. A hypergeometric statistical model has been used for sampling. Measurements were done in bedrooms at pillow level using etched track type Radamon radon detectors. Exposure lasted from January 1999 to July 1999. From the measurements it can be stated that the number of houses with radon concentration exceeding 200 Bq/m 3 is around 82. A high precision determination of activity has been done (errors under 3 %). Mapping indoor radon levels resembles the fault location that is indicated by springs and exhibited by geological studies. Particular points of the program were the soulful and self-aware approach the more than 30 schoolboys and girls participated, and the fact that the program met with a warm response from the public. (author)

The HAZWRAP/Navy Radon Project

International Nuclear Information System (INIS)

Otten, J.A.; Wilson, D.L.

1992-01-01

In 1987, the Naval Facilities Engineering Command (NAVFACENGCOM) was assigned the responsibility of identifying potential hazards from exposure to naturally occurring indoor radon to personnel in Naval facilities and prioritizing corrective actions. In response to this request, NAVFACENGCOM established the Navy Radon Assessment and Mitigation Program (NAVRAMP), which evaluates problems associated with radon levels above current Environmental Protection Agency (EPA)-guidelines (EPA-520/1-86-04) of 4pCi/L. NAVRAMP consists of four phases: screening, assessment, mitigation, and postmitigation. Approximately 300,000 alpha track detectors (ATDs) will be used during the screening and assessment phases. Several unique approaches were developed to verify the quality of the information collected during this large program. To guarantee chain-of-custody, a computerized data management system was developed to track each ATD from initial purchase through field implementation to final analysis and was also used to track and identify quality control (QC) problems related to the manufacture and analysis of ATDs. The QC program addressed potential problems that could occur using ATDs. The potential errors associated with the use of ATDs included (1) lot-to-lot variation, (2) chemical process variation, (3) pouch leakage, and (4) background. The data management and QC programs ensured the quality and integrity of the samples, the accuracy and precision of the analyses, the representatives of the results, and the completeness of the information

Synchrotron x-ray microbeam characteristics for x-ray fluorescence analysis

International Nuclear Information System (INIS)

Iida, Atsuo; Noma, Takashi

1995-01-01

X-ray fluorescence analysis using a synchrotron x-ray microprobe has become an indispensable technique for non-destructive micro-analysis. One of the most important parameters that characterize the x-ray microbeam system for x-ray fluorescence analysis is the beam size. For practical analysis, however, the photon flux, the energy resolution and the available energy range are also crucial. Three types of x-ray microbeam systems, including monochromatic and continuum excitation systems, were compared with reference to the sensitivity, the minimum detection limit and the applicability to various types of x-ray spectroscopic analysis. 16 refs., 5 figs

Real estate transaction radon test tampering

International Nuclear Information System (INIS)

Ritter, D.L.

1990-01-01

A thousand-house study, over the past two years showed 35% of the houses were tampered with. This paper offers statistical charts representing the different methods of tampering; A slide presentation showing houses and the non-tamper controls used to monitor EPA closed-house conditions, movement of detectors and covering of detectors. A strong message must be conveyed now, that tampering will not be tolerated by radon technicians, when performing radon tests in the field. A message that incorporates non-tamper controls that are cost effective and provide for reasonably priced testing; A message that will lend credibility to our Radon industry by means of separating the professional test from a do-it-yourself homeowner test. This paper will address that message and offer a program for the prevention of tampering in a house during a PROFESSIONALLY done Radon test

Radon in your dwellings - problems and mitigation

International Nuclear Information System (INIS)

Srivastava, D.S.

2011-01-01

The problem of radon in dwellings gained importance in 1984 after the Stanely Watra's house incidence in Pennsylvania USA. Since then several radon measuring techniques have been identified and instrumentations developed. National survey programs were started for monitoring radon levels in dwellings by Government authorities in all developed and developing countries including India. Successively, the measurement of thoron levels was also found desirable especially in high radiation background areas. A lot of work has been done since then by scientists and university researches and thousands of publications have been made in this field. Several developed countries have given guide lines for initiating action to reduce radon levels in dwellings if it is beyond 200-400 Bq/m 2 . The recommended 'action level' is found to depend upon the authorities making the recommendations. This talk is aimed to produce public awareness about the health hazard posed by concentration of naturally occurring radon gas in our dwellings, the sources of its production and mitigation of radon problem. The matter will be discussed in a general way using ppt presentation. (author)

Radon and health

International Nuclear Information System (INIS)

Chobanova, Nina

2016-01-01

Radon is radioactive noble gas that can be found in soil, water, outdoor and indoor air. Since environmental radon on average accounts for about half of all human exposure to radiation from natural sources, increasing attention has been paid to exposure to radon and its associated health risks. Many countries have introduced regulations to protect their population from radon in dwellings and workplaces. In this article are discussed main characteristics of radon, including sources of exposure, variation in radon exposure, how managing risks from radon exposure, how to measure the concentration of radon. There are results of measurements conducted under the 'National radon programme' in Bulgaria also. Key words: radon, sources of exposure, risk, cancer, measure to decrease the concentration [bg

Soil radon response around an active volcano

International Nuclear Information System (INIS)

Segovia, N.; Valdes, C.; Pena, P.; Mena, M.; Tamez, E.

2001-01-01

Soil radon behavior related to the volcanic eruptive period 1997-1999 of Popocatepetl volcano has been studied as a function of the volcanic activity. Since the volcano is located 60 km from Mexico City, the risk associated with an explosive eruptive phase is high and an intense surveillance program has been implemented. Previous studies in this particular volcano showed soil radon pulses preceding the initial phase of the eruption. The radon survey was performed with LR-115 track detectors at a shallow depth and the effect of the soil moisture during the rainy season has been observed on the detectors response. In the present state of the volcanic activity the soil radon behavior has shown more stability than in previous eruptive stages

Comparison of radon and radon-daughter grab samples obtained during the winter and summer

International Nuclear Information System (INIS)

Karp, K.E.

1987-08-01

The Technical Measurements Center (TMC), under the auspices of the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) program, is investigating short-term methods for estimating annual average indoor radon-daughter concentrations (RDC). A field study at 40 sample locations in 26 residential structures in Grand Junction, Colorado, was conducted once in the winter and once in the summer. The short-term methods investigated as part of this study include ten-minute radon and radon-daughter grab sampling and hourly RDC measurements. The results of the field study indicate that ten-minute radon grab samples from basement locations are reproducible over different seasons during controlled sampling conditions. Nonbasement radon and RDC grab samples are highly variable even when the use of the location by the occupant is controlled and the ventilation rate is restricted. The grab sampling was performed under controlled occupied conditions. These results confirm that a short-term radon or RDC measurement in a nonbasement location in a house is not a standardized measurement that can be used to infer an annual average concentration. The hourly RDC measurements were performed under three sets of conditions over a 72-hour period. The three sets of conditions were uncontrolled occupied, controlled occupied, and controlled unoccupied. These results indicate that it is not necessary to relocate the occupants during the time of grab sampling. 8 refs., 8 figs., 10 tabs

Advances in radiobiological studies using a microbeam

International Nuclear Information System (INIS)

Hei, Tom K.; Brenner, David J.; Geard, Charles R.; Ballas, Leslie K.

2009-01-01

Recent developments in microbeam technology have made drastic improvements in particle delivery, focusing, image processing and precision to allow for rapid advances in our knowledge in radiation biology. The unequivocal demonstration that targeted cytoplasmic irradiation results in mutations in the nuclei of hit cells and the presence of non-targeted effects, all made possible using a charged particle microbeam, results in a paradigm shift in our basic understanding of the target theory and other radiation-induced low dose effects. The demonstration of a bystander effect in 3D human tissue and whole organisms have shown the potential relevance of the non-targeted response in human health. The demonstration of delayed mutations in the progeny of bystander cells suggest that genomic instability induced following ionizing radiation exposure is not dependent on direct damage to cell nucleus. The identification of specific signaling pathways provides mechanistic insight on the nature of the bystander process. (author)

Predicting radon/radon daughter concentrations in underground mines

International Nuclear Information System (INIS)

Leach, V.A.

1984-01-01

A detailed description of a computer programme is outlined for the calculation of radon/radon daughter concentrations in air. This computer model is used to predict the radon/radon daughter concentrations in Working Level (WL) at the workplace and at the various junctions at either end of the branches in a typical ventilation network proposed for the Jabiluka mine in the Northern Territory

Live cell imaging at the Munich ion microbeam SNAKE – a status report

International Nuclear Information System (INIS)

Drexler, Guido A; Siebenwirth, Christian; Drexler, Sophie E; Girst, Stefanie; Greubel, Christoph; Dollinger, Günther; Friedl, Anna A

2015-01-01

Ion microbeams are important tools in radiobiological research. Still, the worldwide number of ion microbeam facilities where biological experiments can be performed is limited. Even fewer facilities combine ion microirradiation with live-cell imaging to allow microscopic observation of cellular response reactions starting very fast after irradiation and continuing for many hours. At SNAKE, the ion microbeam facility at the Munich 14 MV tandem accelerator, a large variety of biological experiments are performed on a regular basis. Here, recent developments and ongoing research projects at the ion microbeam SNAKE are presented with specific emphasis on live-cell imaging experiments. An overview of the technical details of the setup is given, including examples of suitable biological samples. By ion beam focusing to submicrometer beam spot size and single ion detection it is possible to target subcellular structures with defined numbers of ions. Focusing of high numbers of ions to single spots allows studying the influence of high local damage density on recruitment of damage response proteins. The online version of this article (doi:10.1186/s13014-015-0350-7) contains supplementary material, which is available to authorized users

Nuclear tracks in solids and gas radon measurements

International Nuclear Information System (INIS)

Espinosa, G.

2007-01-01

Full text: The Department of Energy (DOE), the Environmental Protection Agency (EPA) in USA, and the European Community, have dedicated significant budget to the Radon study, its health effects and remedial actions for controlling and achieving lower levels, in these cases, nationwide research programs have been organized. With the aim to contribute on the radon levels knowledge in our country, the Applied Dosimetry Project at the Physics Institute of the University of Mexico has developed an indoor and outdoor radon measurement methodology. In this paper a passive radon detector device based on CR-39 polycarbonate for use in radon research and routine measurements is presented. As well the methodology for the track formation, automatic reading system, calibration procedure and measurements in a different location, are shown in this work. The results had been compared with dynamic detection systems, and another methodologies and research groups in order to have a high confidence in the radon levels reported. (Author)

Radon in homes of the Portland, Oregon Area: Radon data from local radon testing companies collected by CRM (Continuous Radon Measurement) machines

Science.gov (United States)

Whitney, H.; Lindsey, K.; Linde, T.; Burns, S. F.

2013-12-01

Students from the Department of Geology at Portland State University paired up with the Oregon Health Authority to better understand radon gas values in homes of the Portland metropolitan area. This study focuses on radon values collected by continuous radon measurement (CRM) machines, taken by local radon testing companies. The local companies participating in this study include Alpha Environmental Services, Inc., Cascade Radon, Environmental Works, The House Detectives, LLC, and Soil Solutions Environmental Services, Inc. In total, 2491 radon readings spanning across 77 zip codes were collected from local companies in the Portland metropolitan area. The maximum value, average value, percentage of homes greater than 4 pCi/L and total rank sum was calculated and used to determine the overall radon potential for each zip code (Burns et al., 1998). A list and four maps were produced showing the results from each category. Out of the total records, 24 zip codes resulted in high radon potential and the average reading for the entire Portland Metropolitan area was 3.7 pCi/L. High potential zip codes are thought to be a result of sand and gravel (Missoula Flood deposits) and faults present in the subsurface. The CRM data was compared with both long-term and short-term data provided by the Oregon Health Authority to validate radon potentials in each zip code. If a home is located in a zip code with high or moderate radon potential across two types of data sets, it is recommended that those homes be tested for radon gas.

Indoor radon measurements and methodologies in Latin American countries

International Nuclear Information System (INIS)

Canoba, A.; Lopez, F.O.; Arnaud, M.I.; Oliveira, A.A.; Neman, R.S.; Hadler, J.C.; Iunes, P.J.; Paulo, S.R.; Osorio, A.M.; Aparecido, R.; Rodriguez, C.; Moreno, V.; Vasquez, R.; Espinosa, G.; Golzarri, J.I.; Martinez, T.; Navarrete, M.; Cabrera, I.; Segovia, N.; Pena, P.; Tamez, E.; Pereyra, P.; Lopez-Herrera, M.E.; Sajo-Bohus, L.

2001-01-01

According to the current international guidelines concerning environmental problems, it is necessary to evaluate and to know the indoor radon levels, specially since most of the natural radiation dose to man comes from radon gas and its progeny. Several countries have established National Institutions and National Programs for the study of radon and its connection with lung cancer risk and public health. The aim of this work is to present the indoor radon measurements and the detection methods used for different regions of Latin America (LA) in countries such as Argentina, Brazil, Ecuador, Mexico, Peru and Venezuela. This study shows that the passive radon devices based on alpha particle nuclear track methodology (NTM) is one of the more generalized methods in LA for long term indoor radon measurements, CR-39, LR-115 and Makrofol being the more commonly used detector materials. The participating institutions and the radon level measurements in the different countries are presented in this contribution

Radon and radon daughters in public, private and commercial buildings in communities associated with uranium mining and processing in Canada

International Nuclear Information System (INIS)

Eaton, R.S.

1982-01-01

The elevated indoor radon levels in certain communities in Canada have been studied. An overview of the investigational and remedial action programs are presented in this paper. It is suggested that radon daughter concentrations can be controlled by: (a) removing source; (b) placing a barrier between the source and the living space; (c) diverting the radon before it enters a building: (d) increasing the ventilation rate. All methods have been proven but no one technique is the most cost effective because of widely varying conditions found in older housing

Dynamics of a clamped–clamped microbeam resonator considering fabrication imperfections

KAUST Repository

Bataineh, Ahmad M.

2014-10-18

We present an investigation into the static and dynamic behavior of an electrostatically actuated clamped–clamped polysilicon microbeam resonator accounting for its fabrication imperfections, which are commonly encountered in similar microstructures. These are mainly because of the initial deformation of the beam due to stress gradient and its flexible anchors. First, we show experimental data of the microbeam when driven electrically by varying the amplitude and frequency of the voltage loads. The results reveal several interesting nonlinear phenomena of jumps, hysteresis, and softening behaviors. Theoretical investigation is then conducted to model the microbeam, and hence, interpret the experimental data. We solve the Eigen value problem governing the natural frequencies analytically. We then utilize a Galerkin-based procedure to derive a reduced order model, which is then used to simulate both the static and dynamic responses. To achieve good matching between theory and experiment, we show that the exact profile of the deformed beam needs to be utilized in the reduced order model, as measured from the optical profiler, combined with a shooting technique simulation, which is capable of tracing the resonant frequency branches under very-low damping conditions.

A study of radon 222 transfer indoors

International Nuclear Information System (INIS)

Maximilien, R.; Robe, M.C.; Archimbaud, M.

1985-01-01

Indoor exposure can vary considerably depending upon the natural environment (geology, climate), man-made arrangements (building materials, insulation and ventilation systems...) or way of living. In order to specify the sources and assess their respective contribution in a given dwelling, a good knowledge of radon transfer and dispersion processes is required as well as a heavy experimental device (continuous radon and ventilation monitoring...). The study must be limited to some cases selected by a systematic measurement program either because they are representative of dwelling conditions, or preferably on account of their high radon level, the origin of which will be investigated. As a consequence, countermeasures can be developed. A pilot study has been carried out on radon transport in two houses of the Rhone river valley. The two houses -selected among 131 other ones for their high radon levels- are built with the same architectural approach and located very close to each other, yet the factors accounting for domestic exposure are quite different. Indoor parameters are at the origin of various radon concentrations in the case of low natural ventilation; conversely, outdoor parameters only seem to act in the case of high ventilation. For a larger part, however, radon seems to emanate from under the foundations of both houses [fr

Radon analyser

International Nuclear Information System (INIS)

1981-01-01

The process claimed includes the steps of transferring radon gas produced by a sample to a charcoal trap, cooled to a temperature whereby the radon is absorbed by the charcoal, heating the charcoal trap to a sufficient temperature to release the radon, and transferring the radon to a counting device where the gas particles are counted

Protecting People and Families from Radon: A Federal Action Plan for Saving Lives

Science.gov (United States)

This strategy for radon action outlines actions federal agencies can take within existing resources and program capacities to advance the Healthy People 2020 radon objectives and launch a national effort to end all avoidable radon-induced lung cancer death

Radon, a real threat to our health

International Nuclear Information System (INIS)

Mauna, T.; Mauna, A.; Ghita, R.

2005-01-01

Radon is invisible, odorless and tasteless a radioactive gas that comes from the radioactive decay of naturally occurring uranium and thorium in soil and rock, can concentrate in domestic homes, overground workplaces, and caves. Radon has been identified as the second leading cause of lung cancers in the U.S., about 20.000 per year, and is present in millions of homes. The Environmental Protection Agency (EPA) of USA designated January 2005 as National Radon Action Month (NRAM) and held the second week of October every year as National Radon Action Week (NRAW). The focus of NRAM and NRW is to promote awareness about, testing for and mitigation of indoor radon gas with various events and outreach campaigns. The EPA considering radon exposure as capital problem for the population health decided to have a special dedicated free phone number the similar for every county state of USA taking into account the increase easy call by interested people. Many universities and research centers, including NGO from different countries world wide, following the recommendation of 'United Nations Scientific Committee on the Effects of Atomic Radiation' (USNCEAR) and 'International Commission on Radiological Protection ' (ICRP) until 1977, developed their own radon researches in order to clarify the properties, area distribution and concentration, geological production and other needed aspects. This paper compare the radon risk versus radioactive waste gaseous Nuclear Power Plant release in normal or abnormal operation and underlines the needs for Romanian's radiation research laboratories to undertake radon protection programs similar to to those underway in other countries. (authors)

Channeling-based collimators for generation of microbeams produced by silicon micromachining technology

International Nuclear Information System (INIS)

Guidi, V.; Antonini, A.; Milan, E.; Ronzoni, A.; Martinelli, G.; Biryukov, V.M.; Chesnokov, Yu.A.

2006-01-01

The growing interest on micro-beams in recent years and the combined development of channeling technology in high-energy physics have opened the way to new concepts for micro-beams devices. Silicon micromachining technology is here applied to manufacture micro-collimators in inexpensive and feasible ways. Both dry and wet etchings can be employed for the purpose, though the latter technique appears to be cheaper and easier. Two designs for micro-collimator devices have been considered and preliminary samples have been produced accordingly

Investigations of radon and radon daughters in surficial aquifers of florida

International Nuclear Information System (INIS)

1991-05-01

The principal purpose of the investigation was to test the hypothesis that radon soil flux, considered the principal source of indoor radon contamination, has an underlying relationship to the radon content of associated shallow groundwaters. The working hypothesis was that radon build-up in both soil and shallow groundwater is basically a consequence of the same factor, radon emanation from soil grains and the solid surfaces of the aquifers. Groundwater may be advantageous as an indicator of radon potential. Another object of the project was to investigate temporal and spatial trends of radon daughter products in shallow aquifers. After analyzing all of the radon soil, flux, and groundwater measurements made over the two-year study period, it is clear that while there is no direct relationship between either radon soil concentration or flux and groundwater radon. Measurements in wells where polonium is present at very high concentrations have shown that 210Po is largely unsupported by its radioactive predecessor, and that polonium is considerably more variable, in both space and time than other parameters measured in the same wells, including radon

Radon dosimetry: a review of radon and radon daughter exposure conditions in dwellings and other structures

International Nuclear Information System (INIS)

Ryan, M.T.; Goldsmith, W.A.; Poston, J.W.; Haywood, F.F.; Witherspoon, J.P.

1983-07-01

Within the past few years several situations have been brought to light which indicate an increased radiation exposure of certain segments of the general population caused by human activities. The most widely publicized activities are those associated with the mining and milling of uranium in the western United States, the phosphate industry in Florida, and those potential problems represented by former Manhattan Engineer District sites. One of the primary problems involves exposure to radon and radon daughters which are released from large waste piles or, in some cases, evolve from backfill and construction materials used in homes, schools, and other buildings. This report presents a review of the available data on radon and radon daughter concentrations in dwellings and other structures. The primary objectives were to compile and tabulate pertinent radon exposure data and to prepare a statistical summary of the data which will be useful in the prediction of normal levels of radon and radon daughter concentrations in these structures. In addition, other parameters associated with radon exposure conditions are presented and discussed

A survey on radon reduction efficiency of zeolite and bentonite in a chamber with artificially elevated radon concentration

International Nuclear Information System (INIS)

Mortazavi, S.M.J.

2007-01-01

reducing indoor radon levels. Conclusions: Zeolite and bentonite significantly decrease the indoor radon level. The efficiency of zeolite in radon reduction is significantly higher than that of bentonite. As both zeolite and bentonite can be found in many parts of IR Iran, these mineral sorbents can be used in national remedial action programs.

Background concentrations of radon and radon daughters in Canadian homes

International Nuclear Information System (INIS)

McGregor, R.G.; Vasudev, P.; Letourneau, E.G.; McCullough, R.S.; Prantl, F.A.; Taniguchi, H.

1980-01-01

Measurements of radon and radon daughters were carried out in 14 Canadian cities on a total of 9999 homes selected in a statistically random manner. The geometric means of the different cities varied from 0.14 to 0.88 pCi/l. for radon and 0.0009 to 0.0036 Working Levels for radon daughters. The radon originates from natural radioactivity in the soil surrounding the homes. (author)

Converse flexoelectric effect in comb electrode piezoelectric microbeam

Energy Technology Data Exchange (ETDEWEB)

Shen, Zhiyuan, E-mail: shenyuan675603@gmail.com [School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore); Chen, Wei [Microelectronics Centre, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 Singapore (Singapore)

2012-04-09

We demonstrate the converse flexoelectric effect in a lead zirconate titanate microbeam. The fringe electric field of a comb electrode induces converse flexoelectric responses in uniformly poled and depoled beams. The simulated electric field distribution shows that bending of the beam is induced by piezoelectric and μ{sub 11}, μ{sub 12} flexoelectric coefficients. Simulations indicate that piezoelectric displacement occurs in different directions in the two opposite poled samples while flexoelectric displacement remains the same. This finding is verified by the displacement measurement results. -- Highlights: ► We demonstrate the converse flexoelectric effect in a PZT microbeam. ► Beams with upward and downward poling states are fabricated by MEMS technique. ► Converse flexoelectric deformation is induced by the fringe field. ► Electric field distribution is calculated by finite element analysis. ► The simulation results are verified by impedance and displacement measurements.

Experimental, statistical, and biological models of radon carcinogenesis

International Nuclear Information System (INIS)

Cross, F.T.

1991-09-01

Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig

Radon in public buildings; Radon in oeffentlichen Gebaeuden

Energy Technology Data Exchange (ETDEWEB)

Schulz, H.; Flesch, K. [IAF - Radiooekologie GmbH, Dresden (Germany); Hermann, E. [B.P.S. Engineering GmbH, Zwickau (Germany); Loebner, W. [Wismut GmbH, Chemnitz (Germany); Leissring, B. [Bergtechnisches Ingenieurbuero GEOPRAX, Chemnitz (Germany)

2009-07-01

From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

Long term and equilibrium factor indoor radon measurements

International Nuclear Information System (INIS)

Martinez, T.; Lartigue, J.; Navarrete, M.; Cabrera, L.; Ramirez, A.; Elizarraras, V.

1998-01-01

This paper presents the annual radon gas concentrations obtained during the 1994-1995 monitoring campaign using passive electret system (type E-PERM). Radon levels were measured in 154 single family dwellings, in normal occupancy conditions (open house condition) in the metropolitan zone of Mexico City. At the same time radon monitoring was performed outdoors. The results show the general log-normal distribution of integrated indoor radon concentration with an annual indoor mean of 3.8 pCi x l -1 . The seasonal variations show the minimum mean values in the summer season which are 39% lower than that in autumn. Equilibrium factors (F) were measured in 12 typical houses both in autumn and winter using a continuous working level monitor for short-lived radon decay products and H-chamber loaded with a short term electret (HST, E-PERM) for radon gas. The obtained total mean equilibrium factors are: F=0.41±0.17 and F=0.29±0.04 for indoor and outdoor, respectively. A quality program was also improved. (author)

Radon in Austria

International Nuclear Information System (INIS)

Friedmann, H.

2000-01-01

Several projects in Austria deal with the problem of enhanced radon exposure to the public. The Austrian Radon Project is the largest project within this task, with the aim of investigating the radon concentrations in Austrian homes. Another project concerns mitigation methods. According to the EU directive EURATOM 96/29 it is also necessary to check working places for possibly enhanced radon concentrations. These projects are and will be funded by the government. The federal government of Upper Austria sponsored a project to test the indoor air quality in kindergartens including radon measurements. Within an EU research project, the radon concentrations in Austrian springs and groundwater were systematically listed and analyzed. Additional investigations will focus on methods to improve the radon potential maps from the Austrian Radon Project by including geological and other information. (author)

Measurements of indoor radon and radon progeny in Mexico City

International Nuclear Information System (INIS)

Cheng, Y.S.; Rodriguez, G.P.

1996-01-01

Indoor radon has been a public concern associated with increased lung cancer risks. Radon decay products interact with indoor aerosols to form progeny with different size distributions, which may influence the lung dosimetry when the progeny are inhaled. Air pollution in Mexico City is a serious problems with high particulate concentrations, but there are few reports of indoor radon measurement. The purposes of this study were to measure the aerosol concentration, radon concentration, and radon activity size distribution in the living area of three houses in Mexico City. The radon concentration was monitored by a RGM-3 radon gas monitor (Eberline, Inc., Santa Fe, NM). A graded diffusion battery was used to determine the progeny concentration and activity size distribution. The concentration and size distribution of the indoor aerosols were monitored by a quartz, crystal microbalance cascade impactor. Our measurements showed high concentrations of indoor aerosols (20-180 gg m -3 ). However, the radon concentrations-were low ( -1 ), but showed a clear diurnal pattern with peak concentrations from 2-10 AM. The activity size distributions of radon progeny were trimodal, with peaks of 0.6 nm, 4-5 nm, and 100 rim. Most activities were associated with large particle sizes. Our results indicated that indoor radon concentration was not high, due in part to a relatively high air exchange with outdoor air. The high aerosol concentration may also play an important part in the activity size distribution of radon progeny

Element of risk: The politics of radon

International Nuclear Information System (INIS)

Cole, L.A.

1994-01-01

The recent history of the Environmental Protection Agency's (EPA) approach to managing the risk of indoor radon offers a rich base from which to consider US practice in risk assessment, management, and communication. The biological evidence of risks from high-level exposure to radon is in many ways stronger--and the gap to be spanned by extrapolation from laboratory animal studies to ambient exposures narrower--than for many of the toxic and hazardous air pollutants that have been the focus of EPA regulatory attention. The epidemiological evidence about radon is complicated by a number of confounding variables, but this is often the state of epidemiological evidence. Radon has also been the focus of a considerable amount of research on risk communication. To complete the promising ingredients, disagreements between federal regulators at EPA and managers of federal nuclear programs run by the Department of Energy (DOE) concerning radon from uranium mill tailings, for example, and other issues in radiation health physics offer a rich array of opportunities to explore issues in federal bureaucratic politics. This book provides a straightforward report of much of the development of US policy on indoor radon over the past decade. As such, it gives readers unfamiliar with the evolution of radon regulation an opportunity to come quickly up to speed on many historical details

Use of a geographic information system (GIS) for targeting radon screening programs in South Dakota

International Nuclear Information System (INIS)

Kearfott, Kimberlee J.; Whetstone, Zachary D.; Mir, Khwaja M. Rafique

2016-01-01

Because 222 Rn is a progeny of 238 U, the relative abundance of uranium may be used to predict the areas that have the potential for high indoor radon concentration and therefore determine the best areas to conduct future surveys. Geographic Information System (GIS) mapping software was used to construct maps of South Dakota that included levels of uranium concentrations in soil and stream water and uranium deposits. Maps of existing populations and the types of land were also generated. Existing data about average indoor radon levels by county taken from a databank were included for consideration. Although the soil and stream data and existing recorded average indoor radon levels were sparse, it was determined that the most likely locations of elevated indoor radon would be in the northwest and southwest corners of the state. Indoor radon levels were only available for 9 out of 66 counties in South Dakota. This sparcity of data precluded a study of correlation of radon to geological features, but further motivates the need for more testing in the state. Only actual measurements should be used to determine levels of indoor radon because of the strong roles home construction and localized geology play in radon concentration. However, the data visualization method demonstrated here is potentially useful for directing resources relating to radon screening campaigns. (author)

Radon and radon daughters in South African underground mines

International Nuclear Information System (INIS)

Rolle, R.

