[en] The masses of the neutron-rich radon isotopes ^223-229Rn have been determined for the first time, using the ISOLTRAP setup at CERN ISOLDE. In addition, this experiment marks the first discovery of a new nuclide, ²²⁹Rn, by Penning-trap mass measurement. The new, high-accuracy data allow a fine examination of the mass surface, via the valence-nucleon interaction δV_pn. The results reveal intriguing behavior, possibly reflecting either a N=134 subshell closure or an octupolar deformation in this region

[en] The use of Solid State Nuclear Track detectors (SSNTD), LR-115 type II-Quick, is one of the convenient technique to assess the average radiation levels of alpha activities in the environment. This technique has been used to assess the Radon concentration in some areas of San Jose, Costa Rica. Exposed SSNTD films are chemically etched in an alkaline solution and the density of alpha tracks are given as concentration (pCi/L) of Radon. The only known health effect associated with exposure to elevated levels of Radon is an increased risk of developing lung cancer. (authors). 10 refs, 4 figs, 3 tabs

[en] Published in summary form only

[en] Radon and thoron in air were measured during 1 year in 30 houses at a high soil radon risk site. Unlike thoron, radon concentrations exhibited seasonal variations – they were lowest in summer and highest in winter. The mean radon-to-thoron volume activity ratio was approximately 2.8. Although the majority of the homes were built on high-radon subsoil, mean annual radon activity levels higher than the indicative 400 Bq/m³ were observed in one house only. The effect of the subsoil on the radon concentration in the houses was highest in older built before 2000. (orig.)

[en] Due to the short half-life of Rn-220, a primary standard for activity concentration of Rn-220 (thoron) in air (i.e. a homogeneous reference atmosphere consisting of a certified activity in a certified volume) has been considered unachievable in the past. Traceability of Rn-222 reference atmospheres is achievable using radon gas activity standards (; ) and standard volumes, and is an established method. For the short-lived radionuclide Rn-220 this procedure is not feasible, since no Rn-220 gas activity standard with a reasonable activity can be produced. This leads to a lack of traceability for measurements of Rn-220 activity concentration: only atmospheres monitored by reference instruments (i.e. secondary standards) are available. The new primary standard for the activity concentration of ²²⁰Rn developed by PTB now closes this gap in radon metrology.

[en] Ottawa is the capital city of Canada. In the previous cross Canada radon survey, Ottawa was not included. There is great interest to know radon level as well as thoron concentration in Ottawa homes. Therefore, radon/ thoron discrimination detectors developed at the National Inst. of Radiological Sciences in Japan were deployed in 93 houses for a period of 3 months. As expected, thoron is present in Ottawa homes. Radon concentrations ranged from 8 to 1525 Bq m^-3 while thoron concentrations varied from 5 to 924 Bq m^-3. The arithmetic mean of radon and thoron concentrations were found to be 110 ± 168 and 56 ± 123 Bq m^-3, respectively. (authors)

No abstract available

[en] Measurements of ²²⁰Rn and ²²²Rn levels at Wairakei have been studied in relation to a model which considers the times taken for two separate processes, desorption of gases from the rock and fluid movement to a well. The relatively high ²²⁰Rn levels are indicative of fluid movement through porous aquifer rock. (author)

[en] A radon exposure chamber was constructed. Both ²²²Rn and ²²⁰Rn can be injected independently or simultaneously into the chamber from separate dry sources. The airflow in the chamber can be adjusted manually in a 100% flow-through mode, 100% recirculate mode or flow-through/recirculate mode. Water vapour and aerosol particles of variable sizes are injected into the chamber through computer-controlled mechanism. The continuous radon and radon progeny concentration and working level, and aerosol concentration are constantly monitored by the microcomputer. (author)

[en] A brand-new radon-thoron discriminative detector has been developed for the purposes of large-scope surveys. The configuration and features of this facility in comparison to our previous detector are described