Recently a new Thomson scattering diagnostic system was upgraded in EAST tokamak experiment using a multipulse Nd:YAG (neodymium—yttrium aluminium garnet) laser and a multipoint observation volumes. This diagnostic uses a new optical laser alignment technique that was made to determine accurately the laser position, and a new lens collection system that enables the measurement of wider plasma's object. A composite control system made we can get the results in several seconds. Furthermore, a new data processing method was adopted for much exact results.

Primary physical design of the Thomson scattering system for EAST, including the configuration of the system and the design considerations of different sections of the system, is presented. The expected measurability of this design, namely an electron temperature of 50 eV to 5 keV and a plasma density beyond 0.5 x 10(19) m(-3), fulfills the requirements of the EAST operation.

A multipulse and multipoint Nd:YAG (neodymium-yttrium aluminum garnet) laser Thomson scattering diagnostic system was developed on EAST to obtain more accurate electron temperature T-e and electron density n(e) profiles. In this paper, the optical system, the VME (versa module eurocard)-based real-time computer system for laser control, data acquisition, analysis and calibration are discussed in detail. Further more, a developed data processing method is presented.

The paper gives a description and key design features for the EAST power supply system consisting of superconducting coil power supply, inner vessel coil power supply, and additional heating power supply including microwave power supplies and neutral beam injection power supply. These power supplies are all realized by AC/DC converter, H Bridge and IGBT chopper.

Thomson scattering diagnostic is important for measuring electron temperature and density profiles. To improve the signal-to-noise ratio, a silicon avalanche photodiode (APD) with high quantum efficiency, high sensitivity, and high gain up to 100 was adopted to measure the Thomson scattering spectrum. A preamplifier, which has low noise, high bandwidth, and high sensitivity, was designed with suitable transimpedance. Using AD8367 as the post-amplifier, good performance of the APD readout electronics have been obtained. A discussion is presented on the performance of the amplifier using a laser diode to simulate the Thomson scattering light. The test results indicate that the designed circuit has a high amplifying factor and fast rising edge. So reduction of the integral gate of the CAMAC ADC converter can improve the signal-to-noise ratio.

A five-channel polychromator, utilizing high performance interference filters, has been completed for Thomson scattering measurements on HT-7 tokamak. For our instrument, the range of electron temperature varies from 50 eV to 1.5 keV. According to this, the bandpass of the different interference filters are chosen. Unique features of the polychromator are high throughput,easy alignment, flexibility and compact size when compared with other alternatives. In this article,both the method of designing and the measured transmission curves for the polychromator are given.

This article describes the data processing and acquisition system for the HT-7 multipulse Thomson scattering diagnostic. An eight-pulse laser is used in the Thomson scattering system to obtain electron temperature profiles at eight different times throughout an entire plasma discharge. The major components of the diagnostic system consist of a multipulse Nd-glass laser, a photodetector's subsystem, a calibration set and a CAMAC data processing and acquisition system. The data processing software along with LeCroy 2250L will perform the data acquisition. In order to simplify the operation and extend the capability of its compatibility with other math softwares, the processing software has been improved by the authors. The new software based on the VC++ easily utilizes some math softwares to calculate the electron temperature. The new software is simpler and more operational than the old one.