排序方式: 共有6条查询结果,搜索用时 15 毫秒
1
1.
2.
The influence of air pressure on mechanical effect of laser plasma
shock wave in a vacuum chamber produced by a Nd:YAG laser has been
studied. The laser pulses with pulse width of 10ns and pulse energy
of about 320mJ at 1.06$\mu $m wavelength is focused on the aluminium
target mounted on a ballistic pendulum, and the air pressure in the
chamber changes from
$2.8\times 10^{3}$ to 1.01$\times $10$^{5 }$Pa. The experimental results
show that the impulse coupling coefficient changes as the air
pressure and the distance of the target from focus change. The
mechanical effects of the plasma shock wave on the target are
analysed at different distances from focus and the air pressure. 相似文献
3.
In this paper, the compositions in a laser absorption region can be determined from the experiment of laser impulse coupling. When the ambient pressure varies from 9325 to 33325Pa, the compositions are vapour and plasma; while from 35325 to 101325Pa, they are ambient air and plasma. By analysing the relation between the degree of compression and the ambient pressure, the compositions can be determined and the variation of plasma can be explained. 相似文献
4.
Theoretical analysis and numerical simulation of the impulse delivering from laser-produced plasma to solid target 总被引:1,自引:0,他引:1 下载免费PDF全文
A plasma is produced in air by using a high-intensity Q-switch Nd:YAG pulsed laser to irradiate a solid target, and the impulses delivering from the plasma to the target are measured at different laser power densities. Analysing the formation process of laser plasma and the laser supported detonation wave (LSDW) and using fluid mechanics theory and Pirri's methods, an approximately theoretical solution of the impulse delivering from the plasma to the target under our experimental condition is found. Furthermore, according to the formation time of plasma and the variation of pressure in plasma in a non-equilibrium state, a physical model of the interaction between the pulse laser and the solid target is developed. The plasma evolutions with time during and after the laser pulse irradiating the target are simulated numerically by using a three-dimensional difference scheme. And the numerical solutions of the impulse delivering from the plasma to the target are obtained. A comparison among the theoretical, numerical and experimental results and their analyses are performed. The experimental results are explained reasonably. The consistency between numerical results and experimental results implies that the numerical calculation model used in this paper can well describe the mechanical action of the laser on the target. 相似文献
5.
在准真空环境下,采用高功率密度的调Q-Nd:YAG激光照射固体铝靶表面,测量了不同入射激光强度下气化靶物质对靶的冲量.通过分析不同情况下激光与固态靶、气化物质的作用机理,采用流体力学理论和三维有限差分的计算方法,对不同激光强度情况下气化物质对靶产生冲量的过程进行了数值模拟,将模拟计算所得结果与实验测量结果进行了比较和分析,进而对实验结果进行了解释.由数值模拟结果与实验结果的一致性可见,本文采用的模型能反映激光作用下固体靶力学响应的物理过程. 相似文献
6.
比较了铁磁单层膜与铁磁/反铁磁双层膜结构中的磁畴演化行为, 发现由于反铁磁层膜对铁磁层膜的耦合作用使得系统的磁畴壁厚度、 磁畴壁等效质量、磁畴壁移动速度等发生了改变, 系统的矫顽场增强, 并出现了交换偏置场. 文章具体研究了反铁磁层耦合作用下其磁畴壁厚度、 等效质量以及磁畴壁移动速度等与反铁磁层的净磁化、 磁各向异性、界面耦合强度以及温度等的关系; 并研究了其对铁磁/反铁磁双层膜中的交换偏置场、矫顽场的影响. 进而 从磁畴结构的形成及其演化上揭示了铁磁/反铁磁双 层膜中出现交换偏置以及矫顽场增加的物理机制. 相似文献
1