1980-01-01

Radon and the radon daughters are the radionuclides which primarily determine the level of the radiation hazard in underground uranium mines and to a smaller extent in non-uranium mines. Radon is a gas, and its daughters adsorb on aerosol particles which are of respirable size. The hazard thus arises from the alpha decay of radon and its daughters in contact with lung tissue. Radon is itself part of the uranium decay chain. The major radionuclide, 238 U, decays successively through thirteen shorter-lived radionuclides to 206 Pb. Radon is the only gaseous decay product at room temperature; the other twelve are solids. The main hazard presented by the uranium decay chain is normally determined by the radon concentration because gaseous transport can bring alpha emitters close to sensitive tissue. There is no such transport route for the other alpha emitters, and the level of beta and gamma radiation caused by the uranium decay chain generally presents a far lower external radiation hazard. Radon itself is the heaviest of the noble gases, which are He, Ne, Ar, Kr, Xe and Rn. Its chemical reactions are of no concern in regard to its potential hazard in mines as it may be considered inert. It does, however, have a solubility ten times higher than oxygen in water, and this can play a significant part in assisting the movement of the gas from the rock into airways. Radon continuously emanates into mine workings from uranium ores and from the uranium present at low concentrations in practically any rock. It has been found that the control of the exposure level is most effectively achieved by sound ventilation practices. In South African mines the standard of ventilation is generally high and exposure to radon and radon daughters is at acceptably low levels

Evaluation of strategies for promoting effective radon mitigation. Risk communication and economic research series. Final report

International Nuclear Information System (INIS)

Doyle, J.K.; McClelland, G.H.; Schulze, W.D.; Locke, P.A.; Elliott, S.R.

1990-03-01

The Environmental Protection Agency has estimated that as many as 20,000 lung cancer deaths per year in the United States can be attributed to exposure to radon gas. The report evaluates alternative strategies for motivating people to test for radon gas in their homes and to mitigate if necessary. Specifically, two separate radon information and awareness programs were evaluated, one targeted to the general population in the Washington, D.C. area and the other to home buyers in the Boulder, Colorado area. The results suggest that a home buyer program is likely to be far more effective in terms of effective remediation to reduce home radon levels than a program aimed at the general population. The report discusses the empirical findings and develops a recommendation for increasing the effectiveness of radon awareness and mitigation programs

Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

International Nuclear Information System (INIS)

Baumgartner, A.; Maringer, F.J.; Michai, P.; Kreuziger, M.

2006-01-01

In spring 2005 the Federal Office of Metrology and Surveying (B.E.V.) invited all in Austria working radon measuring institutes to an intercomparison exercise at the radon calibration laboratory in the Arsenal. The aim of this intercomparison was on the one hand an objective inquiry and documentation of the current metrological potential on the section of radon measurement in Austria - both quantitative and qualitative- and on the other hand an initiative for the participating laboratories to optimize and improve their applied calibration-, measurement and analyse technique. Ten contacted Austrian radon laboratories were prepared to participate on the radon intercomparison exercise. The intercomparison exercise was carried out from 14. till 29. June at the radon calibration laboratory in the Arsenal of the B.E.V.. As radon emanation source a five stepped arranged, at the Arsenal built radon source was used. The source ( A.D.O.T.T.O. 1 is filled with a certified Ra- 226-standard solution of the Czech Metrological Institute (C.M.I.), Prag. A simple statistic based model was used for the evaluation and assessment of the results from the participants, which consider the statistic nature of the radioactive decay combined uncertainty. Altogether 183 measuring instruments participated the intercomparison exercise. Two reference measuring instruments, 22 active and 159 passive measuring instruments. The active measuring instruments formed 6 types of instruments and as passive radon detectors were 7 different types used from the participants. The positioning of the radon measuring instruments and detectors in the radon calibration laboratory was executed in regard to statistic points of view. From the active measuring instruments 17 could qualify and from the passive methods six from eight participants were in compliance to the given criteria. Radon measurements, which could have financial and economics relating implications (e.g. architectural redevelopment or

The Dynamics of a Doubly Clamped Microbeam Near the Primary Resonance: Experimental and Analytical Investigation

KAUST Repository

Masri, Karim M.

2016-01-20

We present experimental and analytical investigation of the dynamics of a doubly clamped microbeam near its primary resonance. The microbeam is excited electrostatically by an electrode on the first half of the beam. These microbeams are fabricated using polyimide as structural layer coated with nickel from top and chromium and gold layers from bottom. A noise signal is applied to experimentally detect the natural frequencies. Then, frequency sweep tests are generated for various values of DC bias revealing hardening, transition, and softening behavior of the microbeam. We report for the first time the transition from lower stable state, to unstable state, and then to large stable state experimentally. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. Shooting method is used to find the periodic motion and is utilized to generate frequency response curves. The curves show good agreement with the experimental results with hardening behavior at lower DC voltage then softening at higher voltage loads and dynamic pull-in. © Copyright 2015 by ASME.

Study of squeeze film damping in a micro-beam resonator based on micro-polar theory

Directory of Open Access Journals (Sweden)

Mina Ghanbari

Full Text Available In this paper, squeeze film damping in a micro-beam resonator based on micro-polar theory has been investigated. The proposed model for this study consists of a clamped-clamped micro-beam bounded between two fixed layers. The gap between the micro-beam and layers is filled with air. As fluid behaves differently in micro scale than macro, the micro-scale fluid field in the gap has been modeled based on micro-polar theory. Equation of motion governing transverse deflection of the micro- beam based on modified couple stress theory and also non-linear Reynolds equation of the fluid field based on micropolar theory have been non-dimensionalized, linearized and solved simultaneously in order to calculate the quality factor of the resonator. The effect of micropolar parameters of air on the quality factor has been investigated. The quality factor of the of the micro-beam resonator for different values of non-dimensionalized length scale of the beam, squeeze number and also non-dimensionalized pressure has been calculated and compared to the obtained values of quality factor based on classical theory.

Improved radon-flux-measurement system for uranium-tailings pile measurement

International Nuclear Information System (INIS)

Freeman, H.D.

1981-10-01

The Pacific Northwest Laboratory (PNL) is developing cover technology for uranium mill tailings that will inhibit the diffusion of radon to the atmosphere. As part of this cover program, an improved radon flux measurement system has been developed. The radon measurement system is a recirculating, pressure-balanced, flow-through system that uses activated carbon at ambient temperatures to collect the radon. With the system, an area of 0.93 m 2 is sampled for periods ranging from 1 to 12 h. The activated carbon is removed from the radon trap and the collected radon is determined by counting the 214 Bi daughter product. Development of the system included studies to determine the efficiency of activated carbon, relative calibration measurements and field measurements made during 1980 at the inactive tailings pile in Grand Junction, Colorado. Results of these studies are presented

Computer program for the sensitivity calculation of a CR-39 detector in a diffusion chamber for radon measurements

Energy Technology Data Exchange (ETDEWEB)

Nikezic, D., E-mail: nikezic@kg.ac.rs; Stajic, J. M. [Faculty of Science, University of Kragujevac, R. Domanovica 12, Kragujevac 34000 (Serbia); Yu, K. N. [Department of Physics and Materials Science, City University of Hong Kong, 83 Tat Chee Avenue (Hong Kong)

2014-02-15

Computer software for calculation of the sensitivity of a CR-39 detector closed in a diffusion chamber to radon is described in this work. The software consists of two programs, both written in the standard Fortran 90 programming language. The physical background and a numerical example are given. Presented software is intended for numerous researches in radon measurement community. Previously published computer programs TRACK-TEST.F90 and TRACK-VISION.F90 [D. Nikezic and K. N. Yu, Comput. Phys. Commun. 174, 160 (2006); D. Nikezic and K. N. Yu, Comput. Phys. Commun. 178, 591 (2008)] are used here as subroutines to calculate the track parameters and to determine whether the track is visible or not, based on the incident angle, impact energy, etching conditions, gray level, and visibility criterion. The results obtained by the software, using five different V functions, were compared with the experimental data found in the literature. Application of two functions in this software reproduced experimental data very well, while other three gave lower sensitivity than experiment.

Evaluating the peak-to-valley dose ratio of synchrotron microbeams using PRESAGE fluorescence

International Nuclear Information System (INIS)

Annabell, N.; Yagi, N.; Umetani, K.; Wong, C.; Geso, M.

2012-01-01

The peak-to-valley dose ratio of a microbeam array can be measured by fluorescence of PRESAGE dosimeters. Peak-to-valley dose ratios are calculated using this new technique and also by EBT2 film. Synchrotron-generated microbeam radiotherapy holds great promise for future treatment, but the high dose gradients present conventional dosimetry with a challenge. Measuring the important peak-to-valley dose ratio (PVDR) of a microbeam-collimated synchrotron source requires both a dosimeter and an analysis method capable of exceptional spatial resolution. The PVDR is of great interest since it is the limiting factor for potential application of the microbeam radiation therapy technique clinically for its tissue-sparing properties (i.e. the valley dose should be below the tolerance of normal tissue). In this work a new method of measuring the dose response of PRESAGE dosimeters is introduced using the fluorescence from a 638 nm laser on a confocal laser-scanning microscope. This fluorescent microscopy method produces dosimetry data at a pixel size as low as 78 nm, giving a much better spatial resolution than optical computed tomography, which is normally used for scanning PRESAGE dosimeters. Using this technique the PVDR of the BL28B2 microbeam at the SPring-8 synchrotron in Japan is estimated to be approximately 52:1 at a depth of 2.5 mm. The PVDR was also estimated with EBT2 GAFchromic films as 30.5:1 at the surface in order to compare the PRESAGE fluorescent results with a more established dosimetry system. This estimation is in good agreement with previously measured ratios using other dosimeters and Monte Carlo simulations. This means that it is possible to use PRESAGE dosimeters with confocal microscopy for the determination of PVDR

Use of a geographic information system (GIS) for targeting radon screening programs in South Dakota.

Science.gov (United States)

Kearfott, Kimberlee J; Whetstone, Zachary D; Rafique Mir, Khwaja M

2016-01-01

Because (222)Rn is a progeny of (238)U, the relative abundance of uranium may be used to predict the areas that have the potential for high indoor radon concentration and therefore determine the best areas to conduct future surveys. Geographic Information System (GIS) mapping software was used to construct maps of South Dakota that included levels of uranium concentrations in soil and stream water and uranium deposits. Maps of existing populations and the types of land were also generated. Existing data about average indoor radon levels by county taken from a databank were included for consideration. Although the soil and stream data and existing recorded average indoor radon levels were sparse, it was determined that the most likely locations of elevated indoor radon would be in the northwest and southwest corners of the state. Indoor radon levels were only available for 9 out of 66 counties in South Dakota. This sparcity of data precluded a study of correlation of radon to geological features, but further motivates the need for more testing in the state. Only actual measurements should be used to determine levels of indoor radon because of the strong roles home construction and localized geology play in radon concentration. However, the data visualization method demonstrated here is potentially useful for directing resources relating to radon screening campaigns. © The Author 2015. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Indoor radon

International Nuclear Information System (INIS)

1997-12-01

The radon, a natural radioactive gas, is present almost everywhere on the earth's surface. It can be accumulated at high concentration in confined spaces (buildings, mines, etc). In the last decades many studies conducted in several countries showed that inhaling important amounts of radon rises the risk of lung cancer. Although, the radon is a naturally appearing radioactive source, it may be the subject of a human 'enhancement' of concentration. The increasing radon concentration in professional housing constitutes an example of enhanced natural radioactivity which can induce health risks on workers and public. Besides, the radon is present in the dwelling houses (the domestic radon). On 13 May 1996, the European Union Council issued the new EURATOM Instruction that establishes the basic standards of health protection of population and workers against the ionizing radiation hazards (Instruction 96/29/EURATOM, JOCE L-159 of 29 June 1996). This instruction does not apply to domestic radon but it is taken into consideration by another EURATOM document: the recommendation of the Commission 90/143/EURATOM of 21 February 1990 (JOCE L-80 of 27 March 1990). The present paper aims at establishing in accordance to European Union provisions the guidelines for radon risk management in working places, as well as in dwelling houses, where the implied risk is taken into account. This document does not deal with cases of high radon concentration on sites where fabrication, handling or storage of radium sources take place. These situations must be treated by special studies

Radon reduction and radon-resistant construction demonstrations in New York state. Final report

International Nuclear Information System (INIS)

1991-02-01

A survey of radon levels in New York State homes indicates that approximately 4.4 percent of the homes have long-term living area radon concentrations above the U.S. EPA guideline of four pCi/l. The project addressed the effectiveness of techniques to reduce the radon level in existing homes and to prevent the occurrence of high radon concentrations in new homes. The goal of the project was to demonstrate the effectiveness of radon reduction techniques in homes containing indoor radon concentrations of more than the current EPA guidelines of four pCi/l. At the same time, radon-resistant construction techniques were demonstrated in homes under construction to provide guidelines for houses being built in areas with a danger of high radon levels. The project demonstrated new radon mitigation techniques in homes containing indoor radon concentrations exceeding four pCi/l; assessed the value of previously installed radon reduction procedures, and demonstrated new radon-resistant construction methods

Mechanisms of radon injury

International Nuclear Information System (INIS)

Cross, F.T.

1988-01-01

In this new project, they conduct molecular, cellular and whole-animal research relevant to understanding the inhalation toxicology of radon and radon-daughter exposures. The work specifically addresses the exposure-rate effect in radon-daughter carcinogenesis; the induction-promotion relationships associated with exposure to radon and cigarette-smoke mixtures; the role of oncogenes in radon-induced cancers; the effects of radon on DNA as well as on DNA repair processes; and the involvement of growth factors and their receptors in radon-induced carcinogenesis. Preliminary experiments showed that oncogenes are activated in radon-induced lung tumors. They have therefore begun further exposures pertinent to the oncogene and growth-factor studies. An in vitro radon cellular-exposure system was designed, and cell exposures were initiated. Initiation-promotion-initiation studies with radon and cigarette-smoke mixtures have also begun; and they are compiling a radon health-effects bibliography

Evaluation of experiences in long-term radon and radon-daughter measurements

International Nuclear Information System (INIS)

Young, J.A.; Jackson, P.O.; Thomas, V.W.

1982-12-01

Pacific Northwest Laboratory (PNL) is performing side-by-side measurements of radon and radon daughter concentrations using several instruments and techniques, and is comparing these measurements with side-by-side measurements made by other investigators at other locations. The standard deviation of the differences between the (natural) logarithms of the Terradex Track Etch radon concentrations and the logarithms of the Radon Progency Integrating Sampling Units (RPISU) radon daughter concentrations (S.D.-ln) measured in 50 buildings in Edgemont, South Dakota, was 0.37. Using this S.D.-ln, it can be calculated that if the Track Etch radon daughter concentration is 0.010 WL there should be only a 14% probability that the RPISU average would be greater than 0.015 WL, and only a 3% probability tht the RPISU average would be greater than 0.020 WL. If buildings had been cleared from remedial action when the Track Etch averages were less than 0.10 WL, then about 61% of the buildings would have been cleared from remedial action, and only a few percent of these buildings would have actually had average RPISU concentrations greater than 0.015 WL. The S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements made by ALARA at Grand Junction, the PERM radon measurements and the MOD-225 radon daughter measurements made by Mound Facility at Canonsburg and Middlesex, and the PERM and Track Etch radon measurements made by Mound Facility at Salt Lake City were similar to the S.D.-ln between the Track Etch radon measurements and the RPISU radon daughter measurements at Edgemont

Mapping the geogenic radon potential of the eastern Canary Islands.

Science.gov (United States)

Rubiano, Jesús G.; Alonso, Hector; Arnedo, Miguel. A.; Tejera, Alicia; Martel, Pablo; Gil, Juan M.; Rodriguez, Rafael; González, Jonay

2014-05-01

using a calibrated nomogram. As results, maps of radon in soils have been developed for the three islands to identify areas where may appear high activity concentrations of radon due to natural sources. Finally to determine the radon potential of soils analyzed we applied a procedure to classify the radon areas in several levels of risk using the measured values of radon activity concentration and soil permeability. Acknowledgments: This work was financed by the Nuclear Safety Council (CSN) through a grant in its R&D program 2009 and by the European Development Fund (ERDF) through a research project program 2007 granted by Canary Agency for Research, Innovation and Information Society (ACIISI) of the Canary Islands.

Application of microbeam in bio-science and life science. Biological effects induced in bystander cells by particle microbeams

International Nuclear Information System (INIS)

Suzuki, Masao

2006-01-01

Biological events occurring in cells directly hit by radiation appear in bystander cells nearby not hit directly, which is called the bystander effect. This review describes the events and mechanisms of biological bystander effect yielded by the low-dose radiation including the microbeam. Bystander effects, particularly by charged particle beams, have been studied by two representative approaches by α-ray from plutonium (stochastic irradiation) and by particle microbeams (targeted irradiation), where a bystander effect like chromosome aberrations is shown to occur by communication between irradiated and non-irradiated cells through gap junction. Bystander effects that do not require the cell contact also occur in the irradiated cell-conditioned medium (ICCM), where, not only the short-life radicals like reactive oxygen species and NO, but also more long-life factors participate. Authors have shown the presence of such bystander-inducing factors in ICCM, producing the aberrations even 48 hr after irradiation of either low or high linear energy transfer (LET) radiation. Bystander effects can be important from the aspect of risk assessments of radiation in the terrestrial/spatial environment involving aircraft as well as in cancer therapy by low-dose heavy particle beams. (T.I)

Performances of synchrotron radiation microbeam focused by monolithic half focusing polycapillary X-ray lens

International Nuclear Information System (INIS)

Sun Tianxi; Liu Zhiguo; He Bo; Wei Shiqiang; Xie Yaning; Liu Tao; Hu Tiandou; Ding Xunliang

2007-01-01

A monolithic half focusing polycapillary X-ray lens (MHFPXRL) composed of 289,000 capillaries is used to produce a synchrotron radiation microbeam. The energy dependence of the output focal distance, focal spot size, transmission efficiency, vertical beam position, and gain in flux density of this microbeam is studied in detail. There is a slight change in the output focal distance of the MHFPXRL when the X-ray energies change

QA/QC For Radon Concentration Measurement With Charcoal Canister

International Nuclear Information System (INIS)

Pantelic, G.; Zivanovic, M.; Rajacic, M.; Krneta Nikolic, J.; Todorovic, D.

2015-01-01

The primary concern of any measuring of radon or radon progeny must be the quality of the results. A good quality assurance program, when properly designed and diligently followed, ensures that laboratory staff will be able to produce the type and quality of measurement results which is needed and expected. Active charcoal detectors are used for testing the concentration of radon in dwellings. The method of measurement is based on radon adsorption on coal and measurement of gamma radiation of radon daughters. Upon closing the detectors, the measurement was carried out after achieving the equilibrium between radon and its daughters (at least 3 hours) using NaI or HPGe detector. Radon concentrations as well as measurement uncertainties were calculated according to US EPA protocol 520/5-87-005. Detectors used for the measurements were calibrated by 226Ra standard of known activity in the same geometry. Standard and background canisters are used for QA and QC, as well as for the calibration of the measurement equipment. Standard canister is a sealed canister with the same matrix and geometry as the canisters used for measurements, but with the known activity of radon. Background canister is a regular radon measurement canister, which has never been exposed. The detector background and detector efficiency are measured to ascertain whether they are within the warning and acceptance limits. (author).

Size-dependent pull-in instability of electrostatically actuated microbeam-based MEMS

International Nuclear Information System (INIS)

Wang, Binglei; Zhou, Shenjie; Zhao, Junfeng; Chen, Xi

2011-01-01

We present a size-dependent model for electrostatically actuated microbeam-based MEMS using strain gradient elasticity theory. The normalized pull-in voltage is shown to increase nonlinearly with the decrease of the beam height, and the size effect becomes prominent if the beam thickness is on the order of microns or smaller (i.e. when the beam dimension is comparable to the material length scale parameter). Very good agreement is found between the present model and available experimental data. The study may be helpful to characterize the mechanical properties of small size MEMS, or guide the design of microbeam-based devices for a wide range of potential applications. (technical note)

Construction of radon/radon daughter calibraton chamber

International Nuclear Information System (INIS)

Fry, J.; Gan, T.H.; Leach, V.A.; Saddlier, J.; Solomon, S.B.; Tam, K.K.; Travis, E.; Wykes, P.

1983-01-01

The radon/radon daughter test chamber is a copper lined room 1.65x1.75x2.75m with an effective volume of 8000 litres. The air residence time is controlled by circulating the air in the chamber through absolute filters which remove 99.9% of particulates. Radon is drawn into the chamber from a 17 μCi 226 RaCl source using the pressure differential across the blowers (<3 psi)

A technical evaluation of the EDA radon gas continuous monitoring system

International Nuclear Information System (INIS)

Bigu, J.

1979-04-01

Extensive laboratory and underground tests were conducted with a radon gas continuous monitoring system built by EDA Instruments Inc. The system consists of several remote radon gas sensors linked via signal cables to a central control unit that fully controls the operation of the radon monitors. The system enables four operations to be performed: sampling, background, flush and bypass. The sequence and duration of these functions is programmable. Up to 20 functions in any desired pattern each lasting from 1 min to 23 hr 59 min can be programmed. Several programs were used during the experiments in order to obtain radon and thoron gas levels. The performance of the EDA system was quite satisfactory. It is suggested that ruggedization as well as some other modifications be introdouced into the system to: a) better withstand the harsh underground environment; and b) improve its performance

Application of single-chip microcomputer to portable radon and radon daughters monitor

International Nuclear Information System (INIS)

Meng Yecheng; Huang Zhanyun; She Chengye

1992-01-01

Application of single-chip microcomputer to portable radon and radon daughters monitor is introduced in this paper. With the single-chip microcomputer automation comes into effect in the process from sampling to measuring of radon and radon daughters. The concentrations of radon and radon daughters can be easily shown when the conversion coefficients are pre-settled before the measurement. Moreover, the principle and design are briefly discussed according to the characteristics of the monitor

Compact detector for radon and radon daughter products

International Nuclear Information System (INIS)

Alter, H.W.; Oswald, R.A.

1986-01-01

This invention provides an improved compact track registration detector for radon gas. The detector comprises a housing having an open mouth, a bottom, and side walls; track registration means, supported inside the housing, which forms damage tracks along paths traversed by alpha particles; a microporous filter positioned across the mouth of the housing to prevent entry of radon daughters and particulate matter; and a cap that may be placed on the mouth of the housing to retain the filter. The housing has internal wall surfaces dimensioned to optimize the registration of alpha particles from radon and radon daughters present in the housing

Microbeams, microdosimetry and specific dose

International Nuclear Information System (INIS)

Randers-Pehrson, H.

2002-01-01

Dose and its usefulness as a single parameter to describe the amount of radiation absorbed are well established for most situations. The conditions where the concept of dose starts to break down are well known, mostly from the study of microdosimetry. For low doses of high LET radiation it is noted that the process of taking the limiting value of the energy absorbed within a test volume divided by the mass within that volume yields either zero or a relatively large value. The problem is further exacerbated with microbeam irradiations where the uniformity of the energy deposition is experimentally manipulated on the spatial scale of cells being irradiated. Booz introduced a quantity to deal with these problems: the unfortunately named 'mean specific energy in affected volumes'. This quantity multiplied by the probability that a test volume has received an energy deposit is equal to dose (in situations where dose can be defined). I propose that Booz's quantity be renamed 'specific dose', that is the mean energy deposited divided by the mass within a specified volume. If we believe for instance that the nucleus of a cell is the critical volume for biological effects, we can refer to the nuclear specific dose. A microbeam experiment wherein 10 per cent of the cell nuclei were targeted with 10 alpha particles would be described as delivering a nuclear specific dose of 1.6 Gy to 10 per cent of the population. (author)

Theoretical and experimental study of radon measurement with designing and calibration domestic canister with active charcoal

International Nuclear Information System (INIS)

Urosevic, V.; Nikezic, D.; Zekic, R.

2005-01-01

Radon concentration in air may change significantly large variation due to atmospheric variation. Measurement with active charcoal can be inaccurate because the variation in radon concentration. We made model to simulate radon measurements with active charcoal in order to optimize and improve integration characteristic. A numerical method and computer code based on the method of finite elements is developed for the case of variable radon concentration in air. This program simulates radon adsorption by the activated charcoal bed, enabling determination of sensitivity. The dependence of sensitivity on different parameters, such as temperature, thickness of the charcoal, etc. was studied using this program. Using results of theoretical investigation we designed and calibrated our canister with active charcoal for radon measurements. (author)

The use of soil gas as radon source in radon chambers

International Nuclear Information System (INIS)

Al-Azmi, Darwish

2009-01-01

A procedure is described in which soil gas is utilized as an alternative to the 226 Ra source for the supply of the radon gas required to fill a radon chamber where radon-measuring devices are calibrated. The procedure offers opportunities to vary the radon concentration within the chamber around an average value of about 500 Bq/m 3 , which is considered to be sufficient for calibrating indoor radon detectors. The procedure is simple and the radon source does not require radiation protection certification (for import and/or use), unlike the commercially produced standard radioactive ( 226 Ra) sources.

On the Nonlinear Dynamics of a Doubly Clamped Microbeam near Primary Resonance

KAUST Repository

Jaber, Nizar; Masri, Karim M.; Younis, Mohammad I.

2017-01-01

This work aims to investigate theoretically and experimentally various nonlinear dynamic behaviors of a doubly clamped microbeam near its primary resonance. Mainly, we investigate the transition behavior from hardening, mixed, and then softening behavior. We show in a single frequency-response curve, under a constant voltage load, the transition from hardening to softening behavior demonstrating the dominance of the quadratic electrostatic nonlinearity over the cubic geometric nonlinearity of the beam as the motion amplitudes becomes large, which may lead eventually to dynamic pull-in. The microbeam is fabricated using polyimide as a structural layer coated with nickel from top and chromium and gold layers from the bottom. Frequency sweep tests are conducted for different values of DC bias revealing hardening, mixed, and softening behavior of the microbeam. A multi-mode Galerkin model combined with a shooting technique are implemented to generate the frequency response curves and to analyze the stability of the periodic motions using the Floquet theory. The simulated curves show good agreement with the experimental data.

On the Nonlinear Dynamics of a Doubly Clamped Microbeam near Primary Resonance

KAUST Repository

Jaber, Nizar

2017-04-07

This work aims to investigate theoretically and experimentally various nonlinear dynamic behaviors of a doubly clamped microbeam near its primary resonance. Mainly, we investigate the transition behavior from hardening, mixed, and then softening behavior. We show in a single frequency-response curve, under a constant voltage load, the transition from hardening to softening behavior demonstrating the dominance of the quadratic electrostatic nonlinearity over the cubic geometric nonlinearity of the beam as the motion amplitudes becomes large, which may lead eventually to dynamic pull-in. The microbeam is fabricated using polyimide as a structural layer coated with nickel from top and chromium and gold layers from the bottom. Frequency sweep tests are conducted for different values of DC bias revealing hardening, mixed, and softening behavior of the microbeam. A multi-mode Galerkin model combined with a shooting technique are implemented to generate the frequency response curves and to analyze the stability of the periodic motions using the Floquet theory. The simulated curves show good agreement with the experimental data.

Radon in Antarctica

International Nuclear Information System (INIS)

Ilic, R.; Rusov, V.D.; Pavlovych, V.N.; Vaschenko, V.M.; Hanzic, L.; Bondarchuk, Y.A.

2005-01-01

The paper reviews results of radon measurements obtained in Antarctic research stations in the last 40 years by both active and passive radon monitors. A brief description of the radon laboratory set-up in the Ukrainian Academician Vernadsky station on the Antarctic Peninsula (W 64 o 16 ' , S 65 o 15 ' ), where radon is measured by two types of etched track Rn dosimeter and 4 types of continuous radon monitoring devices is presented. Some selected results of research work are described related to: (i) analysis of radon storms, defined as an abrupt increase of 222 Rn during the occurrence of a cyclone, and its applicability for the study of the transport of air masses of continental origin to Antarctica; (ii) a study of the correlation of changes of radon concentration and geomagnetic field induced by tectonic activity and its application to predicting tectonomagnetic anomalies, and (iii) verification of a newly developed theoretical model based on noise analysis of the measured radon signal for earthquake prediction. Suggestions for future utilization of radon for basic research in Antarctica (and not only in Antarctica) conclude the contribution. conclude the contribution

3D mapping of individual cells using a proton microbeam

International Nuclear Information System (INIS)

Michelet, C.; Moretto, Ph.

1999-01-01

Various imaging techniques carried out with a nuclear microprobe make it possible to reveal by 2D mapping, the internal structure of isolated cells. An improvement of those techniques allows today 3D mapping of cells. STIM- and PIXE-Tomography have been recently implemented on the CENBG microbeam line. The performance offered by these methods, which are capable of resolving objects having diameters less then 100 μm, has been validated on reference specimens and on human cells from cultures. In addition to the fineness of the resolution, these techniques offer the advantage of performing volume analyses without prior cutting of the samples. The ultimate aim of this program of research is to perform 3D elemental chemical analysis of individual cells in the field of biomedicine

Radon concentrations in contaminated and uncontaminated premises in two Ontario towns

International Nuclear Information System (INIS)

Aitken, J.H.; Baker, E.G.; Chatterjee, R.M.; Kusiak, R.; Tai-Pow, J.

