Special software design for data acquisition and experi-mental database management of electromagnetic launch system

: Electromagnetic launch systems such as rail guns generate electromagnetic signatures that contain a spectrum of frequencies extending from quasi-DC up to tens of kilohertz. However, electromagnetic compatibility (EMC) considerations pertaining to the potential adverse effects of these fields on nearby electronic equipment remain largely unexplored. This report includes a discussion of the theoretical models used to predict the inductance gradient, the transient behavior of the currents produced in the rail gun structure, the dynamical generation of the external fields, and a comparison of the theoretical model with experimental data. The predicted rail inductance gradient of L'sub R = 0.52 muH/m compares very well with the measured value of 0.522 muH/m. The existence of an inductance gradient efficiency factor, E sub 0, is demonstrated, with a derived value of 0.75. This produces an effective inductance gradient of L' = E sub 0 L' sub R = 0.39 muH/m. Using this value of L' leads to a theoretical exit muzzle velocity of 525 m/s, which is within 5 percent of the measured value.

As the most efficient and compact sources in pulsed power supply for electromagnetic launchers, the air-core pulsed alternator can supply a current as high as 1 MA with a voltage reached several kilovolts. The machine performs various functions, such as kinetic energy storage, electromechanical energy conversion, and power conditioning, making the electromagnetic launch system compact and lightweight. But due to the short history of the machine and the absence of fabrication experience in China, the air-core pulsed alternator is still in an exploratory stage, and there are lots of key technologies and problems needed to be researched deeply. Taking technical risks and manufacturing costs into consideration, a seven-phase air-core pulsed alternator has been proposed and the machine is under development. In this paper, operation principles of the electromagnetic launch system are presented in detail. The mathematical models of the seven-phase alternator and the rail gun are introduced. Based on the mathematical models, a simulation model about the electromagnetic launchers is built, and it is useful to help us figure out the operation characteristic when the self-excitation machine drives the electromagnetic rail gun with a 200-g projectile. As a result, it is convincing by simulation to prove the drive current can be as high as 1 MA and the projectile is with a velocity of 2 km/s at the exit. Simultaneously, violent transient situations will be illustrated in this text, such as the electromagnetic torque and the rotor speed. Meanwhile, simulation results can verify the analytical method and present the current and voltage straightforwardly. They also have great significance on choosing the proper high power switching devices.

Data acquisition software is an essential component of modern macromolecular crystallography (MX) beamlines, enabling efficient use of beam time at synchrotron facilities. Developed at the Paul Scherrer Institute, the DA+ data acquisition software is implemented at all three Swiss Light Source (SLS) MX beamlines. DA+ consists of distributed services and components written in Python and Java, which communicate via messaging and streaming technologies. The major components of DA+ are the user interface, acquisition engine, online processing and database. Immediate data quality feedback is achieved with distributed automatic data analysis routines. The software architecture enables exploration of the full potential of the latest instrumentation at the SLS MX beamlines, such as the SmarGon goniometer and the EIGER X 16M detector, and development of new data collection methods.

Dr. Raymond R. Raylman, Professor and Vice Chair for Research, Radiology Department at WVU was the Principal Investigator for the project. The Jefferson Lab partner on this project was the Radiation Detector and Imaging Group in the Physics Division, led by Dr. Drew Weisenberger who was the coordinator of the project execution and the chief contact with WVU. The responsibility of Jefferson Lab was to facilitate optimization of data acquisition software, conversion of JLab Fortran iterative positron emission mammography computer code to C++ and to act as a computer code repository. During the two year project interactions and exchange of information was directed by Dr. Raylman and Dr. Wesienberger. WVU provided the expertise that allowed JLab to continue development of the current JLab data acquisition software referred to as JDAQ. JDAQ is a highly flexible Java language based data acquisition tool that helps to minimize software induced dead-time while maintaining the highest possible data rates from a JLab built FPGA based analog-to-digital convertor (ADC). JDAQ interfaces directly with the FPGA based multi-channel ADCs. Using JDAQ it is possible process data from a number of different detector types such as the PET systems at WVU. Because of the inherent flexibility of our processing software, we are also able adjust detector readout parameters during operation to provide the best possible data presentation and calibration parameters. To accommodate the high rate nature of PET detector systems JDAQ was designed to be scalable across an Ethernet network as well as for multi-cpu computer systems, and it also has the capability to synchronize many ADCs connected to multiple computers. During the project WVU will provided iterative reconstruction algorithm expertise and Fortran programming assistance to facilitate the conversion to C++ of a JLab developed Fortran positron emission mammography (PEM) reconstruction code. Also WVU provided acceptance testing of the new C++ based PEM reconstruction code. The PEM code is a maximization (MLEM) image reconstruction program that created images from the list-mode data acquired from the PET system.

