HL-2Mװ�õ��Ӳ������Ӳ�������벨�׼���

HL-2M装置低杂波天线被设计为多栅阵列天线，天线由4行波导组成，每行32个子波导。子波导宽度为0.99cm，壁厚0.3cm，相邻子波导相差取90°。计算得到的反射系数R=0.0261，N||峰值中心为2.375。边缘等离子体电子密度梯度对波谱峰值中心位置没有影响，波峰相对宽度则随之增大而减小。在边缘等离子体电子密度梯度 的情况下，相邻子波导相差为81°时，天线方向性系数最好，为0.2010；反射最小，为0.0223，此时波谱峰值中心为2.125。

Grill design and spectrum calculation of LHW antenna on HL-2M tokamak

The antenna for lower hybrid current driving on HL-2M tokamak is designed as 4?32 waveguide arrays. The width of grill is 9.9mm, the wall thickness is 3mm and the phase difference between two adjacent grills is 90?. The calculation shows that the reflectance R is 0.026 and the N|| corresponding the peak value is 2.375. The gradient of edge electron density has nothing to do with the N|| corresponding the peak value. But the larger electron density gradient of the plasma edge is, the smaller peak width is. When the phase difference between two adjacent grills is 81?and , is optimum, 0.2010, R is minimum, 0.0223 and the N|| corresponding the peak value is 2.125.