1977-01-01

Radon-222 concentrations in air were measured by grab sampling in a large number of private homes and other buildings in the town of Port Hope, Ontario. The purpose of the measurements is to identify places where a health hazard might exist due to improper disposal of radium-contaminated materials. Contaminated fill, rubble, lumber, and other building materials have been found in a number of premises in the town. Radon concentrations up to 750 pCi/l have been found in some homes. The thrust of the program is to identify quickly places where concentrations might be high enough to justify some prompt interim remedial action such as installation of special ventilation systems, pending final remedial work by removal of the contamination. The methods and instrumentation immediately available are those formerly used for radon-in-breath analysis in radium workers. Grab sampling for radon and gamma surveying in every building in town are used together in a screening program. Experience showed that both radon sampling and gamma surveying are required to identify contaminated locations

Radon-Instrumentation; Radon-Instrumentacion

Energy Technology Data Exchange (ETDEWEB)

Moreno y Moreno, A. [Departamento de Apoyo en Ciencias Aplicadas, Benemerita Universidad Autonoma de Puebla, 4 Sur 104, Centro Historico 72000 Puebla (Mexico)

2003-07-01

The presentation of the active and passive methods for radon, their identification and measure, instrumentation and characteristics are the objectives of this work. Active detectors: Active Alpha Cam Continuous Air Monitor, Model 758 of Victoreen, Model CMR-510 Continuous Radon Monitor of the Signature Femto-Tech. Passive detectors: SSNTD track detectors in solids Measurement Using Charcoal Canisters, disk of activated coal deposited in a metallic box Electrets Methodology. (Author)

Microbeam high-resolution diffraction and x-ray standing wave methods applied to semiconductor structures

International Nuclear Information System (INIS)

Kazimirov, A; Bilderback, D H; Huang, R; Sirenko, A; Ougazzaden, A

2004-01-01

A new approach to conditioning x-ray microbeams for high angular resolution x-ray diffraction and scattering techniques is introduced. We combined focusing optics (one-bounce imaging capillary) and post-focusing collimating optics (miniature Si(004) channel-cut crystal) to generate an x-ray microbeam with a size of 10 μm and ultimate angular resolution of 14 μrad. The microbeam was used to analyse the strain in sub-micron thick InGaAsP epitaxial layers grown on an InP(100) substrate by the selective area growth technique in narrow openings between the oxide stripes. For the structures for which the diffraction peaks from the substrate and the film overlap, the x-ray standing wave technique was applied for precise measurements of the strain with a Δd/d resolution of better than 10 -4 . (rapid communication)

An Experimental and Theoretical Investigation of Electrostatically Coupled Cantilever Microbeams

KAUST Repository

Ilyas, Saad; Chappanda, Karumbaiah N.; Hafiz, Md Abdullah Al; Ramini, Abdallah; Younis, Mohammad I.

2016-01-01

We present an experimental and theoretical investigation of the static and dynamic behavior of electrostatically coupled laterally actuated silicon microbeams. The coupled beam resonators are composed of two almost identical flexible cantilever

Wind direction correlated measurements of radon and radon progeny in atmosphere: a method for radon source identification

International Nuclear Information System (INIS)

Akber, R.A.; Pfitzner, J.; Johnston, A.

1994-01-01

This paper describes the basic principles and methodology of a wind direction correlated measurement technique which is used to distinguish the mine-related and background components of radon and radon progeny concentrations in the vicinity of the ERA Ranger Uranium Mine. Simultaneous measurements of atmospheric radon and radon progeny concentrations and wind speed and direction were conducted using automatic sampling stations. The data were recorded as a time series of half hourly averages and grouped into sixteen 22.5 degrees wind sectors. The sampling interval and the wind sector width were chosen considering wind direction variability (σ θ ) over the sampling time interval. The data were then analysed for radon and radon progeny concentrations in each wind sector. Information about the wind frequency wind speed seasonal and diurnal variations in wind direction and radon concentrations was required for proper data analysis and interpretation of results. A comparison with model-based estimates for an identical time period shows agreement within about a factor of two between the two methods. 15 refs., 1 tab., 5 figs

Monte Carlo dose calculation of microbeam in a lung phantom

International Nuclear Information System (INIS)

Company, F.Z.; Mino, C.; Mino, F.

1998-01-01

Full text: Recent advances in synchrotron generated X-ray beams with high fluence rate permit investigation of the application of an array of closely spaced, parallel or converging microplanar beams in radiotherapy. The proposed techniques takes advantage of the hypothesised repair mechanism of capillary cells between alternate microbeam zones, which regenerates the lethally irradiated endothelial cells. The lateral and depth doses of 100 keV microplanar beams are investigated for different beam dimensions and spacings in a tissue, lung and tissue/lung/tissue phantom. The EGS4 Monte Carlo code is used to calculate dose profiles at different depth and bundles of beams (up to 20x20cm square cross section). The maximum dose on the beam axis (peak) and the minimum interbeam dose (valley) are compared at different depths, bundles, heights, widths and beam spacings. Relatively high peak to valley ratios are observed in the lung region, suggesting an ideal environment for microbeam radiotherapy. For a single field, the ratio at the tissue/lung interface will set the maximum dose to the target volume. However, in clinical application, several fields would be involved allowing much greater doses to be applied for the elimination of cancer cells. We conclude therefore that multifield microbeam therapy has the potential to achieve useful therapeutic ratios for the treatment of lung cancer

Instruments to measure radon activity concentration or exposure to radon. Interlaboratory comparison 2011

International Nuclear Information System (INIS)

Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

2011-10-01

According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by BfS. A radon measuring service is recognized by the competent authority if it proves its organizational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the website www.bfs.de/de/ion/radon/fachinfomessung/vergleichspruefungen.html and from the European Information System on Proficiency Testing Schemes (eptis) available in the internet. (orig.)

Uncertainties of estimating average radon and radon decay product concentrations in occupied houses

International Nuclear Information System (INIS)

Ronca-Battista, M.; Magno, P.; Windham, S.

1986-01-01

Radon and radon decay product measurements made in up to 68 Butte, Montana homes over a period of 18 months were used to estimate the uncertainty in estimating long-term average radon and radon decay product concentrations from a short-term measurement. This analysis was performed in support of the development of radon and radon decay product measurement protocols by the Environmental Protection Agency (EPA). The results of six measurement methods were analyzed: continuous radon and working level monitors, radon progeny integrating sampling units, alpha-track detectors, and grab radon and radon decay product techniques. Uncertainties were found to decrease with increasing sampling time and to be smaller when measurements were conducted during the winter months. In general, radon measurements had a smaller uncertainty than radon decay product measurements. As a result of this analysis, the EPA measurements protocols specify that all measurements be made under closed-house (winter) conditions, and that sampling times of at least a 24 hour period be used when the measurement will be the basis for a decision about remedial action or long-term health risks. 13 references, 3 tables

Radon programme: presence and future

International Nuclear Information System (INIS)

Hulka, J.

2009-01-01

In this presentation an overview of radon programme experiences is presented. The paper summarises national radon policy, national programmes, legislation, the role of preventive measures and interventions with respect to existing and future exposure and knowledge of radon risk, problems of remediation strategies, practical protection in dwellings, radon measurements strategies, progress in radon measurement of an individual house (radon diagnosis), radon mapping process and sense of delineation of radon prone areas, natural radioactivity of building materials and radioactivity in public water and their role in the radon programme, public awareness on radon issue and publicity campaign. Some research activities are proposed aiming at effective solutions of radon issues in future

The heightened activity of radon in water analysis from Lounovice area, Czech Republic

International Nuclear Information System (INIS)

Thinova, L.; Berka, Z.; Fridrichova, L.; Kaderova, J.; Cernohorska, E.; Pokorna, T.; Kosar, V.; Patak, M.; Kracmarova, I.

2004-01-01

The Lounovice area is located approximately 20 km south-east of Prague. Radon activity in fresh water from drilled-wells, used for village water supply, ranges between 700 and 900 Bq/l, which exceeds the standard for drinkable water by a factor higher than 100. Therefore, water is treated by aeration before use. Some residents, however, use drinking water from their own wells. A comprehensive radon and natural radioactivity survey was therefore conducted in this area. Secondary school students were engaged in this survey within the 'Physics Week' scientific program for young physicists, run by the Czech Technical University in Prague every year. in year 2004. The program included the following items: Laboratory gamma spectrometric measurement of the bedrock; Radon activity measurement in water before and after the aeration process; Radon monitoring at workplaces of the water company (the values provided by ionization chamber instruments and semiconductor detector instruments were compared); Radon daughters measurement at workplaces of the water company; In situ gamma spectrometry; In situ effective dose rate measurement; and Determination of a 'radon index' in the neighborhood of a drilled well

Memory and survival after microbeam radiation therapy

International Nuclear Information System (INIS)

Schueltke, Elisabeth; Juurlink, Bernhard H.J.; Ataelmannan, Khalid; Laissue, Jean; Blattmann, Hans; Braeuer-Krisch, Elke; Bravin, Alberto; Minczewska, Joanna; Crosbie, Jeffrey; Taherian, Hadi; Frangou, Evan; Wysokinsky, Tomasz; Chapman, L. Dean; Griebel, Robert; Fourney, Daryl

2008-01-01

Background: Disturbances of memory function are frequently observed in patients with malignant brain tumours and as adverse effects after radiotherapy to the brain. Experiments in small animal models of malignant brain tumour using synchrotron-based microbeam radiation therapy (MRT) have shown a promising prolongation of survival times. Materials and methods: Two animal models of malignant brain tumour were used to study survival and memory development after MRT. Thirteen days after implantation of tumour cells, animals were submitted to MRT either with or without adjuvant therapy (buthionine-SR-sulfoximine = BSO or glutamine). We used two orthogonal 1-cm wide arrays of 50 microplanar quasiparallel microbeams of 25 μm width and a center-to-center distance of about 200 μm, created by a multislit collimator, with a skin entrance dose of 350 Gy for each direction. Object recognition tests were performed at day 13 after tumour cell implantation and in monthly intervals up to 1 year after tumour cell implantation. Results: In both animal models, MRT with and without adjuvant therapy significantly increased survival times. BSO had detrimental effects on memory function early after therapy, while administration of glutamine resulted in improved memory

Radon

International Nuclear Information System (INIS)

1990-01-01

This leaflet in the At-a-Glance Series, describes what radon is, where it is found, why it presents a risk to health, the official advice, and the remedies that are available to reduce radon levels. (author)

The Montana Radon Study: Social Marketing via Digital Signage Technology for Reaching Families in the Waiting Room

Science.gov (United States)

2015-01-01

Objectives. I tested a social marketing intervention delivered in health department waiting rooms via digital signage technology for increasing radon program participation among priority groups. Methods. I conducted a tri-county, community-based study over a 3-year period (2010–2013) in a high-radon state by using a quasi-experimental design. We collected survey data for eligible participants at the time of radon test kit purchase. Results. Radon program participation increased at the intervention site (t38 = 3.74; P = .001; 95% confidence interval [CI] = 4.8, 16.0) with an increase in renters (χ21,228 = 4.3; P = .039), Special Supplementary Nutrition Program for Women, Infants, and Children families (χ21,166 = 3.13; P = .077) and first-time testers (χ21,228 = 10.93; P = .001). Approximately one third (30.3%; n = 30) attributed participation in the radon program to viewing the intervention message. The intervention crossover was also successful with increased monthly kit sales (t37 = 2.69; P = .01; 95% CI = 1.20, 8.47) and increased households participating (t23 = 4.76; P marketing message was an effective population-based intervention for increasing radon program participation. The results prompted policy changes for Montana radon programming and adoption of digital signage technology by 2 health departments. PMID:25121816

Radon: A health problem and a communication problem

International Nuclear Information System (INIS)

Johnson, R.H.

1992-01-01

The US Environmental Protection Agency (USEPA) is making great efforts to alert the American public to the potential health risks of radon in homes. The news media have widely publicized radon as a problem; state and local governments are responding to public alarms; and hundreds of radon open-quotes expertsclose quotes are now offering radon detection and mitigation services. Apparently, USEPA's communication program is working, and the public is becoming increasingly concerned with radon. But are they concerned with radon as a open-quotes healthclose quotes problem in the way USEPA intended? The answer is yes, partly. More and more, however, the concerns are about home resale values. Many homebuyers are now deciding whether to buy on the basis of a single radon screening measurement, comparing it with USEPA's action guide of 4 pCi L -1 . They often conclude that 3.9 is OK, but 4.1 is not. Here is where the communication problems begin. The public largely misunderstands the significance of USEPA's guidelines and the meaning of screening measurements. Seldom does anyone inquire about the quality of the measurements, or the results of USEPA performance testing? Who asks about the uncertainty of lifetime exposure assessments based on a 1-hour, 1-day, 3-day, or even 30-day measurement? Who asks about the uncertainty of USEPA's risk estimates? Fortunately, an increasing number of radiation protection professions are asking such questions. They find that USEPA's risk projections are based on many assumptions which warrant further evaluation, particularly with regard to the combined risks of radon and cigarette-smoking. This is the next communication problem. What are these radiation professions doing to understand the bases for radon health-risk projections? Who is willing to communicate a balanced perspective to the public? Who is willing to communicate the uncertainty and conservatism in radon measurements and risk estimates?

Radon emanation from soils

International Nuclear Information System (INIS)

Markkanen, M.; Arvela, H.

1992-01-01

The results of gamma spectrometric sample measurements of radon ( 222 Rn) emanation coefficients and radium concentrations ( 226 Ra) from about 800 Finnish soil samples are presented. The radon emanation rate was measured in about 400 soil samples, using radon-tight cans and Lucas cells. The effects of water content and temperature on radon emanation were investigated, using various samples of different soil types. Radon emanation and the effect of water content on radon emanation were investigated separately for different grain sizes (samples of till). The results provide some information on radon emanation in different soil types and relate emanation in laboratory conditions to conditions in ground soil. In routine measurements of radon emanation from soil samples, use of a 5% water content was considered advisable. The correction coefficients of radon emanation varied between 0.3 and 1.5, depending on the water content and soil type. At 5% water content, hardly any difference was found between radon emanation at temperatures of 20 and 1 o C. Radon emanation was found to be an inverse function of grain sizes larger than 0.5 mm in diameter. (author)

Result of the intercomparison exercise on radon measuring instruments and radon detectors 'bev- radon ring 2005'

Energy Technology Data Exchange (ETDEWEB)

Baumgartner, A. [Vienna Univ. of Technology, Atominstitut, Wien (Austria); Maringer, F.J.; Michai, P.; Kreuziger, M. [BEV-Federal Office of Metrology and Surveying, Wien (Austria)

2006-07-01

In spring 2005 the Federal Office of Metrology and Surveying (B.E.V.) invited all in Austria working radon measuring institutes to an intercomparison exercise at the radon calibration laboratory in the Arsenal. The aim of this intercomparison was on the one hand an objective inquiry and documentation of the current metrological potential on the section of radon measurement in Austria - both quantitative and qualitative- and on the other hand an initiative for the participating laboratories to optimize and improve their applied calibration-, measurement and analyse technique. Ten contacted Austrian radon laboratories were prepared to participate on the radon intercomparison exercise. The intercomparison exercise was carried out from 14. till 29. June at the radon calibration laboratory in the Arsenal of the B.E.V.. As radon emanation source a five stepped arranged, at the Arsenal built radon source was used. The source ( A.D.O.T.T.O. 1 is filled with a certified Ra- 226-standard solution of the Czech Metrological Institute (C.M.I.), Prag. A simple statistic based model was used for the evaluation and assessment of the results from the participants, which consider the statistic nature of the radioactive decay combined uncertainty. Altogether 183 measuring instruments participated the intercomparison exercise. Two reference measuring instruments, 22 active and 159 passive measuring instruments. The active measuring instruments formed 6 types of instruments and as passive radon detectors were 7 different types used from the participants. The positioning of the radon measuring instruments and detectors in the radon calibration laboratory was executed in regard to statistic points of view. From the active measuring instruments 17 could qualify and from the passive methods six from eight participants were in compliance to the given criteria. Radon measurements, which could have financial and economics relating implications (e.g. architectural redevelopment or

Online imaging of initial DNA damages at the PTB microbeam

International Nuclear Information System (INIS)

Giesen, U.; Langner, F.; Mielke, C.; Mosconi, M.; Dirks, W. G.

2011-01-01

In an inter-disciplinary collaboration of Physikalisch-Technische Bundesanstalt (PTB), German Collection of Microorganisms and Cell Cultures (DSMZ) and Heinrich-Heine Univ., live-cell imaging has been established at the charged-particle microbeam facility of PTB. Candidate genes participating in DNA strand-break repair pathways such as PARP-1, MRE11, MSH2, MDC1 and p53BP1 have been modified to generate fluorescent fusion proteins. Using multi-cistronic expression vectors, stable genomic integration was achieved in HT-1080 fibroblasts. The aim of this study is to characterise and use these highly reliable cell lines for studying initial steps of DNA damage responses and kinetics of repair after microbeam irradiation with high- and low-linear energy transfer (LET) particles in living cells at physiological conditions. (authors)

Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo

OpenAIRE

Br?nnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Rapha?l; Br?uer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

2016-01-01

International audience; Our goal was the visualizing the vascular damage and acute inflammatory response to micro-and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25– 100 μm wide) and minibeams (200–800 μm wide) on vasculature, inflammation and surro...

Radon in geological medium

Energy Technology Data Exchange (ETDEWEB)

Hricko, J [GEOCOMPLEX, a.s., Bratislava (Slovakia)

1996-12-31

The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a{sub v} has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km{sup 2}. The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a{sub v} > 50 kBq/m{sup 3}). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs.

Radon in geological medium

International Nuclear Information System (INIS)

Hricko, J.

1995-01-01

The paper presented deals with behavior of the radon in geological medium and with some results of the radon survey in Bratislava and Kosice regions. 1) The a v has been detected in the holes 0.80 m deep. The density of observations - 3 reference areas (one represents 20 stations) per 1 km 2 . The radon risk maps in 1:25000 and 1:50000 scales have been compiled. The 56.8% of the project area lies in low radon risk, 37.6% in medium radon risk and 5.6% in high radon risk. Follow-up monitoring of the equivalent volume radon activity (EVRA) at the flats, located in the areas with high radon risk of the surface layer, has showed values several times higher than Slovak limits (Marianka, Raca, Vajnory). The evidence that neotectonic is excellent medium for rising up emanation to the subsurface layer, is shown on the map. The tectonic zone of Liscie udolie in Bratislava-Karlova Ves area has been clearly detected by profile radon survey (a v > 50 kBq/m 3 ). 2) At present, northern half of the area of Kosice in question was covered by radon survey. The low and medium radon risks have been observed here, while localities with high radon risk are small in extent. The part of radon risk and soil permeability map from northern Kosice area is shown. (J.K.) 3 figs., 2 refs

Nonlinear behavior of capacitive micro-beams based on strain gradient theory

International Nuclear Information System (INIS)

Fathalilou, Mohammad; Sadeghi, Morteza; Rezazadeh, Ghader

2014-01-01

This paper studies the size dependent behavior of materials in MEMS structures. This behavior becomes noticeable for a structure when the characteristic size such as thickness or diameter is close to its internal length-scale parameter and is insignificant for the high ratio of the characteristic size to the length-scale parameter, which is the case of the silicon base micro-beams. However, in some types of micro-beams like gold or nickel bases, the size dependent effect cannot be overlooked. In such cases, ignoring this behavior in modeling will lead to incorrect results. Some previous researchers have applied classic beam theory on their models and imposed a considerable hypothetical value of residual stress to match their theoretical results with the experimental ones. The equilibrium positions or fixed points of the gold and nickel micro-beams are obtained and shown that for a given DC voltage, there is a considerable difference between the obtained fixed points using classic beam theory, modified couple stress theory, and modified strain gradient theory. In addition, it is shown that the calculated static and dynamic pull-in voltages using higher order theories are much closer to the experimental results and are higher several times than those obtained by classic beam theory.

Radiation exposure due to radon and radon daughters

International Nuclear Information System (INIS)

Ullmann, W.

1976-01-01

Underground miners working over long periods of time in mines with a high content of radon and radon daughters belong to that group of occupationally exposed persons who are subject to the greatest somatic risk, with values especially high if the permissible dose limits are exceeded. Follwing an overview of the permissible limits currently in use for radon and radon daughters as well as the results of examinations performed in nationally-owned underground mining of the G.D.R., considerations are presented on the measuring quantities requisite for statistical, control and safety measurements in this field. Finally, conclusions are drawn concerning the measuring procedures and instruments to be employed for practical work. (author)

BGS Radon Protective Measures GIS

International Nuclear Information System (INIS)

Appleton, D.; Adlam, K.

2000-01-01

The British Geological Survey Radon Protective Measures Geographical Information System is described. The following issues are highlighted: Identification of development sites where radon protection is required in new dwellings; Mapping radon potential on the basis of house radon and geology; Radon Protective Measures GIS; Radon site reports; and Follow-up radon protective measures sire reports

Heavy Ion Microbeam and Broadbeam Transients in SiGe HBTs

Science.gov (United States)

Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Dodd, Paul E.; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philippe; Duhamel, Olivier; Phillips, Stanley D.;

Integral measurement system for radon

International Nuclear Information System (INIS)

Garcia H, J.M.; Pena E, R.

1996-01-01

The Integral measurement system for Radon is an equipment to detect, counting and storage data of alpha particles produced by Radon 222 which is emanated through the terrestrial peel surface. This equipment was designed in the Special Designs Department of the National Institute of Nuclear Research. It supplies information about the behavior at long time (41 days) on each type of alpha radiation that is present into the environment as well as into the terrestrial peel. The program is formed by an User program, where it is possible to determine the operation parameters of a portable probe that contains, a semiconductor detector, a microprocessor as a control central unit, a real time clock and calendar to determine the occurred events chronology, a non-volatile memory device for storage the acquired data and an interface to establish the serial communications with other personal computers. (Author)

Occurrence of radon in the Polish underground tourist routes

Directory of Open Access Journals (Sweden)

Jerzy Olszewski

2015-08-01

Full Text Available Background: There are about 200 underground tourist routes in Poland. There are caves, mines or underground structures. This paper presents the results of the research intended to identify the extent of the occurrence of radon concentrations in underground areas of tourist routes. Material and Methods: We conducted the measurement of periodic concentrations of radon (1–2 months in the summer using type Tastrak trace detectors. We determined the average concentrations of radon in air in 66 underground tourist routes in Poland. Results: The research results comprise 259 determinations of average radon concentrations in 66 routes. The arithmetic average of the results was 1610 Bqm–3, and the maximum measured concentration was over 20 000 Bqm–3. The minimum concentration was 100 Bqm–3 (threshold method considering the arithmetic average of the measurements. It was found that in 67% of the routes, the average concentration of radon has exceeded 300 Bqm–3 and in 22 underground routes it exceeded 1000 Bqm–3. Conclusions: Radon which occurs in many Polish underground tourist routes may be an organizational, legal and health problem. It is necessary to develop a program of measures to reduce radon concentrations in underground routes, especially routes located in the former mines. Med Pr 2015;66(4:557–563

Radon testing in schools in New York State: a 20-year summary

International Nuclear Information System (INIS)

Kitto, Michael

2014-01-01

For nearly 20 years the Department of Health has conducted programs to assist in the measurement and reduction of indoor radon concentrations in 186 schools located primarily in Zone 1 areas of New York State. Although many schools had few or no rooms containing radon above 148 Bq/m 3 , some rooms had >740 Bq/m 3 and remediation techniques were utilized to reduce exposure. Short-term radon measurements in the schools showed little correlation to basement and first-floor radon results from single-family homes in the towns. - Highlights: • Relatively few schools in New York State have been tested for indoor radon. • We provide a summary of radon-testing results for measured schools. • The radon potential in schools is often less than in local houses. • Short-term measurement results exceeded their long-term counterparts in nearly every case

Quality assurance for radon exposure chambers at the National Air and Radiation Environmental Laboratory, Montgomery, Alabama

Energy Technology Data Exchange (ETDEWEB)

Semler, M.O.; Sensintaffar, E.L. [National Air and Radiation Environmental Laboratory, Montgomery, AL (United States)

1993-12-31

The Office of Radiation and Indoor Air, U.S. Environmental Protection Agency (EPA), operates six radon exposure chambers in its two laboratories, the National Air and Radiation Environmental Laboratory (NAREL) in Montgomery, Alabama, and the Las Vegas Facility, Las Vegas, Nevada. These radon exposure chambers are used to calibrate and test portable radon measuring instruments, test commercial suppliers of radon measurement services through the Radon Measurement Proficiency Program, and expose passive measurement devices to known radon concentrations as part of a quality assurance plan for federal and state studies measuring indoor radon concentrations. Both laboratories participate in national and international intercomparisons for the measurement of radon and are presently working with the National Institute of Standards and Technology (NIST) to receive a certificate of traceability for radon measurements. NAREL has developed an estimate of the total error in its calibration of each chamber`s continuous monitors as part of an internal quality assurance program. This paper discusses the continuous monitors and their calibration for the three chambers located in Montgomery, Alabama, as well as the results of the authors intercomparisons and total error analysis.

Influence of squeeze film damping on the higher-order modes of clamped–clamped microbeams

KAUST Repository

Alcheikh, Nouha

2016-05-06

This paper presents an experimental study and a finite-element analysis of the effect of squeeze film damping on the resonance frequency and quality factor of the higher-order flexure vibrations modes of clamped-clamped microbeams. Viscoelastic and silicon nitride microbeams are fabricated and are electrostatically actuated by various electrode configurations to trigger the first, second, and third modes. The damping characteristic and the resonance frequency of these modes are examined for a wide range of gas pressure and electrostatic voltage loads. The results of the silicon nitride beams and viscoelastic beams are compared. It is found that the intrinsic material loss is the major dissipation mechanism at low pressure for the viscoelastic microbeams, significantly limiting their quality factor. It is also found that while the silicon nitride beams show higher quality factors at the intrinsic and molecular regimes of pressure, due to their low intrinsic loss, their quality factors near atmospheric pressure are lower than those of the viscoelastic microbeams. Further, the higher-order modes of all the beams show much higher quality factors at atmospheric pressure compared to the first mode, which could be promising for operating such resonators in air. Experimental results and finite element model simulations show good agreement for resonance frequency and quality factor for the three studied modes. © 2016 IOP Publishing Ltd.

Radon and cancer

International Nuclear Information System (INIS)

2011-01-01

This publication proposes an overview on what is known about the carcinogenic effect of radon. It recalls the origin of radon, its presence in the environment, and its radioactivity. It comments data on the relationship between exposure to radon and lung cancer, and with other forms of cancer. It discusses the role of the exposure level, and the cases of professional and domestic exposure with respect to these risks. It indicates the hazardous areas in France which are well identified, outlines that smokers are more likely victims of risks related to radon, that this risk is still underrated and underestimated (notably by the public). It gives an overview of existing regulations regarding exposure to radon, of public health policies and national plans concerning radon, and recalls some WHO recommendations

Risk assessment and control management of radon in drinking water

International Nuclear Information System (INIS)

Mills, W.A.

1990-01-01

The role of risk assessment and risk management of radon in drinking water was reviewed. It is noted that risk assessments for the public health consequences of radon in drinking water require information on radon concentration in water, exposure pathways, and dose-response relationships. On the other hand, risk management involves assumptions of risk acceptance and the establishment of governmental policies in accord with society's acceptance of these assumptions. Although risk assessment for radon exposures can be reasonably qualitative, risk management is clearly judgmental. The following conclusions/recommendations were made. (1) The presence of radon in drinking water is estimated to have its greatest health impact on the 18% of the US population served by private wells. (2) Although no direct evidence exists associated radon in water with health problems, the diseases that are associated with radon in drinking water are stomach cancer from ingestion and lung cancer from inhalation of radon decay products released during household use of water. (3) Using a number of questionable assumptions, the total number of cancer deaths per year attributable to radon in water is estimated to be about 5,000 as a maximum value, with essentially all cases occurring in the population served by private wells. (4) Promulgating federal regulations to control radon levels in water under the Safe Drinking Water Act seems unwarranted, since private wells would not likely be regulated. (5) Government control programs should be limited to emphasizing an awareness of possible substantially higher than average levels of radon in water in certain geological areas. 12 refs., 4 tabs

Energy deposition and radiation quality of radon and radon daughters. Final report

International Nuclear Information System (INIS)

Karam, L.R.; Caswell, R.S.

1996-01-01

This program was aimed at creating a quantitative physical description, at the micrometer and nanometer levels, of the physical interactions of the alpha particles from radon and its daughters with cells at risk in the bronchial epithelium. The authors calculated alpha-particle energy spectra incident upon the cells and also energy deposition spectra in micrometer- and nanometer-sized sites as a function of cell depth, site size, airway diameter, activities of 218 Po and 214 Po, and other parameters. These data are now being applied, using biophysical models of radiation effects, to predict cell killing, mutations, and cell transformation. The model predictions are then compared to experimental biophysical, biochemical, and biological information. These studies contribute to a detailed understanding of the mechanisms of the biological effectiveness of the radiations emitted by radon and its progeny

Radon awareness in Ireland: a assessment of the effectiveness of radon road shows

International Nuclear Information System (INIS)

Synnott, H.