Compared with steam catapult system, electromagnetic launcher (EML) system is highly integrated, and it has high and well matching performance. It will be widely used aircraft carriers ejection, rocket launchers etc in future. Double-side tabular permanent magnet linear synchronous motor (PMLSM) for electromagnetic launcher can meet the requirements of big thrust and high efficiency etc. It can accelerate the launcher at the expected speed in short time. The thrust characteristic of the launcher is essential to the whole electromagnetic launcher system. Large thrust and small thrust ripple are both expected. This paper studies thrust characteristic of different pole arc coefficients, compares the series and parallel magnetic circuit structures, and analyses the method of staggering a certain distance between poles on both sides. In order to achieve the goal of large thrust, the Launcher is often designed with high current density. As a result, it is of great loss and has quick temperature rise. This paper establishes numerical model of the two-dimensional (2D) primary transient temperature field. The temperature field of the short-term system is analyzed. The calculated and experimental results of the electromagnetic launchers can provide a basis for optimum design.

The electromagnetic railgun system based on capacitive pulsed-power supply (CPPS) has obtained widespread applications because of its obvious advantages over the inductive ones on mature technology, operational reliability and feasible financial condition. However, the existing CPPS-based electromagnetic railgun system works with low efficiency. In this paper, the systematical study on the system efficiency of the synchronously-triggered capacitive pulsed-power supply in a 1MJ electromagnetic railgun system is proposed. Firstly, all PFUs are supposed to be triggered synchronously and the load is simplified as a resistor. Then the system performance criteria, i.e. the launch velocity of the armature v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">end</sub> and the system efficiency η, are expressed as the function of four independent system variables, i.e. the capacitance of each pulse forming unit (PFU) C, the pre-charged voltage U <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</sub> of capacitors, the rail length l, and the armature mass m. The relationship between η (or v <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">end</sub> ) and any two independent variables can be found under the environment of Matlab®R2012a by fixing the other two parameters. The results are then verified under the environment of Simplorer®8. These figures can be used to in instruct the design of the pulsedpower supply for a designated load or the railgun for a designated source. The study can provide a theoretical foundation for the future designs to get higher system efficiency.

Data acquisition (DAQ) and control software has been developed for gamma-ray process tomography system in Malaysian Nuclear Agency. The gamma-ray computed tomography (CT) system uses Computer Automated Measurement and Control (CAMAC) standard for nuclear counting and data acquisition instead of the common Nuclear Instrumentation Module (NIM) standard. For scanning configuration, the system consists of an array of NaI(Tl) scintillation detectors that moves in a small degree of angle by using a stepper motor. The gamma-ray CT software comprises of graphical user interface (GUI) for the system automation that includes CAMAC modules setup, motor and scanning control, data acquisition from CAMAC crate controller via ethernet interface and data recording. The software is developed by using National Instruments LabView development package.

In order to not only reduce thrust fluctuations but also improve transient state performance of primary winding segmented PMLSM(PWS-PMLSM) applied in electromagnetic launch system, this thesis proposes the inter-stator current synchronous tracking and predictive control (ISCSTPC) algorithm based on two inverters alternating supply method for multi-stators PMLSM. The study adopts the finite element model (FEM) to calculate variation rules of electromagnetism parameters when shuttle moves among stators. For this, the accurate PWS-PMLSM mathematical model and control system models are established according to the above mentioned rules, respectively. Through the calculation and simulation on inter-stator thrust ripple and on transient response ability, the experimental result illustrates that the current control algorithms achieve the most satisfied effect for EML.

The gamma-ray scanning technique is widely used for evaluating the operating characteristics of distillation columns considered as the most critical components in petrochemical plants. Gamma-ray scanning provides essential data to optimize the performance of the columns and to identify maintenance requirements. New and more efficient data acquisition and processing software has been developed for Gamma-ray scanning. This new software permits to conduct gamma scanning explorations with all necessary information concerning the columns directly incorporated in the software. New features help a lot to interpret on-line the obtained results. A first version of the new data acquisition and processing software has been successfully tested in real conditions of utilization. For enhancing the interpretation of the experimental results of the technique, Geant 3 and Geant 4 Monte carlo simulation tools, developed at the CERN, have been used, to help identifying any possible malfunction inside a column and providing specific information, as a level liquid on a tray. In this study, the Geant simulations are performed for a distillation column. A set of parameters, principally the source energy ( <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">60</sup> Co) and the source-detector separation are fixed. Also many simulations were carried out to prove that there is no effect of the distillate chemical composition on the obtained results. To assure that the code runs correctly, a number of simulations were done to reproduce a density profile in the ideal case (no malfunctions in column). The distillation column process malfunctions that have been examined were principally liquid entrainment and weeping between trays. These phenomena were modelled by varying the thickness of the liquid layer on and under the tray.

One of the diagnostic systems critical to the success of the DIII-D tokamak experiment is the Thomson scattering diagnostic. This diagnostic is unique in that it measures local electron temperature and density: (1) at multiple locations within the tokamak plasma; and (2) at different times throughout the plasma duration. Thomson data are digitized signals of scattered light, measured at different times and locations, from the laser beam paths fired into the plasma. Real-time acquisition of this data is performed by specialized hardware. Once obtained, the raw data are processed into meaningful temperature and density values which can be analyzed for measurement quality. This paper provides an overview of the entire Thomson scattering diagnostic software and focuses on the data acquisition, processing, and analysis software implementation. The software falls into three general categories: 1. Set-up and Control: Initializes and controls all Thomson hardware and software, sychronizes with other DIII-D computers, and invokes other Thomson software as appropriate. 2. Data Acquisition and Processing: Obtains raw measured data from memory and processes it into temperature and density values. 3. Analysis: Provides a graphical user interface in which to perform analysis and sophisticated plotting of analysis parameters.

