Measurement of indoor and outdoor radon concentrations during Superstorm Sandy.

Superstorm Sandy affected much of the US East Coast extending over 1800 km. It passed over the test location in the State of Maryland on 29 October 2012. Being 350 km away from the regions of highest intensity the storm was of lower intensity at the test location.

Electret ion chamber-based passive radon-thoron discriminative monitors.

Electret ion chambers (EICs), commercially available under brand name E-PERM(®), are widely used for measuring indoor and outdoor (222)Rn concentrations in air. These are designed to respond only to (222)Rn and not to (220)Rn by restricting diffusional entry area. Such radon EIC (R EIC) monitors are modified by increasing the entry area to allow (220)Rn, in addition to (222)Rn.

Radon exhalation rates from building materials using electret ion chamber radon monitors in accumulators.

An electret ion chamber (EIC) radon monitor in a sealed accumulator measures the integrated average radon concentration at the end of the accumulation duration. Theoretical equations have been derived to relate such radon concentrations (Bq m(-3) ) to the radon emanation rate (Bq d(-1)) from building materials enclosed in the accumulator. As an illustration, a 4-L sealable glass jar has been used as an accumulator to calculate the radon emanation rate from different granite samples.

One cubic metre NIST traceable radon test chamber.

With the availability of the National Institute of Standards and Technology (NIST) Radon Emanation Standard with a content of approximately 5000 Bq of 226Ra, it is possible to build a flow through a practical radon test chamber. A standard glove box with four gloves and a transfer port is used. Air is pumped through a flow integrator, water jar for humidification and NIST source holder, and into the glove box through a manifold.

Performance of electret ionization chambers in magnetic field.

Electret ionization chambers are widely used for measuring radon and radiation. The radiation measured includes alpha, beta, and gamma radiation. These detectors do not have any electronics and as such can be introduced into magnetic field regions.

Electrets to measure ion concentration in air.

Positive and negative ions are produced in air, mainly due to radon and terrestrial/cosmic radiation sources. Measuring ion concentration in air indirectly provides a measure of these sources. Electrets (electrically charged pieces of Teflon), when exposed in the environment, collect ions of opposite sign leading to a measurable decrease in charge, depending upon the exposure time and ion concentration.

Radon monitor calibration using NIST radon emanation standards: steady flow method.

The National Institute of Standards and Technology (NIST) polyethylene-encapsulated 226Ra/222Rn emanation (PERE) standards (old SRM 4968 and new SRMs 4971, 4972, and 4973) provide precise radon emanation rate, certified to a high degree of accuracy (approximately to 2%). Two new SRM 4973 standards containing totally 1036 Bq (0.028 microCi) of 226Ra, emanate 0.

Measurement of alpha particle energy using windowless electret ion chambers.

Electret ion chambers are inexpensive, lightweight, robust, commercially available, passive, charge-integrating devices for accurate measurement of different ionizing radiations. In an earlier work a chamber of dimensions larger than the range of alpha particles having aluminized Mylar windows of different thickness was used for measurement of alpha radiation. Correlation between electret mid-point voltage, alpha particle energy, and response was developed and it was shown that this chamber could be used for estimating the effective energy of an unknown alpha source.

Calibration of Electret-Based Integral Radon Monitors Using NIST Polyethylene-Encapsulated Ra/Rn Emanation (PERE) Standards.

The recently developed Rn emanation standards that are based on polyethylene-encapsulated Ra solutions were employed for a first field-measurement application test to demonstrate their efficacy in calibrating passive integral radon monitors. The performance of the capsules was evaluated with respect to the calibration needs of electret ionization chambers (E-PERM, Rad Elec Inc.).

Electret method for continuous measurement of the concentration of radon in water.

A passive system using an electret ion chamber to measure dissolved radon in a water sample has been recently described. In the current work, an electret ion chamber has been used to measure time-averaged concentration of dissolved radon in water. A steady concentration of radon in water is generated by bubbling radon gas into water in a 20-L jar and maintaining constant rates of feed and bleed of the water.

Field test of electret ion chambers for environmental monitoring.

A field test of electret ion chambers was performed to evaluate their performance in making environmental exposure measurements at nuclear facilities. The objectives of the study were to determine electret ion chamber variability and to perform comparisons with thermoluminescent dosimeter and high-pressure ion chamber measurements. Three electret ion chambers were placed at each of 40 monitoring locations in the vicinity of a commercial nuclear power station during four consecutive quarters.

Electret ion chamber radon monitors measure dissolved 222Rn in water.

This paper describes a simple and relatively inexpensive method of determining the concentration of dissolved 222Rn in water. The method involves a recently developed electret-passive environmental radon monitor, which uses an electret ion chamber. The procedure consists of sealing a known volume of a carefully collected water sample with one of these monitors in an exposure container and determining the average equilibrium 222Rn gas concentration in the air phase during the exposure time period.

Elevation correction factors for E-PERM radon monitors.

E-PERM radon monitors are based on the principle of electret ion chambers and are usually calibrated in a standard radon chamber located at sea level. Corrections are needed if the monitors are used at elevations other than sea level. These were experimentally determined for three models of commercially available electret ion chambers (E-PERM) as functions of elevation above sea level.

A practical E-PERM (electret passive environmental radon monitor) system for indoor 222Rn measurement.

The technical and scientific basis for the measurement of indoor 222Rn concentration using an E-PERM (Electret passive environmental radon monitor) has been described in our earlier work. The purpose of this paper is to describe further development of a practical and convenient system that can be used routinely for indoor 222Rn measurement. The ion chamber is now made of electrically conducting plastic to minimize the response from natural gamma radiation.

An electret passive environmental 222Rn monitor based on ionization measurement.

The electret passive environmental 222Rn monitor (E-PERM) is an extension of electret dosimeters used for measurement of x and gamma radiation. An E-PERM consists of a small cup or canister, having an electret at the bottom, and a filtered inlet at the top. The 222Rn gas entering through the filter and the decay products formed inside the cup generate ions which are collected by the electret.

Measurement of 220Rn in exhaled breath of Th plant workers.

The concentration of 220Rn in the exhaled breath of workers currently employed in a Th plant was measured using a double filter system. The results are expressed in terms of the equivalent activity of 224Ra freely emanating 220Rn at the mouth. Measurements performed on 176 subjects, without isolating them from day-to-day work, showed 220Rn levels having a median of 0.

Radium-226 body burden in U miners by measurement of Rn in exhaled breath.

Uranium miners were made to inhale Rn-free medical O2 and exhale through a 5.2-1 A1 chamber before reporting to work. The chamber was sealed and isolated from the sampling circuit.

Passive measurement of radon and thoron using TLD or SSNTD on electrets.

An electret is an electrical analogue of a permanent magnet and it carries a permanent electric charge. Our previous work has shown that such electrets are suitable for collecting decay products of radon and thoron in passive chambers. In the present work, the decay products are directly collected on the surface of a TLD or SSNTD providing in situ registration of the radiation from the decay products of radon and thoron.