Research On Handhold Alpha Spectrometric Instrument

With the development of technology and the living standards of people constantly improve, people has become increasingly concerned about their own environment, and the radioactive contamination has become one of the most serious social problems. To understand promptly the pollution situation which the radionuclide decay causes, needs to use the special instrument to carry on the survey.The alpha ray is composed of alpha particle, alpha particle is the quick movement hellion, it is a stable atomic nucleus, alpha particle is produced when the instability nucleus have alpha decay emits.The alpha spectrometer is the important instrument to measure alpha ray pollution, mainly used in radioprotection, environmental samples, medical and health, agricultural sciences, import and export commodities inspection, geological exploration, nuclear power plants to survey alpha pollution. This paper is supported by Ministry of Science and Technology the science instrument rebuild project "The development of new generation series surface nuclear pollution intelligence measuring instrument", aims to integrate advanced nuclear detection, electronics, information processing and mechanical design process, research and develope a portable, high-precision handheld alpha spectrometer.Along with the scene analysis's demand and the electronic technology microminiaturization's development, the demand of portable instrument or handhold instrument getting more and more obvious, the scene analytic instrument are also getting more and more. At present, all scene nuclear measuring instrument are developed toward the characteristics of small size, light weight, low background, low power, high-performance and fast analysis. The handheld instrument has the merits of convenience user to carry on the stochastic survey, and increase the amount of data measurements, reduce the sample survey troublesome.At the same time, grasps the instrument to add on the corresponding communication way to be possible to install on the intelligent robot, the survey is unable to realize the sampling place artificially.At the same time, handheld devices coupled with appropriate communication can be installed in the intelligent robot, measuring the local sampling can not be achieved.The spectrometer selects the silicon surface barrier detector, take the embedded singlechip as the control platform, develope the system's core component circuits and software. To meet the requirements of precision, as far as possible to reduce power consumption, reduced size, improved accuracy and feasibility analysis. The hardware circuit mainly includes the preamplifier circuit, the main amplifier, the multi-channel pulse rate analyzer, SCM system design, LCD displays and touch-screen control, and serial communications. Software system is mainly for hardware circuits control and PC software.After nearly a year of development work, the results are:1. Has used the SCM C8051F060 construction system's core control section, because the C8051F060 integration rate is high, the power loss was small, has satisfied the handhold instrument's design requirements;2. Selected the silicon surface barrier detector, has designed the miniaturized charge-sensitive preamplifier, and sealed together with the detector, has guaranteed the detect precision;3. In the electric circuit, all of the amplifier uses the single power supply component, simplified the power source design circuit, reduced the instrument volume;4. Uses the LCD with touchscreen as the system's man-machine interface, not only reduced the instrument volume, the demonstration has been more artistic;5. The superior machine spectrum analysis software interface is friendly, and feasibility.The system performance test indicated that the handhold alpha spectrometric instrument power loss is low, the energy resolution is high, the system stability is good, the man-machine interaction is good, suits the field use.