影响产生均匀等离子体状态的几个因素

 用数值模拟方法研究利用辐射加热来产生均匀等离子体状态,它可被用来测量元素的辐射不透明度,校验辐射不透明度理论。研究了在辐射加热铁的“三明治”型靶时影响生成均匀等离子体状态的几个重要因素（样品厚度、CH膜厚度和辐射源）所起的作用，研究发现，当铁等离子体通过热传导达到均匀状态时，其尺度必须与此时的传热距离相当，从而定出铁样品的厚度；低Z介质CH膜对铁等离子体有明显的箍束作用，调整CH膜的厚度可以调节所产生的等离子体状态；调整不同方向上的CH膜厚度，可以控制铁等离子体的膨胀方向，使它尽可能地达到一维膨胀，使得反推出的等离子体密度可以更加准确；样品的种类、厚度以及外面的低Z介质厚度决定了在某时刻能获得的等离子体状态，以及为产生此等离子体状态所需的最低辐射能。

Impact of tamped sample target structure on production of uniform plasmas

The X-ray radiation can be used in heating sandwich type tamped sample targets to produce a uniform plasmas, which is essential for absorption spectrum measurement experiments to provide meaningful quantitative data on radiative and material properties. With 1D multi-group radiation transport program, this paper studies the impact of those target's structure on the plasma states produced by X-ray heating. A CH layers tamped iron target is heated by X-ray from one side in our simulation. In order to produce a uniform plasma states at a moment, the scale of plasma produced must be shorter than the heat conducting distances, which determines the initial thickness of iron samples. The thickness of CH layer has obvious confining effect on the plasma expansion, it also affects the uniform plasma states produced. By adjusting the thickness of CH layer at different directions, a 1D plasma expansion and desired plasma state can be obtained. More radiation energy to heat the target is not better. Limited by the target's ability to absorb energy, extra energy will pass the sample without being absorbed.