2006-01-01

Full text: In late 2004 the Radiological Protection Institute of Ireland (R.P.I.I.) initiated a series of radon road shows in areas designated as High Radon Areas 1 in the R.P.I.I. s national radon survey of homes. The main objective of these road shows was to provide information to a local audience on the risks of exposure to radon. These road shows target both employers and householders. Each road show has the same general format. A presentation and/or meeting with a major employer representative group within the area. The purpose is to make employers aware of the risks associated with exposure to radon in the workplace and to highlight their obligations under current Irish health and safety legislation regarding radon in the workplace. An information stand on radon manned by R.P.I.I. staff members in a local shopping centre or other similar area. This provides those concerned about radon with accessible information on radon exposure risks, how to measure radon and the steps a home owner could take to reduce radon concentrations where necessary. Where possible R.P.I.I. staff members visit one or more schools in the general area. A short presentation on radon was given to students and students were given an opportunity to asks questions Maximizing media exposure to publicize our visits is vital to the success of these visits. Each visit is preceded by a Press Release whose main aim is to brief local and national media on the radon issue so as to achieve maximum publicity mainly through radio and television coverage. In general the media are very interested in the whole radon area and R.P.I.I. staff members have given 57 radio and 10 television interviews to date since the commencement of this initiative. The four road shows carried out to date have been successful in encouraging householders to carry out radon measurements. Since the start of the road shows to the present, the R.P.I.I. has seen a 44% increase in the number of householders requesting radon

Diagnosis of spatial resolution for microbeam scanning PIXE using STIM method and CR-39 track detector in PASTA

International Nuclear Information System (INIS)

Hamano, T.; Imaseki, H.; Yukawa, M.; Ishikawa, T.; Iso, H.; Matsumoto, K.

2003-01-01

In PIXE analysis system and Tandem Accelerator facility (PASTA) of NIRS, we are using Scanning Transmission Ion Microscopy (STIM) method and solid track detector to diagnose the spatial resolution of scanning microbeam PIXE analysis system. These methods are widely used by many microbeam facilities. (author)

Project Radon

International Nuclear Information System (INIS)

Ekholm, S.

1988-01-01

The project started in March 1987. The objective is to perform radon monitoring in 2000 dwellings occupied by people employed by State Power Board and to continue to contribute to the development of radon filters. The project participates in developing methods for radon measurement and decontamination and in adapting the methods to large scale application. About 400 so called radon trace measurements (coarse measurement) and about 10 action measurements (decontamination measurement) have been made so far. Experience shows that methods are fully applicable and that the decontamination measures recommended give perfectly satisfactory results. It is also established that most of the houses with high radon levels have poor ventilation Many of them suffer from moisture and mould problems. The work planned for 1988 and 1989 will in addition to measurements be directed towards improvement of the measuring methods. An activity catalogue will be prepared in cooperation with ventilation enterprises. (O.S.)

A Radon Chamber without Radium Source for Detector Calibration and Radon Measurements

International Nuclear Information System (INIS)

Al-Azmi, D.; Karunakara, N.

2008-01-01

A radon chamber of volume 216 liters was designed and constructed for calibration of radon detectors and radon test measurements. The main feature of this chamber is that the active 226 Ra source, to generate the 222 Rn inside the chamber volume, is not required. Instead, 222 Rn from soil gas is utilized for this purpose. The supply of radon comes from the soil gas. Soil gas is drawn from the soil to fill the chamber with high radon concentration levels (∼ 80 kBq/m3). Desired radon concentration levels can be obtained by drawing the soil gas for different time durations and/or flow rate (author)

Radon reduction in waterworks

International Nuclear Information System (INIS)

Raff, O.; Haberer, K.; Wilken, R.D.; Funk, H.; Stueber, J.; Wanitschek, J.; Akkermann-Kubillus, A.; Stauder, S.

2000-01-01

The removal of radon from water using water aeration is one of the most effective methods for reducing radon in waterworks. Therefore, this report describes investigations on packed tower columns and shallow aeration devices and a method for mathematical modelling of gas exchange processes for dimensioning packed tower columns for radon removal. Moreover, possibilities for removing radon using active carbon filtration under waterworks typical conditions and for reducing indoor radon levels in waterworks are discussed. Finally, conclusions on the necessity of radon removal in German waterworks are drawn. (orig.) [de

Low-cost Radon Reduction Pilot Study

Energy Technology Data Exchange (ETDEWEB)

Rose, William B. [Univ. of Illinois, Urbana-Champaign, IL (United States); Francisco, Paul W. [Univ. of Illinois, Urbana-Champaign, IL (United States); Merrin, Zachary [Univ. of Illinois, Urbana-Champaign, IL (United States)

2015-09-01

The U.S. Department of Energy's Building America research team Partnership for Advanced Residential Retrofits conducted a primary scoping study on the impact of air sealing between the foundation and the living space on radon transport reduction across the foundation and living space floor assembly. Fifteen homes in the Champaign, Illinois, area participated in the study. These homes were instrumented for hourly continuous radon measurements and simultaneous temperature and humidity measurements. Blower door and zone pressure diagnostics were conducted at each house. The treatments consisted of using air-sealing foams at the underside of the floor that separated the living space from the foundation and providing duct sealing on the ductwork that is situated in the foundation area. The hypothesis was that air sealing the floor system that separated the foundation from the living space should better isolate the living space from the foundation; this isolation should lead to less radon entering the living space from the foundation. If the hypothesis had been proven, retrofit energy-efficiency programs may have chosen to adopt these isolation methods for enhanced radon protection to the living space.

Operation manual of microbeam system in Takasaki for biological application (MiST-BA)

International Nuclear Information System (INIS)

Sakashita, Tetsuya; Yokota, Yuichiro; Wada, Seiichi; Funayama, Tomoo; Kobayashi, Yasuhiko

2004-03-01

Microbeam System is a powerful tool for micro-radiosurgery studies and direct investigation of cell-to-cell communications such as 'bystander effects'. Microbeam system in Takasaki for biological application (MiST-BA) has been developed for several years and applied to some cases. There were fate mapping of the cellular blastoderm stage egg of the silkworm and bystander effects such as inhibition of cell proliferation, induction of micronuclei, and so on. The aim of this report (operation manual) is to provide a simple and easy usage of MiST-BA for current and new users. MiST-BA consists of three parts; (1) Offline microscope control system for cell-finding. (2) Online microscope control system for cell-targeting and irradiating, and (3) Beam shutter control system for cell irradiation with a precise number of heavy ions. The report presents the outline of MiST-BA, the operation protocol of each part, examples of a microbeam irradiation experiment using CHO-K1 cells, silkworm eggs, and Tobacco protoplast cells, and Trouble shooting. (author)

Reasons for increasing radon concentrations in radon remediated houses

International Nuclear Information System (INIS)

Clavensjoe, B.

1997-01-01

The study comprises 31 single-dwelling houses where remedial actions were carried out in the 1980s. In all of them the radon concentrations have increased more than 30% according to recent control measurements. Radon sources are building material as well as the soil. The remedial actions dealt with ventilation systems, leakage through the basement floor, air cushions, sub-slab suction or radon wells according to the original problems. Causes for the increase varied: In many houses with soil radon problems, the installation of a normal mechanical ventilation system is not a good remedial action. In some houses on a ground with high permeability and high radon content in the soil air, the radon concentration may increase by the lowering of the indoor air pressure. In other houses the increase was a measurement effect, where sites/rooms were confused. Living related causes were identified in a number of cases, where fan speeds were reduced for energy conservation/noise reduction purposes or different use of windows airing had occurred. Extension of the dwelling space without changing the ventilation system caused the increase in one house. 23 refs

Mortality and indoor radon daughter concentrations in 13 Canadian cities

International Nuclear Information System (INIS)

Letourneau, E.G.; Wigle, D.T.

1980-01-01

A study was carried out to determine if lung cancer and general mortality rates in 13 Canadian cities were significantly correlated with average indoor radon daughter concentrations. The radon daughter measurements were obtained from a study of 10,000 homes chosen in a statistically valid grab sample basis. Cancer deaths by year of death, sex, age, and cause were retrieved for each of the cities for the period 1957-1976. Age specific and age standardized mortality rates were calculated. The results showed no evidence of any substantial association between general or lung cancer mortality rates and indoor radon daughter concentrations. The limitations of this study and the feasibility of a common international program of epidemiology of radon daughter exposure are discussed. A proposal is made for the use of case control studies of lung cancer to assess the relative importance of smoking, occupational and domestic exposure to radon daughters

Radon-daughter exposures in energy-efficient buildings

International Nuclear Information System (INIS)

Nero, A.V.; Berk, J.V.; Boegel, M.L.; Hollowell, C.D.; Ingersoll, J.G.; Nazaroff, W.W.

1981-10-01

A radon concentration of 1 pCi/1 (37 Bq/m 3 ) appears to lie in the range that is typical for air inside US residential buildings. Moreover, some US residences have concentrations higher than 1 pCi/1, sometimes by an order of magnitude, implying significant individual risk to occupants. For typical radon daughter equilibrium ratios, this concentration corresponds to a radon daughter exposure rate of 0.2 working level months (WLM) per year. This exposure rate may account for a significant lung cancer incidence if data on lung cancers per unit exposure in miners are applicable to such low exposures. Reductions in air exchange rates may rise the typical exposure rate and even increase it to unacceptable levels in some cases. Measures that reduce energy use by reducing natural infiltration or mechanical ventilation in new or retrofit buildings are therefore undergoing severe scrutiny. Lawrence Berkeley Laboratory has performed measurements in buildings specifically designed to use energy efficiently or utilize solar heating. In many of these buildings radon concentrations appear to arise primarily from soil underlying the buildings. Measures to control higher levels, e.g., by mechanical ventilation with heat recuperation, appear to be economical. However, to evaluate energy-saving programs adequately requires a much more comprehensive characterization of radon sources (for example, by geographical area) and a much fuller understanding of the dynamics of radon and its daughters indoors than now exist

[Estimation of effective doses derived from radon in selected SPA centers that use geothermal waters based on the information of radon concentrations].

Science.gov (United States)

Walczak, Katarzyna; Zmyślony, Marek

2013-01-01

Geothermal waters contain, among other components, soluble radon gas. Alpha radioactive radon is a health hazard to humans, especially when it gets into the respiratory tract. SPA facilities that use geothermal water can be a source of an increased radiation dose to people who stay there. Based on the available literature concerning radon concentrations, we assessed exposure to radon among people - workers and visitors of Spa centers that use geothermal waters. Radon concentrations were analyzed in 17 geothermal centers: in Greece (3 centers), Iran (5), China (4) and India (5). Doses recived by people in the SPA were estimated using the formula that 1 hour exposure to 1 Bq/m3 of radon concentration and equilibrium factor F = 0.4 corresponds to an effective dose of 3.2 nSv. We have found that radon levels in SPAs are from a few to several times higher than those in confined spaces, where geothermal waters are not used (e.g., residential buildings). In 82% of the analyzed SPAs, workers may receive doses above 1 mSv/year. According to the relevant Polish regulations, people receiving doses higher than 1 mSv/year are included in category B of radiation exposure and require regular dosimetric monitoring. Doses received by SPA visitors are much lower because the time of their exposure to radon released from geothermal water is rather short. The analysis of radon concentration in SPA facilities shows that the radiological protection of people working with geothermal waters plays an important role. It seems reasonable to include SPA workers staying close to geotermal waters into a dosimetric monitoring program.

Indoor radon measurements and radon prognosis for the province of Kymi, southeastern Finland

International Nuclear Information System (INIS)

Pennanen, M.; Maekelaeinen, I.; Voutilainen, A.

1996-12-01

The purpose of the regional radon prognosis is to classify areas with different levels of radon risk. The radon prognosis gives the percentages of future homes expected to have indoor radon concentrations exceeding the levels of 200 and 400 Bq/m 3 . It is assumed that no protection against the entry of radon is used in construction. In this study about 5900 indoor radon measurements made in single family houses, semi-detached houses and row houses were used. Data on the location, geology and construction of buildings were determined from maps and questionnaires. An empirical statistical model, the adjusted indoor radon measurements and geological data were used to assess the radon risk from soil and bedrock in different areas. The building sites of the province of Kymi were divided into thirteen sub-areas. The radon prognosis are calculated for the most radon-prone foundation types including 1) houses with a slab-on-grade and 2) houses with a basement or hillside houses with open stairwells between basement and first floor. The radon levels are generally greater in the western part of the area. The radon risk is highest in gravel-dominated esker areas in southwestern, western (in Pyhtaa, Kotka, Anjalankoski, litti, Valkeala) and central (Taipalsaari) parts of the area. The radon risk is also high in some bedrock and till areas, also in southwestern and western parts of the area. In these areas the level of 200 Bq/m 3 will be exceeded in 80 % of new houses. About half of the future houses in these areas will have indoor radon concentrations exceeding 400 Bq/m 3 . The radon risk is lowest in the eastern part of the province of Kymi in every soil type. In this area the level of 200 Bq/m 3 will be exceeded in 30 % of new houses. Below 10 % will exceed 400 Bq/m 3 . (orig.) (14 refs.)

Instruments to measure radon-222 activity concentration or exposure to radon-222. Intercomparison 2014

International Nuclear Information System (INIS)

Foerster, Elisabeth; Beck, Thomas; Buchroeder, Helmut; Doering, Joachim; Schmidt, Volkmar

2014-10-01

According to the Directive 96/29/EURATOM the monitoring of occupational radiation exposures shall base on individual measurements carried out by an approved dosimetric service. Pursuant to the European Directive an approved dosimetric service is a body responsible for the calibration, reading or interpretation of individual monitoring devices.., whose capacity to act in this respect is recognized by the competent authorities. This concept will also be applied to radon services issuing passive radon measurement devices. Passive radon measurement devices 1 using solid state nuclear track detectors or electrets are recommended for individual monitoring of exposures to radon. German regulations lay down that radon measuring devices are appropriate for purposes of occupational radiation monitoring if the devices are issued by recognized radon measurement services, and the measurement service submits devices of the same type issued for radon monitoring to regular intercomparisons conducted by the Bundesamt fuer Strahlenschutz (BfS). A radon measuring service is recognized by the competent authority if it proves its organisational and technical competence, e. g. by accreditation. These regulations have been introduced in the area of occupational radiation exposures. Nevertheless, it is recommended that radon measuring services which carry out radon measurements in other areas (e.g. dwellings) should subject themselves to these measures voluntarily. The interlaboratory comparisons comprise the organization, exposure, and evaluation of measurements of radon activity concentration or exposure to radon. The comparisons only concern radon-222; radon-220 is not in the scope. Radon services being interested can get further information from the European Information System on Proficiency Testing Schemes (EPTIS) and from the BfS websites.

Radon in workplaces

International Nuclear Information System (INIS)

Reichelt, A.; Lehmann, K.-H.; Reineking, A.; Porstendoerfer, J.; Schwedt, J.; Streil, T.

2000-01-01

The radiological assessment of the results of radon measurements in dwellings is not automatically applicable to workplaces due to different forms of utilization, constructional conditions, time of exposure, heating and ventilation conditions, additional aerosol sources, aerosol parameters, chemical substances, etc. In order to investigate the peculiarities of the radon situation in workplaces located inside buildings compared with that in dwellings, long-time recordings of radon, attached radon progeny and unattached radon progeny concentrations ( 218 Po, 214 Pb, 214 Bi) are carried out at several categories of workplaces (e.g. offices, social establishments, schools, production rooms, workshops, kitchens, agricultural facilities). 36 workplaces have been investigated. There have been carried out at least 2-3 long-time recordings for each workplace during different seasons. At the same time the gamma dose rate, meteorological conditions, aerosol particle concentrations have been registered. Many special dates from the workplaces and the buildings have been recorded. Activity size distribution of the aerosol-attached and unattached fraction of short-lived radon decay products have been determinated in 20 workplaces. Mainly the following measurement systems were used: Radon- and Radon Progeny Monitor EQF 3020, SARAD GmbH, Germany. Alpha-Track Radon Detectors, BfS Berlin, Germany. Screen Diffusion Batteries with Different Screens, University of Goettingen, Germany. Low-Pressure Cascade Impactor, Type BERNER. Condensation Nuclei Counter, General Electric, USA. PAEC-f p -Rn-Monitor, University of Goettingen, Germany. Through the measurements, many peculiarities in the course of the radon-concentration, the equilibrium factor F, the unattached fraction f p and the activity size distribution have been determined. These amounts are influenced mainly by the working conditions and the working intervals. The influence of these peculiarities in workplaces on the dose have

Public perceptions of radon risk

International Nuclear Information System (INIS)

Mainous, A.G. III; Hagen, M.D.

1993-01-01

Since 1984, a significant amount of media attention has focused on health threats from radon gas exposure. Using a probability telephone survey of adults (n = 685), we studied public perceptions of risk from radon exposure versus other environmental health risks. The results indicated that 92% of those individuals who had heard of radon believe radon to be a health risk, although only 4% believe they are currently exposed to high levels of radon gas. Perception of risk from radon was positively related to other perceptions of environmental risks. Younger and less educated individuals were more likely to perceive radon as a health risk. Women were three-and-one-half times as likely as men to perceive risk from radon. However, there was no significant relationship between perceived risk from radon and cigarette smoking. Media attention has apparently led to public awareness of radon hazards, but further attention is needed to improve smokers' awareness of their special risks from radon

Environmental radon

International Nuclear Information System (INIS)

Majumdar, S.K.; Schmalz, R.F.; Miller, E.W.

1990-01-01

This book covers many aspects of environmental radon, including: historical perspectives; occurrence and properties; detection, measurement, and mitigation, radon and health; and political, economic, and legislative impacts

Radon discrimination for work place air samples

International Nuclear Information System (INIS)

Bratvold, T.

1994-01-01

Gross alpha/beta measurement systems are designed solely to identify an incident particle as either an alpha or a beta and register a count accordingly. The tool of choice for radon identification, via decay daughters, is an instrument capable of identifying the energy of incident alpha particles and storing that information separately from detected alpha emissions of different energy. In simpler terms, the desired instrument is an alpha spectroscopy system. K Basins Radiological Control (KBRC) procured an EG ampersand G ORTEC OCTETE PC alpha spectroscopy system to facilitate radon identification on work place air samples. The alpha spectrometer allows for the identification of any alpha emitting isotope based on characteristic alpha emission energies. With this new capability, KBRC will explicitly know whether or not there exists a true airborne concern. Based on historical air quality data, this new information venue will reduce the use of respirators substantially. Situations where an area remains ''on mask'' due solely to the presence of radon daughters on the grab air filter will finally be eliminated. This document serves to introduce a new method for radon daughter detection at the 183KE Health Physics Analytical Laboratory (HPAL). A new work place air sampling analysis program will be described throughout this paper. There is no new technology being introduced, nor any unproven analytical process. The program defined over the expanse of this document simply explains how K Basins Radiological Control will employ their alpha spectrometer

Modelling of radon control and air cleaning requirements in underground uranium mines

International Nuclear Information System (INIS)

El Fawal, M.; Gadalla, A.

2014-01-01

As a part of a comprehensive study concerned with control workplace short-lived radon daughter concentration in underground uranium mines to safe levels, a computer program has been developed and verified, to calculate ventilation parameters e.g. local pressures, flow rates and radon daughter concentration levels. The computer program is composed of two parts, one part for mine ventilation and the other part for radon daughter levels calculations. This program has been validated in an actual case study to calculate radon concentration levels, pressure and flow rates required to maintain acceptable levels of radon concentrations in each point of the mine. The required fan static pressure and the approximate energy consumption were also estimated. The results of the calculations have been evaluated and compared with similar investigation. It was found that the calculated values are in good agreement with the corresponding values obtained using ''REDES'' standard ventilation modelling software. The developed computer model can be used as an available tool to help in the evaluation of ventilation systems proposed by mining authority, to assist the uranium mining industry in maintaining the health and safety of the workers underground while efficiently achieving economic production targets. It could be used also for regulatory inspection and radiation protection assessments of workers in the underground mining. Also with using this model, one can effectively design, assess and manage underground mine ventilation systems. Values of radon decay products concentration in units of working level, pressures drop and flow rates required to reach the acceptable radon concentration relative to the recommended levels, at different extraction points in the mine and fan static pressure could be estimated which are not available using other software. (author)

Radon thematic days - Conference proceedings

International Nuclear Information System (INIS)

2011-03-01

This document brings together the available presentations given at the Radon thematic days organized by the French society of radiation protection (SFRP). Twenty five presentations (slides) are compiled in the document and deal with: 1 - General introduction about radon (Sebastien Baechler, IRA); 2 - Survey of epidemiological studies (Dominique Laurier, IRSN); 3 - Dosimetric model (Eric Blanchardon, Estelle Davesne, IRSN); 4 - Radon issue in Franche-Comte: measurement of the domestic exposure and evaluation of the associated health impact (Francois Clinard, InVS); 5 - WHO's (World Health Organization) viewpoint in limiting radon exposure in homes (Ferid Shannoun, OMS); 6 - Radon measurement techniques (Roselyne Ameon, IRSN); 7 - Quality of radon measurements (Francois Bochud, IRA); 8 - International recommendations (Jean-Francois Lecomte, IRSN); 9 - Radon management strategy in Switzerland - 1994-2014 (Christophe Murith, OFSP); 10 - 2011-2015 action plan for radon risk management (Jean-Luc Godet, Eric Dechaux, ASN); 11 - Radon at work place in Switzerland (Lisa Pedrazzi, SUVA); 12 - Strategies of radiation protection optimization in radon exposure situations (Cynthia Reaud, CEPN); 13 - Mapping of the radon potential of geologic formations in France (Geraldine Ielsch, IRSN); 14 - Radon database in Switzerland (Martha Gruson, OFSP); 15 - Radon 222 in taps water (Jeanne Loyen, IRSN); 16 - Buildings protection methods (Bernard Collignan, CSTB, Roselyne Ameon, IRSN); 17 - Preventive and sanitation measures in Switzerland (Claudio Valsangiacomo, SUPSI); 18 - Training and support approach for building specialists (Joelle Goyette-Pernot, Fribourg engineers and architects' school); 19 - Status of radon bulk activity measurements performed between 2005-2010 in public areas (Cyril Pineau, ASN); 20 - Neuchatel Canton experiments (Didier Racine, SENE); 21 - Montbeliard region experience in the radon risk management (Isabelle Netillard, Pays de Montbeliard Agglomeration); 22

Application of heavy-ion microbeam system at Kyoto University: Energy response for imaging plate by single ion irradiation

International Nuclear Information System (INIS)

Tosaki, M.; Nakamura, M.; Hirose, M.; Matsumoto, H.

2011-01-01

A heavy-ion microbeam system for cell irradiation has been developed using an accelerator at Kyoto University. We have successfully developed proton-, carbon-, fluorine- and silicon-beams in order to irradiate a micro-meter sized area with ion counting, especially single ion irradiation. In the heavy-ion microbeam system, an imaging plate (IP) was utilized for beam diagnostics on the irradiation. The IP is widely used for radiography studies in biology. However, there are a few studies on the low linear energy transfer (LET) by single ions, i.e., low-intensity exposure. Thus we have investigated the energy response for the IP, which can be utilized for microbeam diagnostics.

Radon-film-badges by solid radiators to complement track detector-based radon monitors

International Nuclear Information System (INIS)

Tommasino, L.; Tommasino, M.C.; Viola, P.

2009-01-01

Existing passive radon monitors, based on track detectors, present many shortcomings, such as a limited response sensitivity for one-week-indoor measurements and a limited response linearity for the assessment of large radon exposures indoors, in thermal spa, in caves, and in soil. Moreover, for in-soil measurements these monitors are too bulky and are often conducive to wrong results. For what concerns the radon-in-water measurements, they are just not suitable. A new generation of passive radon monitors is introduced in this paper, which are very similar to the compact badges used in neutron- and gamma-dosimetry and will be referred to as radon-film-badges. These film-badges are formed by thin-film radiators with suitable radon-sorption characteristics, facing track detectors. The key strategy adopted for these radiators is to exploit an equilibrium type of radon sorption in solids. Even though this new generation of passive monitors is at its infancy, it appears already clear that said monitors make it finally possible to overcome most of the shortcomings of existing passive radon monitors. These devices are uniquely simple and can be easily acquired by any existing radon service to complement their presently used passive radon monitors with little or no effort.

Radon in buildings

International Nuclear Information System (INIS)

Connell, J.J.

1991-01-01

This guide is intended to inform designers, householders and other building owners about the radon problem and to help in deciding if there is need to take any action to reduce radon levels in their homes or other buildings.It explains what radon is, how it enters buildings and what effect it may have on health. Reference is made to some of the usual ways of reducing the level of radon and guidance is given on some sources of assistance

Radon and its hazards

International Nuclear Information System (INIS)

Chang Guilan

2002-01-01

The author describes basic physical and chemical properties of radon and the emanation, introduces methods of radon measurement, expounds the hazards of non-mine radon accumulation to the health of human being and the protection, as well as the history how the human being recognizes the hazards of radon through the specific data and examples, and finally proposes protecting measures to avoid the hazards of radon to the health of human being, and to do ecologic evaluation of environments

Radon detection system, design, test and performance

International Nuclear Information System (INIS)

Balcazar, M.; Chavez, A.; Pina-Villalpando, G.; Navarrete, M.

1999-01-01

A portable radon detection system (α-Inin) has been designed and constructed for using it in adverse environmental conditions where humidity, temperature and chemical vaporous are present. The minimum integration time is in periods of 15 min during 41 days. A 12 V battery and a photovoltaic module allow the α-Inin autonomy in field measurements. Data is collected by means of a laptop computer where data processing and α-Inin programming are carried out. α-Inin performance was simultaneously tested in a controlled radon chamber, together with a commercial α-Meter

Neurocognitive sparing of desktop microbeam irradiation.

Science.gov (United States)

Bazyar, Soha; Inscoe, Christina R; Benefield, Thad; Zhang, Lei; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

2017-08-11

Normal tissue toxicity is the dose-limiting side effect of radiotherapy. Spatial fractionation irradiation techniques, like microbeam radiotherapy (MRT), have shown promising results in sparing the normal brain tissue. Most MRT studies have been conducted at synchrotron facilities. With the aim to make this promising treatment more available, we have built the first desktop image-guided MRT device based on carbon nanotube x-ray technology. In the current study, our purpose was to evaluate the effects of MRT on the rodent normal brain tissue using our device and compare it with the effect of the integrated equivalent homogenous dose. Twenty-four, 8-week-old male C57BL/6 J mice were randomly assigned to three groups: MRT, broad-beam (BB) and sham. The hippocampal region was irradiated with two parallel microbeams in the MRT group (beam width = 300 μm, center-to-center = 900 μm, 160 kVp). The BB group received the equivalent integral dose in the same area of their brain. Rotarod, marble burying and open-field activity tests were done pre- and every month post-irradiation up until 8 months to evaluate the cognitive changes and potential irradiation side effects on normal brain tissue. The open-field activity test was substituted by Barnes maze test at 8th month. A multilevel model, random coefficients approach was used to evaluate the longitudinal and temporal differences among treatment groups. We found significant differences between BB group as compared to the microbeam-treated and sham mice in the number of buried marble and duration of the locomotion around the open-field arena than shams. Barnes maze revealed that BB mice had a lower capacity for spatial learning than MRT and shams. Mice in the BB group tend to gain weight at the slower pace than shams. No meaningful differences were found between MRT and sham up until 8-month follow-up using our measurements. Applying MRT with our newly developed prototype compact CNT-based image-guided MRT system

Development of the Jyvaeskylae microbeam facility

Energy Technology Data Exchange (ETDEWEB)

Norarat, Rattanaporn, E-mail: rattanaporn.norarat@phys.jyu.fi [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Sajavaara, Timo; Laitinen, Mikko; Heikkinen, Pauli; Ranttila, Kimmo; Ylikorkala, Kari; Haenninen, Vaeinoe; Rossi, Mikko; Jones, Pete [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Marjomaeki, Varpu; Gilbert, Leona [Department of Environmental and Biological Sciences, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland); Whitlow, Harry J. [Department of Physics, University of Jyvaeskylae, P.O. Box 35 (YFL), FIN-40014 Jyvaeskylae (Finland)

2012-02-01

Research highlights: Black-Right-Pointing-Pointer A MeV ion microbeam for biomedical materials research is being developed. Black-Right-Pointing-Pointer High accuracy scanning using electrostatic post-focus deflection. Black-Right-Pointing-Pointer Imaging and direct lithographic image writing using time-stamping methods. Black-Right-Pointing-Pointer New scanning modes and fluorescence detectors permit low ion-fluence cell imaging. Black-Right-Pointing-Pointer Thermal compensated beam-line support design for high positional accuracy. - Abstract: A new microbeam facility is being constructed at the 1.7 MV Pelletron Accelerator in Jyvaeskylae. The facility is designed for easy upgrading and incorporates a number of innovative features. Initially, it is based on a Heidelberg doublet with a design capability of a 3 Multiplication-Sign 5 {mu}m beamspot at PIXE intensities and later upgraded to nanobeam performance. A thermal-expansion compensated rigid frame mounted on a mechanically isolated floor section is used to support the ion optical components. A compact-post focusing electrostatic deflector is used for high linearity beam scanning. This together with a novel time-stamped data collection (TDC) allows dynamic effects in IBIC, fluorescence bleaching to be studied as well as facilitating multi-resolution image support for low-fluence imaging of cells. The target chamber is fitted with a novel low-cost large working distance optical microscope, extremely compact large solid angle photon detectors as well as conventional secondary electron, PIXE and Scanning Transmission Ion Microscopy (STIM) detectors.

