An automatic beam alignment system based on relative reference points for Thomson scattering diagnosis system.

An automatic beam alignment system based on relative reference points is developed for the Thomson scattering system on Keda Torus eXperiment. Two critical apertures around the vacuum vessel are designed to shield stray light, and a probe beam is required to go through the centers of these two apertures, which are the reference points for alignment. Since these two apertures are coated with light absorbing materials, three fibers with glowing tips are employed to indicate the centers of two apertures. CMOS cameras are used to monitor beam deviations. The misalignment correction is achieved by driving piezomotor mirror mounts via a program developed with LabVIEW, which includes the image acquisition and processing module and the deviation correction module. As a result, this system can correct beam misalignment in less than 20 s and suppress the long-term drift of laser pointing in ±10 µrad. Also, this system has the capability to correct up to about 2.3 mm of camera shift with our experiment condition.

Combined fenton oxidation and biological activated carbon process for recycling of coking plant effluent.

Fenton oxidation and coagulation-flocculation-sedimentation (CFS) were both effective in removing many organic constituents of the biotreated coking plant effluent before the final treatment in an activated carbon adsorber. Fenton oxidation broke down most persistent organic pollutants and complex cyanides present in the feed stream and caused the eventual biodegradation of the organic residues in the adsorber. The results of Fenton oxidation followed by adsorption and biodegradation in two biological activated carbon (BAC) adsorbers show that the combined treatment consistently produced a high quality final effluent of <50mg/L in COD(Cr) and <0.5mg/L in total cyanide during the 70-d study without replacing any activated carbon. The BAC function of the adsorber substantially reduced the need for replacing activated carbon making the combined Fenton oxidation-BAC treatment process a cost effective treatment process to recycle the final effluent for many beneficial reuses while meeting the much more stringent discharge limits of the future.

Magnetically and optoelectronically isolated trigger for pulse-power applications.

In this article the design of a magnetically and optically isolated trigger is discussed. Critical issues for trigger design are presented together with some experimental usages. In this trigger, an optical coupler is used to cut off the ground loop between the circuits of the preceding control system and the power supplies of the double functional device KT-5D (as a simple magnetic torus or a tokamak). A magnetic coupler is used to provide a pulse-power output for the silicon controlled rectifier. The output is a 230 mus transistor-transistor logic (TTL) with an amplitude of 3.0 V. The rising time and the trailing time are no more than 4.0 mus. The delay time between the input and the output of the trigger is 6.8+/-0.2 mus. A resistance-capacity branch is integrated into the trigger to provide an adjustable delay time of up to 72 ms. The zero quiescent dissipation character endows the trigger with a long lifetime of years dispensing with any charging or replacing batteries. It is observed that the trigger has a good stability even in a high electromagnetic circumstance (at the order of 1 T). Using it as a trigger for the silicon controlled rectifier, we realized the compatible operation of the steady state mode and the pulse mode in KT-5D.