Global energy balance, radiation profiles and dominant impurity radiation sources are compared for Ohmically heated limiter and divertor discharges in the ASDEX tokarnak. In discharges with a poloidal stainless-steel limiter, total radiation from the plasma is the dominant energy loss channel. The axisymmetric divertor reduces this volume-integrated radiation to 30–35% of the heating power and additional Ti-gettering halves it again to 10–15%. Local radiation losses in the plasma centre, which are mainly due to the presence of iron impurity ions, are reduced by about one order of magnitude. In high-current (Ip = 400 kA) and high-density (e = 6 × 1013 cm−3) ungettered divertor discharges, up to 55% of the heating power is dumped into a cold-gas target inside the divertor chambers. The bolometrically detected volume power losses in the chambers can mainly be attributed to neutral hydrogen atoms with kinetic energies of a few eV. In this parameter range, the divertor plasma is dominated by inelastic molecular and atomic processes, the main process being Franck-Condon dissociation of H2 molecules.
全球能量平衡、辐射分布以及主要杂质辐射源在ASDEX托卡马克装置中进行了欧姆加热限制器与偏滤器放电的对比研究。在采用不锈钢限制器的放电中，等离子体总辐射是主要的能量损失通道。轴对称偏滤器将这种体积积分辐射降低至加热功率的30%–35%，而进一步采用钛吸气处理后，该比例再次减半至10%–15%。等离子体中心区域的局部辐射损失（主要源于铁杂质的存在）降低了约一个数量级。在高电流（Ip = 400 kA）和高密度（ne = 6 × 10^13 cm^−3）的无钛吸气偏滤器放电中，高达55%的加热功率被沉积到偏滤器室内的冷气体靶上。通过辐射量热法探测到的偏滤器室内体积功率损失主要可归因于具有数个电子伏特动能的中性氢原子。在该参数范围内，偏滤器等离子体由非弹性分子和原子过程主导，其中主要过程为H2分子的弗兰克-康登离解。