H. Friedmann - Academia.edu (original) (raw)

Papers by H. Friedmann

Applied Radiation and Isotopes, 2017

In this study the radon activity concentration of water samples from the so called "Thermenlinie"... more In this study the radon activity concentration of water samples from the so called "Thermenlinie" are measured using two different techniques: currents measured with an ionisation chamber setup developed by H. Friedmann are compared with results obtained using a commercially available AlphaGUARD. A fit to compensate for measurements made in non-equilibrium state is applied and the detection limit is estimated. Highlights  Comparison and evaluation of radon measurement techniques  AlphaGUARD and ionisation chamber measurement generally in good agreement  Water samples from spa and drinking water springs were measured  Samples taken in "Thermenlinie" region in Austria

Radiation Protection Dosimetry, 2011

The observation of anomalies in the radon concentration in soil gas and ground water before earth... more The observation of anomalies in the radon concentration in soil gas and ground water before earthquakes initiated systematic investigations on earthquake precursor phenomena. The question what is needed for a meaningful earthquake prediction as well as what types of precursory effects can be expected is shortly discussed. The basic ideas of the dilatancy theory are presented which in principle can explain the occurrence of earthquake forerunners. The reasons for radon anomalies in soil gas and in ground water are clarified and a possible classification of radon anomalies is given.

The chapter deals with basic aspects related to natural ionizing radioactivity and focuses on the... more The chapter deals with basic aspects related to natural ionizing radioactivity and focuses on the main parameters to be controlled in building products. The definitions of ionizing radioactivity in general, parent and daughter nuclides, different types of ionizing radiation (i.e., alpha, beta, gamma, and X-rays), external and internal radiation, naturally occurring radioactive materials (NORM), and naturally occurring radionuclides (NOR), are introduced and explained. The structure of radiation dose is discussed. It is shown that 80% of the dose has natural origin and besides medicine, only about 1% comes from artificial radioactivity, while the major segment of the natural radiation comes from the exposure to radon (including thoron). It is concluded that the main parameter characterizing the external radiation dose, created solely by building materials of mineral origin, is the activity concentration of the three main natural radionuclides: 232Th, 226Ra (in a state of radioactive ...

Abstract This chapter describes the most important measure methods to determine the activity conc... more Abstract This chapter describes the most important measure methods to determine the activity concentration of gamma emitting radionuclides, the measurement of dose rates, and the determination of radon concentrations as well as radon exhalation rates. Several aspects concerning sampling, detector calibration, and uncertainty estimation are discussed.

Tectonophysics, 1988

Radon (2"Rn) concentration has been continuously measured since 1983 in groundwater at a spring a... more Radon (2"Rn) concentration has been continuously measured since 1983 in groundwater at a spring and in subsurface soil gas at five sites along a 200 km segment of the North Anatolian Fault Zone near Bolu, Turkey. The groundwater radon concentration showed a significant increase before the Biga earthquake of magnitude 5.7 on 5 July 1983 at an epicentrat distance of 350 km, and a long-term increase between March 1983 and April 1985. The soil-gas radon concentration showed large changes in 1985, apparently not meteorologically induced. The soil-gas and groundwater data at Bohr did not show any obvious correlation.

Nukleonika, 2010

Because radon (at least in high concentrations) is known as a health risk, it is necessary to red... more Because radon (at least in high concentrations) is known as a health risk, it is necessary to reduce high indoor radon concentrations as well as to take precautions to avoid high indoor concentrations in new buildings. For mitigating existing high radon concentrations, it is necessary to know where the most affected buildings are located. Therefore, the administrations of many countries funded or performed themselves radon surveys to determine the radon exposure of the public and to reveal radon prone areas. But high indoor radon concentrations are not only found in areas where high soil gas radon concentrations exist and vice versa even in areas with a high geogenic radon hazard the indoor radon concentrations need not to be very high. The reason is the different construction-types of houses and partially different living styles of the inhabitants. So, there are two questions and consequently working programmes: Where to mitigate high indoor radon concentra – tions? Where to take s...

