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.

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.

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.