Entrop I, Jaspers R, Finken KH
FOM-Instituut voor Plasmafysica "Rijnhuizen," Association Euratom-FOM, P.O. Box 1207, 3430 BE Nieuwegein, The Netherlands.
Phys Rev Lett. 2000 Apr 17;84(16):3606-9. doi: 10.1103/PhysRevLett.84.3606.
Measurements of synchrotron radiation emitted by 30-MeV runaway electrons in the TEXTOR-94 tokamak show that the runaway population decays after switching on neutral beam injection (NBI). The decay starts only with a significant delay, which decreases with increasing NBI heating power. This delay provides direct evidence of the energy dependence of runaway confinement, which is expected if magnetic modes govern the loss of runaways. Application of the theory by Mynick and Strachan [Phys. Fluids 24, 695 (1981)] yields estimates for the "mode width" (delta) of magnetic perturbations: delta<0.5 cm in Ohmic discharges, increasing to delta = 4.4 cm for 0. 6 MW NBI.
在TEXTOR - 94托卡马克装置中对30兆电子伏特逃逸电子发出的同步辐射进行测量，结果表明在开启中性束注入（NBI）后逃逸粒子数会衰减。这种衰减开始时会有显著延迟，且该延迟会随着NBI加热功率的增加而减小。这种延迟直接证明了逃逸粒子约束的能量依赖性，而如果磁模控制着逃逸粒子的损失，那么这种依赖性是可以预期的。应用Mynick和Strachan [《物理流体》24, 695 (1981)] 提出的理论，可以估算出磁扰动的“模宽”（δ）：在欧姆放电中δ < 0.5厘米，对于0.6兆瓦的NBI，δ增大到δ = 4.4厘米。