Radiation Protection Dosimetry, 2017

The European Basic Safety Standards demand the prediction of areas where a significant number of ... more The European Basic Safety Standards demand the prediction of areas where a significant number of households exceed the reference level for the radon activity concentration. Therefore, radon maps are established which are based on indoor and soil gas measurements. In this study results of soil gas measurements are interpolated to get a value for the radon activity concentration in the soil gas at the coordinates of an indoor measurement and enable a direct comparison of both results. For the interpolation the inverse weighting value is applied. This way a prediction of the indoor radon activity concentration at the location of indoor measurements is attempted for verification. Quotients between the radon activity concentration in soil gas and indoors are analyzed. Building characteristics are also taken into account to evaluate parameters which lead to the reference level being exceeded. The results assist in the interpretation of soil gas measurements regarding the prediction of indoor radon activity concentrations.

Physical Review C, 2021

The reactions 6,7 Li + 27 Al were compared with the reactions 17,18 O + 16 O which form the same ... more The reactions 6,7 Li + 27 Al were compared with the reactions 17,18 O + 16 O which form the same compound nuclei 33,34 S. Cross-section data for the reactions 6,7 Li + 27 Al were derived from experimentally determined γ-ray production cross sections for transitions in several residual nuclei. For the reactions 17,18 O + 16 O experimental results from the literature were used. It could be shown that the weakly bound projectiles 6,7 Li undergo not only fusion processes, but also breakup reactions quite in contrast to the tightly bound projectiles 18 O and 17 O, respectively. Especially below the Coulomb barrier such direct reactions play an important role in competition to complete fusion. Calculations based on the statistical model agree well with the available data for 17,18 O + 16 O, but failed to represent the behavior of the experimentally determined production cross sections for the evaporation residues in the reactions 6,7 Li + 27 Al. But coupled-channel codes and calculations based on a nucleus-nucleus proximity potential are able to reproduce the energy dependence of the complete fusion cross sections.

Radiation Protection Dosimetry, 2014

With the aim to predict the radon potential by geological data, radon soil gas measurements were ... more With the aim to predict the radon potential by geological data, radon soil gas measurements were made in a selected region in Styria, Austria. This region is characterised by mean indoor radon potentials of 130-280 Bq m(-3) and a high geological diversity. The distribution of the individual measuring sites was selected on the basis of geological aspects and the distribution of area settlements. In this work, the radon soil gas activity concentration and the soil permeability were measured at 100 sites, each with three single measurements. Furthermore, the local dose rate was determined and soil samples were taken at each site to determine the activity concentration of natural radionuclides. During two investigation periods, long-term soil gas radon measurements were made to study the time dependency of the radon activity concentration. All the results will be compared and investigated for correlation among each other to improve the prediction of areas with high radon potential.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997

The basic features of VERA, a new AMS facility based on a 3-MV Pelletron tandem accelerator insta... more The basic features of VERA, a new AMS facility based on a 3-MV Pelletron tandem accelerator installed at the University of Vienna, are presented.

Journal of Physics: Conference Series, 2011

The aim of our study is to determine excitation functions for the formation of different reaction... more The aim of our study is to determine excitation functions for the formation of different reaction products with light ions near the Coulomb barrier and to compare the results with computations according to different reaction mechanisms (compound reactions, direct reactions). In the present study results from experiments with a beam of 9 Be on a thin Aluminum target below and around the Coulomb barrier are presented. The formation of several reaction products was determined by the characteristic gamma emissions from these nuclei. Excitation functions of the reactions 27 Al(9 Be, 8 Be→2α) 28 Al, 27 Al(9 Be,2n) 34 Cl, 27 Al(9 Be,pn) 34 S and 27 Al(9 Be,α2n) 30 P with lab energies between 5 and 14 MeV have been determined.