Radon/radon-daughter measurement methods and instrumentation

International Nuclear Information System (INIS)

Rock, R.L.

1977-01-01

Radon-daughter measurement equipment and techniques have been continuously improved over the last 25 years. Improvements have been in the areas of accuracy, time and convenience. We now have miniaturized scalers and detectors available for measuring the alpha particle count rates from aerosol samples collected on filter papers. We also have small lightweight efficient pumps for conveniently collecting samples and we have various counting methods which allow us to choose between making very precise measurements or nominal measurements. Radon-daughter measurement methods used in uranium mines and mills are discussed including a personal radon-daughter-exposure integrating device which can be worn by miners

Piezoelectric transduction of flexural modes in pre-stressed microbeam resonators

NARCIS (Netherlands)

Torri, G.B.; Janssen, N.M.A.; Zeng, Z.; Rottenberg, X.; Karabacak, D.M.; Vandecasteele, M.; Hoof, C.V.; Puers, R.; Tilmans, H.A.C.

2014-01-01

This paper reports on the optimization of the design of piezoelectric transducer elements integrated on doubly-clamped microbeam resonators utilized as (bio)chemical sensors. We report and emphasize the often forgotten influence of membrane stresses on defining the dimensions and optimal position of

Radon level and radon effective dose rate determination in Moroccan dwellings using SSNTDs

International Nuclear Information System (INIS)

Oufni, L.; Misdaq, M.A.; Amrane, M.

2005-01-01

Inhalation of radon ( 222 Rn) and its daughter product are a major source of natural radiation exposure. The measurement of radon activity in dwelling is assuming ever increasing importance. It is known from recent surveys in many countries that radon and its progeny contribute significantly to total inhalation dose and it is fairly established that radon when inhaled in large quantity causes lung disorder. Keeping this in view, the indoor radon activity level and radon effective dose rate were carried out in the dwellings of Beni-Mellal, Khouribgra and Ben Guerir cities, Morocco, using the solid state nuclear track detectors (SSNTD) technique. Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, we found that the 222 Rn effective dose rate in the studied dwellings ranges from 1.01 to 7.90mSvy -1 . The radon activity in the corresponding dwellings was found to vary from 40 to 532Bqm -3 . The radon activity has not only been found to vary with seasonal changes, but also with the age, the construction mode of houses, the ventilation conditions and with specific sites and geological materials

Radon therapy; Radon in der Therapie

Energy Technology Data Exchange (ETDEWEB)

Spruck, Kaija [Technische Hochschule Mittelhessen, Giessen (Germany). Inst. fuer Medizinische Physik und Strahlenschutz

2017-04-01

Radon therapies are used since more than 100 years in human medicine. Today this method is controversially discussed due to the possible increase of ionizing radiation induced tumor risk. Although the exact mode of biological radiation effect on the cell level is still not known new studies show the efficiency of the radon therapy without side effect for instance for rheumatic/inflammatory or respiratory disorders.

Estimation of effective doses derived from radon in selected SPA centers that use geothermal waters based on the information of radon concentrations

Directory of Open Access Journals (Sweden)

Katarzyna Walczak

2013-04-01

Full Text Available Background: Geothermal waters contain, among other components, soluble radon gas. Alpha radioactive radon is a health hazard to humans, especially when it gets into the respiratory tract. SPA facilities that use geothermal water can be a source of an increased radiation dose to people who stay there. Based on the available literature concerning radon concentrations, we assessed exposure to radon among people - workers and visitors of Spa centers that use geothermal waters. Material and Methods: Radon concentrations were analyzed in 17 geothermal centers: in Greece (3 centers, Iran (5, China (4 and India (5. Doses recived by people in the SPA were estimated using the formula that 1 hour exposure to 1 Bq/m3 of radon concentration and equilibrium factor F = 0.4 corresponds to an effective dose of 3.2 nSv. Results: We have found that radon levels in SPAs are from a few to several times higher than those in confined spaces, where geothermal waters are not used (e.g., residential buildings. In 82% of the analyzed SPAs, workers may receive doses above 1 mSv/year. According to the relevant Polish regulations, people receiving doses higher than 1 mSv/year are included in category B of radiation exposure and require regular dosimetric monitoring. Doses received by SPA visitors are much lower because the time of their exposure to radon released from geothermal water is rather short. Conclusions: The analysis of radon concentration in SPA facilities shows that the radiological protection of people working with geothermal waters plays an important role. It seems reasonable to include SPA workers staying close to geotermal waters into a dosimetric monitoring program. Med Pr 2013;64(2:193–198

The April 1994 and October 1994 radon intercomparisons at EML

International Nuclear Information System (INIS)

Fisenne, I.M.; George, A.C.; Perry, P.M.; Keller, H.W.

1995-10-01

Quality assurance/quality control (QA/QC) are the backbone of many commercial and research processes and programs. QA/QC research tests the state of a functioning system, be it the production of manufactured goods or the ability to make accurate and precise measurements. The quality of the radon measurements in the US have been tested under controlled conditions in semi-annual radon gas intercomparison exercises sponsored by the Environmental Measurements Laboratory (EML) since 1981. The two Calendar Year 1994 radon gas intercomparison exercises were conducted in the EML exposure chamber. Thirty-two groups including US Federal facilities, USDOE contractors, national and state laboratories, universities and foreign institutions participated in these exercises. The majority of the participant's results were within ±10% of the EML value at radon concentrations of 570 and 945 Bq m -3

Communicating radon risk effectively: a mid-course evaluation. Interim report

International Nuclear Information System (INIS)

Smith, V.K.; Desvousges, W.H.; Fisher, A.; Johnson, F.R.

1987-07-01

A panel of 2300 homeowners was divided into subgroups to test the effectiveness of six alternative ways of explaining the risk from naturally occurring radon gas. The research design focused on two dimensions: qualitative vs. quantitative and directive vs. evaluative. These characteristics led to 4 experimental booklets, which were compared with EPA's Citizen's Guide and a one-page fact sheet. The evaluation examined how much people learned about radon; whether they could form risk perceptions consistent with their home's measured radon level; and whether they felt they had enough information to make a decision about mitigation. The fact sheet did not perform well on any of these evaluation criteria. None of the five booklets clearly was best for all 3 evaluation criteria; the report discusses the implications for designing an effective radon-risk communication program

Development of a Charged Particle Microbeam for Single-Particle Subcellular Irradiations at the MIT Laboratory for Accelerator Beam Application

International Nuclear Information System (INIS)

Yanch, Jacquelyn C.

2004-01-01

The development of a charged particle microbeam for single particle, subcellular irradiations at the Massachusetts Institute of Technology Laboratory for Accelerator Beam Applications (MIT LABA) was initiated under this NEER aeard. The Microbeam apparatus makes use of a pre-existing electrostatic accelerator with a horizontal beam tube

A new paradigm in radioadaptive response developing from microbeam research

International Nuclear Information System (INIS)

Matsumoto, Hideki; Tomita, Masanori; Otsuka, Kensuke; Hatashita, Masanori

2009-01-01

A classic paradigm in radiation biology asserts that all radiation effects on cells, tissues and organisms are due to the direct action of radiation on living tissue. Using this model, possible risks from exposure to low dose ionizing radiation (below 100 mSv) are estimated by extrapolating from data obtained after exposure to higher doses of radiation, using a linear non-threshold model (LNT model). However, the validity of using this dose-response model is controversial because evidence accumulated over the past decade has indicated that living organisms, including humans, respond differently to low dose/low dose-rate radiation than they do to high dose/high dose-rate radiation. These important responses to low dose/low dose-rate radiation are the radiation-induced adaptive response, the bystander response, low-dose hypersensitivity, and genomic instability. The mechanisms underlying these responses often involve bio-chemical and molecular signals generated in response to targeted and non-targeted events. In order to define and understand the bystander response to provide a basis for the understanding of non-targeted events and to elucidate the mechanisms involved, recent sophisticated research has been conducted with X-ray microbeams and charged heavy particle microbeams, and these studies have produced many new observations. Based on these observations, associations have been suggested to exist between the radio-adaptive and bystander responses. The present review focuses on these two phenomena, and summarizes observations supporting their existence, and discusses the linkage between them in light of recent results obtained from experiments utilizing microbeams. (author)

Radon atlas of Finland

International Nuclear Information System (INIS)

Voutilainen, A.; Maekelaeinen, I.; Pennanen, M.; Reisbacka, H.; Castren, O.

1997-11-01

The most efficient means of reducing indoor radon exposure is to locate and mitigate dwellings with radon concentration exceeding the action level of 400 Bq/m 3 and to build new houses so that radon concentrations do not exceed 200 Bq/m 3 . The maps and tables in this report are useful tools for those who plan and decide what kind of radon mitigation measures are needed in municipalities. STUK (The Radiation and Nuclear Safety Authority) has an indoor radon database of 52 000 dwellings, for which the indoor radon concentration and construction details are known. The building site soil type of about 38 000 dwellings is known. This atlas is a summary of all indoor radon measurements made by STUK in lowrise dwellings and in first-floor flats. The results are shown as arithmetic means of 5- or 10-km squares on maps of the provinces. Three radon maps have been made for each province. On one map the data consist of all measurements the position coordinates of which are known. On the two other maps the building sites of houses are classified into permeable and low-permeable soil types. The tables show statistics for all indoor radon measurements by municipality and building site soil type. (orig.)

Scopingreport radon

International Nuclear Information System (INIS)

Blaauboer, R.O.; Vaas, L.H.; Hesse, J.M.; Slooff, W.

1989-09-01

This report contains general information on radon concerning the existing standards, sources and emissions, the exposure levels and effect levels. lt serves as a basis for the discussion during the exploratory melting to be held in November/December 1989, aimed at determining the contents of the Integrated Criteria Document Radon. Attention is focussd on Rn-222 (radon) and Rn-220 (thoron), presently of public interest because of radon gas pollution in private homes. In the Netherlands air quality standards nor product standards for the exhalation rate of building materials have been recommended. The major source of radon in the Netherlands is the soil gas (> 97%), minor sources are phosphate residues and building materials (> 2% in total). Hence, the major concern is the transfer through the inhalation of air, the lung being the most critical organ at risk to develop cancer. Compared to risks for humans, the risks of radon and its daughters for aquatic and terrestric organisms, as well as for agricultural crops and livestock, are assumed to be limited. In the Netherlands the average dose for man due to radon and thoron progeny is appr. 1.2 mSv per year, the estimated dose range being 0.1-3.5 mSv per year. This dose contributes for about 50% to rhe total exposure due to all sources of ionizing radiation. Of this dose respectively 80% is caused by radon and about 90% is received indoor. The estimated dose for the general population corresponds to a risk for inducing fatal cancers of about 15 x 10-6 per year, ranging from 1.2 x 10-6 to 44 x 10-6 which exceeds the risk limit of 1 x 10-6 per year -as defined in the standardization policy in the Netherlands for a single source of ionizing radiation-with a factor 15 (1- 44). Reduction of exposure is only possible in the indoor environment. Several techniques have been described to reduce the indoor dose, resulting from exhalation of the soil and building materials. )aut- hor). 37 refs.; 3 figs.; 8 tabs

Size-dependent dynamic stability analysis of microbeams actuated by piezoelectric voltage based on strain gradient elasticity theory

Energy Technology Data Exchange (ETDEWEB)

Sahmani, Saeid; Bahrami, Mohsen [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

2015-01-15

In the current paper, dynamic stability analysis of microbeams subjected to piezoelectric voltage is presented in which the microbeam is integrated with piezoelectric layers on the lower and upper surfaces. Both of the flutter and divergence instabilities of microbeams with clamped-clamped and clamped-free boundary conditions are predicted corresponding to various values of applied voltage. To take size effect into account, the classical Timoshenko beam theory in conjunction with strain gradient elasticity theory is utilized to develop nonclassical beam model containing three additional internal length scale parameters. By using Hamilton's principle, the higher-order governing differential equations and associated boundary conditions are derived. Afterward, generalized differential quadrature method is employed to discretize the size-dependent governing differential equations along with clamped-clamped and clamped-free end supports. The critical piezoelectric voltages corresponding to various values dimensionless length scale parameter are evaluated and compared with those predicted by the classical beam theory. It is revealed that in the case of clamped-free boundary conditions, the both of flutter and divergence instabilities occur. However, for the clamped-clamped microbeams, only divergence instability takes place.

The effect of natural ventilation on radon and radon progeny levels in houses

International Nuclear Information System (INIS)

Cavallo, A.; Gadsby, K.; Reddy, T.A.; Socolow, R.

1992-01-01

In contradiction to the widely held assumption that ventilation is ineffective as a means of reducing indoor radon concentrations, experiments in a research house have shown that the basement radon level can be reduced by a factor of 5-10 using only natural ventilation. Measurements of the outdoor-basement pressure differential and the radon entry rate show that this unexpectedly large reduction in indoor radon levels is caused by two complementary physical processes. The first mechanism is the obvious one: dilution. Radon concentrations are lowered by the addition of uncontaminated outdoor air. The second mechanism is less evident: an open basement window reduces basement depressurisation. This decreases the rate at which radon-laden soil gas is drawn into the house. It was also found that the radon entry rate is a linear function of basement depressurisation up to a differential pressure of about 4 Pa, as would be expected for laminar soil gas flow; opening two basement windows approximately doubles the building air exchange rate and reduces the radon entry rate by up to a factor of 5. (author)

Effects of geometric nonlinearity in an adhered microbeam for measuring the work of adhesion

Science.gov (United States)

Fang, Wenqiang; Mok, Joyce; Kesari, Haneesh

2018-03-01

Design against adhesion in microelectromechanical devices is predicated on the ability to quantify this phenomenon in microsystems. Previous research related the work of adhesion for an adhered microbeam to the beam's unadhered length, and as such, interferometric techniques were developed to measure that length. We propose a new vibration-based technique that can be easily implemented with existing atomic force microscopy tools or similar metrology systems. To make such a technique feasible, we analysed a model of the adhered microbeam using the nonlinear beam theory put forth by Woinowsky-Krieger. We found a new relation between the work of adhesion and the unadhered length; this relation is more accurate than the one by Mastrangelo & Hsu (Mastrangelo & Hsu 1993 J. Microelectromech. S., 2, 44-55. (doi:10.1109/84.232594)) which is commonly used. Then, we derived a closed-form approximate relationship between the microbeam's natural frequency and its unadhered length. Results obtained from this analytical formulation are in good agreement with numerical results from three-dimensional nonlinear finite-element analysis.

Development of micro-optics for high-resolution IL spectroscopy with a proton microbeam probe

International Nuclear Information System (INIS)

Kada, Wataru; Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro

2014-01-01

Confocal optics for ion luminescence (IL) was developed for the precise analysis of the chemical composition of microscopic targets with an external proton microbeam probe. Anti-reflection-coated confocal micro-lens optics with an effective focus area of approximately 800 × 800 μm was installed on the microbeam line of a single-ended accelerator. Chromatic aberrations of the confocal optics were examined at wavelengths of 300–900 nm. An electrically-cooled back-thinned charge coupled device spectrometer with a wavelength resolution of 0.5 nm was used for the microscopic spectroscopy and IL imaging of microscopic mineral targets. Simultaneous microscopic IL and micro-PIXE analysis were performed using an external 3 MeV H + microbeam with a current of less than 100 pA. A spectral resolution of 3 nm was achieved for a single IL peak which corresponded to Cr 3+ impurities in a single-crystal of aluminum oxide. The use of IL spectroscopy and imaging for aerosol targets revealed microscopic distributions of the chemical and elemental composition in the atmosphere

Radon og boligen

DEFF Research Database (Denmark)

Rasmussen, Torben Valdbjørn

Radon er en radioaktiv og sundhedsskadelig luftart, som ved indånding øger risikoen for lungekræft. Der er ingen dokumenteret nedre grænse for, hvornår radon er ufarligt. Derfor anbefales det, at man tilstræber et så lavt radonindhold i indeluften som muligt. Man kan hverken lugte, se, høre eller...... smage radon, så vil du vide, om du har radon i din bolig, må du måle radonindholdet i indeluften. Radon forekommer naturligt i jorden og kan suges ind sammen med jordluft, hvis der inde er et undertryk, og hvis konstruktionerne mod jord er utætte. Jordluft trænger ind gennem revner og utætte samlinger......, fx omkring rør til kloak, vand og varmeforsyning. Koncentrationen af radon i jorden varierer meget fra sted til sted, også lokalt og gennem året. Tidligere undersøgelser har vist, at der kan forekomme høje koncentrationer i Sydgrønland, specielt i området syd for Narsalik ved Paamiut, 61°30’N....

Radon campaigns. Status report 2008

International Nuclear Information System (INIS)

Arvela, H.; Valmari, T.; Reisbacka, H.; Niemelae, H.; Oinas, T.; Maekelaeinen, I.; Laitinen-Sorvari, R.

2008-12-01

Radon campaigns aim at activating citizens to make indoor radon measurements and remediation as well as increasing the common awareness of indoor radon questions. Indoor radon increases the risk of lung cancer. Through radon campaigns Radiation and Nuclear Safety Authority (STUK) also promotes the attainment of those goals that the Ministry of Social Affairs and Health has set for municipal authorities in Finland for prevention of the harmful effects of radon. The Ministry of Social Affairs and Health supports this campaign. Radon campaigns were started in autumn 2003. By autumn 2008 the campaigns have been organised already in 64 regions altogether in 160 municipalities. In some municipalities they have already arranged two campaigns. Altogether 14 100 houses have been measured and in 2 100 of these the action limit of radon remediation 400 Bq / m 3 has been exceeded. When participating in radon campaigns the house owners receive a special offer on radon detectors with a reduced price. In 2008 a new practice was introduced where the campaign advertisements were distributed by mail to low-rise residential houses in a certain region. The advertisement includes an order / deposit slip with postage paid that the house owner can send directly to STUK to easily make an order for radon measurement. In the previous radon campaigns in 2003 - 2007 the municipal authorities collected the orders from house owners and distributed later the radon detectors. The radon concentrations measured in the campaign regions have exceeded the action limit of 400 Bq / m 3 in 0 - 39% of houses, depending on the region. The total of 15% of all measurements made exceeded this limit. The remediation activities have been followed by sending a special questionnaire on remedies performed to the house owners. In 2006 - 2007 a questionnaire was sent to those households where the radon concentration of 400 Bq / m 3 was exceeded during the two first campaign seasons. Among the households that replied

RECOMMENDED HVAC STANDARD OF THE FLORIDA RADON RESEARCH PROGRAM

Science.gov (United States)

The report contains the recommended language for the heating, ventilation, and air conditioning (HVAC) section of the "Florida Code for Radon-resistant Construction and Mitigation." t deals with elements of construction that relate to the HVAC of houses. ts primary intent is to p...

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. Movement of the subject to an environment with a lower radon concentration from an environment with a higher level of radon would result in an exhalation of radon, and the initial exhalation rate of radon should depend on the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. We report a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. (author).

Radon in balneology - measurement of radon retention by patients and radiation protection for personell

International Nuclear Information System (INIS)

Just, G.; Falkenbach, A.; Grunewald, W.A.; Philipsborn, H. von

2001-01-01

In radon balneology patients are exposed to radon either from water or air through the skin or through inhalation. Drinking radon water was not included in the study. Previously, the radon transfer has been determined for an estimate of the medically active amount of radon retained in the patient. A simpler approach of measuring radon in expiration under and after exposure has now been standardised and applied to probands under different conditions of exposure. In addition, radon decay products were measured in sweat, saliva and in the skin. Experimental parameters were evaluated for a comparison of different concentrations observed under different conditions. Results are likely to improve both therapy for patients and radiation protection for members of the personnel. (orig.) [de

The Columbia University proton-induced soft x-ray microbeam.

Science.gov (United States)

Harken, Andrew D; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

2011-09-15

A soft x-ray microbeam using proton-induced x-ray emission (PIXE) of characteristic titanium (K(α) 4.5 keV) as the x-ray source has been developed at the Radiological Research Accelerator Facility (RARAF) at Columbia University. The proton beam is focused to a 120 μm × 50 μm spot on the titanium target using an electrostatic quadrupole quadruplet previously used for the charged particle microbeam studies at RARAF. The proton induced x-rays from this spot project a 50 μm round x-ray generation spot into the vertical direction. The x-rays are focused to a spot size of 5 μm in diameter using a Fresnel zone plate. The x-rays have an attenuation length of (1/e length of ~145 μm) allowing more consistent dose delivery across the depth of a single cell layer and penetration into tissue samples than previous ultra soft x-ray systems. The irradiation end station is based on our previous design to allow quick comparison to charged particle experiments and for mixed irradiation experiments.

Radon Mapping of the Osijek Town

International Nuclear Information System (INIS)

Radolic, V.; Faj, Z.; Smit, G.; Culo, D.; Planinic, J.

1998-01-01

After ten years investigation of radon seasonal variations at three very different locations, as well as radon concentration measurements in kindergartens and schools, systematical indoor radon measurements were undertaken in dwellings of Osijek. Indoor radon was measured by means of the LR-115 nuclear track detector at 48 town locations that gave the arithmetic mean of 71.6 Bq m -3 , standard deviation of 44.0 Bq m -3 and geometric mean of 60.1 Bq m -3 , for the radon concentration range from 23 to 186 Bq m -3 . The empirical frequency distribution of radon concentrations, with the class width of 20 Bq m -3 , was in accordance with the theoretical log-normal distribution which was shown with χ 2 - test. The radon map pointed out a region of higher radon concentrations (central part of the town) that was ascribed to the geological soil structure. Thus supposition was confirmed by radon measurement in the soil gas using radon emanators with the LR-115 film that showed the positive correlation between radon concentrations in the soil and indoors. Radon measurements in Osijeks primary schools pointed out a school that had the highest radon concentration (300 Bq m -3 ) considering all the former indoor radon measurements. The radon distribution in the school building was investigated afterwards radon mitigation procedures were undertaken. (author)

The effect and the amendment of thermoregulation to the stability of radon concentration in radon chamber

International Nuclear Information System (INIS)

Zhang Xiongjie; Wang Renbo; Qu Jinhui; Tang Bin; Zhu Zhifu; Man Zaigang

2010-01-01

When the temperature in the airtight radon chamber was adjusted, it would induce the frequent changes of the air pressure in chamber, then the radon concentration in the radon chamber would continuously reduce, which could seriously destroy the stability of the radon concentration in radon chamber. In this paper, on the study of the effect reasons to the stability of radon concentration in airtight radon chamber due to the thermoregulation, a new amendment scheme was put forward, and the solutions of the relevant parameters were discussed. The amendment scheme had been successfully applied to HD-6 radon chamber, and achieved good results. (authors)

Excess bottom radon 222 distribution in deep ocean passages

International Nuclear Information System (INIS)

Sarmiento, J.L.; Broecker, W.S.; Biscaye, P.E.

1978-01-01

Radon 222 and STD profiles were obtained as part of the Geosecs program in the Vema Channel in the southwest Atlantic Ocean and in the Samoan, Clarion, and Wake Island passages in the Pacific Ocean. The standing crop of excess radon 222 is higher in the passages than at other nearby locations. The most likely explanation for this is that there is a high flux of radon 222 from the floor of the passages. Since much of the floor is covered with manganese nodules and encrustations, the high flux of radon 222 may be attributable to the high concentrations of radium 226 in the outer few millimeters of such deposits. Laboratory measurements of radon 222 emissivity from maganese encrustations obtained in Vema Channel support this hypothesis. The excess radon 222 in the Vema Channel and Wake Island Passage is found in substantial quantities at heights above bottom greatly exceeding the heights at which excess radon 222 is found in nonpassage areas. The horizontal diffusion of radon emanating from the walls of the passages is unlikely to be the cause of the observed concentrations because the ratio of wall surface area to water volume is very low. The profiles must therefore be a result of exceptionally high apparent vertical mixing in the passages. Further work is needed to determine the nature of this apparent vertical mixing. The excess radon 222 and STD data in all four passages have been fit with an empirical model in which it is assumed that the bouyancy flux is constant with distance above bottom. The fits are very good and yield apparent buoyancy fluxes that are between 1 and 3 orders of magnitude greater than those obtained at nearby stations outside the passages for three of the four passages

Application of a radon model to explain indoor radon levels in a Swedish house

International Nuclear Information System (INIS)

Font, LL.; Baixeras, C.; Joensson, G.; Enge, W.; Ghose, R.

1999-01-01

Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75±30 and 200±80 Bq m -3 . Results of the model adaptation to the house indicate that soil constitutes the most relevant radon source in both parts of the house. The radon concentration values predicted by the model indoors fall into the same range as the experimental results

CONTRIBUTION OF RADON FLOWS AND RADON SOURCES TO THE RADON CONCENTRATION IN A DWELLING

NARCIS (Netherlands)

DEMEIJER, RJ; STOOP, P; PUT, LW

1992-01-01

In this paper a model is presented for analysis of the radon concentrations in a compartment in terms of contributions from transport by flows of air between compartments and from radon sources in the compartment. Measurements were made to study the effect of increased natural ventilation of the

Radon and radon daughter monitoring (including thoron daughter monitoring)

International Nuclear Information System (INIS)

Leach, V.A.; Grealy, G.; Gan, W.

1982-01-01

Radon/radon daughter and thoron daughter measurement techniques are outlined. The necessary precautions and critical assessments of each method are also presented with a view to providing a better understanding of the various measurement methods

Uranium prospecting through radon detection; La prospection de l'uranium par le radon

Energy Technology Data Exchange (ETDEWEB)

Pradel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

Prospecting rests on the determination of the concentration of ground air in radon. Radon diffusing from deep uranium bearing layers is detected in upper ground layers. (author) [French] La prospection est basee sur l'etude de la concentration en radon dans l'air du sol. Dans les terrains superficiels, on decele le radon qui diffuse a partir des couches profondes uraniferes. (auteur)

Certain problems about radon. Pt.1

International Nuclear Information System (INIS)

Wu Huishan

2005-01-01

Discussion has been made on certain pointed out problems which presently influence the work and development of radon survey, and certain specific problems have been put forward which should be paid much attention and taken measures. Among the problems, some come from cognition, i.e. two kinds of balance and examination about radon, chief culprit of radon's daughter, multiply control and migration, the significance of radon in the water and soil, important standards for designing and evaluating the sites of construction projects, thoughts on the mechanism of the harm of radon and its daughters, diseases causing of both high and low radon, difficulty of emanation of indoor radon, normal low radon from natural marble; and others must be resolved specifically, i.e. establishment of national radon standards as quickly as possible, improvement of on-the-spot examination technique, national-wide radon survey with multiple disciplines and technology, the research on the mechanism of radon's harm and the establishment national radon study center. (authors)

Radon and its daughters in vivo

Energy Technology Data Exchange (ETDEWEB)

Rundo, J

1984-05-01

Prolonged exposure to radon should build up a reservoir of radon in body fat and fluids. If the subject moved to an environment with a lower radon concentration from an environment with a higher level of radon, the result would be an exhalation of radon, and the initial exhalation rate of radon should depend of the radon concentration inhaled. This paper describes the behavior of radon and its daughters in vivo and a relationship between the radon exhalation rate and the time after a meal. A major but short-lived postprandial increase in the exhalation rate of radon was observed. The author reports a similar effect in the exhalation rate of radon by persons containing no radium. It should be noted that the possibility exists that a large amount of radon daughters in the chest may interfere in the investigation of possible internal contamination with plutonium or other actinides by external counting. 8 figures.

Measurement of exhalation rate of radon and radon concentration in air using open vial method

International Nuclear Information System (INIS)

Horiuchi, Kimiko; Ishii, Tadashi.

