Dense Plasma Formation by Carbon Thin Film Liner Compression

我们提出了一种Z箍缩碳薄膜线性压缩方案，该方案对于高强度脉冲X射线源和X射线激光器的应用是有效的。实验证明该原理是有效的。利用沉积在放电管壁表面的导电薄膜作为压缩衬里的方法，可以克服处理机械薄弱的圆柱形金属衬里的技术困难。如果选择合适的制膜工艺，可以在连续泵浦的放电容器中进行一系列的实验。由于衬里是由任何变成薄膜的东西制成的，所以在软X射线的波长范围内可以获得各种不同的辐射光谱。夹点动力学的数值模拟表明，传统的电容器组可以很容易地驱动碳薄膜衬里。采用射频辉光、交流辉光或直流辉光、脉冲放电、弧光等离子体和真空气相沉积等方法研究了薄膜的最佳制备方法。采用真空气相沉积法制备了均匀的导电薄膜。但由于碳膜沉积时间过长，导致碳膜衬里压缩不成功。我们把衬里的材料改成了铝。采用真空气相沉积的方法在直径为7 cm的放电管管壁上形成铝薄膜衬里。电容器(20KV，900J)放电驱动线性压缩。当电流达到最大值70kA时，衬里被压缩到轴线上，并观察到软X射线发射。

We proposed carbon thin film liner compression scheme in Z-pinches which is effective for the application of high intensity pulsed X-ray sources and X-ray lasers. The experiments proved the principle to be valid. The method of using a conductive thin film deposited on the surface of discharge tube wall as a compression liner can overcome the technical difficulties in handling mechanically weak oylindrical metal liners. If the process of making the thin film is properly chosen, a series of experiments can be done in the discharge vessel which is continuously pumped. Since the liner is made from anything which becomes thin film, a great variety of radiation spectra can be obtained in the wavelength range of soft X-ray. A numerical simulation on pinch dynamics shows that conventional capacitor banks can easily drives the carbon thin film liner. The optimum way of producing the thin film was examined by applying several methods, namely, RF, AC or DC glow, and pulsed discharge, arc plasma, and vacuum vapor deposition. Uniform and conductive thin films were produced by vacuum vapor deposition. However; the film deposition time was so long that the carbon film liner compression was unsuccessful. We changed carbon to aluminum as the liner material. Aluminum thin film liner is formed on the tube wall of a 7cm diameter discharge tube by vacuum vapor deposition. A capacitor (20kV,900J) discharge drives the liner compression. The liner is compressed to the axis when the current reaches its maximum of 70kA and the soft X-ray emission is observed.