Zeitschrift f�r Physik A Atoms and Nuclei, 1981

Radiation Protection Dosimetry, 2011

Soil gas radon measurements are carried out in a pilot study in three municipalities in Upper Aus... more Soil gas radon measurements are carried out in a pilot study in three municipalities in Upper Austria. The selected municipalities are characterised by a high radon potential. Sixty measuring sites--well distributed over the region and over the different geological areas--were selected. Additionally, the permeability of the soil was determined where the soil gas samples were taken and at various sites where soil samples were analysed by gamma spectrometry. Long-term soil-gas radon concentration measurements are carried out at several sites to study the long-term behaviour of radon activity concentration in soil, the influence of meteorological parameters and seasonal variations. The final goal of the project is to correlate the collected data with geological data and indoor radon concentration. First results of this ongoing study are presented and discussed.

Science of The Total Environment, 2001

ABSTRACT The aim of the Austrian Radon Project (ARP) is to investigate the 222Rn concentration in... more ABSTRACT The aim of the Austrian Radon Project (ARP) is to investigate the 222Rn concentration in 0.3-0.5% of all Austrian dwellings to identify areas with elevated radon exposure. The survey is carried out using short-term and long-term integrating radon detectors covering a population of 2 800 000 persons so far. The homes were randomly selected from the telephone directory. The radon concentration distribution showed a log-normal shape. County-means between 60 and 330 Bq/m3 were found. A radon potential was introduced to deduce a geological risk from the data taken under different circumstances in different types of houses. This radon potential was defined as the annual mean radon concentration in a standard dwelling and is computed by normalizing the measured radon data to this standard dwelling.

Radiation Protection Dosimetry

Tectonophysics, 1988

... Exploration Institute of Turkey (MTA), Ankara (Turkey) (Received October 29,1986; accepted Ma... more ... Exploration Institute of Turkey (MTA), Ankara (Turkey) (Received October 29,1986; accepted March 15,1987) Abstract Friedmann, H., Aric, K., Gutdeutsch, R ... Earlier results of our observations were reported in King (1978, 1980), Friedmann and Hemegger (1978, 1985), Arie et al. ...

Science of The Total Environment, 2007

Indoor radon (Rn) concentrations have been measured intensively in many countries to assess the b... more Indoor radon (Rn) concentrations have been measured intensively in many countries to assess the burden of diseases associated with exposure to this radioactive gas. So-called radon-risk maps have consequently been produced to delineate areas with high levels. Geostatistical techniques are commonly used nowadays to map a range of environmental variables, in particular to generate probability maps of exceeding a given threshold. However, very few case studies in which indoor radon measurements have been investigated using geostatistical techniques have been published so far. By analyzing around 12,000 Rn measurements made in Austrian ground floors during a 10-year survey, we aim here to review and discuss the potential of geostatistics for mapping an environmental variable that shows very strong local variability. In particular, we show how kriging of the scale components can shed new light on various factors that affect the very high spatial variability of the variable.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997

We propose two new detector concepts that may be particularly well suited for AMS measurements wi... more We propose two new detector concepts that may be particularly well suited for AMS measurements with small accelerators: (i) an all solid state AE -E detector for light ions utilizing ion-induced electron emission from thin foils, and (ii) a time-of-flight system that does not use a start foil but derives the start information from the spatial information imposed on the beam by a time dependent deflection field.

Zeitschrift f�r Physik A Atoms and Nuclei, 1976

Radiation protection dosimetry, Jan 24, 2015

According to current European and international recommendations (e.g. by IAEA, WHO and European U... more According to current European and international recommendations (e.g. by IAEA, WHO and European Union), countries shall identify high radon areas. In Austria, this task was initiated already in the early 1990s, which yielded the first Austrian Radon Potential Map. This map is still in use, updated with recent indoor radon data in 2012. The map is based on radon gas measurements in randomly selected dwellings, normalised to a standard situation. To meet the current (legal) requirements, uncertainties in the existing Austrian radon map should be reduced. A new indoor radon survey with a different sampling strategy was started, and possible mapping methods are studied and tested. In this paper, the methodology for the existing map as well as the planned strategies to improve this map is discussed.