1991-01-01

It was recognized that more than half of total exposure dose on human subject is caused by radon and its decay products which originate from naturally occurring radioactive substances (1988 UNSCEAR). Since then the exhalation of radon from the ground surface has received increasing attention. The authors have developed a new method for the determination of radon in natural water using toluene extraction of radon and applying a liquid scintillation counter of an integral counting technique which is able to get the absolute counting of radon. During these studies, the authors found out that when a counting vial containing of Liquid scintillator (LS)-toluene solution, without a lid, is exposed to the atmosphere for a while, dissolution of radon clearly occurs due to high solubility of radon into toluene layer. To extend this finding for the determination of radon in the atmosphere, the authors devised a new method to actively collect the atmosphere containing radon in a glass bottle by discharging a definite amount of water in it, which is named as open-vial dynamic method. The radon concentration can be easily calculated after the necessary corrections such as the partition coefficient and others. Applying proposed method to measure the radon exhalation rate from the ground surface and radon concentration in air of the dwelling environment, radioactive mineral spring zone and various geological formation such as granitic or sedimentary rocks. (author)

Risks from radon

International Nuclear Information System (INIS)

Doll, Richard

1992-01-01

The best estimate of risk to which everyone is exposed from natural radon in buildings is now obtained by extrapolation from observations on men exposed to radon in mines. The relationship between dose and effect derived by the US National Research Council implies that about 6% of the current life-time risk of developing the disease in the UK is attributable to radon, but for residents of some houses it will be much greater. This estimate is dependent on many assumptions, some of which are certainly wrong, and reliable estimates can be obtained only by direct observations on people living in different houses. It is possible that radon may also cause some risk of other cancers, notably leukaemia, but such risks, if real, are certainly small. Studies in progress should provide reliable estimates of all radon induced risks within a few years. (author)

Radon: Detection and treatment

International Nuclear Information System (INIS)

Loken, S.; Loken, T.

1989-01-01

Within the last few years, natural radon exposure in non-industrial settings, primarily homes, has become a health concern. Research has demonstrated that many homes throughout the United States have radon concentrations much higher than the legal federal limits set for miners. Thousands of unsuspecting people are being exposed to high levels of radiation. It is estimated that up to 15 percent of lung cancers are caused from radon. This is a significant health risk. With basic knowledge of the current information on radon, a primary health care provider can address patients' radon concerns and make appropriate referrals

Radon at the Mauna Loa Observatory: transport from distant continents

International Nuclear Information System (INIS)

Whittlestone, S.; Robinson, E.; Ryan, S.

1992-01-01

Continuous measurements of radon have been made at an altitude of 3400m at the Mauna Loa Observatory, Hawaii. Concentrations ranged from about 20 to more than 700mBq m -3 . These were similar to values at remote Macquarie I., some 2000 km south of Australia in the Southern Ocean. At Mauna Loa, the radon concentrations could usually be separated into free tropospheric and island influenced categories on the basis of local meteorological observations. On one occasion a long range transport event from Asia brought relatively high radon concentrations to Mauna Loa and persisted for several days. The Asian origin of this event was supported by wind trajectories. This measurement program demonstrates the value of radon data in evaluating air transport models and the influence of transport from distant continents on baseline atmospheric measurements. (author)

First trial of spatial and temporal fractionations of the delivered dose using synchrotron microbeam radiation therapy

International Nuclear Information System (INIS)

Serduc, Raphael; Braeuer-Krisch, Elke; Bouchet, Audrey; Brochard, Thierry; Bravin, Alberto; Le Duc, Geraldine; Renaud, Luc; Laissue, Jean Albert

2009-01-01

The technical feasibility of temporal and spatial fractionations of the radiation dose has been evaluated using synchrotron microbeam radiation therapy for brain tumors in rats. A significant increase in lifespan (216%, p<0.0001) resulted when three fractions of microbeam irradiation were applied to the tumor through three different ports, orthogonal to each other, at 24 h intervals. However, there were no long-term survivors, and immunohistological studies revealed that 9 L tumors were not entirely ablated. (orig.)

First trial of spatial and temporal fractionations of the delivered dose using synchrotron microbeam radiation therapy

Energy Technology Data Exchange (ETDEWEB)

Serduc, Raphael [Toulouse Univ. (France). UPS Centre de Recherche Cerveau et Cognition; CNRS, CerCo, Toulouse (France); European Synchrotron Radiation Facility, 38 - Grenoble (France); Braeuer-Krisch, Elke; Bouchet, Audrey; Brochard, Thierry; Bravin, Alberto; Le Duc, Geraldine [European Synchrotron Radiation Facility, 38 - Grenoble (France); Renaud, Luc [Toulouse Univ. (France). UPS Centre de Recherche Cerveau et Cognition; CNRS, CerCo, Toulouse (France); Laissue, Jean Albert [Bern Univ. (Switzerland). Inst. of Pathology

2009-07-15

The technical feasibility of temporal and spatial fractionations of the radiation dose has been evaluated using synchrotron microbeam radiation therapy for brain tumors in rats. A significant increase in lifespan (216%, p<0.0001) resulted when three fractions of microbeam irradiation were applied to the tumor through three different ports, orthogonal to each other, at 24 h intervals. However, there were no long-term survivors, and immunohistological studies revealed that 9 L tumors were not entirely ablated. (orig.)

Radon in workplaces

International Nuclear Information System (INIS)

Gooding, Tracy

1995-01-01

The naturally occurring radioactive gas radon has been found at excessive levels in many workplaces other than mines throughout the country. Prolonged exposure to radon and its decay products increases the risk of developing lung cancer, and controls to protect employees from excessive exposure are included in the Ionising Radiations Regulations 1985. The control of occupational exposure to radon is discussed here. (author)

Radon and radon daughter measurements at and near the former Middlesex Sampling Plant, Middlesex, New Jersey

International Nuclear Information System (INIS)

Haywood, F.F.; Perdue, P.T.; Christian, D.J.; Leggett, R.W.; Dickson, H.W.; Myrick, T.E.

1980-03-01

The results of the radon and radon daughter measurements made to date (1978) at the Middlesex Sampling Plant in Middlesex, New Jersey, are presented in this report. These measurements were one portion of a more comprehensive radiological survey conducted at this site and the surrounding area from 1976 to 1978. The surveyed property served as a uranium ore sampling plant during the 1940's and early 1950's and as a result contains elevated levels of surface an subsurface contamination. On-site indoor radon daughter and radon concentrations exceeded both the US Surgeon General Guidelines and the Nuclear Regulatory Commission's maximum permissible concentration limits for radon (10 CFR Part 20) in all structures surveyed. Off-site structures showed concentrations of radon and radon daughters at or only slightly above background levels, except for one site where the radon levels were found to be above the 10 CFR Part 20 guidelines. Outdoor radon ad radon daughter concentrations, measured both on and off the site, were well below the guidelines, and the data give no indication of significant radon transport from the site

Geographical associations between radon and cancer: is domestic radon level a marker of socioeconomic status?

International Nuclear Information System (INIS)

Wolff, S.P.; Stern, G.

1991-01-01

Previous studies showing a geographical association between radon and various cancers, particularly the leukaemias and lymphomas, appear to be confounded by the role of radon levels as a surrogate for socioeconomic status. Higher socioeconomic status (at least at the UK county level) is correlated with higher levels of domestic radon. Controlling for the relationship between socioeconomic status and radon removes the correlation between radon exposure and lymphoproliferative disease. Reported associations between radon and lymphoproliferative disease (and possibly other cancers) may be secondary to socioeconomic variables. (author)

Inverse method for determining radon diffusion coefficient and free radon production rate of fragmented uranium ore

International Nuclear Information System (INIS)

Ye, Yong-jun; Wang, Li-heng; Ding, De-xin; Zhao, Ya-li; Fan, Nan-bin

2014-01-01

The radon diffusion coefficient and the free radon production rate are important parameters for describing radon migration in the fragmented uranium ore. In order to determine the two parameters, the pure diffusion migration equation for radon was firstly established and its analytic solution with the two parameters to be determined was derived. Then, a self manufactured experimental column was used to simulate the pure diffusion of the radon, the improved scintillation cell method was used to measure the pore radon concentrations at different depths of the column loaded with the fragmented uranium ore, and the nonlinear least square algorithm was used to inversely determine the radon diffusion coefficient and the free radon production rate. Finally, the solution with the two inversely determined parameters was used to predict the pore radon concentrations at some depths of the column, and the predicted results were compared with the measured results. The results show that the predicted results are in good agreement with the measured results and the numerical inverse method is applicable to the determination of the radon diffusion coefficient and the free radon production rate for the fragmented uranium ore. - Highlights: • Inverse method for determining two transport parameters of radon is proposed. • A self-made experimental apparatus is used to simulate radon diffusion process. • Sampling volume and position for measuring radon concentration are optimized. • The inverse results of an experimental sample are verified

Radon exhalation rates corrected for leakage and back diffusion – Evaluation of radon chambers and radon sources with application to ceramic tile

Directory of Open Access Journals (Sweden)

M. Abo-Elmagd

2014-10-01

Full Text Available The natural radon decay, leakage and back diffusion are the main removal processes of radon from its container. Ignoring these processes leads to underestimate the measured value of radon related parameters like exhalation rate and radium content. This work is aimed to evaluate two different radon chambers through determining their leakage rate λv and evaluation of radon source by determine its back diffusion rate λb inside the evaluated radon chambers as well as a small sealed cup. Two different methods are adapted for measuring both the leakage rate and the back diffusion rate. The leakage rate can be determined from the initial slope of the radon decay curve or from the exponential fitting of the whole decay curve. This can be achieved if a continuous monitoring of radon concentration inside the chamber is available. Also, the back diffusion rate is measured by sealing the radon source in the chamber and used the initial slope of the buildup curve to determine λb and therefore the exhalation rate of the source. This method was compared with simple equation for λb based on the ratio of the source to the chamber volume. The obtained results are applied to ceramic tile as an important radon source in homes. The measurement is targeted the ceramic glaze before and after firing as well as the obtained tile after adhere the glaze on the tile main body. Also, six different tile brands from Egyptian market are subjected to the study for comparison.

Studies of Radon and Radon Progeny in Air Conditioned Rooms in Hospitals

International Nuclear Information System (INIS)

Marley, F.; Denman, A.R.; Phillips, P.S.

1998-01-01

A series of continuous real-time radon and radon progeny measurements together with passive etched track detector measurements were performed in hospital premises during 1996. In one small room, detailed measurements over several weeks showed that both the radon concentration and the Equilibrium Factor depended on the intermittent operation of a filtered positive pressure displacement air-conditioning system, which was designed to conform to operating theatre standards. The average radon level measured while the air-conditioning was off was almost four times higher than that recorded whilst it was on. The progeny level was over five times higher than that whilst it was on. Thus, the Equilibrium Factor (F), was significantly lower when the air-conditioning was on. Measurements in similar rooms in two hospitals, confirmed that the reduction in radon level was a general finding. Thus staff working in such environments receive significantly lower radiation dose from radon than staff working in nearby normally ventilated rooms. (author)

A comparison of contemporary and retrospective radon gas measurements in high radon dwellings in Ireland

International Nuclear Information System (INIS)

Kelleher, K.; McLaughlin, J.P.; Fenton, D.; Colgan, P.A.

2006-01-01

Little correlations has been found between contemporary radon gas measurements made in the past and retrospective radon gas measurements in Irish dwellings. This would suggest that these two techniques would result in two significantly different cumulative radon exposure estimates. Contemporary radon gas measurements made a few years apart in the same room of a dwelling were found to be significantly different. None of these differences could be explained by known changes to the rooms themselves., such ventilation or structural alterations to the room. This highlights the limitations of the contemporary radon gas measurements as a surrogate measurement for use in residential radon epidemiology. The contemporary radon gas measurements made by the Radiological Protection Institute of Ireland (R.P.I.I.) and University College of Dublin (U.C.D.) do not cover the same exposure period as the retrospective estimates and so the accuracy of the retrospective measurements cannot be demonstrated. A weak correlation can be seen between the retrospective radon gas estimates and a combination of the two contemporary radon gas estimates. It is not unreasonable to expect improvement in the correlation if further contemporary radon gas measurements were made in these rooms. (N.C.)

Radon in workplaces

International Nuclear Information System (INIS)

Markkanen, M.; Annanmaeki, M.; Oksanen, E.

2000-01-01

The EU Member States have to implement the new Basic Safety Standards Directive (BSS) by May 2000. The Title VII of the Directive applies in particular to radon in workplaces. The Member States are required to identify workplaces which may be of concern, to set up appropriate means for monitoring radon exposures in the identified workplaces and, as necessary, to apply all or part of the system of radiological protection for practices or interventions. The BSS provisions on natural radiation are based on the ICRP 1990 recommendations. These recommendations were considered in the Finnish radiation legislation already in 1992, which resulted in establishing controls on radon in all types of workplaces. In this paper issues are discussed on the practical implementation of the BSS concerning occupational exposures to radon basing on the Finnish experiences in monitoring radon in workplaces during the past seven years. (orig.) [de

Modeling of indoor radon

International Nuclear Information System (INIS)

Paschoa, A.S.

1990-01-01

This paper reports on models for radon, which are developed not only to describe the behavior of radon and daughters since the moment that radon is created in natural sources by the alpha decay of 226 Ra up to the point that doses to humans are estimated based on the inhalation of radon and its progeny. The objective of a model should be determinant in defining the model structure and boundaries. Modeling indoors radon is particularly useful when the 226 Ra concentration in building materials and soils can be known before a house will be built with such 226 Ra bearing materials and over 226 Ra rich soils. The reported concentrations of 226 Ra in building materials range from 0.3 Bq · kg -1 in wood to about 2.6 x 10 3 Bq · kg -1 in aerated concrete based on alum shale. 30 In addition, when a house is built on a soil containing a high 226 Ra concentration, radon exhalation from the soil contributes to increase radon concentration indoors. The reported radon exhalation from soils range from 3.4 Bq · m -2 · s -1 in latosolic soil from Osaka, Japan to about 53 mBq · m -2 · s -1 in chernozemic soil from Illinois

Computational modelling of the cerebral cortical microvasculature: effect of x-ray microbeams versus broad beam irradiation

Science.gov (United States)

Merrem, A.; Bartzsch, S.; Laissue, J.; Oelfke, U.

2017-05-01

Microbeam Radiation Therapy is an innovative pre-clinical strategy which uses arrays of parallel, tens of micrometres wide kilo-voltage photon beams to treat tumours. These x-ray beams are typically generated on a synchrotron source. It was shown that these beam geometries allow exceptional normal tissue sparing from radiation damage while still being effective in tumour ablation. A final biological explanation for this enhanced therapeutic ratio has still not been found, some experimental data support an important role of the vasculature. In this work, the effect of microbeams on a normal microvascular network of the cerebral cortex was assessed in computer simulations and compared to the effect of homogeneous, seamless exposures at equal energy absorption. The anatomy of a cerebral microvascular network and the inflicted radiation damage were simulated to closely mimic experimental data using a novel probabilistic model of radiation damage to blood vessels. It was found that the spatial dose fractionation by microbeam arrays significantly decreased the vascular damage. The higher the peak-to-valley dose ratio, the more pronounced the sparing effect. Simulations of the radiation damage as a function of morphological parameters of the vascular network demonstrated that the distribution of blood vessel radii is a key parameter determining both the overall radiation damage of the vasculature and the dose-dependent differential effect of microbeam irradiation.

Scopingsreport Radon

NARCIS (Netherlands)

Blaauboer RO; Vaas LH; Hesse JM; Slooff W

1989-01-01

Dit scopingsrapport vormt een onderdeel van de voorbereiding tot het opstellen van het basisdocument radon. Het doel van dit rapport is het algemene kennisniveau van de deelnemers aan de scopingsbijeenkomst aangaande radon op eenzelfde peil te brengen en discussie- en beslispunten inzake de

Radon in dwellings

International Nuclear Information System (INIS)

Erikson, B.E.; Boman, C.A.; Nyblom, L.; Swedjemark, G.A.

1980-06-01

The report presents the function of the ventilation by natural draught in three-storey houses. In some cases also the measurement of gamma radiation, radon and radon daughters was made. The investigation took place in Uppsala. The houses were built of light weight concrete made of alum-shale. The measurements showed that the contents of radon daughters were far below the provisional limits. (G.B.)

S. 2844: A Bill to provide for radon testing. Introduced in the Senate of the United States, One Hundredth Congress, Second Session, September 29, 1988

International Nuclear Information System (INIS)

Anon.

1988-01-01

This bill, entitled as the Department of Housing and Urban Development Radon Policy Act, has been introduced to provide for radon testing. The purposes of this Act are to: provide the Department of Housing and Urban Development with a mandate to establish a departmental radon policy and program; require the Department of Housing and Urban Development to use its programs to assist the EPA in addressing radon contamination; and require the Department of Housing and Urban Development, in coordination with the EPA, to develop a radon assessment and mitigation program which utilized EPA recommended guidelines and standards to ensure that occupants of housing covered under this Act are not exposed to elevated levels of radon

Application of a radon model to explain indoor radon levels in a Swedish house

CERN Document Server

Font, L; Jönsson, G; Enge, W; Ghose, R

1999-01-01

Radon entry from soil into indoor air and its accumulation indoors depends on several parameters, the values of which normally depend on the specific characteristics of the site. The effect of a specific parameter is often difficult to explain from the result of indoor radon measurements only. The adaptation of the RAGENA (RAdon Generation, ENtry and Accumulation indoors) model to a Swedish house to characterise indoor radon levels and the relative importance of the different radon sources and entry mechanisms is presented. The building is a single-zone house with a naturally-ventilated crawl space in one part and a concrete floor in another part, leading to different radon levels in the two parts of the building. The soil under the house is moraine, which is relatively permeable to radon gas. The house is naturally-ventilated. The mean indoor radon concentration values measured with nuclear track detectors in the crawl-space and concrete parts of the house are respectively 75+-30 and 200+-80 Bq m sup - sup 3...

Vibration analysis of a rotating functionally graded tapered microbeam based on the modified couple stress theory by DQEM

Science.gov (United States)

Ghadiri, Majid; Shafiei, Navvab; Alireza Mousavi, S.

2016-09-01

Due to having difficulty in solving governing nonlinear differential equations of a non-uniform microbeam, a few numbers of authors have studied such fields. In the present study, for the first time, the size-dependent vibration behavior of a rotating functionally graded (FG) tapered microbeam based on the modified couple stress theory is investigated using differential quadrature element method (DQEM). It is assumed that physical and mechanical properties of the FG microbeam are varying along the thickness that will be defined as a power law equation. The governing equations are determined using Hamilton's principle, and DQEM is presented to obtain the results for cantilever and propped cantilever boundary conditions. The accuracy and validity of the results are shown in several numerical examples. In order to display the influence of size on the first two natural frequencies and consequently changing of some important microbeam parameters such as material length scale, rate of cross section, angular velocity and gradient index of the FG material, several diagrams and tables are represented. The results of this article can be used in designing and optimizing elastic and rotary-type micro-electro-mechanical systems like micro-motors and micro-robots including rotating parts.

Protocol for the estimation of average indoor radon-daughter concentrations: Second edition

International Nuclear Information System (INIS)

Langner, G.H. Jr.; Pacer, J.C.

1988-05-01

The Technical Measurements Center has developed a protocol which specifies the procedures to be used for determining indoor radon-daughter concentrations in support of Department of Energy remedial action programs. This document is the central part of the protocol and is to be used in conjunction with the individual procedure manuals. The manuals contain the information and procedures required to implement the proven methods for estimating average indoor radon-daughter concentration. Proven in this case means that these methods have been determined to provide reasonable assurance that the average radon-daughter concentration within a structure is either above, at, or below the standards established for remedial action programs. This document contains descriptions of the generic aspects of methods used for estimating radon-daughter concentration and provides guidance with respect to method selection for a given situation. It is expected that the latter section of this document will be revised whenever another estimation method is proven to be capable of satisfying the criteria of reasonable assurance and cost minimization. 22 refs., 6 figs., 3 tabs

Measurement of minute local strain in semiconductor materials and electronic devices by using a highly parallel X-ray microbeam

International Nuclear Information System (INIS)

Matsui, J.; Tsusaka, Y.; Yokoyama, K.; Takeda, S.; Katou, M.; Kurihara, H.; Watanabe, K.; Kagoshima, Y.; Kimura, S.

2003-01-01

We have developed an X-ray microbeam with a small angular divergence by adopting X-ray optics with successive use of asymmetric Bragg reflection from silicon crystals for the both polarizations of the synchrotron X-rays. The microbeam actually obtained is several microns in size and possesses an angular divergence of less than 2 arcsec which enables us to measure the strain of 10 -5 -10 -6 . By scanning the sample against the microbeam, distribution of the minute local strain in various regions of semiconductor crystals for electronic devices, e.g., the strain around the SiO 2 /Si film edge in silicon devices, the strain in an InGaAsP/InP stripe laser were measured

Comparing summer and winter indoor radon and radon daughters activity in Campinas, Brazil

International Nuclear Information System (INIS)

Guedes, O.S.; Hadler, N.J.C.; Iunes, P.J.; Neman, R.S.; Souza, W.F.; Tello, S.C.A.; Paulo, S.R.

2002-01-01

We developed a technique - based on alpha particle track detection using CR-39 - where the activity originated from indoor radon can be potentially separated into three fraction: (i) radon in the air, (ii) radon daughters (RD), 218 Po and 214 Po, in the air and (iii) RD plated-out on the detector surface during exposure. In this work only a partial separation was carried out, then our results are limited to radon plus RD in the air and RD attached to detector surface. These activities can be separated if size and gray level of the round tracks are measured using an automatic optical microscopy system.Our group carried out an indoor radon and radon daughters (RD) survey in Campinas made up by a summer (November, 96 to May, 97) and a winter (May, 97 to November, 97) exposure, where the detectors were placed in the same rooms of the same dwellings (approximately 100) in both cases. Comparing winter and summer alpha activity for the detectors analyzed up to now, approximately 45 dwellings, we observed that: i) it seems that the source of radon is the material (brick and concrete mainly) making up walls, floor and ceiling of the dwellings, ii) there is no clear relationship between intensity of aeration and the activities measured in this work, and iii) the average ratio between winter and summer activity in the air (radon plus RD) is approximately equal to similar ratios observed in other countries, but for radon only. (author)

Application of the can technique and radon gas analyzer for radon exhalation measurements

Energy Technology Data Exchange (ETDEWEB)

Fazal-ur-Rehman E-mail: fazalr@kfupm.edu.sa; Al-Jarallah, M.I.; Musazay, M.S.; Abu-Jarad, F

2003-12-01

A passive 'can technique' and an active radon gas analyzer with an emanation container were applied for radon exhalation rate measurements from different construction materials, viz. five marble seven ceramic and 100 granite tiles used in Saudi Arabia. The marble and ceramic tiles did not show detectable radon exhalation using the active radon gas analyzer system. However the granite tiles showed relatively high radon exhalations, indicating a relatively high uranium content. A comparison of the radon exhalation rates measured by the two techniques showed a linear correlation coefficient of 0.57. The radon exhalation rates from the granites varied from 0.02 to 6.58 Bq m{sup -2} h{sup -1} with an average of 1.35{+-}1.40 Bq m{sup -2} h{sup -1}. The geometric mean and the geometric standard deviation of the frequency distribution were found to be 0.80 and 3.1, respectively. The track density found on the nuclear track detectors in the can technique exposed to the granites, having high exhalation rates, varied linearly with exposure time with a linear correlation coefficient of 0.99. This experimental finding agrees with the theoretical prediction. The can technique showed sensitivity to low radon exhalation rates from ceramic, marble and some granite over a period of 2 months, which were not detectable by the active radon gas analyzer system. The reproducibility of data with both measuring techniques was found to be within a 7% deviation.

Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

International Nuclear Information System (INIS)

Guedes, S.; Hadler, J.C.N.; Iunes, P.J.; Navia, L.M.S.; Neman, R.S.; Paulo, S.R.; Rodrigues, V.C.; Souza, W.F.; Tello, C.A.S.; Zuniga, A.

1999-01-01

The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied

Indoor radon and radon daughters survey at Campinas-Brazil using CR-39: First results

CERN Document Server

Guedes, S; Iunes, P J; Navia, L M S; Neman, R S; Paulo, S R; Rodrigues, V C; Souza, W F; Tello, C A S; Zúñiga, A G

1999-01-01

The first results of a radon and radon daughters (RD) survey performed at Campinas-SP, Brazil, are presented. We employed a technique that, potentially, makes possible to measure the radon and RD activity in the air and to separate from this result the activity of radon, alone. In this preliminary paper only the former activity is studied.

Radon as a hydrological indicator

Energy Technology Data Exchange (ETDEWEB)

Komae, Takami [National Research Inst. of Agricultural Engineering, Tsukuba, Ibaraki (Japan)

1997-02-01

The radon concentration in water is measured by a liquid scintillation method. After the radioactive equilibrium between radon and the daughter nuclides was attained, the radon concentration was determined by the liquid scintillation analyzer. {alpha}-ray from radon, then two {beta}- and two {alpha}-ray from the daughter nuclei group were released, so that 500% of the apparent counting efficiency was obtained. The detector limit is about 0.03 Bq/l, the low value, which corresponds to about 5.4x10{sup -15} ppm. By determining the radon concentration in groundwater, behavior of radon in hydrological process, the groundwater exchange caused by pumping and exchange between river water and groundwater were investigated. The water circulation analysis by means of radon indicator in the environment was shown. By using the large difference of radon concentration between in river water and in groundwater, arrival of injected water to the sampling point of groundwater was detected. (S.Y.)

Control of radon in Finnish workplaces

International Nuclear Information System (INIS)

Markkanen, M.

2002-01-01

Natural radiation in Finland is regulated in the Finnish Radiation Act from 1992. Occupational exposure to natural radiation is regulated by an amendment of the Radiation Decree in 1998. The most important issues in Finland are radon in workplaces, radioactivity in drinking water and in building materials, and mining and industrial processes. Radon levels in mines have been measured regularly since 1972. Finland has an action level for radon in workplaces of 400 Bq/m 3 . Radon prone areas have been identified primarily from measurements of radon in dwellings. Radon measurements are compulsory in workplaces in radon prone areas unless it can be shown by other means that radon levels are low. A programme focusing on radon in workplaces was initiated in 1992. To date, radon measurements have been carried out in 10,000 workplaces and remedial actions have been taken in 200 of these. The average reduction in radon concentration in remediated buildings is about 1,500 Bq/m 3 . Identification of NORM industries is based on the radionuclide content of the materials used (>1.4 Bq/g U and >0.4 Bq/g Th). The occupational exposure should not exceed 1 mSv/y (excluding radon)

Laser-induced radiation microbeam technology and simultaneous real-time fluorescence imaging in live cells.

Science.gov (United States)

Botchway, Stanley W; Reynolds, Pamela; Parker, Anthony W; O'Neill, Peter

2012-01-01

The use of nano- and microbeam techniques to induce and identify subcellular localized energy deposition within a region of a living cell provides a means to investigate the effects of low radiation doses. Particularly within the nucleus where the propagation and processing of deoxyribonucleic acid (DNA) damage (and repair) in both targeted and nontargeted cells, the latter being able to study cell-cell (bystander) effects. We have pioneered a near infrared (NIR) femtosecond laser microbeam to mimic ionizing radiation through multiphoton absorption within a 3D femtoliter volume of a highly focused Gaussian laser beam. The novel optical microbeam mimics both complex ionizing and UV-radiation-type cell damage including double strand breaks (DSBs). Using the microbeam technology, we have been able to investigate the formation of DNA DSB and subsequent recruitment of repair proteins to the submicrometer size site of damage introduced in viable cells. The use of a phosphorylated H2AX (γ-H2AX a marker for DSBs, visualized by immunofluorescent staining) and real-time imaging of fluorescently labeling proteins, the dynamics of recruitment of repair proteins in viable mammalian cells can be observed. Here we show the recruitment of ATM, p53 binding protein 1 (53BP1), and RAD51, an integral protein of the homologous recombination process in the DNA repair pathway and Ku-80-GFP involved in the nonhomologous end joining (NHEJ) pathway as exemplar repair process to show differences in the repair kinetics of DNA DSBs. The laser NIR multiphoton microbeam technology shows persistent DSBs at later times post laser irradiation which are indicative of DSBs arising at replication presumably from UV photoproducts or clustered damage containing single strand breaks (SSBs) that are also observed. Effects of the cell cycle may also be investigated in real time. Postirradiation and fixed cells studies show that in G1 cells a fraction of multiphoton laser-induced DSBs is persistent for >6h

Radon mitigation in schools

International Nuclear Information System (INIS)

Leovic, K.W.; Craig, A.B.; Saum, D.W.

1990-01-01

This article reports on radon mitigation in school buildings. Subslab depressurization (SSD) has been the most successful and widely used radon reduction method in houses. Thus far, it has also substantially reduced radon levels in a number of schools. Schools often have interior footings or thickened slabs that may create barriers for subslab air flow if a SSD system is the mitigation option. Review of foundation plans and subslab air flow testing will help to determine the presence and effect of such barriers. HVAC systems in schools vary considerable and tend to have a greater influence on pressure differentials (and consequently radon levels) than do heating and air-conditioning systems encountered in the radon mitigation of houses. As part of any radon mitigation method, ASHRAE Standard 62-1989 should be consulted to determine if the installed HVAC system is designed and operated to achieve minimum ventilation standards for indoor air quality

Health effects of radon

International Nuclear Information System (INIS)

Easterly, C.

