相关论文: Collisional Charging in the Low Pressure Range of …
Collisional charging is one potential initial step in generating lightning. In this work, we study the charging of colliding monodisperse, spherical basalt grains depending on ambient pressure. We used grains of 1.0 to 1.2 mm in one set and…
We introduce collisions of solids as a new and efficient ionization mechanism for gas in protoplanetary disks, which especially operates in the dense midplane of protoplanetary disks. This idea is sparked by laboratory experiments where we…
Context. Particles in protoplanetary disks go through a number of phases that are dominated by collisions. In each of these events, grains exchange electrical charge via triboelectric effects. This enhances the stability of particle…
We study the role of dust-dust collisional charging in protoplanetary discs. We show that dust-dust collisional charging becomes an important process in determining the charge state of dust and gas, if there is dust enhancement and/or dust…
Recent work identified a growth barrier for dust coagulation that originates in the electric repulsion between colliding particles. Depending on its charge state, dust material may have the potential to control key processes towards planet…
Protoplanetary disk are the foundation of planet formation. Lightning can have a profound impact on the chemistry of planetary atmospheres. The emergence of lightning in a similar manner in protoplanetary disks, would substantially alter…
In recent years, the tribocharging of colliding and bouncing submillimeter (submm) particles has been studied as a possible mechanism promoting the formation of large pebbles on centimeter (cm) to decimeter (dm) scales in protoplanetary…
The formation of a solar system is believed to have followed a multi-stage process around a protostar. Whipple first noted that planetesimal growth by particle agglomeration is strongly influenced by gas drag; there is a "bottleneck" at the…
Electrostatic charging of insulating fine particles can be responsible for numerous phenomena ranging from lightning in volcanic plumes to dust explosions. However, even basic aspects of how fine particles become charged are still unclear.…
Early dust evolution in protoplanetary disks is dominated by sticking collisions. However, this initial phase of particle growth faces constraints - notably from destructive encounters. To find the maximum particle size achievable, we…
In (pre)-planetary environments, dust and sand grains regularly collide. They electrically charge and discharge during these events. In this work, we study if cosmic radiation has any influence on the equilibrium charge state on timescales…
Mutual sticking of dust aggregates is the first step toward planetesimal formation in protoplanetary disks. In spite that the electric charging of dust particles is well recognized in some contexts, it has been largely ignored in the…
Gas-phase microdroplets have recently demonstrated exceptional chemical properties via suspected mechanisms such as contact electrification and surface charge pinning, producing high surface electric fields. Here, microdroplets are injected…
Contact electrification of dielectric grains forms the basis for a myriad of physical phenomena. However, even the basic aspects of collisional charging between grains are still unclear. Here we develop a new experimental method, based on…
Collisions electrically charge grains which promotes growth by coagulation. We present aggregation experiments with three large ensembles of basalt beads ($150\,\mu\mathrm{m} - 180\,\mu\mathrm{m})$, two of which are charged, while one…
Planets grow via the collisional accretion of small bodies in a protoplanetary disk. Such small bodies feel strong gas drag and their orbits are significantly affected by the gas flow and atmospheric structure around the planet. We…
Ionization-recombination balance in dense interstellar and circumstellar environments is a key factor for a variety of important physical processes, such as chemical reactions, dust charging and coagulation, coupling of the gas with…
Much of a planet's composition could be determined right at the onset of formation. Laboratory experiments can constrain these early steps. This includes static tensile strength measurements or collisions carried out under Earth's gravity…
Collisional growth of dust occurs in all regions of protoplanetary disks with certain materials dominating between various condensation lines. The sticking properties of the prevalent dust species depend on the specific temperatures. The…
Following the recent insight in the material structure of comets, protoplanetesimals are assumed to have low densities and to be highly porous agglomerates. It is still unclear if planetesimals can be formed from these objects by…