Research & Development On Radon Monitor With Semiconductor Detector

It's well-known that the study about radon of the environment is a hot topic recent years. Radon is acknowledged the second factor resulting in lung cancer by some organizations such as WHO. Spot radon monitor will be sold well in the future. Gas detector, scintilla and semiconductor radon detectors are widely used by people. Now and aftertime, radon monitor with semiconductor detector has been a dominant developing direction of radon monitor. However, we are still short of the device of this type developed and produced by ourselves to analyze alpha spectrum with multi- channel analyzer. The paper is about the study of radon monitor and the main content is the design of analog circuit which collects and disposes pulse signal and makes it fit for the latter analysis.The instrument is designed on the whole. The analog circuit is divided into several parts and hardware circuit of system composing is finished. The paper describes signal processing and data-collecting circuit of the device in detail. Signal disposal circuit consists of pulse shaped and linear amplifier circuit. Before data-collecting, pulse signal must be analyzed and this part consists of peak holding and control circuit controlled by a single-chip micro-controller Z8018010PSC. Data-collecting part mainly includes 256-channel pulse-height analyzer and multi-channel buffer. Otherwise, the circuit also comprises offset high-voltage, semiconductor detector and preamplifier, etc. In the end, suggestions about further research and improvement of the instrument are made and development of radon monitor in the future is prospected.Software Multisim7 passes circuit debugging including preamplifier, pulse shaped and linear amplifier circuit, peak holding and control circuit controlled by a single-chip micro-controller Z8018010PSC. The hardware circuit debugging proves that the data-collecting circuit has the function of signal collecting, magnifying, pulse shaped and peak holding. However, multi-channel analyzer, the core part of radon monitor, still needs detailed analysis and research and in order to finish the multi- channel analysis function of alpha spectrum, it's necessary to choose right analog-to-digital converter chip.