Applied Radiation and Isotopes, 2017

In this study the radon activity concentration of water samples from the so called "Thermenlinie"... more In this study the radon activity concentration of water samples from the so called "Thermenlinie" are measured using two different techniques: currents measured with an ionisation chamber setup developed by H. Friedmann are compared with results obtained using a commercially available AlphaGUARD. A fit to compensate for measurements made in non-equilibrium state is applied and the detection limit is estimated. Highlights  Comparison and evaluation of radon measurement techniques  AlphaGUARD and ionisation chamber measurement generally in good agreement  Water samples from spa and drinking water springs were measured  Samples taken in "Thermenlinie" region in Austria

Radiation Protection Dosimetry, 2011

The observation of anomalies in the radon concentration in soil gas and ground water before earth... more The observation of anomalies in the radon concentration in soil gas and ground water before earthquakes initiated systematic investigations on earthquake precursor phenomena. The question what is needed for a meaningful earthquake prediction as well as what types of precursory effects can be expected is shortly discussed. The basic ideas of the dilatancy theory are presented which in principle can explain the occurrence of earthquake forerunners. The reasons for radon anomalies in soil gas and in ground water are clarified and a possible classification of radon anomalies is given.

The chapter deals with basic aspects related to natural ionizing radioactivity and focuses on the... more The chapter deals with basic aspects related to natural ionizing radioactivity and focuses on the main parameters to be controlled in building products. The definitions of ionizing radioactivity in general, parent and daughter nuclides, different types of ionizing radiation (i.e., alpha, beta, gamma, and X-rays), external and internal radiation, naturally occurring radioactive materials (NORM), and naturally occurring radionuclides (NOR), are introduced and explained. The structure of radiation dose is discussed. It is shown that 80% of the dose has natural origin and besides medicine, only about 1% comes from artificial radioactivity, while the major segment of the natural radiation comes from the exposure to radon (including thoron). It is concluded that the main parameter characterizing the external radiation dose, created solely by building materials of mineral origin, is the activity concentration of the three main natural radionuclides: 232Th, 226Ra (in a state of radioactive ...

Abstract This chapter describes the most important measure methods to determine the activity conc... more Abstract This chapter describes the most important measure methods to determine the activity concentration of gamma emitting radionuclides, the measurement of dose rates, and the determination of radon concentrations as well as radon exhalation rates. Several aspects concerning sampling, detector calibration, and uncertainty estimation are discussed.

Tectonophysics, 1988

Radon (2"Rn) concentration has been continuously measured since 1983 in groundwater at a spring a... more Radon (2"Rn) concentration has been continuously measured since 1983 in groundwater at a spring and in subsurface soil gas at five sites along a 200 km segment of the North Anatolian Fault Zone near Bolu, Turkey. The groundwater radon concentration showed a significant increase before the Biga earthquake of magnitude 5.7 on 5 July 1983 at an epicentrat distance of 350 km, and a long-term increase between March 1983 and April 1985. The soil-gas radon concentration showed large changes in 1985, apparently not meteorologically induced. The soil-gas and groundwater data at Bohr did not show any obvious correlation.

Nukleonika, 2010

Because radon (at least in high concentrations) is known as a health risk, it is necessary to red... more Because radon (at least in high concentrations) is known as a health risk, it is necessary to reduce high indoor radon concentrations as well as to take precautions to avoid high indoor concentrations in new buildings. For mitigating existing high radon concentrations, it is necessary to know where the most affected buildings are located. Therefore, the administrations of many countries funded or performed themselves radon surveys to determine the radon exposure of the public and to reveal radon prone areas. But high indoor radon concentrations are not only found in areas where high soil gas radon concentrations exist and vice versa even in areas with a high geogenic radon hazard the indoor radon concentrations need not to be very high. The reason is the different construction-types of houses and partially different living styles of the inhabitants. So, there are two questions and consequently working programmes: Where to mitigate high indoor radon concentra – tions? Where to take s...

