Charge moderated aggregation of global granular gases in low-velocity tribocharging experiments (LANNISTER)

abstract

Planet formation starts with the coagulation of micrometer-sized particles in protoplanetary disk. When clusters reach a size of centimeters they can no longer stick in a collision but are bounced back. This is because the attractive forces due to adhesion are no more able to hold the particles together. In Lannister we are going to investigate if electrostatic charge can help to overcome that bouncing barrier. For that, millimeter-sized spheres from glass or basalt are shaken with high frequency in a small volume. During shaking there are a lot of collision so that the spheres charge - the so-called tribocharging. When microgravity starts these spheres are released into a capacitor and an electrical field is applied. The trajectories of the spheres are heavily depending on their charge. Trajectories and collisions with the electrodes and with other spheres reveal information about the charge distribution, charge transfer and clustering. New insights into the formation of centimeter-sized clusters using alternating voltage are expected.

• Felix Jungmann, Tobias Steinpilz, Jens Teiser, and Gerhard Wurm, Sticking and restitution in collisions of charged sub-mm dielectric grains, Journal of Physics Communications, Volume 2, Number 9, 2018

• Tobias Steinpilz, Kolja Joeris, Felix Jungmann, Dietrich Wolf, Lothar Brendel, Jens Teiser, Troy Shinbrot, Gerhard Wurm, Electrical charging overcomes the bouncing barrier in planet formation, Nat. Phys., 2019

experiment year: 2019
number of catapult launches: 24

experiment year: 2018
number of catapult launches: 8