This effort investigates the underlying physics of ejecta production for high explosive (HE) shocked Sn surfaces prepared with finishes typical to those roughened by tool marks left from machining processes. To investigate the physical mechanisms of ejecta production, we compiled and re-examined ejecta data from two experimental campaigns [W. S. Vogan et al., J. Appl. Phys. 98, 113508 (1998); M. B. Zellner et al., ibid. 102, 013522 (2007)] to form a self-consistent data set spanning a large parameter space. In the first campaign, ejecta created upon shock release at the back side of HE shocked Sn samples were characterized for samples with varying surface finishes but at similar shock-breakout pressures PSB. In the second campaign, ejecta were characterized for HE shocked Sn samples with a constant surface finish but at varying PSB.

Articles you may be interested inPower law and exponential ejecta size distributions from the dynamic fragmentation of shock-loaded Cu and Sn metals under melt conditions Erratum: "Effects of shock breakout pressure on ejection of micron scale material from shocked tin surfaces" [J.This effort investigates the relation between ejecta production and shock-breakout pressure ͑P SB ͒ for Sn shocked with a Taylor shockwave ͑unsupported͒ to pressures near the solid-on-release/partial melt-on-release phase transition region. The shockwaves were created by detonation of high explosive ͑HE͒ PBX-9501 on the front side of Sn coupons. Ejecta production at the backside or free side of the Sn coupons was characterized through use of piezoelectric pins, optical shadowgraphy, x-ray attenuation radiography, and optical-heterodyne velocimetry. Ejecta velocities, dynamic volume densities, and areal densities were then correlated with the shock-breakout pressure of Sn surfaces characterized by roughness average of R a =16 in or R a =32 in.

ABSTRACT:The NMR-MOUSE is a nuclear magnetic resonance (NMR) sensor for unilateral NMR of materials suitable for process and quality control. Practical aspects of the sensor construction are described, in particular radiofrequency coil design and shielding procedures to reduce probe ringing. Dead times of less than 20 s can be achieved at frequencies in the vicinity of 20 MHz with permanent magnets within sensitive volumes up to 4 mm deep. First applications of the NMR-MOUSE to the analysis of historical books are reported.

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