Untersuchungen an Kratern von Mikroprojektilen im Geschwindigkeitsbereich von 0,5 bis 10 km/sec

Rudolph, V.

doi:10.1515/zna-1969-0304

Cited by 21 publications

(7 citation statements)

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“…The form function g(v): d/dp (see Figure 7), which is a measure of the deformation of the projectile, shows a decrease by factors of 5 and 16 for A1 and Cu in a transition region around 2 km/sec. The decrease as a function of v is very similar to the v dependence of the crater shape parameter T/D, measured by Rudolph [1969] and Kineke [1960]. Because the macroscopic shear modulus G is a measure of the form-elasticity of a material, it may be related to the onset of the observed effects insofar as the quasi-elastic state ends and is transformed to a fiuidal one.…”

Section: Comparison Of the Experimental Results With Theoretical Argusupporting

confidence: 79%

Micrometeoroid simulation studies on metal targets

Dietzel¹,

Neukum²,

Rauser³

1972

J. Geophys. Res.

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Experiments on impact craters and impact ionization of dust particles have been performed using iron microparticles from a 2‐Mv Van de Graaff accelerator. The particle velocity υ ranged from 0.2 to 40 km/sec and the mass m ranged from 1 × 10−15 g to 5 × 10−10 g. The analysis and mass determination of iron microspheres on smooth targets and of iron layers of the projectile in the middle of impact craters have been done with an electron microprobe. The Kα radiation emitted by the iron layer in the crater has been measured as a function of mass and velocity of the projectile. The radiation measurement gives, in combination with the crater diameter D, a means for the determination of the projectile parameters m and υ. The targets used were Ag, Al, Cu, Cd, and W. Within an error of approximately 20% the total mass of the iron projectile has been found inside the craters in W, Cu, and Al targets at velocities of ≤13 km/sec. The impact ionization has been studied for impact velocities of up to 40 km/sec and projectile masses of down to 10−15g. The yield of either ions or electrons, normalized to the incident mass m, can be described by an empirical relation of the form Q = const ƒ(θ, υ) · mα · υβ, where θ is the angle of incidence. Analysis of impact ionization has been applied to extremely sensitive detectors of cosmic dust particles. The impact cratering and ionization are discussed in terms of shock effects by applying the Rankine‐Hugoniot theory. The energy partition in the form of kinetic energy and internal energy (e.g., elastic compression and irreversible heating) is discussed as a function of the velocity of iron particles impacting the targets Al, Cu, W, and Au. As a result, W and Au are targets that transform a greater fraction of the primary energy into heating and ionization of projectile material.

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Section: Comparison Of the Experimental Results With Theoretical Argusupporting

confidence: 79%

Micrometeoroid simulation studies on metal targets

Dietzel¹,

Neukum²,

Rauser³

1972

J. Geophys. Res.

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“…Some important results were obtained by Gault et al (1963), Rudolph (1969), and Eichhorn (1978), for example. Most authors use rock or metal as target materials.…”

Section: Introductionmentioning

confidence: 82%

“…Other authors, e.g., Nagel and Fechtig (1980)-using silicate and metal targets-report a decrease of D/d with increasing velocities up to a certain critical velocity. Rudolph (1969) …”

Section: Diameter-to-depth Ratiomentioning

confidence: 99%

Impacts into Ice–Silicate Mixtures: Crater Morphologies, Volumes, Depth-to-Diameter Ratios, and Yield

Koschny

Grün

2001

Icarus

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“…The number density of the ejecta is then proportional to Kt4/Km, and the total surface area is proportional to KaKt/Km. The secondary projectiles (i.e., the high-velocity fine ejecta) have irregular shapes, while the projectiles used by Rudolph [1969] are spheres with diameter d. In this case, the diameter shape factor Kd is introduced as d = Kds. The impact energy sufficient to form a microcrater with diameter D is then proportional to K,dKa 3. distribution function of fragments with size I. cumulative number of fragments larger than size I per unit solid angle.…”

Section: Appendix: Shape Factormentioning

confidence: 99%

Fine fragments in high‐velocity impact experiments

Asada¹

1985

J. Geophys. Res.

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Ejection angle dependences of size and kinetic energy of high‐velocity fine fragments ejected by high‐velocity impact into basalt targets were studied by exposing secondary targets to the ejecta. According to the properties of the fine ejecta the ejection angles were divided into four regions: outer region (region I, 10° < θ < 40°), outer belt region (region II, 40° < θ < 45°), inner belt region (region III, 45° < θ < 55°) and inner region (region IV, θ > 55°), where θ was measured from the target surface. The size distributions of the fine ejecta were expressed by power law functions with power indices of about −3.5, except for region IV (about −3) in the size range of 1–70 μm. The secondary microcraters smaller than 100 μm in diameter were most abundant in region II, and their diameter distributions were also expressed by power law functions with power indices of about −3. Comminution energy, which was estimated from surface energy of the fine ejecta, was about 10% of the impact energy, and kinetic energy of the high‐velocity fine ejecta, which was estimated from formation energy of the secondary microcraters, was about 40% of the impact energy.

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Untersuchungen an Kratern von Mikroprojektilen im Geschwindigkeitsbereich von 0,5 bis 10 km/sec

Cited by 21 publications

References 0 publications

Micrometeoroid simulation studies on metal targets

Micrometeoroid simulation studies on metal targets

Impacts into Ice–Silicate Mixtures: Crater Morphologies, Volumes, Depth-to-Diameter Ratios, and Yield

Fine fragments in high‐velocity impact experiments

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