New alpha radiation detection systems for environmental surveys.
Siehe auch: Sensors and Actuators B
We report on the development of low-cost alpha-particle sensor systems for radon and radon daughter monitoring and dosimetry (Ealpha=5.5-7.9 MeV) and on the first application for environmental surveys. Using the experience of the MEGARAD-microsystem, we have developed an alpha-particle spectroscopic sensor array with special PMOS transistors in a floating n-well as sensor cells. 1024 sensor cells, the preamplifiers, the analog memories, a fast four-bit parallel A/D converter and the address-coding system are integrated on a single chip. The energy resolution for 5 MeV alpha particles is better than 300 keV. The dead time is smaller than 10 percent for up to 10 high 6 alpha particles per second and per square centimetre. The systems are tested in several radiation fields (neutron, proton, alpha, beta and gamma radiation). The efficiency of the alpha-radiation detection systems in radon-monitoring systems is proved in various applications.