Measurement of the plasma parameters during the first two milliseconds (Iϕ < 10 kA) of the LT-3 discharge indicates that the plasma passes through three distinctive phases. The first phase is a low- βθ phase during which the electron density is small. The second phase is ionization phase which often features hollow current profiles. The third phase is an impurity-influx phase which closely follows the completion of the hydrogen ionization. It is found that inclusion of some Z- and θ-pinching during these stages would produce hotter discharges. However, Z-pinching often induces extra impurity influx and θ-pinching reduces the current channel significantly. The θ-pinching often causes sudden partial filling of the hollow current channel, accompanied by positive voltage spikes.
LT-3放电装置最初两毫秒内（Iϕ < 10 kA）等离子体参数的测量表明，等离子体经历了三个不同的阶段。第一阶段为低βθ阶段，此时电子密度较小。第二阶段为电离阶段，该阶段常呈现空心电流分布特征。第三阶段为杂质流入阶段，紧随氢电离完成之后。研究发现，在这些阶段中加入一定的Z箍缩和θ箍缩效应可产生更高温度的放电。然而，Z箍缩常会引发额外的杂质流入，而θ箍缩则会显著缩小电流通道。θ箍缩还常导致空心电流通道突然部分填充，并伴随正向电压尖峰的出现。