Abstract: A package for shielded handling of a detector element and for selective exposure of said detector element to radiation, typically in radon detection of emitted alpha particle radiation, is provided in a unitary assembly. The package provides a support structure for securement of a detector member within the package and includes a shielding structure for selective insulation of the detector member in a shielding position of the support structure to prevent background irradiation of the detector member during handling and transport to and from the irradiation monitoring location. The package provides selective exposure of the detector element to irradiation in an exposing position of the support structure at the monitoring location. The package is provided with transport structure for relatively moving the support structure with the detector member so that the detector member can be selectively displaced between shielding and exposing positions.

Abstract: A detector member having the property of forming damage tracks along the paths traversed by impinging alpha particles is provided with at least two opposing detection surfaces exposed on respective opposite sides of the detector member. The opposing detection surfaces enable the detector member to form damage tracks by alpha particles impinging either of the detection surfaces which are simultaneously exposed to irradiation. Conventional cellulosic film such as cellulose nitrate can be employed with both sides of the film serving as detection surfaces. The dual-surfaced film can be framed and packaged in a compact configuration convenient to use in homes or offices. The damage tracks from both of the irradiated surfaces can be simultaneously counted using preferred spark counting techniques.

Abstract: A compact low cost track registration detector for radon gas and radon daughter products includes a housing with a removable closure cap for retaining a strip of track registration material having the property of forming damage tracks along paths traversed by alpha particles. The strip is retained within the housing by integrally formed upstanding ribs located closely adjacent diametrically opposite inner side wall portions of the housing, a first set of ribs forming a pedestal support and second set of longer ribs providing transverse support. A microporous filter impervious to particles and radon daughter products admits only radon gas to the interior of the housing. The apertured closure cap has a central solid portion providing a radiation shield for the upper surface of the strip to enable the lower exposure surface to be readily distinguished after the detector has been retrieved from an exposure site.