Fiber photometry is the process of recording bulk neural activity by measuring fluorescence changes in activity sensitive indicators such as GCaMP through an optical fiber. We present a system of open source hardware and software for fiber photometry data acquisition consisting of a compact, low cost, data acquisition board built around the Micropython microcontroller, and a cross platform graphical user interface (GUI) for controlling acquisition and visualising signals. The system can acquire two analog and two digital signals, and control two external LEDs via built in LED drivers. Time-division multiplexed illumination allows independent readout of fluorescence evoked by different excitation wavelengths from a single photoreceiver signal. Validation experiments indicate this approach offers better signal to noise for a given average excitation light intensity than sinusoidally-modulated illumination. pyPhotometry is substantially cheaper than commercial hardware filling the same role, and we anticipate, as an open source and comparatively simple tool, it will be easily adaptable and therefore of broad interest to a wide range of users.

Software development for the simultaneous control of ten intelligent overview video cameras at W7-X

We recently developed a new, man-portable, electromagnetic induction (EMI) sensor designed to detect and classify small, unexploded sub-munitions and discriminate them from non-hazardous debris. The ability to distinguish innocuous metal clutter from potentially hazardous unexploded ordnance (UXO) and other explosive remnants of war (ERW) before excavation can significantly accelerate land reclamation efforts by eliminating time spent removing harmless scrap metal. The EMI sensor employs a multi-axis transmitter and receiver configuration to produce data sufficient for anomaly discrimination. A real-time data inversion routine produces intrinsic and extrinsic anomaly features describing the polarizability, location, and orientation of the anomaly under test. We discuss data acquisition and post-processing software development, and results from laboratory and field tests demonstrating the discrimination capability of the system. Data acquisition and real-time processing emphasize ease-of-use, quality control (QC), and display of discrimination results. Integration of the QC and discrimination methods into the data acquisition software reduces the time required between sensor data collection and the final anomaly discrimination result. The system supports multiple concepts of operations (CONOPs) including: 1) a non-GPS cued configuration in which detected anomalies are discriminated and excavated immediately following the anomaly survey; 2) GPS integration to survey multiple anomalies to produce a prioritized dig list with global anomaly locations; and 3) a dynamic mapping configuration supporting detection followed by discrimination and excavation of targets of interest.

Software for practical training in medical biophysics

본 논문은 트리거 시간을 조절하여 펄스 성형이 가능한 150 MW 펄스 파워 시스템의 설계와 동작특성을 알아보았다. 이 시스템은 2개의 커패시터 뱅크 모듈로 구성되어 있고, 각 커패시터 뱅크 모듈은 병렬로 연결되어 있다. 그리고 커패시터 뱅크 모듈은 메인스위치, 커패시터, 에너지 덤프회로, 크로바 회로, 펄스 성형 인덕터로 구성되어 있다. 또한 이 시스템의 모듈 선택과 트리거 시간은 트리거 제어부에서 조정된다. Pspice 시뮬레이션은 실험회로의 결과를 예측하고, 시스템의 구성품의 파라미터를 결정하기 위한 것으로 사용하였다. 실험 결과, 시뮬레이션은 실험결과와 잘 일치하였다. 출력 전류의 펄스폭은 커패시터 뱅크 모듈에서의 순간적 점화 시간 제어로 300~650 us의 펄스폭이 형성되었다. 그리고 최대 전류값은 2개의 커패시터 뱅크 모듈이 동시에 트리거 되었을 때 약 40 kA 정도이다. 이 150 MW 펄스 파워 시스템은 파암 전원, Rail Gun, Coil Gun, 나노분말 제조, HPM 등과 같은 대전류 펄스 파워 시스템에 적용할 수 있다. This paper presents design and operational characteristics of 150 MW pulse power system for high current pulse forming network to control trigger time. The system is composed of two capacitor bank modules. Each capacitor bank module consist of a trigger vacuum switch, 9k 33kJ capacitor, an energy dump circuit, a crowbar circuit and a pulse shaping inductor and is connected in parallel. It is controlled by trigger controller to select operational module and determine triggering time. Pspice simulation was conducted about determining parameters of components such as crowbar circuit, capacitor, pulse forming inductor, trigger vacuum switch and predicting results of experiment circuit. The result of the experiment was in good agreement with the result of the simulation. The various current shapes with 300~650 us pulse width is formed by sequential firing time control of capacitor bank module. The maximum current is about 40 kA during simultaneous triggering of two capacitor bank modules. The developed 150 MW pulse power system can be applied to high current pulse power system such as rock fragmentation power sources, Rail gun, Coil gun, nano-powers, high power microwave.