A fragmentation model approach for low velocity impact charging

2020 ◽  
Author(s):  
Tarjei Antonsen ◽  
Ingrid Mann ◽  
Jakub Vaverka ◽  
Libor Nouzak
Keyword(s):  
Impact Ionization ◽  
Low Velocity Impact ◽  
Fragmentation Model ◽  
Low Velocity ◽  
Saha Equation ◽  
Contact Charging ◽  
The Earth ◽  
Volume Ionization ◽  
Model Approach

<p>This work addresses the generation of charge during impacts of nano- to microscale projectiles on metal surfaces at speeds from 0.1 to 10 km/s. These speeds are well above the range of elastic deformation and well below speeds where volume ionization occures. Earlier models have utilized impurity diffusion through molten grains together with a Saha-equation to model impact ionization at these speeds. In this work we employ a model of capacitive contact charging in which we allow for projectile fragmentation upon impact. We show that this model well describes laboratory measurements of metal projectiles impacting metal targets. It also can describe in-situ measurements of dust in the Earth’s atmosphere made from rockets. We also address limitations of the currently most used model for impact ionization.</p>

scholarly journals A comparison of contact charging and impact ionization in low-velocity impacts: implications for dust detection in space

2021 ◽  
Vol 39 (3) ◽  
pp. 533-548
Author(s):  
Tarjei Antonsen ◽  
Ingrid Mann ◽  
Jakub Vaverka ◽  
Libor Nouzak ◽  
Åshild Fredriksen
Keyword(s):  
Shock Wave ◽  
Impact Ionization ◽  
Dust Particles ◽  
Low Velocity ◽  
Direct Ionization ◽  
Contact Charging ◽  
Naturally Occurring ◽  
Metal Metal ◽  
Dust Detection ◽  
Volume Ionization

Abstract. We investigate the generation of charge due to collision between projectiles with sizes below ∼1 µm and metal surfaces at speeds ∼0.1 to 10 km s−1. This corresponds to speeds above the elastic limit and well below speeds where volume ionization can occur. Impact charge production at these low to intermediate speeds has traditionally been described by invoking the theory of shock wave ionization. By looking at the thermodynamics of the low-velocity solution of shock wave ionization, we find that such a mechanism alone is not sufficient to account for the recorded charge production in a number of scenarios in the laboratory and in space. We propose a model of capacitive contact charging that involves no direct ionization, in which we allow for projectile fragmentation upon impact. Furthermore, we show that this model describes measurements of metal–metal impacts in the laboratory well. We also address contact charging in the context of ice-on-metal collisions and apply our results to rocket observations of mesospheric dust. In general, we find that contact charging dominates at speeds of up to a few kilometres per second and complements shock wave ionization up to speeds where direct ionization can take place. The conditions that we consider can be applied to dust particles naturally occurring in space and in Earth's upper atmosphere and their direct impacts on rockets, spacecraft, and impacts of secondary ejecta.

Research Progress in High Velocity Penetration into Concrete Theory

2013 ◽  
Vol 405-408 ◽  
pp. 2487-2491
Author(s):  
Cun Cheng Shi ◽  
Xin Fan ◽  
Sheng Guo Zou ◽  
Meng Shen Li
Keyword(s):  
Material Properties ◽  
High Velocity ◽  
Target Material ◽  
Low Velocity Impact ◽  
Research Progress ◽  
Future Research ◽  
Low Velocity ◽  
The Earth ◽  
Hypervelocity Penetration ◽  
Velocity Region

With the development of the earth penetration weapon, the research interest has gradually changed from low velocity impact to high velocity or hypervelocity penetration. This paper reviews the the theoretic research status on velocity region ascertaining of penetration, the target material properties near penetration cavity and mass abrasion of projectiles in high velocity penetration, and makes suggestions on the future research.

scholarly journals A Comparison of Contact Charging and Impact Ionization in Low Velocity Impacts: Implications for Dust Detection in Space

2020 ◽  
Author(s):  
Tarjei Antonsen ◽  
Ingrid Mann ◽  
Jakub Vaverka ◽  
Libor Nouzak ◽  
Åshild Fredriksen
Keyword(s):  
Impact Ionization ◽  
Interplanetary Space ◽  
Dust Particles ◽  
Low Velocity ◽  
Charge Generation ◽  
Earth’S Atmosphere ◽  
Contact Charging ◽  
Metal Metal ◽  
Dust Detection ◽  
Earth's Atmosphere

Abstract. We investigate the generation of charge during collision of projectiles with sizes below ~ 1 μm and metal surfaces at speeds ~ 0.1 km/s. This corresponds to speeds above the elastic limit and well below speeds where volume ionization can occur. The conditions that we consider apply to dust particles naturally occurring in space and in Earth's upper atmosphere and their direct impacts on rockets, spacecraft, and impacts of secondary ejecta. We introduce a model of capacitive contact charging in which we allow for projectile fragmentation upon impact, and show that this model describes measurements of metal-metal impacts in the laboratory and in-situ measurements of dust in the Earth's atmosphere well. We have considered the utilization of our model for different scenarios in interplanetary space and in Earth's atmosphere. From this discussion we find it likely that our work can be employed in a number of situations where impact velocities are relatively small. Furthermore, we have discussed the thermodynamics of the low velocity solution of shock wave ionization, and conclude that the impurity charging effect utilized in the much used model of Drapatz and Michel (1974) does not sufficiently describe charge generation at impact speeds below a few kilometers per second. Consequently, impact charging at low speeds cannot be described with a Saha-solution.

Rendez vous with Saturn's rings

1984 ◽  
Vol 75 ◽  
pp. 743-759 ◽  
Author(s):  
Kerry T. Nock
Keyword(s):  
Solar Energy ◽  
Electric Propulsion ◽  
Power Source ◽  
Propulsion System ◽  
Low Thrust ◽  
Ring Plane ◽  
The Earth ◽  
Total Impulse ◽  
Saturn's Rings

ABSTRACTA mission to rendezvous with the rings of Saturn is studied with regard to science rationale and instrumentation and engineering feasibility and design. Future detailedin situexploration of the rings of Saturn will require spacecraft systems with enormous propulsive capability. NASA is currently studying the critical technologies for just such a system, called Nuclear Electric Propulsion (NEP). Electric propulsion is the only technology which can effectively provide the required total impulse for this demanding mission. Furthermore, the power source must be nuclear because the solar energy reaching Saturn is only 1% of that at the Earth. An important aspect of this mission is the ability of the low thrust propulsion system to continuously boost the spacecraft above the ring plane as it spirals in toward Saturn, thus enabling scientific measurements of ring particles from only a few kilometers.

Predictions of Localised Damage to Concrete Caused by a Low-Velocity Impact

2021 ◽  
Vol 149 ◽  
pp. 103799
Author(s):  
Zireen Z.A. Majeed ◽  
Nelson T.K. Lam ◽  
Emad F. Gad
Keyword(s):  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact
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