Radiation Protection Dosimetry, 2017

The European Basic Safety Standards demand the prediction of areas where a significant number of ... more The European Basic Safety Standards demand the prediction of areas where a significant number of households exceed the reference level for the radon activity concentration. Therefore, radon maps are established which are based on indoor and soil gas measurements. In this study results of soil gas measurements are interpolated to get a value for the radon activity concentration in the soil gas at the coordinates of an indoor measurement and enable a direct comparison of both results. For the interpolation the inverse weighting value is applied. This way a prediction of the indoor radon activity concentration at the location of indoor measurements is attempted for verification. Quotients between the radon activity concentration in soil gas and indoors are analyzed. Building characteristics are also taken into account to evaluate parameters which lead to the reference level being exceeded. The results assist in the interpretation of soil gas measurements regarding the prediction of indoor radon activity concentrations.

Physical Review C, 2021

The reactions 6,7 Li + 27 Al were compared with the reactions 17,18 O + 16 O which form the same ... more The reactions 6,7 Li + 27 Al were compared with the reactions 17,18 O + 16 O which form the same compound nuclei 33,34 S. Cross-section data for the reactions 6,7 Li + 27 Al were derived from experimentally determined γ-ray production cross sections for transitions in several residual nuclei. For the reactions 17,18 O + 16 O experimental results from the literature were used. It could be shown that the weakly bound projectiles 6,7 Li undergo not only fusion processes, but also breakup reactions quite in contrast to the tightly bound projectiles 18 O and 17 O, respectively. Especially below the Coulomb barrier such direct reactions play an important role in competition to complete fusion. Calculations based on the statistical model agree well with the available data for 17,18 O + 16 O, but failed to represent the behavior of the experimentally determined production cross sections for the evaporation residues in the reactions 6,7 Li + 27 Al. But coupled-channel codes and calculations based on a nucleus-nucleus proximity potential are able to reproduce the energy dependence of the complete fusion cross sections.

Radiation Protection Dosimetry, 2014

With the aim to predict the radon potential by geological data, radon soil gas measurements were ... more With the aim to predict the radon potential by geological data, radon soil gas measurements were made in a selected region in Styria, Austria. This region is characterised by mean indoor radon potentials of 130-280 Bq m(-3) and a high geological diversity. The distribution of the individual measuring sites was selected on the basis of geological aspects and the distribution of area settlements. In this work, the radon soil gas activity concentration and the soil permeability were measured at 100 sites, each with three single measurements. Furthermore, the local dose rate was determined and soil samples were taken at each site to determine the activity concentration of natural radionuclides. During two investigation periods, long-term soil gas radon measurements were made to study the time dependency of the radon activity concentration. All the results will be compared and investigated for correlation among each other to improve the prediction of areas with high radon potential.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997

The basic features of VERA, a new AMS facility based on a 3-MV Pelletron tandem accelerator insta... more The basic features of VERA, a new AMS facility based on a 3-MV Pelletron tandem accelerator installed at the University of Vienna, are presented.

Journal of Physics: Conference Series, 2011

The aim of our study is to determine excitation functions for the formation of different reaction... more The aim of our study is to determine excitation functions for the formation of different reaction products with light ions near the Coulomb barrier and to compare the results with computations according to different reaction mechanisms (compound reactions, direct reactions). In the present study results from experiments with a beam of 9 Be on a thin Aluminum target below and around the Coulomb barrier are presented. The formation of several reaction products was determined by the characteristic gamma emissions from these nuclei. Excitation functions of the reactions 27 Al(9 Be, 8 Be→2α) 28 Al, 27 Al(9 Be,2n) 34 Cl, 27 Al(9 Be,pn) 34 S and 27 Al(9 Be,α2n) 30 P with lab energies between 5 and 14 MeV have been determined.

