A laboratory platform for studying rotational dust flows in a plasma crystal irradiated by a 10 keV electron beam

Abstract

A novel laboratory platform has been designed and built for the irradiation of a plasma crystal (PC) with an electron beam (e-beam) having an energy around 10 keV and a current of tens of milliamperes. The pulsed e-beam collimated to a few millimeter-size spot is aimed at a crystal made of dust particles levitated in a radio-frequency (RF) plasma. The platform consists of three vacuum chambers connected in-line, each with different utility: one for generating free electrons in a pulsed hollow-anode Penning discharge, another for the extraction and acceleration of electrons at $$\sim 10$$ ∼ 10 kV and for focusing the e-beam in the magnetic field of a pair of circular coils, and the last one for producing PCs above a RF-driven electrode. The main challenge is to obtain both a stable e-beam and PC by insuring appropriate gas pressures, given that the e-beam is formed in high vacuum ($$\lesssim 10^{-4}$$ ≲ 10 - 4 Torr), while the PC is produced at much higher pressures ($$\gtrsim 10^{-1}$$ ≳ 10 - 1 Torr). The main diagnostics include a high speed camera, a Faraday cup and a Langmuir probe. Two applications concerned with the creation of a pair of dust flow vortices and the rotation of a PC by the drag force of the e-beam acting on the strongly coupled dust particles are presented. The dust flow can become turbulent as demonstrated by the energy spectrum, featuring vortices at different space scales.

Induced ageing of ZnS:Ag microparticles exposed to 13 keV electron beam

“…Irradiation of the microparticles was carried out by an electron gun consisting of a hollow-anode plasma source and two focusing electromagnetic coils set at 83 and 171 Gauss respectively. The electron gun, described in detail in [54,55], delivers a pulsed electron beam into an interaction chamber found under vacuum conditions of 10 -4 torr achieved by using a turbomolecular pump. The beam was pulsed at a frequency of 46 Hz and the pulse duration was 40 μs.…”

Enhancing heat transfer in MHD Falkner's‐Skan flow with thermal radiation, free convection and dusty fluid between parallel plates

“…The purpose of this research was to learn how magnetic field orientation impacts the system's flow behavior and heat transfer properties. Ticoş et al 28 studied rotating dust flows in a plasma crystal exposed to a 10 keV electron beam, shedding light on the complex interaction between plasma and dust in such systems by explaining the kinetics and behavior of dust particles in a plasma environment.…”