A Comparison of Retrospective Radon Gas Measurement Techniques Carried Out in the Serbian Spa of Niska Banja

Indoor radon retrospective concentrations were obtained and compared using two radon measurement methods. Both methods rely on the measurement of the long-lived radon progeny (210)Pb, collected either on the surfaces (surface trap technique), most frequently glass, or in a volume trap, usually sponge from furniture (volume trap technique). These techniques have been used to retrospectively estimate radon gas concentrations that have existed in dwellings in the past. The work presented here compares the results provided by the surface trap technique devised at the University College of Dublin, Ireland, and the volume trap technique devised at the Scientific Research Center, Mol, Belgium. The field campaign was carried out by the research team of the ECE Laboratory of the Vinca Institute of Nuclear Sciences at the spa of Niska Banja, identified as a region of Serbia with a high indoor radon and ground water radium and radon content

An above-barrier narrow resonance in ¹⁵F

Intense and purified radioactive beam of post-accelerated $^{14}$O was used to study the low-lying states in the unbound $^{15}$F nucleus. Exploiting resonant elastic scattering in inverse kinematics with a thick target, the second excited state, a resonance at E$\_R$=4.757(6)(10)~MeV with a width of $\Gamma$=36(5)(14)~keV was measured for the first time with high precision. The structure of this narrow above-barrier state in a nucleus located two neutrons beyond the proton drip line was investigated using the Gamow Shell Model in the coupled channel representation with a $^{12}$C core and three valence protons. It is found that it is an almost pure wave function of two quasi-bound protons in the $2s\_{1/2}$ shell.Comment: 8 pages, 2 figures, 1 table, Submitted to Phys. Lett.

Radon survey in the high natural radiation region of Niska Banja, Serbia

A radon survey has been carried out around the town of Niska Banja (Serbia) in a region partly located over travertine formations, showing an enhanced level of natural radioactivity. Outdoor and indoor radon concentrations were measured seasonally over the whole year, using CR-39 diffusion type radon detectors. Outdoor measurements were performed at 56 points distributed over both travertine and alluvium sediment formations. Indoor radon concentrations were measured in 102 living rooms and bedrooms of 65 family houses. In about 50% of all measurement sites, radon concentration was measured over each season separately, making it possible to estimate seasonal variations, which were then used to correct values measured over different periods, and to estimate annual values. The average annual indoor radon concentration was estimated at over 1500 Bq/m(3) and at about 650 Bq/m(3) in parts of Niska Banja located over travertine and alluvium sediment formations, respectively, with maximum values exceeding 6000 Bq/m(3). The aver age value of outdoor annual radon concentration was 57 Bq/m(3), with a maximum value of 168 Bq/m(3). The high values of indoor and outdoor radon concentrations found at Niska Banja make this region a high natural background radiation area. Statistical analysis of our data confirms that the level of indoor radon concentration depends primarily on the underlying soil and building characteristics. (c) 2006 Elsevier Ltd. All rights reserved

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

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 2 Po-10 on the surface of glass objects (surface traps, ST) or in the bulk of porous materials (volume traps, VT). Both surface implanted 2 1 Po-210 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 GT 0.05). Geometric means (GM) are similar, 3 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. (C) 2007 Elsevier B.V. All rights reserved

A campaign of discrete radon concentration measurements in soil of Niska Banja town, Serbia

The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides Ra-226, Th-228 and K-40. Radon concentrations were found to range from 1270 to 155000 Bq m(-3) with an average of 33765 Bq m(-3) and a median value of 12626 Bq m(-3). The geometrical mean value and geometrical standard deviation were calculated as 16160 Bq m(-3) and 3.5 Bq m(-3), respectively. Gamma dose rate varies from 92 to 316 nGy h(-1), with an average of 132 nGy h(-1). The radium content in collected soil samples ranges from 24 to 1810 Bq kg(-1) with an average of 187 Bq kg(-1). High correlations (r(2) GT 0.8) between soil gas radon concentration, gamma dose rate and Ra-226 content in soil were found for each pair. The distribution of radon concentrations in soil gas shows bimodal shape. (C) 2007 Elsevier Ltd. All rights reserved

Card for Mr Wadsworth to attend Federal Capital Ceremony

The paper deals with a specific aspect of a general survey, that is being carried out during last ten years in several regions of Serbia (former Yugoslavia, former Serbia and Montenegro) to assess population exposure to natural radioactivity based on geochemical and integrative pattern research approach. The originality regarding this work is related to the facts such as follows: the first identification and assessment of high areas of natural radiation in Serbia which provides insight into its regional characteristics, the interpretation of the results in terms of geological aspects, building types and human habits, the first introduction and field applicability of both (surface and volume trap) retro techniques in Serbia and assessment of doses and risks to the population in investigated high natural radiation rural communities

Lifetime measurements of low-lying states in 73Ga and 70,72,74Zn isotopes

Lifetimes of low-lying states in 73Ga and 70,72,74Zn were measured using the Recoil Distance Doppler Shift (RDDS) method. These nuclei were produced in deep-inelastic reactions in inverse kinematics with a 208Pb beam impinging on a 76Ge target. Prompt γ rays were detected using the AGATA tracking array coupled to the VAMOS++ spectrometer. Lifetime of the 5/2- state in 73Ga, measured for the first time, provides additional evidence for the existence of a 1/2-, 3/2- ground-state doublet. The lifetimes of the 4+ states in 70,72,74Zn were remeasured in an attempt to understand the discrepancies observed between earlier measurements. Our results are in agreement with those of previous plunger experiments

High precision measurement of the 19^{19}Ne β\beta-decay half-life using real-time digital acquisition

International audienceThe half-life of Ne19 was measured using a real-time digital multiparametric acquisition system, providing an accurate time stamp and relevant information on the detector signals for each decay event. An exhaustive offline analysis of the data gave unique access to experimental effects potentially biasing the measurement. After establishing the influence factors impacting the measurement such as after-pulses, pile-up, gain, and baseline fluctuations, their effects were accurately estimated and the event selection optimized. The resulting half-life, 17.2569±0.0019(stat)±0.0009(syst) s, is the most precise up to now for Ne19. It is found to be in agreement with two recent precise measurements and not consistent with the most recent one [L. J. Broussard , Phys. Rev. Lett. 112, 212301 (2014)PRLTAO0031-900710.1103/PhysRevLett.112.212301] by 3.0 standard deviations. The full potential of the technique for nuclei with half-lives of a few seconds is discussed