1994-01-01

Exposure of people to radon has taken on increased interest during the last decade because of the understanding that buildings can serve to trap radon and its daughters, and thereby build up undesirable concentrations of these radioactive elements. Numerous studies of underground miners (often uranium miners) have shown an increased risk of lung cancer in comparison with nonexposed populations. Laboratory animals exposed to radon daughters also develop lung cancer. The abundant epidemiological and experimental data have established the carcinogenicity of radon progeny. Those observations are of considerable importance, because uranium, from which radon and its progeny arise, is ubiquitous in the earth's crust, including coal mines. Risk estimates of the health effects of long-term exposures at relatively low levels require continued development, especially to address the potential health effects of radon and radon daughters in homes and occupational settings where the exposure levels are less than levels in underground uranium and other metal mines that have been the subject of epidemiological studies. Two approaches can be used to characterize the lung-cancer risks associated with radon-daughter exposure: mathematical representations of the respiratory tract that model radiation doses to target cells and epidemiological investigation of exposed populations, mainly underground uranium miners. The mathematically-based dosimetric approach provides an estimate of lung cancer risk related to radon-daughter exposure based specifically on modeling of the dose to target cells. The various dosimetric models all require assumptions, some of which are not subject to direct verification, as to breathing rates; the deposition of radon daughters in the respiratory tract; and the type, nature, and location of the target cells for cancer induction. The most recent large committee effort drawn together to evaluate this issue was sponsored by the National Research Council

A proton microbeam deflection system to scan target surfaces

International Nuclear Information System (INIS)

Heck, D.

1978-12-01

A system to deflect the proton beam within the Karlsruhe microbeam setup is described. The deflection is achieved whithin a transverse electrical field generated between parallel electrodes. Their tension is controlled by a pattern generator, thus enabling areal and line scans with a variable number of scan points at variable scan speed. The application is demonstrated at two different examples. (orig.) [de

Radon risk in the house; Il rischio radon nelle abitazioni

Energy Technology Data Exchange (ETDEWEB)

Bressa, G. [Padua Univ., Padua (Italy). Dipt. di Farmacologia e Anestesiologia, Lab. di Tossicologia

2001-04-01

Radon was discovered in 1900, but its potential dangerousness for man was fully understood only in 1950. Being a radioactive natural gas - and therefore particularly dangerous - radon results from the long decay chain of radionuclides, such as thorium and radium. Some igneous rocks (granite, tufa and lava) as well as coal are considered to be the main sources of this radionuclide. A number of epidemiologic studies have shown the carcinogenicity of this element, particularly among miners and workers subjected to high level exposure in confined spaces such as basements, garages, cellars, etc. There are, however, some techniques to remove radon in order to reduce exposure to minimum values. [Italian] Il radon fu scoperto nel 1900, ma solo nel 1950 si comprese la sua potenziale pericolosita' per l'uomo. Il radon e' particolarmente pericoloso essendo un gas naturale radioattivo. Esso proviene dalla lunga catena di decadimento di radionuclidi come il torio e di radio. Sorgenti di tale radionuclide sono da considerarsi principalmente alcune rocce ignee (graniti, tufi e lave) e il carbone. Diversi studi epidemiologici hanno evidenziato la cancerogenicita' di tale elemento, specie tra i minatori e soggetti esposti ad alti livelli in ambienti confinati quali scantinati, garage sotterranei, ecc.. Esistono comunque tecniche di intervento per la rimozione del gas radon in modo tale da ridurre l'esposizione a valori minimi.

Radon evasion rates in the Atlantic and Pacific oceans as determined during the Geosecs program

International Nuclear Information System (INIS)

Peng, T.; Broecker, W.S.; Mathieu, G.G.; Li, Y.; Bainbridge, A.E.

1979-01-01

During the Geosecs expedition in the Atlantic and the Pacific oceans, more than 100 stations were occupied for the measurement of surface radon profiles. The radon deficiency in these profiles gives estimates of the gas transfer rate across the sea-air interface. The global mean transfer rate is estimated to be 2.9 m/d (at 20 0 C) which is corresponding to a hypothetical stagnant films thickness of about 36 microns. No clear relationship can be found between the gas exchange rate and wind speed. The CO 2 exchange rate as determined by the radon method is 80% of that given by the distributions of natural and of bomb-produced radiocarbon. One possible explanation may be that the Geosecs radon measurements were made during periods of lower than average wind speed. Another is that the conversion of CO 2 to HCO 3 - is catalyzed within the sea

Radon in Syrian houses

International Nuclear Information System (INIS)

Othman, I.; Hushari, M.; Raja, G.; Alsawaf, A.

1996-01-01

A nationwide investigation of radon levels in Syrian houses was carried out during the period 1991-1993. Passive radon diffusion dosemeters using polycarbonate detectors were distributed in houses all over Syria. Detectors were subjected to electrochemical etching to reveal latent tracks of alpha particles. The mean radon concentration in Syrian houses was found to be 45 Bq m -3 with some values several times higher. This investigation indicated that there were a few houses in Syria that require remedial action. Most houses that have high levels of radon were found in the southern area, especially in the Damascus governorate. The study also indicated that radon concentrations were higher in old houses built from mud with no tiling. (author)

A Galerkin-Parameterization Method for the Optimal Control of Smart Microbeams

Directory of Open Access Journals (Sweden)

Marwan Abukhaled

2009-01-01

Full Text Available A proposed computational method is applied to damp out the excess vibrations in smart microbeams, where the control action is implemented using piezoceramic actuators. From a mathematical point of view, we wish to determine the optimal boundary actuators that minimize a given energy-based performance measure. The minimization of the performance measure over the actuators is subjected to the full motion of the structural vibrations of the micro-beams. A direct state-control parametrization approach is proposed where the shifted Legendre polynomials are employed to solve the optimization problem. Legendre operational matrix and the properties of Kronecker product are utilized to find the approximated optimal trajectory and optimal control law of the lumped parameter systems with respect to the quadratic cost function by solving linear algebraic equations. Numerical examples are provided to demonstrate the applicability and efficiency of the proposed approach.

The therapeutic use of radon; Radon als Heilmittel

Energy Technology Data Exchange (ETDEWEB)

Deetjen, P [Innsbruck Univ. (Austria). Inst. fuer Physiologie und Balneologie

1995-09-01

Spas with a somewhat elevated concentration of Radon{sup 222} (between 300 and 3000 Bq/l) are described to achieve good clinical results in the treatment of chronic rheumatic diseases. Recently a prospective randomized doubel-blind-study proved the pain reducing efficacy of Radon therapy in patients with cervical pain. Studies in experimental animal models have accumulated remarkable data in tissues and organs that provide a rationale to explain the observed effects of Radon therapy in patients. (orig.) [Deutsch] In verschiedenen europaeischen und asiatischen Laendern werden oft schon seit vielen Jahrhunderten Quellen als besonders heilkraeftig beschrieben, die eine etwas erhoehte Aktivitaet an Radon{sup 222} aufweisen (etwas zwischen 300 und 3000 Bq/l). Neuerdings liegt auch eine prospektive randomisierte Doppelblind-Studie vor, die den klinischen Nachweis der Schmerzlinderung durch eine Radonkur erbringt. In tierexperimentellen Untersuchungen wurden unter Radonexposition zahlreiche stimulierende Effekte auf Zellstoffwechsel, Immunabwehr, Abbau toxischer Radikale, DNA-Reparatur-Systeme oder Synthese von Mediatorsubstanzen gemessen, die rationale Ansaetze fuer das Verstaendnis der Wirkung einer Radonexposition im niedrigen Dosisbereich ergeben. (orig.)

Radon and its measurement

International Nuclear Information System (INIS)

Penzo, Silvia

2006-03-01

The work reviews the topics concerning the problem of the indoor radon and its measurement. The initial stage deals with the general features of radon, from the historical remarks about its discovery to the formation mechanisms in the soil, then passing to describe the transport processes that lead the radon to enter into the buildings. The mean radon concentration distribution among the Italian regions is reported and compared with the situation in the other countries of the world. A particular importance is given to present the national law concerning the radioprotection from the natural sources of ionizing radiations; a paragraph is completely devoted to this argument and to discuss the differences between the Italian approach and the regulations applied in the Test of Europe for both workplaces and dwellings. Chapter 3 describes the different detectors and methods to measure the radon and its short mean live decay products concentrations, together with the operative procedures and guides provided by the Italian law and by the international bodies. As an example of typical radon passive measurement device. the new ENEA detector developed at the Institute of Radioprotection is presented and discussed. Appendix 1 is entirely devoted to discuss the main remedial actions for decreasing the radon indoor concentration both for old and new buildings; appendix 2 reports the main quantities related to radon and radioprotection [it

Radon in public buildings

International Nuclear Information System (INIS)

Schulz, H.; Flesch, K.; Hermann, E.; Loebner, W.; Leissring, B.

2009-01-01

From the Free State of Saxony, a study was commissioned to survey how reliable measurements to characterize the radon situation in public buildings at a reasonable financial and human effort can be carried out to reduce radiation exposure in public buildings. The study approach was for 6 objects. To characterize the radon situation the time evolution measurement of radon concentrations of more than 1 to 2 weeks turned out to be sufficient. A novel data analysis enables the identification of a ''typical daily alteration of the radon concentration'' depending on the ventilation conditions and the daily use of the offices or class rooms. The identification of typical diurnal radon variations for the working time and weekends or holidays is of fundamental importance for assessing the exposure situation in public buildings. It was shown that the radon concentration during working time are in general much lower than in the times when the buildings (offices) are unused. It turned out that the long-term radon measurements with nuclear track detectors within distinct time regimes (day / night, working hours / leisure time) by utilizing switch modules are very efficient to estimate the actual exposure. (orig.)

Improved thomas formula for radon measurement

International Nuclear Information System (INIS)

Ji Changsong

1991-06-01

The FT 648 type portable absolute radon meter has been developed and the designing principle of this instrument is introduced. The absolute radon meter differs from relative radon meter. By using structure parameters, operating parameters and readout of this instrument, the radon content of measured gas is obtained directly without calibration in advance. Normally, the calibration is done by a standard radioactive gaseous source of which the radon concentration is known. The systematic error is removed by adding filter-efficiency Σ, α self-absorption correction β, energy spectrum correction S, geometric factor Ω of probe and gravity dropping correction factor G to the Thomas formula for radon measurement of two-filter method. The atmosphere radon content, which is given in hour-average, in Beijing area was measured by FT 648 type absolute radon meter. The measurement lasted continuously for several days and nights and a 'saddle shape' of radon content-time curve was observed. The day's average radon content was 8.5 Bq·m -3

Technique and equipment for measuring volume activity of radon in the air of radon laboratories and clinics

International Nuclear Information System (INIS)

Vorob'ev, I.B.; Krivokhatskij, A.S.; Nekrasov, E.V.; Nikolaev, V.A.; Potapov, V.G.; Terent'ev, M.V.

1990-01-01

Usability of a new equipment-technique combination for measuring radon activity in the air of radon laboratories and balneological clinics is studied. The complex includes nitrate-cellulose detector, radon chamber, Aist, Istra type spark counters and technique of spark counting. The method sensitivity is 50 Bqxm 3 , the error is 30%. Usability and advisability of track method in radon laboratories and balneological clinics for simultaneous measurement in several points of integral volumetric radon activities are confirmred. The method permits to carry out rapid and accurate bulk investigations. The results of determining mean volumetric radon activity in the air in different points of radon laboratory and radon clinics are presented

Radon in dwellings the national radon survey Cork and Kerry

International Nuclear Information System (INIS)

McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.

1998-07-01

This report presents the results of the third phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Cork and Kerry. The average radon concentrations for the houses measured in these counties were 76 Bq/m 3 and 70 Bq/m 3 . The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

Geographical information system for radon gas from soil measurement; Il sistema informativo territoriale per la valutazione del potenziale di esalazione di radon dal suolo

Energy Technology Data Exchange (ETDEWEB)

Orlando, P.; Amici, M.; Altieri, A.; Massari, P.; Miccadei, E.; Onofri, A.; Orlando, C.; Paolelli, C.; Paron, P.; Perticaroli, P.; Piacentini, T.; Silvestri, C. [Milan Univ. Sacro Cuore, Milan (Italy). Servizio Centralizzato Radioisotopi; Belli, M.; Marchetti, A.; Petrocchi, A.; Rosamilia, S.; Serva, L.; Singh, G.; Tommasino, L. [Agenzia Nazionale per la Protezione dell' Ambiente, Rome (Italy); Minach, L.; Verdi, L. [Agenzia Provinciale per la Protezione dell' Ambiente, Bolzano (Italy); Bertolo, A.; Trotti, F. [Agenzia Regionale per la Protezione dell' Ambiente, Regione Veneto (Italy)

2000-07-01

The working program foresees the realization of an geographical information system for the check in field of the geological parameters and determination of uranium and radium contents in various type of rocks. It is here also pointed out a measuring method for radon concentration in soil. [Italian] In questo documento viene presentato il lavoro svolto fino ad oggi: dalla definizione dei parametri geologici ritenuti piu' significativi per la presenza di radon nel suolo e dalle misure in campo e in laboratorio, fino alla realizzazione del Sistema Informativo Territoriale (SIT) per la gestione dei suddetti parametri. Nel primo capitolo sono descritte le caratteristiche del radon, dal punto di vista chimico-fisico e geologico, per introdurre i criteri adottati nella scelta dei paramentri geologici e del loro peso per la valutazione del PERS (Potenziale di Esalazione Radon dal Suolo). Il secondo capitolo descrive il progetto in generale, mentre i successivi capitoli descrivono piu' in dettaglio la parte informatica e quella delle indagini sperimentali.

Radon programmes and health marketing.

Science.gov (United States)

Fojtikova, Ivana; Rovenska, Katerina

2011-05-01

Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed.

Leukaemia risks and radon

International Nuclear Information System (INIS)

Wolff, S.P.

1991-01-01

A correlation has been established between domestic radon exposure and mutation in peripheral T lymphocytes. Some caution must be exercised, however, in interpreting this result as evidence that levels of domestically encountered radon are sufficient to cause leukaemogenic chromosomal alterations. Radon may simply be acting as a surrogate for some other mutagenic factor. Correlations with Local Authority statistics collected in the United Kingdom 1981 Census appear to show that lower domestic radon levels reflect relatively greater socioeconomic deprivation whereas higher levels reflect greater prosperity. The relative risk of lymphoproliferative disease correlates with the same factors that determine domestic radon levels at the county level. Putative relationships between domestic radon exposure and cancer thus need to be controlled for socioeconomic status and associated factors, at least at the county level. (The correlations may not apply to smaller areas.) Similarly, the causative factors underlying the relationships between higher regional socioeconomic status and leukaemia require closer examination. (author)

Radon in workplaces: First results of an extensive survey and comparison with radon in homes

International Nuclear Information System (INIS)

Bucci, S.; Pratesi, G.; Viti, M. L.; Pantani, M.; Bochicchio, F.; Venoso, G.

2011-01-01

Extensive radon surveys have been carried out in many countries only in dwellings, whereas surveys in workplaces are rather sparse and generally restricted to specific workplaces/activities, e.g. schools, spas and caves. Moreover, radon-prone areas are generally defined on the basis of radon surveys in dwellings, while radon regulations use this concept to introduce specific requirements in workplaces in such areas. This approach does not take into account that work activities and workplace characteristics can significantly affect radon concentration. Therefore, an extensive survey on radon in different workplaces have been carried out in a large region of Italy (Tuscany), in order to evaluate radon distribution in workplaces over the whole territory and to identify activities and workplace characteristics affecting radon concentration. The results of this extensive survey are compared with the results of the survey carried out in dwellings in the same period. The workplaces monitored were randomly selected among the main work activities in the region, including both public and industrial buildings. The survey monitored over 3500 rooms in more than 1200 buildings for two consecutive periods of ∼6 months. Radon concentration was measured by means of passive nuclear track detectors. (authors)

The significance of radon in radioactive pollution of environment. Pt. 2. Radon effect on living organism

International Nuclear Information System (INIS)

Kossakowski, S.; Dziura, A.; Kossakowski, A.

1998-01-01

Authors review the history of radon monitoring. Epidemiological studies of lung cancer and its correlation to radon concentration in mines and buildings are described. The influence of radon on animals living in the buildings built from waste materials is described. Authors review plans concerning creation of radon monitoring system in Poland. The necessity of monitoring influence of radon on animals is described

Monitoring of radon concentration in dwellings

International Nuclear Information System (INIS)

Kurosawa, Ryuhei

1991-01-01

Radon problems in dwellings have recently received much attention. Radon concentration in dwellings, as well as in the general environment, varies with various factors such as meteorological conditions and soil components. Therefore, a long term monitoring of radon concentration is required to obtain an average concentration. This paper reviews a passive type radon monitor that is handy and allows a long term radon monitoring. It provides the structure and principle of the radon monitor, covering the type, filter function, sensitivity of diffusion collecting type (cup type), electrostatic collecting type, adsorption collecting type, and detector of radon monitor. Actual examples of the radon monitor are also given. Radon daughter nuclides will have become major foci of exposure countermeasures. In the future, the development of a passive type monitor for determining potential alpha energy concentration is required. (N.K.)

Intercomparison of active and passive instruments for radon and radon progeny in North America

International Nuclear Information System (INIS)

George, A.C.; Tu, Keng-Wu; Knutson, E.O.

1995-02-01

An intercomparison exercise for radon and radon progeny instruments and methods was held at the Environmental Measurements Laboratory (EML) from April 22--May 2, 1994. The exercise was conducted in the new EML radon test and calibration facility in which conditions of exposure are very well controlled. The detection systems of the intercompared instruments consisted of. (1) pulse ionization chambers, (2) electret ionization chambers, (3) scintillation detectors, (4) alpha particle spectrometers with silicon diodes, surface barrier or diffused junction detectors, (5) registration of nuclear tracks in solid-state materials, and (6) activated carbon collectors counted by gamma-ray spectrometry or by alpha- and beta-liquid scintillation counting. 23 private firms, government laboratories and universities participated with a 165 passive integrating devices consisting of: Activated carbon collectors, nuclear alpha track detectors and electret ionization chambers, and 11 active and passive continuous radon monitors. Five portable integrating and continuous instruments were intercompared for radon progeny. Forty grab samples for radon progeny were taken by five groups that participated in person to test and evaluate their primary instruments and methods that measure individual radon progeny and the potential alpha energy concentration (PAEC) in indoor air. Results indicate that more than 80% of the measurements for radon performed with a variety of instruments, are within ±10% of actual value. The majority of the instruments that measure individual radon progeny and the PAEC gave results that are in good agreement with the EML reference value. Radon progeny measurements made with continuous and integrating instruments are satisfactory with room for improvement

Workshop on dosimetry for radon and radon daughters

International Nuclear Information System (INIS)

Turner, J.E.; Holoway, C.F.; Loebl, A.S.

1978-05-01

Emphasis is placed on the dosimetry for radon and daughters, rather than on monitoring and instrumentation. The objectives of the meeting were to exchange scientific information, to identify problem areas in radon-daughter dosimetry, and to make any observations or recommendations by the participants through issuance of this report. The discussion topics included the history of dosimetry for radon and daughters, human data, aerosols, deposition and movement in the respiratory tract, dose calculations, dose-to-working-level-month (WLM) conversion factors, animal experiments, and the development of regulations and remedial criteria for reducing population exposures to radon daughters. This report contains a summary of Workshop discussions plus individual statements contributed by several of the participants. The outstanding problem areas from the standpoint of dosimetry appear to involve the appropriate lung organ mass to be used (average lung-tissue dose vs. high-level local dose); recognition of the discrete, rather than continuous, structure of the mucus; lack of knowledge about lung clearance; the variability of dose with the degree of disequilibrium and the unattached fraction of radon daughters for a given WLM; and questions about the character of uranium mine atmospheres actually breathed in the older mines from which much of the epidemiological information originates. The development of criteria for taking remedial action to reduce exposures involves additional concerns of basing long-term risk assessment on short-term sampling and applying WLM data for miners to general populations

The Montana Radon Study: social marketing via digital signage technology for reaching families in the waiting room.

Science.gov (United States)

Larsson, Laura S

2015-04-01

I tested a social marketing intervention delivered in health department waiting rooms via digital signage technology for increasing radon program participation among priority groups. I conducted a tri-county, community-based study over a 3-year period (2010-2013) in a high-radon state by using a quasi-experimental design. We collected survey data for eligible participants at the time of radon test kit purchase. Radon program participation increased at the intervention site (t38 = 3.74; P = .001; 95% confidence interval [CI] = 4.8, 16.0) with an increase in renters (χ(2)1,228 = 4.3; P = .039), Special Supplementary Nutrition Program for Women, Infants, and Children families (χ(2)1,166 = 3.13; P = .077) and first-time testers (χ(2)1,228 = 10.93; P = .001). Approximately one third (30.3%; n = 30) attributed participation in the radon program to viewing the intervention message. The intervention crossover was also successful with increased monthly kit sales (t37 = 2.69; P = .01; 95% CI = 1.20, 8.47) and increased households participating (t23 = 4.76; P signage technology by 2 health departments.

The Pennsylvania radon story

International Nuclear Information System (INIS)

Gerusky, T.M.

1987-01-01

In December 1984, the Pennsylvania Bureau of Radiation Protection found itself confronted with the discovery of a home in eastern Pennsylvania having the highest level of radon daughters ever reported. The Bureau responded with a massive radon monitoring, educational, and remediation effort. As of November, 1986, over 18,000 homes had been screen for radon daughters, of which approximately 59% were found to have levels in excess of the 0.020 Working Level guideline. Pennsylvania's response to the indoor radon problem is detailed in this article

Radon problems

International Nuclear Information System (INIS)

Cohen, B.L.

1985-01-01

This chapter examines the health hazards resulting from the release of naturally occurring radioactive gas derived from the decay of uranium. It is estimated that random inhalation is now causing about 10,000 fatal lung cancers per year in the US. Radon is constantly being generated in rocks and soils (in which uranium is naturally present) and in materials produced from them (e.g., brick, stone, cement, plaster). It is emphasized that radon levels in buildings are typically 5 times higher than outdoors because radon diffusing up from the ground below or out of bricks, stone, cement, or plaster is trapped inside for a relatively long time

Unattached radon daughter atoms and radon daughter equilibrium ratios in uranium mines. Final report

International Nuclear Information System (INIS)

Holaday, D.A.

1972-01-01

Uranium mines in Colorado and New Mexico were surveyed for airborne concentrations of radon (10043922) and radon daughters. A procedure for measuring individual daughters and the fraction of each existing as free atoms was developed and used for field monitoring. Samples were taken in working areas and particle counts were made. The data was analyzed to determine the ratio of radon to radon daughters as well as the ratios among the radon daughters. The author concludes that since the radon to working level ratios have not changed much in 20 years, using the ratio as the basis for estimating relative biological hazard is just as uncertain now as then. The large number of daughters present as free atoms indicate that the lung radiation doses calculated using any of the lung models need reexamination

Measurement of minute local strain in semiconductor materials and electronic devices by using a highly parallel X-ray microbeam

CERN Document Server

Matsui, J; Yokoyama, K; Takeda, S; Katou, M; Kurihara, H; Watanabe, K; Kagoshima, Y; Kimura, S

2003-01-01

We have developed an X-ray microbeam with a small angular divergence by adopting X-ray optics with successive use of asymmetric Bragg reflection from silicon crystals for the both polarizations of the synchrotron X-rays. The microbeam actually obtained is several microns in size and possesses an angular divergence of less than 2 arcsec which enables us to measure the strain of 10 sup - sup 5 -10 sup - sup 6. By scanning the sample against the microbeam, distribution of the minute local strain in various regions of semiconductor crystals for electronic devices, e.g., the strain around the SiO sub 2 /Si film edge in silicon devices, the strain in an InGaAsP/InP stripe laser were measured.

Measurement of minute local strain in semiconductor materials and electronic devices by using a highly parallel X-ray microbeam

Energy Technology Data Exchange (ETDEWEB)

Matsui, J. E-mail: matsui@sci.himeji-tech.ac.jp; Tsusaka, Y.; Yokoyama, K.; Takeda, S.; Katou, M.; Kurihara, H.; Watanabe, K.; Kagoshima, Y.; Kimura, S

2003-01-01

We have developed an X-ray microbeam with a small angular divergence by adopting X-ray optics with successive use of asymmetric Bragg reflection from silicon crystals for the both polarizations of the synchrotron X-rays. The microbeam actually obtained is several microns in size and possesses an angular divergence of less than 2 arcsec which enables us to measure the strain of 10{sup -5}-10{sup -6}. By scanning the sample against the microbeam, distribution of the minute local strain in various regions of semiconductor crystals for electronic devices, e.g., the strain around the SiO{sub 2}/Si film edge in silicon devices, the strain in an InGaAsP/InP stripe laser were measured.

Modeling the potential impacts of different radon policies for the U.S. housing stock

International Nuclear Information System (INIS)

Peterson, M.D.; Ritchie, I.M.

1995-01-01

According to the Environmental Protection Agency (EPA) and other public health agencies in the United States, radon may be the leading cause (along with passive smoking) of lung cancer deaths among nonsmokers. Radon is estimated to be the second leading cause of lung cancer death in smokers behind smoking-related lung cancer. EPA estimates that 7,000 to 30,000 lung cancer deaths each year are due to radon exposure. (It is implied that radon-related lung cancer deaths can be prevented by reducing radon levels below EPA's guideline levels). Current EPA radon policy is based on a strategy of education, the transfer of testing and remediation technologies to the public and private sectors, and recently proposed radon-resistant construction standards for new homes. This paper models the effectiveness of current proposed, and alternative policies for reducing radon risks in U.S. residential construction. The results of our analysis suggest that EPS's projections of 2,200 'lives saved annually' as a result of its current action level of 4 pCi/l will not be achieved with its current policy in the near future. Overall, the response of radon-related mortality to most policy options is delayed and flat due in part to the large number of houses with low radon levels and the long latency period between radon exposure and the development of cancer. The modeling results suggest that more aggressive smoking reduction programs may yield greater benefits in overall lung cancer mortality (but not reduced radon exposure) than most radon-related policies. (au)

Decommissioning/closeout of Malargue site: measurement of radon daughter

International Nuclear Information System (INIS)

Avila Cadena, Guadalberto

2000-01-01

In Malargue complex there are about 700,000 mt of uranium tailings disposed off during 32 years of operation of the Malargue facility. The objective of the Malargue Site is to undertake the necessary actions to execute remediation programs. A summary of measurements of concentrations of radon daughter taken in different buildings of the city and in the field shows the influence of radon source. The results obtain for concentrations of radon daughter indicate that they do not differ significantly between each others. The environmental remediation of uranium mill tailings at Malargue Site is a requirement of Nuclear Regulatory Authority (NRA) and of the Mendoza province and a commitment to reduce the doses as low as reasonably achievable, social and economic factors being taken into account (ALARA concept). (author)

Radon - The management of the risk related to radon

International Nuclear Information System (INIS)

2010-01-01

This leaflet briefly explains what radon is, where it comes from, and what it becomes. It indicates and briefly comments its concentrations in French departments, describes how radon can affect our health (lung cancer), describes how the risk can be reduced in buildings, and indicates the existing regulatory provisions

Radon programmes and health marketing

International Nuclear Information System (INIS)

Fojtikova, I.; Rovenska, K.

2011-01-01

Being aware of negative health effects of radon exposure, many countries aim for the reduction of the radon exposure of their population. The Czech radon programme was commenced >20 y ago. Since then experts have gathered a lot of knowledge, necessary legislation has been enacted, tens of thousands of inhabitants have been offered free measurement and subsidy for the mitigation. Despite the effort, the effectiveness of the radon programme seems to be poor. Newly built houses still exhibit elevated radon concentrations and the number of houses mitigated is very low. Is it possible to enhance the effectivity of radon programme while keeping it on a voluntary basis? One possible way is to employ health marketing that draws together traditional marketing theories and science-based strategies to prevention. The potential of using marketing principles in communication and delivery of radon information will be discussed. (authors)

Simulation model of lung cancer incidence related to smoking and radon daughter exposure

International Nuclear Information System (INIS)

Stolowijk, J.A.J.

1990-01-01

A mathematical model of lung cancer and radon daughter exposure is presented. It is aimed to provide a quantitative estimate in the form of dose-effect relationship. The nature of the cigarette smoking and radon exposure interaction it is shown to be a multiplicative or sub-multiplicative function rather than a simpler model in which the effect of the two exposures would be summed. The model was written in the SAS programming language. An annotated listing of the program is given. 4 refs

Radon in buildings

International Nuclear Information System (INIS)

Ryan, N.M.; Finn, M.

