Abstract: A continuous air monitor is provided with the capabilities of monitoring certain transuranic and other airborne radioactive particulate with high accuracy and low false alarm rates in the presence of radon and thoron daughter products. A multiple filter sampling approach is used wherein air flow is directed on a alternating basis to each sampling filter in turn. Each filter collects particulate in the size range of interest. Beta and/or alpha activity can be continuously measured on each filter. The air flow can be directed through a chamber where radon and/or thoron gas portions of the air may decay into their daughters and the quantities thereof may be separately measured.

Abstract: A radon detection system is provided with the capability of monitoring certain environmental parameters together with certain other conditions indicative of possible tampering. The environmental data allows the calculation of an accurate projection of average long-term radon levels in the structure under test on the basis of a relatively short measurement period, while the tamper data indicates whether an attempt has been made to tamper with the detection unit or the measurement conditions during the test period. When an indication of possible tampering occurs, the system enters an accelerated data collection mode during which data is gathered that can later be used to determine whether tampering has actually occurred. The detection system may be provided with first and second detectors for separately monitoring airborne levels of radon gas and radon decay products.

Abstract: A reflector apparatus with multiple reflecting facets for chemical vapor deposition reactors. For vertical and barrel reactors, the facets are annular and fit around the bell-jar shaped process enclosure. The facets may be adjusted by orienting or curving the reflecting facet surfaces so that the radiant energy from the reactor susceptor may be reflected back to the susceptor and wafers as desired for uniform heating of the processed semiconductor wafers.

Abstract: A vertical reactor for chemical vapor deposition having an H.sub.1 /D.sub.1 ratio in the range of 1.10 to 1.40, where H.sub.1 is the height of the reactor bell jar enclosure above the susceptor and D.sub.1 is the diameter of the susceptor. Reactor performance is further improved by extending the outermost coil of the induction coil heating the susceptor beyond the outer diameter of the susceptor and by extending the innermost coil of the induction coil within the inner diameter of the susceptor.