Zeitschrift f�r Physik A Atoms and Nuclei, 1981

Radiation Protection Dosimetry, 2011

Soil gas radon measurements are carried out in a pilot study in three municipalities in Upper Aus... more Soil gas radon measurements are carried out in a pilot study in three municipalities in Upper Austria. The selected municipalities are characterised by a high radon potential. Sixty measuring sites--well distributed over the region and over the different geological areas--were selected. Additionally, the permeability of the soil was determined where the soil gas samples were taken and at various sites where soil samples were analysed by gamma spectrometry. Long-term soil-gas radon concentration measurements are carried out at several sites to study the long-term behaviour of radon activity concentration in soil, the influence of meteorological parameters and seasonal variations. The final goal of the project is to correlate the collected data with geological data and indoor radon concentration. First results of this ongoing study are presented and discussed.

Science of The Total Environment, 2001

ABSTRACT The aim of the Austrian Radon Project (ARP) is to investigate the 222Rn concentration in... more ABSTRACT The aim of the Austrian Radon Project (ARP) is to investigate the 222Rn concentration in 0.3-0.5% of all Austrian dwellings to identify areas with elevated radon exposure. The survey is carried out using short-term and long-term integrating radon detectors covering a population of 2 800 000 persons so far. The homes were randomly selected from the telephone directory. The radon concentration distribution showed a log-normal shape. County-means between 60 and 330 Bq/m3 were found. A radon potential was introduced to deduce a geological risk from the data taken under different circumstances in different types of houses. This radon potential was defined as the annual mean radon concentration in a standard dwelling and is computed by normalizing the measured radon data to this standard dwelling.

Radiation Protection Dosimetry

Tectonophysics, 1988

... Exploration Institute of Turkey (MTA), Ankara (Turkey) (Received October 29,1986; accepted Ma... more ... Exploration Institute of Turkey (MTA), Ankara (Turkey) (Received October 29,1986; accepted March 15,1987) Abstract Friedmann, H., Aric, K., Gutdeutsch, R ... Earlier results of our observations were reported in King (1978, 1980), Friedmann and Hemegger (1978, 1985), Arie et al. ...

Science of The Total Environment, 2007

Indoor radon (Rn) concentrations have been measured intensively in many countries to assess the b... more Indoor radon (Rn) concentrations have been measured intensively in many countries to assess the burden of diseases associated with exposure to this radioactive gas. So-called radon-risk maps have consequently been produced to delineate areas with high levels. Geostatistical techniques are commonly used nowadays to map a range of environmental variables, in particular to generate probability maps of exceeding a given threshold. However, very few case studies in which indoor radon measurements have been investigated using geostatistical techniques have been published so far. By analyzing around 12,000 Rn measurements made in Austrian ground floors during a 10-year survey, we aim here to review and discuss the potential of geostatistics for mapping an environmental variable that shows very strong local variability. In particular, we show how kriging of the scale components can shed new light on various factors that affect the very high spatial variability of the variable.

Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 1997

We propose two new detector concepts that may be particularly well suited for AMS measurements wi... more We propose two new detector concepts that may be particularly well suited for AMS measurements with small accelerators: (i) an all solid state AE -E detector for light ions utilizing ion-induced electron emission from thin foils, and (ii) a time-of-flight system that does not use a start foil but derives the start information from the spatial information imposed on the beam by a time dependent deflection field.

Zeitschrift f�r Physik A Atoms and Nuclei, 1976

Radiation protection dosimetry, Jan 24, 2015

According to current European and international recommendations (e.g. by IAEA, WHO and European U... more According to current European and international recommendations (e.g. by IAEA, WHO and European Union), countries shall identify high radon areas. In Austria, this task was initiated already in the early 1990s, which yielded the first Austrian Radon Potential Map. This map is still in use, updated with recent indoor radon data in 2012. The map is based on radon gas measurements in randomly selected dwellings, normalised to a standard situation. To meet the current (legal) requirements, uncertainties in the existing Austrian radon map should be reduced. A new indoor radon survey with a different sampling strategy was started, and possible mapping methods are studied and tested. In this paper, the methodology for the existing map as well as the planned strategies to improve this map is discussed.