中文摘要：

为给环境磁场对人体健康影响的研究提供基础,设计并测试了一种用于动物长期曝露实验的大型工频磁场曝露系统。首先通过分析计算2个方形载流线圈的磁场分布确定了产生特定均匀磁场的电磁参数。据此设计、制造出的4组磁场曝露系统均为一对间距2m、边长5m的正方形线圈。计算和测试表明：制造的线圈内,磁场强度在目标场值±10%范围内的工作区域约为4m×4m的正方形,比使用Helmholtz线圈时的工作区域面积增加56%;采用双线双绕方法制作的对照组和磁场组线圈具有相同的形状和电流,可消除线圈散热和电源噪声等因素对实验的影响;采用无功功率补偿的方法降低了电源的输出电压,可以节约成本。结果表明所设计的工频磁场曝露装置可以用于长期磁场曝露对动物健康影响的实验。

英文摘要：

To provide a basis for studying effects of environmental magnetic field on human health,we designed,manufactured,and tested a large power frequency magnetic field exposure system for long-term animal experiments.Based on the computation of magnetic field produced by a pair of current-carrying square coils,the parameters of coils and power sources were chosen to generate specific magnetic field,then 4 exposure systems were fabricated according to these parameters.Each of the finished magnetic field exposure systems was composed of two square coils with a side length of 5 m and a 2 m interval between themselves.According to further calculation and tests,the working area,where the magnetic flux density was within the 90%-110% of the target value,was a square area of 4 m×4 m,which was 56% larger than that produced by Helmholtz coils.Two strands of copper wires with different current directions were winded on the same coil skeleton to form a bifilar choke as control,which successfully eliminated the influence of heat produced by coils and noise generated by power sources between different experiments.Reactive power compensation was used to lower the output voltage of the power source as well as its cost.Results show that the proposed apparatus can be used in studies of health risk under long-term magnetic field exposure.