受电子束辐照的硬铝靶的喷射冲量耦合系数随能通量的变化规律

VARIATION OF THE COUPLING COEFFICIENTS OF BLOWOFF IMPULSE VERSUS ENERGY FLUX IN LY-12 ALUMINUM ALLOY TARGETS BOMBARDED BY ELECTRON BEAM

采用通光式传感法和直接测量特定时间间隔的探头原理，在“闪光２号”装置上进行了电子束辐照硬铝靶产生的喷射冲量耦合系数与能通量关系的研究。结果表明：在能通量为１１５～２４０Ｊ／ｃｍ~２范围内，喷射冲量和亏损质量面密度都随能通量近似线性变化，而喷射冲量耦合系数随能通量增大而缓慢递增，并趋于一渐近值；硬铝产生喷射冲量的能通量阈值为４０Ｊ／ｃｍ~２左右；喷射冲量值为８１～２１８Ｐａ·ｓ，亏损质量面密度为３．１× １０^（－２）～８．６×１０^（－２）ｇ／ｃｍ~２，喷射冲量耦合系数为０．７０～０．９８Ｐａ·ｓ／（Ｊ／ｃｍ ~２）。

When a pulsed,high-energy,high-intensity particle beam such as electron beam bombards a solid target, there will often exist melting, vaporizing and mass blowoff phenomena on the front surface,which give it a blowoff impulse load. In the latest years,we studied the relations between the coupling coefficients of blowoff impulse, which were produced in LY12 aluminum alloy target bombarded by electron beam on 'FLASH-II' with the light transducing probe and directly measuring the specific time interval. In the range of the energy fluxes from 115 to 240J/cm^2,the experimental results show that: 1. The blowoff impulse and the area density of loss mass change approximately linearly with energy flux and the coupling coefficient of blowoff impulse increases slowly with the increase of energy flux up to an asymptotic value. 2. The threshold flux used for producing blowoff impulse in LY-12 aluminum alloy is about 40J/cm^2. 3. The value of blowoff impulse is in the range 81-2118Pa. s, the area density of loss mass is 3.1×10^(-2)- 8. 6 × 10^(-2) g / cm^2, the coupling coefficient of blowoff impulse are 0. 70-0. 98Pa. s/(J/cm^2).