Papers by Keyword: PMT

Abstract: Because the output signals of photon detectors are scattered under weak light, the single photon counting method uses pulse discrimination technique and digital counting technique to identify and count weak signals. Compared with analog recording technique, the single photon counting technique has the advantages of high signal-to-noise ratio and good anti drift performance. Discrimination voltage is an important part of single photon counting, which will greatly affect the signal to noise ratio (SNR). The selected process of discrimination voltage is very complicated, especially the number of photomultiplier tube spectral analysis system [1], discrimination voltage selection process more time-consuming. This paper presents a software for automatically searching voltage discrimination. The software can automatically measure the discrimination voltage of a plurality of photomultiplier tubes, greatly improve the efficiency and accuracy of screening voltage selection, and verify the effectiveness of the screening voltage software by calculating the signal-to-noise ratio.

Abstract: Thermoluminescence reader is an important tool and a requisite for a researcher to study and characterize Thermoluminescence (TL) materials in different forms. Requirement for a versatile PC Controlled TL Reader has been felt for quite some time globally. Nucleonix Systems, Hyderabad, India, have developed a PC Controlled TL Reader by integrating complete electronics hardware circuits (comprising of Power Electronics, Low/High voltage Supplies, Temperature Controller, Micro Controller based data acquisition circuits having serial counter, ADC, DAC, EEPROM, PMT, PMT housing, sample heating system, drawer assembly, etc.) in a single enclosure. The system also integrated with software to calculate the activation energy (E), frequency factor (S) and order of kinetics ‘1’ for the prominent glow peaks using different equations.This Integral TL Reader unit gets connected to the Personal Computer System through serial port RS232C/USB port. The user interface to the system is through front–end VB software defined Graphics User Interface (GUI). The system also contains some of the software features like glow curve acquisition, analysis, filing, printing, plotting, overlapping, maker data reporting, etc. Additionally, system facilitates single/two/three plateau heating with variable heating rates.The primary objective of this development is to bring out versatile TL instrumentation system and also to make it affordable to many of the researchers in the Universities and other areas, including Radio-therapist, Medical Physicists in Cancer Hospitals. This system has been evaluated for its performance with CaSO₄: Dy discs, powder, as well as with LiF: Mg, Ti chips. Linearity and reproducibility have been found to be quite satisfactory also within +2%. This system is quite useful to study the TL of phosphor, minerals and characterization of various solid semiconducting materials, and also can be used in personal dosimetry measurements and research studies in medical dosimetry, environmental radiation monitoring, and host of other applications in R&D Labs., etc.

Abstract: Noise is one of the most significant indicators to measure the performance of the PMT, which is regarded as a photoelectric detector. Moreover, the excess noise factor F is an important parameter to describe the noise. Excess noise factor expressions for PMT in different situations are derived and analyzed by simulation in this paper. Some numerical simulations are made to obtain the maximum and minimum excess noise factor F and the changing trend of F with each parameter. From the analysis, we can minimize the noise for PMT to increase the detection precision as a photoelectric detector.

Abstract: The characteristics of petroleum exploration and development project in China are large investment, strong technology, trans-department and long periodic, etc. A well drilling engineering project needs the cooperation of exploration academy, exploration division, and drilling division. In recent years, the IPMT project management pattern has been carried on in China in order to decrease management hierarchy and improve the efficiency of exploration and development. In this paper, Innovation of IPMT project management pattern of petroleum exploration and development engineering in China have been analyzed. The author believes that would be beneficial to improve management efficiency of oil and gas industry in China.

Abstract: This paper puts forward a dielectric barrier discharge detection system using PMT for photoelectric element. According to faint light signal characteristics and testing purpose of dielectric barrier discharge, this system is designed, including three parts: optical fiber transmission, photoelectric conversion and signal processing circuit. This paper introduces design and ideas of the system framework and presents circuit design parameter. Results in atmospheric pressure of dielectric barrier discharge detection experiment show that the system has high sensitivity, fast response, can effectively distinguish discharge and interference signals, gather more signals in different areas.

Abstract: A novel redundantly actuated parallel machine tool was introduced. The inverse kinematic of 5-UPS/PRPU PMT with redundant actuation was analysed and the driven force of redundant actuation limb was planned. The force/position hybrid control strategy and dynamic differential calculation control strategy were proposed. Then the experiment of evaluating dynamics in the position control mode and in the force/position hybrid control was carried out respectively. The experiment shows that, the force/position hybrid control can improve driven torque of each limb better, balance the load of each limb and is of great help for enhance the dynamic performance of entire PMT.

Abstract: By adding methyl alcohol/water solution with certain concentration into sol to hydrolysis directly and sintering the fresh sol directly, lead titanate(PbTiO3) ceramics doped with magnesium are prepared by using magnesium acetate as doper to prohibit the disadvantages contained in conventional sol-gel method, such as low hydrolytic rate, high sintering temperature, long preparation period. The changes of structure, microstructure, synthesis process and electric properties of modified ceramics are studied in detail. The sizes and morphology of high purely and high density magnesium doped lead titanate nanocrystals thus obtained are observed by TEM photographs and the structures and affection of sintering temperature of to lattice constant and sizes of nanocrystals are detected by XRD. Electric properties detection results show that doped lead titanate ceramics exhibite excellent dielectric, ferroelectric and pyroelectric properties compare with pure lead titanate.

Abstract: This paper introduces a kind of new homemade and low cost multi-channel nucleic acid pyrosequence detector for at least ninety-six channels and presents the detail of related software and hardware development. We construct a kind of automatic instrument to fulfill the pyrosequencing processes. First we select the X-86 personal computer as host computer, the AT89C51 micro-controller as slave computer, the PMT (photoelectric multiply tube) as photoelectric transformation equipment, and the HY-6022 as data sampling device; Second we use the Visual C++ 6.0 as coding tools to design the measure and control system based on Windows 2000 operating system; Third we sample the fluorescent signal in all of the cuvettes during the reaction between nucleic acid and reagent; Last we analyze these data to realize the function of the multi-channel nucleic acid detection. In this paper the whole instrument design and key parts design are both introduced such as the liquid injection process and related structure design, the communication module between the host personal computer and the MCS51, the high sensitivity multi-channel detector (at least 96 channels, the sensitivity is 2.45×10-9w) etc. The result of the instrument for two channels data processing is also reported in this paper.