Based on thin annular electron beam approximation, the focusingeffect of plasma is investigated.
在薄环形束的近似下讨论了等离子体对空心电子束的聚束作用。
2
The result shows that under the constant current exciting mode, the exciting magnetic field is the strongest and has a focusingeffect, which improves the eddy detection sensitivity considerably.
结果表明，在恒流激励方式下的激励磁场最强，且具有聚焦效果，因而可有效地提高涡流探伤的灵敏度。
3
Which brings me back to the destructive effect of focusing on invisible monsters.