Multi-purpose Portable Multi-channel Pulse Amplitude Analyzer

With the growing shortage of global fossil fuel, due to its highly efficient andstable characteristics, nuclear energy has been universally accepted by a lot ofcountries, and is developed as a future strategic energy. Then, the nuclear fueluranium, as nuclear energy, will be bound to become the focus of worldwidecompeting, which presents a challenge for the nuclear fuel uranium exploration andwill promote the rapid development of relevant Prospecting Techniques.As a nuclear geophysical detecting instrument, Multi-channel pulse amplitudeanalyzer is widely used in uranium exploration. However, lots of better multi-channelpulse amplitude analyzer are foreign goods, our local instruments mostly with largevolume, high-power consumption, without the automatically locate function, couldnot adapt to indoor, outdoor, and many other applications, and could not compete withforeigner’s. Based on this situation, this subject designs a low-power consumption,multi-purpose, portable multi-channel pulse amplitude analyzer. It can automaticallylocate, and be made into a data acquisition card. Aim to explore uranium withself-developed instruments. The main control unit of the acquisition card uses ahigh-speed, low-power consumption, patch32-bit microcontrollers ARM7LPC2368,which is with rich on-chip resources. In order to make the system with good linearity,system uses high speed with good linear op amp AD8620in circuit design to realizetwice linear amplification. In order to improve the energy resolution of the system, ituse the Sallen-Key filter shaping circuit, shape the pulse signal to a Gaussian pulse. Inorder to improve the system’s performance at high count rates, it takes a CDDbaseline restoration circuit with good performance. This system designshigh-performance pulse amplitude analysis circuit and high-speed A/D convertercircuit to realize pulse amplitude analysis. In order to stabilize the spectrum, it takesAD545314-bit digital-analog controller to realize high-precision automatic spectrumstabilization by the SPI interface of LPC2368. Embedded GPS positioning and timingtechnology can automatically position to adapt to indoor, outdoor and multi-purposeneeds, and can facilitate follow-up data processing. For data transfer, it uses thefull-speed12Mbps USB2.0interface with DMA controller of LPC2368, to finishhigh-speed data transmission. As for System power design, take efficient switchingpower chip, extended the battery life, and also design power adapter to use220V ACwhen using indoor. This data acquisition card can match with different nuclear crystaldetector depending on the needs to acquire the nuclear spectrum data. The Researchand Development of this instrument will make a positive contribution to our country’suranium exploration.