Ghim Kim Young-Chul, Field A R, Zoletnik S, Dunai D
Rudolf Peierls Centre for Theoretical Physics, University of Oxford, Oxford OX1 3NP, United Kingdom.
Rev Sci Instrum. 2010 Oct;81(10):10D713. doi: 10.1063/1.3479037.
The beam emission spectroscopy (BES) turbulence diagnostic on MAST is to be upgraded in June 2010 from a one-dimensional trial system to a two-dimensional imaging system (8 radial×4 poloidal channels) based on a newly developed avalanche photodiode array camera. The spatial resolution of the new system is calculated in terms of the point spread function to account for the effects of field-line curvature, observation geometry, the finite lifetime of the excited state of the beam atoms, and beam attenuation and divergence. It is found that the radial spatial resolution is ∼2-3 cm and the poloidal spatial resolution ∼1-5 cm depending on the radial viewing location. The absolute number of detected photons is also calculated, hence the photon noise level can be determined.
MAST上的束发射光谱（BES）湍流诊断系统将于2010年6月从一维试验系统升级为基于新开发的雪崩光电二极管阵列相机的二维成像系统（8个径向×4个极向通道）。新系统的空间分辨率根据点扩散函数计算，以考虑磁力线曲率、观测几何结构、束原子激发态的有限寿命以及束衰减和发散的影响。结果发现，根据径向观测位置的不同，径向空间分辨率约为2 - 3厘米，极向空间分辨率约为1 - 5厘米。还计算了检测到的光子的绝对数量，从而可以确定光子噪声水平。
