tokens: spherical target and the stripped mass from the envelope as functions of time. Time is scaled with the mean pusher transit time (≈19.4 ns). The stripped mass is normalized with the total envelope mass and is identified as forward ( v z > 0) traveling mass above the mass center (MC, blue line). Also plotted is the stripped mass obtained when its velocity becomes larger than 4 km s −1 (green line). The evolution of the stripped mass and core velocity obtained with this criterion is shown by the green line in Figure 11 . Our second procedure simply counts as stripped any envelope material with coordinates above the center of mass of the target. This second method leads to the blue line in Figure 11 . As can be seen, the precise criterion to decide when the mass element has been stripped mainly affects the rising part of the curves, which is steeper with the second criterion. Nevertheless, both criteria lead to a similar asymptotic behavior. The curves show a similar overall trend to the astrophysical case presented in Figure 7 . Furthermore, by taking the ratio between the asymptotic core velocity (AACV) and the average ejecta velocity (AEV) this results in values of AACV/AEV ≈ and 1.6 × 10 –2 for the astrophysical and the laboratory simulations respectively, which fulfills Equation ( 9 ). Figure 12 shows a plot of the angular distribution of stripped mass from the two-layer companion/target. The baseline curve labeled t = 0 depicts the mass distribution function of the Cu envelope of the target before the impact (the shell in gray in the sketch) as a function of the axial angle θ (). Figure 12 shows the laboratory and astrophysics distributions at the common time . The lines for the laboratory and astrophysical simulations lie above the reference line, indicating that much of the stripped material is coming from the lower hemisphere of the target. The consequences of using planar or spherical blasts in the laboratory setting are quite evident from the figure, and support the conclusions from the simple toy model stated in Section 2 above. For curved fronts the agreement between the astrophysical and laboratory simulations is excellent. Figure 12. Distribution of stripped mass of the companion star/two-layer target envelope as a function the azimuth measured from its center of mass (CM). The curve labeled “ t = 0” is the initial mass distribution before the collision. The curves labeled “Companion Star” and “Hemispherical” refer to the astrophysical and experimental simulations respectively. For comparison, the simulation of the experiment using a planar blast wave generated with the same laser conditions (labeled “Planar”) is also presented. 5. Discussion and Conclusions We presented the results of a proposed design for a laboratory experiment at high energy density in which a spherically expanding blast wave collides with a spherical target composed of a dense core surrounded by a low-density shell. The experiment was optimized to match
ner_tags: O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-TextGarbage I-TextGarbage O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O B-Formula I-Formula I-Formula O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O