1995-01-01

This guide is intended to inform designers, contractors, householders and other building owners about radon in buildings and to provide guidance where it has been decided to take action to reduce radon levels. It gives some pointers to good practice insofar as it relates to non complex buildings of normal design and construction. Reference is made to the usual ways of reducing l;levels of radon and guidance is given on sources of further information. I

Radon in dwellings the national radon survey Galway and Mayo

International Nuclear Information System (INIS)

McGarry, A.T.; Fennell, S.G.; Mackin, G.M.; Madden, J.S.; O'Colmain, M.

1999-07-01

This report presents the results of the final phase of the National Radon Survey carried out by the Radiological Protection Institute of Ireland. The counties included in this phase are Galway and Mayo. The average radon concentrations for the houses measured in these counties were 112 Bq/m 3 and 100 Bq/m 3 , respectively. The measurement data were grouped on the basis of the 10 km grid squares of the Irish National Grid System and used to predict the percentage of dwellings in each grid square which exceeds the Reference Level of 200 Bq/m 3 . Grid squares where this percentage is predicted to be 10% or higher are designated High Radon Areas. The health effects of exposure to high radon levels are discussed and recommendations are made regarding both new and existing dwellings. (author)

The use of mechanical ventilation with heat recovery for controlling radon and radon-daughter concentrations

International Nuclear Information System (INIS)

Nazaroff, W.W.; Boegel, M.L.; Hollowell, C.D.; Roseme, G.D.

1980-01-01

An energy research house in Maryland was found to have radon concentrations far in excess of recommended guidelines. A mechanical ventilation system with heat recovery was installed in this house to test its effectiveness as an energy-efficient control technique for indoor radon. Radon concentration was monitored continuously for two weeks under varying ventilation conditions (0.07 to 0.8 air changes per hour (ach)) and radon daughter concentrations were measured by grab-sample techniques about nine times daily during this period. At ventilation rates of 0.6 ach and higher radon and radon daughter levels dropped below guidelines for indoor concentrations. Comparison with other studies indicates that indoor radon buildup may be a problem in a considerable portion of houses characterized by their low infiltration rates. The use of mechanical ventilation systems with air-to-air heat exchangers may offer a practical, cost-effective, and energy-efficient means of alleviating not only the radon problem specifically but also the general deterioration of indoor air quality in houses designed or retrofitted to achieve low infiltration

Measurement of radon concentration in water using the portable radon survey meter.

Science.gov (United States)

Yokoyama, S; Mori, N; Shimo, M; Fukushi, M; Ohnuma, S

2011-07-01

A measurement method for measuring radon in water using the portable radon survey meter (RnSM) was developed. The container with propeller was used to stir the water samples and release radon from the water into the air in a sample box of the RnSM. In this method, the measurement of error would be water was >20 Bq l(-1).

Determination of radon flux rates in a uranium mine (Cluff Lake, Saskatchewan)

International Nuclear Information System (INIS)

1989-12-01

The Atomic Energy Control Board contracted SENES Consultants Limited to design and implement a field program at Amok Limited's Cluff Lake uranium mine, with the overall objective of obtaining reliable radon flux data applicable for use in the VENTRAD computer model. The VENTRAD model was developed to model underground mine ventilation systems. To avoid the uncertainties inherent in localized flux measurements made on small surfaces, radon flux measurements were determined through measurement of incremental changes in the concentration of radon between the incoming and outgoing air in selected areas of the underground workings. The locations were selected throughout the mine in both ore and sterile rock. Average radon flux rates measured during three field campaigns were as follows: sterile rock decline 4 pCi/m 2 .second; sterile rock mainway 25 pCi/m 2 .second; worked-out stope 100 pCi/m 2 .second; active work stope 240 pCi/m 2 .second; and work face 14,000 pCi/m 2 .second. Data collected during the three field programs were used to validate the VENTRAD computer model. The results of the validation exercise suggest close agreement between predicted and measured air flow rates and radon concentrations were overestimated for areas immediately impacted by auxiliary ventilation fans and ore transfer mill holes which connect the ore extraction and haulage levels of the mine

1981 radon barrier field test at Grand Junction uranium mill tailings pile

International Nuclear Information System (INIS)

Hartley, J.N.; Gee, G.W.; Baker, E.G.; Freeman, H.D.

1983-04-01

Technologies to reduce radon released from uranium mill tailings are being investigated by Pacific Northwest Laboratory as part of the Department of Energy's Uranium Mill Tailings Remedial Action Project (UMTRAP) Technology development program. These technologies include: (1) earthen cover systems, (2) multilayer cover systems, and (3) asphalt emulsion radon barrier systems. During the summer of 1981, a field test was initiated at the Grand Junction, Colorado, uranium tailings pile to evaluate and compare the effectiveness of each radon barrier system. Test plots cover about 1.2 ha (3 acres). The field test has demonstrated the effectiveness of all three cover systems in reducing radon release to near background levels ( 2 s - 1 ). In conjunction with the field tests, column tests (1.8 m diameter) were initiated with cover systems similar to those in the larger field test plots. The column tests allow a direct comparison of the two test procedures and also provide detailed information on radon transport

Radon and radiation biology of the lung

International Nuclear Information System (INIS)

Crameri, R.; Burkart, W.

1989-01-01

The main papers presented at the meeting dealt with the behaviour of radon and the indoor environment, radiation biology of the lung, lung dosis and the possible cancer risk caused by radon in homes, contamination of the room air. A series of special papers treated the radon problem in detail: sources and transport mechanisms of radon, geological aspects of the radon radiation burden in Switzerland, radon in homes, search for radon sources, and the Swiss radon-programme RAPROS. 67 figs., 13 tabs., 75 refs

Multivariate signal processing in measurements of radon and radon daughters in air

International Nuclear Information System (INIS)

Urbanski, P.; Machaj, B.

2000-01-01

Extensive measurements of radon and radon daughters concentration gauge in a radon chamber were carried out. Count rate 'spectra' against time at the output of radiation detectors were measured and registered. The count rate spectra were then processed employing Principal Component Regression (PCR). A root mean square error of the count rate was estimated. It was found that PCR processing removes a great part of count rate random fluctuations originating from the radiation statistics that results in a decrease of count rate random error. The root mean square error of count rate in a radon daughter monitor is about 3 times lower, which is equivalent to the error of the gauge with a 9 times higher air flow rate if no PCR processing is used. In case of the radon concentration gauge the increase of sensitivity is even higher and amounts to 5 times. (author)

Variation of radon levels in US homes with various factors

International Nuclear Information System (INIS)

Cohen, B.L.; Gromicko, N.

1988-01-01

A program combining 70,000 purchased and 3500 random selection-no charge measurements with extensive questionnaires is described. Methods for reducing biases in purchased measurements have been reasonably successful. Distributions are roughly lognormal with σ/sub g/ ≅ 3.0 but with an excess of very high measurements. Winter and spring-fall measurements average about 60 percent and 40 percent, respectively, higher than summer measurements. Basements average 2.5 times higher radon levels than upper floors. Tightening of homes since 1974 has increased radon levels by less than 10 percent, but well-weatherized houses have ∼ 40 percent higher levels than poorly weatherized houses. Open windows reduce levels by a factor of about 2.5. Low-cost newer houses have much lower levels than more expensive newer houses, but among older houses this is reversed. Low income families have substantially lower radon levels than average. There is little variation with education level. Nonsmokers have higher radon levels than smokers, but this seems to apply mainly to living rooms and dining rooms. Suburban houses have higher levels than urban, and rural houses have still higher levels. Owner-occupied houses have much higher levels than rented houses. Variations of radon levels with weatherization do not seem to be due to cost factors. A strategy for locating areas with high mean radon levels is described

Radon measurements in indoor workplaces

International Nuclear Information System (INIS)

Tokonami, S.; Matsumoto, M.; Furukawa, M.; Fujimoto, K.; Fujitaka, K.; Pan, J.; Kurosawa, R.

1996-01-01

Radon measurements in several office buildings located in Tokyo were carried out with two types of device to study the time-dependent radon concentration in indoor workplaces. Both types of device use the electrostatic field for the collection of 218 Po onto the electrode of the detector. One provides an average radon concentration throughout the day. The other, in which a weekly timer is installed in the circuit of the electrode of the device, provides an average radon concentration during working hours (9:00-17:00, Monday-Friday). Although radon concentrations in Japanese dwellings have been found to be generally low, relatively high concentrations were observed in the office buildings. No consistent seasonal variation was recognised in this study. Little difference of average radon concentrations between working hours and the whole day was found throughout the year in two offices. On the other hand, a significant difference was observed in other offices. The operation of an air conditioner might change the radon concentration during working hours. From the results of radon measurements the average effective dose in the workplace was estimated to be 0.23 mSv for 2000 working hours in a year. (Author)

Radon studies in Indian dwellings

International Nuclear Information System (INIS)

Khan, A.J.

2000-01-01

The indoor radon ( 222 Rn) concentration has been measured by Solid State Nuclear Track Detectors (SSNTDs) in large number of Indian dwellings. Radon concentrations were measured in different parts of the country. In the first study, radon concentrations were measured in 143 dwellings of Udaipur, Bikaner and Banswara towns of Rajasthan province. The distributions of the time-averaged indoor radon concentration in these three towns of the Rajasthan fit an approximately log normal distribution. The geometric mean (GM) values of radon concentrations in these three places were found to be 74 Bq m -3 , 46 Bq m -3 and 66 Bq m -3 with a geometric standard deviation (GSD) of 2.2, 2.2 and 2.5 respectively. In another study, radon concentrations were measured in about 150 dwellings of hilly regions of the country. The measurements were carried out in Kohima (Nagaland), Baijnath and Palampur (Himachal Pradesh). The distribution of radon concentration in Kohima dwellings was found to be approximately log normal, however, the radon distribution in Baijnath and Palampur dwellings seems to be bimodal. The GM values of the radon concentrations for 65 dwellings in Kohima and 43 dwellings in Baijnath and Palampur were 88 Bq m -3 and 134 Bq m -3 with GSD of 1.7 and 2.5 respectively. The results are discussed in detail. (author)

Review of selected state-of-the-art applications of diagnostic measurements for radon-mitigation planning. Report for April 1986-June 1987

International Nuclear Information System (INIS)

Hubbard, L.M.; Harrje, D.T.; Gadsby, K.J.; Sanchez, D.C.; Turk, B.H.

1987-09-01

Since late-1984, EPA's AEERL has supported a program to develop and demonstrate radon-mitigation techniques for single-family detached dwellings. As part of the program, projects have been started, directed at developing and demonstrating the use of diagnostic measurements in all phases of the radon-mitigation process. Diagnostic measurements are used to assess: (1) the radon sources strengths, variability, and locations; and, (2) radon transport to the house and its entry and distribution in the house as influenced by environmental, house characteristics, and occupancy factors. The diagnostic measurements reported include: (1) soil-gas grab sampling; (2) communication (air flow or pressure-field extension) tests; (3) whole house infiltration; (4) differential pressure, (5) gamma radiation; and, (6) radon flux. The paper concludes that the above selected diagnostic measurements were especially useful in characterizing houses with indoor radon problems attributable to soil-gas-borne radon that may be amenable to mitigation through the use of subslab ventilation

Cost-benefit considerations in the development of policies and procedures for controlling indoor exposure to radon and its decay products

International Nuclear Information System (INIS)

Puskin, J.S.; Guimond, R.J.; Napolitano, S.; Nelson, C.B.

1989-01-01

The applicability of ALARA to the problem of controlling residential radon levels is limited. Cost-benefit considerations can nevertheless be useful in guiding policy in this area. From a societal perspective, the cost-benefit balance for mitigating radon in homes to the EPA action level of 4 pCi/L, or lower, is generally better than for most programs aimed at reducing environmental risks. Reduction of radon levels in new homes tends to be less costly; moreover, reduced radon levels in new construction may be achievable with a net cost savings to the homeowner due to concomitant decreases in energy expenses. Since programs to reduced radon exposure rely on voluntary actions by homeowners, the societal cost-benefit balance cannot dictate the extent of radon mitigation efforts. However, both economic incentives and governmental guidance can influence these efforts. Cost-benefit analysis can be an important tool in formulating such guidance

Radon prevention coating in hot and humid environment

International Nuclear Information System (INIS)

Yang Yushan; Dong Faqin; Deng Yuequan; Qu Ruixue

2013-01-01

The radon prevention performance of a new self-made radon prevention coating was researched in the radon contamination provided by the releasing radon modules. With coating thickness of 0.8 mm, the radon mitigation efficiency in 1 # radon module concentration is optimal when the addition of defoaming agent is 0.3% (mass fraction). The radon mitigation efficiency increases with the coating thickness when the defoaming agent of 0.3% is added, but the radon mitigation efficiency tends to be stable as the coating thickness is more than 2.0 mm. The radon mitigation efficiency of radon prevention coating appended precipitated barium sulphate decreases obviously, and the addition of ash calcium, white cement and gesso don't decrease radon mitigation efficiency. The addition of white cement and gesso addition affects the radon prevention stability, while radon mitigation efficiency of radon prevention coating with ash calcium keeps a good performance. Under the hot and humid environment, the radon prevention coating still has good radon mitigation efficiency in 2 # radon module concentration. (authors)

Radon in homes: The Alaskan experience

International Nuclear Information System (INIS)

Seifert, R.D.

1990-01-01

For the past four years, since radon was first found to be a concern in Alaska in 1986, the interest and awareness of radon as a special housing and health concern has continued to grow. This paper will discuss the features of a house in Alaska which would characterize it as at risk for radon, and also those efforts at mitigation which have been most effective in reducing radon under Alaskan conditions. Clearly radon must be able to enter a home in order to be a problem. Riefenstuhl and Kline (personal communication, 1988) have analyzed the conditions for radon transport from soils to home interiors very lucidly through the following scheme: four factors must exist in a house locale for it to be a radon at risk house. Two of the factors are geological in nature: (1) there must be adequate uranium and therefore ample radon to provide a source for transport; (2) there must be enough permeability in the soil to allow rapid soil gas movement to carry radon from its origin to the interior of the home within two half-lives of time (six days) or so. The other two factors are determined by the structure of the house itself and the way in which it is operated: (3) the house must have soil contact and imperfections, holes, cracks, intentional perforations which allow movement of soil gas with radon through the envelope of the basement or crawlspace; (4) there must be a lower pressure inside the house than in the soil so that soil gas flows into the house. All four of these characteristics are required to have radon be a problem. The absence of any single characteristic will eliminate radon (in general). This presents a series of options for mitigation of radon then, since elimination of any of the four characteristics will mitigate radon

Monitoring for radon in water

International Nuclear Information System (INIS)

Deininger, R.A.

1994-01-01

This article focuses on radionuclides elements of interest to utilities and consumers alike. Each of these groups may be interested in a low-cost radiation detector that can be connected to a laptop or desktop computer through either the serial or the parallel port. A complete set of software comes with the detector, and a detailed manual describes operation of the program and discusses the various forms of common radiation sources in a home. Computer programs can run in the foreground and display a scrolling bar chart or in the background while the incoming data are logged, so the user can continue to work on the computer. Data are automatically stored on a disk file. Data collection times can be set for minutes, hours, days, or weeks, thus allowing long-term trends to be identified. The detector can be connected to the computer by a modular telephone cable and can be placed as far away as several hundred feet. Utilities that use surface water supplies are unlikely to detect any radon. Only those plants that use groundwater supplies from areas where radioactive materials are in the ground will have some radon in the water

A calibration facility for radon fluxmeter

International Nuclear Information System (INIS)

Li Xianjie; Qiu Shoukang; Zhou Jianliang; Liu Chunkui; Pan Jialin; Yang Mingli

1998-01-01

Calibration facilities for radon fluxmeter with three kinds of different emanation medium have been developed. The stability of radon flux is 5%, 9% (RSD) respectively. The uniformity of radon flux is 4.5%, 8.5% (RSD) respectively. These specifications fulfill the calibration requirement for radon fluxmeter. The determination of radon flux of facility takes full account of eliminating the main error source-attenuation effect (including leakage and back diffusion etc.): not only prevent attenuation and make a relevant correction. Therefore the accuracy of determination is assured. The calibration, intercomparison of radon flux meter and the quantitatively evaluation on the measurement method of radon flux are made to be possible by the successful establishment of this facility. (author)

Automatically processed alpha-track radon monitor

International Nuclear Information System (INIS)

Langner, G.H. Jr.

1993-01-01

An automatically processed alpha-track radon monitor is provided which includes a housing having an aperture allowing radon entry, and a filter that excludes the entry of radon daughters into the housing. A flexible track registration material is located within the housing that records alpha-particle emissions from the decay of radon and radon daughters inside the housing. The flexible track registration material is capable of being spliced such that the registration material from a plurality of monitors can be spliced into a single strip to facilitate automatic processing of the registration material from the plurality of monitors. A process for the automatic counting of radon registered by a radon monitor is also provided

The householders' guide to radon

International Nuclear Information System (INIS)

1988-06-01

This guide is a follow-up to the leaflet Radon in Houses which was issued previously by the Department of the Environment. It is intended for people who live in areas with high levels of radon. It is written particularly for householders whose homes have already been tested and found to have an appreciable level of radon. It explains what radon is, how it gets into houses and what the effects on health may be. It also outlines some of the ways of reducing the level of radon and gives guidance both on how to get the work done and likely costs. (author)

Radon surveys and their implications

International Nuclear Information System (INIS)

Miles, J.C.H.; Cliff, K.D.; Dixon, D.W.; Green, B.M.R.; Strong, J.C.

1989-01-01

In the UK, as in other countries, radon daughter inhalation is the most significant cause of human exposure to ionising radiation either at home or at work whether one considers the mean or the maximum dose. Substantial studies of radon are under way in the UK, and the importance of radon is recognised in several spheres. NRPB investigations of the radon levels in buildings and mines are reported, the distributions of doses presented and risk factors calculated. The bases of radon limitation for workers and members of the public are given and the means of compliance discussed. (author)

Radon exposure and lung cancer

International Nuclear Information System (INIS)

Planinic, J.; Vukovic, B.; Faj, Z.; Radolic, V.; Suveljak, B.

2003-01-01

Although studies of radon exposure have established that Rn decay products are a cause of lung cancer among miners, the lung cancer risk to the general population from indoor radon remains unclear and controversial. Our epidemiological investigation of indoor radon influence on lung cancer incidence was carried out for 201 patients from the Osijek town. Ecological method was applied by using the town map with square fields of 1 km 2 and the town was divided into 24 fields. Multiple regression study for the lung cancer rate on field, average indoor radon exposure and smoking showed a positive linear double regression for the mentioned variables. Case-control study showed that patients, diseased of lung cancer, dwelt in homes with significantly higher radon concentrations, by comparison to the average indoor radon level of control sample. (author)

Radon and radon-daughter concentrations in air in the vicinity of the Anaconda Uranium Mill

International Nuclear Information System (INIS)

Momeni, M.H.; Lindstrom, J.B.; Dungey, C.E.; Kisieleski, W.E.

1979-11-01

Radon concentration, working level, and meteorological variables were measured continuously from June 1977 through June 1978 at three stations in the vicinity of the Anaconda Uranium Mill with measurements integrated to hourly intervals. Both radon and daughters show strong variations associated with low wind velocities and stable atmospheric conditions, and diurnal variations associated with thermal inversions. Average radon concentration shows seasonal dependence with highest concentrations observed during fall and winter. Comparison of radon concentrations and working levels between three stations shows strong dependence on wind direction and velocity. Radon concentrations and working-level distributions for each month and each station were analyzed. The average maximum, minimum, and modal concentration and working levels were estimated with observed frequencies. The highest concentration is 11,000 pCi/m 3 on the tailings. Working-level variations parallel radon variations but lag by less than one hour. The highest working levels were observed at night when conditions of higher secular radioactive equilibrium for radon daughters exist. Background radon concentration was measured at two stations, each located about 25 km from the mill, and the average is 408 pCi/m 3 . Average working-level background is 3.6 x 10 -3

External gamma exposure to radon progeny in indoor air

International Nuclear Information System (INIS)

Fujimoto, Kenzo

1985-01-01

The external γ-exposure from radon progeny uniformly distributed in indoor air was estimated by a computer program that was developed. This program can calculate the fluence rate, exposure rate and average energy for any given point in a room of any given size. As numerical example, the exposure rate normalized to unit airborne activity is presented, together with the fluence-weighted and exposure-weighted average photon energies, for a room of representative geometry containing radon progeny in equilibrium. To cover other conditions encountered in practice, quantitative evaluations are additionally presented of the effect on the exposure brought by changes in certain parameters, such as equilibrium factor, wall thickness, room size and receptor position. The study has quantitatively substantiated the prevailing postulate that the effective dose equivalent due to external exposure resulting from normal indoor concentrations of airborne radon progeny in the room of representative geometry should only amount to 0.04 % of that from the internal exposure from the same sources, and that it should be of similarly negligible order compared with internal exposure also in the case of other room geometries. (author)

Consumer's Guide to Radon Reduction

Science.gov (United States)

... Labs and Research Centers Radon Contact Us Share Consumer's Guide to Radon Reduction: How to Fix Your ... See EPA’s About PDF page to learn more. Consumer's Guide to Radon Reduction: How to Fix Your ...

The ORNL Indoor Air Quality Study: Re-cap, Context, and Assessment on Radon

Energy Technology Data Exchange (ETDEWEB)

Tonn, Bruce Edward [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Rose, Erin M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ternes, Mark P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2015-10-01

As part of the retrospective evaluation of the U.S. Department of Energy s low-income Weatherization Assistance Program that was led by Oak Ridge National Laboratory (ORNL), an assessment of the impacts of weatherization on indoor air quality (IAQ) was conducted. This assessment included nearly 500 treatment and control homes across the country. Homes were monitored for carbon monoxide, radon, formaldehyde, temperature and humidity pre- and post-weatherization. This report focuses on the topic of radon and addresses issues not thoroughly discussed in the original IAQ report. The size, scope and rigor of the radon component of the IAQ study are compared to previous studies that assessed the impacts of weatherization on indoor radon levels. It is found that the ORNL study is by far the most extensive study conducted to date, though the ORNL results are consistent with the findings of the other studies. However, the study does have limitations related to its reliance on short-term measurements of radon and inability to attribute changes in radon levels in homes post-weatherization to specific weatherization measures individually or in combination.

Radon programme in the Czech Republic

International Nuclear Information System (INIS)

Hulka, J.; Thomas, J.

2003-01-01

The framework of the Radon programme in the Czech republic includes both precautionary measures and interventions. The programme informally started in early eighties has been now incorporated in national legislation (Atomic Act, Radiation Protection Decree, etc.). Aim of precautionary measures is to avert construction of building above natural radiation guidance levels (200 Bq/m 3 for indoor radon concentration and 0.5 Sv/h for gamma dose rate) by protection of new buildings against soil radon ingress, by regulation of natural radioactivity in building materials and supplied water. Aim of interventions is to identify buildings affected by enhanced natural radioactivity and help owners to put into effect reasonable remedial measures. Two sets of intervention levels for indoor natural exposure were established: guidance intervention levels 400 Bq/m 3 (indoor radon), 1.0 Sv/h (indoor gamma dose rate) and limit values 4000 Bq/m 3 and 10 Sv/h. The radon programme is based both on governmental and private activities. The governmental activities include representative and targeted indoor radon survey, subsidy for radon mitigation, mitigation test measurements and public information on radon issue. The private activities include radon measurement (radon index of building site, indoor measurements, radon diagnosis) and remedial measures. More than 100 commercial companies were authorised by Radiation Protection Authority (SUJB) to provide these measurements

Radon survey techniques

International Nuclear Information System (INIS)

Anon.

1976-01-01

The report reviews radon measurement surveys in soils and in water. Special applications, and advantages and limitations of the radon measurement techniques are considered. The working group also gives some directions for further research in this field

Comparison of retrospective and contemporary indoor radon measurements in a high-radon area of Serbia

International Nuclear Information System (INIS)

Zunic, Z.S.; Yarmoshenko, I.V.; Kelleher, K.; Paridaens, J.; Mc Laughlin, J.P.; Celikovic, I.; Ujic, P.; Onischenko, A.D.; Jovanovic, S.; Demajo, A.; Birovljev, A.; Bochicchio, F.

2007-01-01

In Niska Banja, Serbia, which is a high-radon area, a comparison was made between two retrospective radon measuring methods and contemporary radon measurements. The two retrospective methods derive the radon concentrations that occurred in dwellings over longer periods in the past, based on the amount of trapped 210 Po on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted 210 Po in glass objects and contemporary radon in air were measured in 46 rooms, distributed in 32 houses of this radon spa-town, using a dual alpha track detector configuration (CR-39 and LR115) and CR-39 track etched detectors, respectively. In addition to the use of surface trap measurements, in 18 rooms (distributed in 15 houses) VT samples of suitable material were also collected, allowing to compare ST and VT retrospective radon concentration estimates. For each room, contemporary annual radon concentrations (CONT) were measured or estimated using seasonal correction factors. The distribution of the radon concentration in all data sets was found to be close to lognormal (Chi-square test > 0.05). Geometric means (GM) are similar, ranging from 1040 to 1380 Bq m -3 , whereas geometric standard deviations (GSD) for both the retrospective methods are greater than for the CONT method, showing reasonable agreement between VT, ST and CONT measurements. A regression analysis, with respect to the lognormal distribution of each data set, shows that for VT-ST the correlation coefficient r is 0.85, for VT-CONT r is 0.82 and for ST-CONT r is 0.73. Comparison of retrospective and contemporary radon concentrations with regard to supposed long-term indoor radon changes further supports the principal agreement between the retrospective and conventional methods

The use of track registration detectors to reconstruct contemporary and historical airborne radon ( sup 2 sup 2 sup 2 Rn) and radon progeny concentrations for a radon-lung cancer epidemiologic study

CERN Document Server

Steck, D J

1999-01-01

Epidemiologic studies that investigate the relationship between radon and lung cancer require accurate estimates for the long-term average concentrations of radon progeny in dwellings. Year-to-year and home-to-home variations of radon in domestic environments pose serious difficulties for reconstructing an individual's long-term radon-related exposure. The use of contemporary radon gas concentrations as a surrogate for radon-related dose introduces additional uncertainty in dose assessment. Studies of glass exposed in radon chambers and in a home show that radon progeny deposited on, and implanted in, glass hold promise for reconstructing past radon concentrations in a variety of atmospheres. We developed an inexpensive track registration detector for the Iowa Radon Lung Cancer Study (IRLCS) that simultaneously measures contemporary airborne radon concentrations, surface deposited alpha activity density, and implanted sup 2 sup 1 sup 0 Po activity density. The implanted activity is used to reconstruct the cum...

Quality assurance for radon measurements in Germany

International Nuclear Information System (INIS)

Beck, T.R.; Buchroeder, H.; Foerster, E.; Schmidt, V.

2005-01-01

Full text: Radiation protection regarding work activities at workplaces with naturally occurring radiation has been regulated in the German Radiation Protection Ordinance. Regulations refer only to workplaces where the presence of natural radiation leads to a significant increase in the exposure of workers. These workplaces were identified in the following working areas with enhanced exposures to radon-222: underground mines, including visitor mines and show caves; radon-spas and galleries; water supply and distribution industries. Presently, regulations are being initiated by the German government to limit the exposures to radon in homes. For radon measurements at workplaces passive radon devices for individual monitoring as well as active measuring systems for workplace monitoring can be used. However, passive radon devices are preferred for radon measurements in homes because of low costs and availability in large quantities. To assure the quality of radon measurements the German Federal Office for Radiation Protection (BfS) has established annual interlaboratory comparisons for passive radon devices. The comparisons are carried out in the BfS radon calibration laboratory accredited by the German Calibration Service. Passive radon devices which use solid state track detectors, electrets or activated charcoal can be submitted. Approved radon services which offer radon measurements to determine radon exposure in homes and at workplaces have to pass the comparisons successfully. (author)

Metrology of the radon in air volume activity at the italian radon reference chamber

Energy Technology Data Exchange (ETDEWEB)

Sciocchetti, G.; Cotellessa, G.; Soldano, E.; Pagliari, M. [Istituto Nazionale di Metrologia delle Radiazioni Ionizzanti, ENEA Centro Ricerche Casaccia Roma (Italy)

2006-07-01

The approach of the Italian National Institute of Ionising Radiations (I.N.M.R.I.-ENEA) on radon metrology has been based on a complete and integrated system which can be used to calibrate the main types of {sup 222}Rn in air measuring instruments with international traceability. The Italian radon reference chamber is a research and calibration facility developed at the Casaccia Research Center in Roma. This facility has an inner volume of one m{sup 3}. The wall is a cylindrical stainless steel vessel coupled with an automated climate apparatus operated both at steady and dynamic conditions. The control and data acquisition equipment is based on Radotron system, developed to automate the multitasking management of different sets of radon monitors and climatic sensors. A novel approach for testing passive radon monitors with an alpha track detector exposure standard has been developed. It is based on the direct measurement of radon exposure with a set of passive integrating monitors based on the new ENEA piston radon exposure meter. This paper describes the methodological approach on radon metrology, the status-of-art of experimental apparatus and the standardization procedures. (authors)