Tokamak heat transport – a study of heat pulse propagation in JET
Tokamak heat transport – a study of heat pulse propagation in JET
复制标题
DOI：
10.1088/0029-5515/27/11/009
复制
发表时间：
1987-11
期刊：
影响因子：
3.3
通讯作者：
B. Tubbing;N. Lopes Cardozo;M. J. van der Wiel
中科院分区：
文献类型：
--
作者：
B. Tubbing;N. Lopes Cardozo;M. J. van der Wiel
本文研究了在等离子体电流Ip = 3 MA、环向磁场BT = 3 T和伸长率κ = 1.45的限制器放电中，由JET中的电子活动产生的热脉冲的传播。改变辅助功率，使得总功率在2至13.5MW的范围内。用12通道电子回旋发射多色仪，以高时间分辨率记录了小半径r =（2/3）a附近20 cm范围内的电子温度扰动。从这些测量的电子热扩散率导出。在所考虑的整个功率范围内，发现与功率无关，并且在2.5 ± 0.5 m2·s−1的范围内。将该量与从全局功率平衡分析得出的量进行比较。对于欧姆加热，后者低于2.5倍。为了增加辅助动力。局部χe n的温度梯度的依赖性的模型，它允许一个统一的描述的热脉冲的行为，恶化的限制和一定程度的轮廓一致性。该模型不调用非局部参数，如总功率输入。结果表明，根据这种解释，目前的热脉冲数据与典型形式τE P−0.5的τE标度律相矛盾。
The propagation of heat pulses originating from sawtooth activity in JET has been investigated in a series of limiter discharges with the following parameters: plasma current, Ip ≃ 3 MA, toroidal magnetic field, BT ≃ 3 T and elongation, κ = 1.45. The auxiliary power was varied such that the total power ranged from 2 to 13.5 MW. Electron temperature perturbations in a 20 cm region around a minor radius of r = (2/3)a were recorded with high time resolution, using a 12 channel electron cyclotron emission polychromator. From these measurements the electron heat diffusivity was derived. Over the whole range of powers considered, was found to be independent of power and to lie in the range of 2.5 ± 0.5 m2·s−1. The quantity is compared to as derived from global power balance analysis. For Ohmic heating, the latter is lower than by a factor of 2.5. For increasing auxiliary power, approaches . A model for the dependence of the local χe n the temperature gradient is presented; it permits a unified description of the heat pulse behaviour, the deterioration of confinement and a certain degree of profile consistency. The model does not invoke non-local parameters such as the total power input. It is shown that the present heat pulse data, subject to this interpretation, contradict the τE scaling laws of the typical form τE ∝ P−0.5.