Sheng Peng

Data Processing Middleware in a High-Powered Neutral Beam Injection Control System

A set of data-processing middleware for a high-powered neutral beam injection (NBI) control system is presented in this paper. The middleware, based on TCP/IP and multi-threading technologies, focuses mainly on data processing and transmission. It separates the data processing and compression from data acquisition and storage. It provides universal transmitting interfaces for different software circumstances, such as WinCC, LabView and other measurement systems. The experimental data acquired on Windows, QNX and Linux platforms are processed by the middleware and sent to the monitoring applications. There are three middleware deployment models: serial processing, parallel processing and alternate serial processing. By using these models, the middleware solves real-time data-processing problems on heterogeneous environmental acquisition hardware with different operating systems and data applications.

Development of a Data Acquisition Control System for the First NBI on EAST

Neutral beam injection (NBI) heating is one of the most efficient auxiliary plasma heating methods for fusion devices. The data acquisition control system (DACS) with PXI (peripheral component interconnect extensions for instrumentation) data acquisition card for the first NBI system in the experimental advanced superconducting tokamak (EAST) is presented in this paper. As an important sub-system, DACS is designed to obtain physical measurement signals in the EAST NBI system and to deal and store these data with the Lempel-Ziv-Oberhumer (LZO) lossless data compression algorithm, as well as offer convenient data call-back and access interfaces to the user for examining and analyzing the data. Experimental results show that accurate data will ensure that researchers correctly analyze it and then properly adjust the experimental parameters or operation, so DACS should take a large step in improving experimental efficiency. The hardware and software sections are briefly presented in this paper, and now this system has been tested to be able to work reliably and steadily.

The Recent Development of the EAST Neutral Beam Injector

Neutral beam injection has been recognized as one of the most effective means for plasma heating. According to the research plan of the EAST physics experiment, two sets of neutral beam injectors (4–8 MW, 10–100 s) were built and operated in 2014. We present the development of the EAST neutral beam injector (NBI) and the latest experiment results obtained on the test-stand about operation of ion source, beam extraction, and measurement of key parameters. Those results show that all targets reach or almost reach the design targets. All these lay a solid foundation for the achievement of plasma heating and current drive for EAST in 2014.

Design of Timing Synchronization Software on EAST-NBI

To ensure the uniqueness and recognition of data and make it easy to analyze and process the data of all subsystems of the neutral beam injector (NBI), it is required that all subsystems have a unified system time. In this paper, the timing synchronization software is presented which is related to many kinds of technologies, such as shared memory, multithreading, TCP protocol and so on. Shared memory helps the server save the information of clients and system time, multithreading can deal with different clients with different threads, the server works under Linux operating system, the client works under Linux operating system and Windows operating system. With the help of this design, synchronization of all subsystems can be achieved in less than one second, and this accuracy is enough for the NBI system and the reliability of data is thus ensured.

The Timing System of the Neutral Beam Injector on EAST

In order to synchronize the elements of the EAST Neutral Beam Injector (NBI) spatially located in several places, a distributed Timing System (TS) is developed in this paper. The timing system provides a clock reference for synchronization and an interlock protection of the EAST NBI system. It sends timing signals to field devices, controls the pulse widths of the timing sequences, and provides a sampling clock for the Data Acquisition System (DAS). The timing system also generates analog waveforms to control power supplies and gas supplies according to the operators configuration. The timing system is developed on a PXI (PCI eXtensions for Instrumentation) platform consisting of a LabVIEW workstation and a timing control terminal. The timing control terminal consists of a timing node and several control interface crates. Two timing nodes are configured in one beam line. Each node is responsible for the timing sequence, analog generation and feedback control for one ion source. The architecture and implementation of the timing system are presented in this paper.

Development of Data Processing Software for NBI Spectroscopic Analysis System

A set of data processing software is presented in this paper for processing NBI spectroscopic data. For better and more scientific managment and querying these data, they are managed uniformly by the NBI data server. The data processing software offers the functions of uploading beam spectral original and analytic data to the data server manually and automatically, querying and downloading all the NBI data, as well as dealing with local LZO data. The set software is composed of a server program and a client program. The server software is programmed in C/C++ under a CentOS development environment. The client software is developed under a VC 6.0 platform, which offers convenient operational human interfaces. The network communications between the server and the client are based on TCP. With the help of this set software, the NBI spectroscopic analysis system realizes the unattended automatic operation, and the clear interface also makes it much more convenient to offer beam intensity distribution data and beam power data to operators for operation decision-making.

Development of Distributed Control System for Neutral Beam Injector on EAST

A distributed control system of Neutral Beam Injector (NBI) on the Experimental Advanced Superconducting Tokamak (EAST-NBI) is brie∞y presented in this paper. The control system is developed in accordance with the experimental operational characteristics of the EAST- NBI. The NBI control system (NBICS), which is based on the computer network technologies and classifled according to the control levels, consists of three levels: a remote monitoring layer, a server control layer, and a fleld control layer. The 3-layer architecture is capable of extending the system functions and upgrading devices. The timing system provides the reference clock of the synchronization and interlock for the EAST-NBI system. An interlock system ensures the safety of the experiment operators and fleld devices. Both of the ion sources of the beamline are designed to operate independently. This lays an important foundation for developing a control system for the second beamline on EAST. Experimental results demonstrate that the NBICS meets functional requirements of the EAST-NBI control, and makes experimental operations visual and automatic.

Design of Control Server Application Software for Neutral Beam Injection System

For the remote control of a neutral beam injection (NBI) system, a software NBIcsw is developed to work on the control server. It can meet the requirements of data transmission and operation-control between the NBI measurement and control layer (MCL) and the remote monitoring layer (RML). The NBIcsw runs on a Linux system, developed with client/server (C/S) mode and multithreading technology. It is shown through application that the software is with good efficiency.

Using Adaptive Discrete-Time Gas Supply Control for Long Pulse Arc Discharge of Ion Source on NBI

A control model of gas supply system is introduced for ion source and an adaptive discrete-time control algorithm to regulate the hydrogen injection. A real-time feedback control system (RFCS) is designed to control the gas supply for ion source based on the control model and the discrete-time control algorithm. The experimental results have proved that RFCS could regulate the gas supply smoothly, suppress the arcs abrupt over-current at the end of the ion source discharging, prolong the discharge pulse and stabilize the ion concentration. With RFCS, the ion source for neutral beam injection has reached its longest pulse with a length of 4.5 seconds in a stable status.