Development of a data acquisition and control system for the International Thermonuclear Experimental Reactor neutron flux monitor

To satisfy high-precision,widc-rangc,and real-time neutron flux measurement requirements by the International Thermonuclear Experimental Reactor(ITF.R),a data acquisition and control system based on fission chamber detectors and fast controller technology,has been developed for neutron flux monitor in ITER Equatorial Port#7.The signal processing units which arc based on a field programmable gate array and the PXI Express platform arc designed to realize the neutron flux measurement with I ms time resolution and a fast response less than 0.2 ms,together with real-time timestamps provided by a timing hoard.The application of the wide-range algorithm allows the system to measure up to 10^10cps with a relative error of less than 5%.Furthermore,the system is managed and controlled by a software based on the Experimental Physics and Industrial Control System,compliant with COntrol.Data Access and Communication architecture.

A novel digital neutron flux monitor for international thermonuclear experimental reactor

A novel full-digital real-time neutron flux monitor（NFM） has been developed for the International Thermonuclear Experimental Reactor.A measurement range of 10~9 counts per second is achieved with 3 different sensitive fission chambers.The Counting mode and Campbelling mode have been combined as a means to achieve higher measurement range.The system is based on high speed as well as parallel and pipeline processing of the field programmable gate array and has the ability to upload raw-data of analog-to-digital converter in real-time through the PXIe platform.With the advantages of the measurement range,real time performance and the ability of raw-data uploading,the digital NFM has been tested in HL-2 A experiments and reflected good experimental performance.

Development of a real-time magnetic island reconstruction system based on PCIe platform for HL-2A tokamak

A real-time magnetic island reconstruction(MIR)system based on PCI express platform for HL-2 A tokamak is introduced.The front-end analog circuit and high performance analog-to-digital converters complete high-precision synchronous sampling of 18 channel Mirnov signals,and the application of PCIe platform and direct memory access technology enables high speed data transmission between graphics processing unit and field programmable gate array(FPGA).FPGA,as a mainstream high speed parallelizable computing tool,was used to implement the MIR algorithm,while a parameter table is established in an external double data rate SDRAM to improve the computational efficiency.The software of the MIR system is developed with Compute Unified Device Architecture 8.0 in Centos 6 system,which mainly realizes driver development,data transmission,network communication,parameter calculation and system control.This system has been tested in HL-2 A plasma discharge experiment,and the reconstructed magnetic island structure can achieve a spatial resolution of 1.02 cm while the time resolution can reach 2 ms.

CONCEPTUAL DEVELOPMENT OF THE EARTH TUBE COOLING SYSTEM FOR A TALL BUILDING

Earth tubes are earth-to-air heat exchangers that are frequently utilized in energy conscious low-rise buildings, but are scarcely reported for tall buildings. The feasibility of applying earth tube cooling to tall buildings in a hot summer and cold winter climate zone was studied in this paper. Firstly, the designed cooling load of a tall building was obtained from the energy simulation using the baseline and the modified models with applicable energy efficiency measures. Based on the load, the required cooling capacity, the overall section area and the effective length of the earth tube system was deduced from the heat transfer and fluid flow calculation analytically. Then the performance of the earth tube system was crosschecked and verified via the Computational Fluid Dynamics (CFD) simulation. In the CFD simulation, earth tubes with different diameters and lengths, as well as a full-scale earth tube model with surrounding soil above the depth of constant temperature, were investigated. The outlet air temperatures of the full-scale models were computed with the consideration of different axial distances between adjacent tubes. Meanwhile, multiple conceptual design schemes and the tunnel construction method for the earth tube system were proposed from the perspective of performance enhancement, constructability, efficiency and economy. It revealed that earth tube systems are conditionally feasible for some tall buildings if their design guidelines for climate, underground spaces, construction method, friction of tube interior surface, optimization of effective length and axial distance, as well as synergy with other energy efficiency measures are followed. Even the cooling capacity of earth tubes degrade with time due to the accumulated heat underground, but in a hot summer and cold winter climate zone it can still possibly produce cooled air for a tall building with a Floor Area Ratio of less than 7 effectively in summer.