Research On Influence Of Pre-pulse And Main-pulse Current On Capillary Discharge Laser At 46.9nm

In this paper,the characteristics of 46.9 nm capillary discharge soft x-ray laser with 4.0mm inner diameter are studied under different experimental conditions.Based on the combination of theoretical simulation and experiment,the parameters such as pre-pulse current,main pulse current and the initial pressure of capillary are changed,and the Change Law of parameters to improve the characteristics of 46.9 nm laser is obtained.The experiment was carried out at 24 k A,30 k A and 36 k A amplitude of main pulse current.The experiment results show that with the increase of the amplitude of the main pulse current,the minimum pressure,the maximum pressure and the range of the pressure are all increasing,and the strongest laser output is obtained under the condition of main pulse current 30 k A.Then,under the condition of the best initial gas pressure of each main pulse current,changing the amplitude of the pre-pulse current,the experiment was carried out,with the increase of the amplitude of the prepulse current,the output intensity of the laser first increases rapidly and then decreases slowly,and with the increase of the amplitude of the main pulse current,the amplitude of the prepulse current that is most suitable for the output light also increases.A one dimensional magnetohydrodynamics model was used to simulate the Z pinch process of the initial plasma with a diameter of 4.0 mm,the main pulse current of 30 k A is more suitable for generating 46.9 nm laser.The plasma electron temperature is about 110 e V and the electron density is about 2.0-3.0×10¹⁸cm^-3.The changes of plasma electron temperature,density and relative abundance of High Valence Argon Ions at the time of laser generation caused by the changes of initial gas pressure and main pulse current were summarized.