W.F. Rivera

DPLX: Experiment to Investigate Heating and Stability in Magnetized Rotating Dusty Plasmas

An experimental setup is under construction at the Dusty Plasma Laboratory of the University of Maryland, Baltimore County to study viscous heating and stability in magnetized rotating dusty plasmas. Azimuthal rotation will be imposed on dust, electrons, and ions by having an axial magnetic field B in a vacuum chamber placed inside a 16-cm bore Bitter-type magnet, and a radial electric field E centered at the chamber axis. The resulting E × B rotation is expected to have sheared rotation, which leads to viscous heating from the radial velocity profile. However, heating may also lead to interchange modes that destabilize the rotation. The planned experiments are motivated by the observations of parabolic ion and electron temperature profiles in hydrogen plasmas in a supersonic rotating magnetic mirror, where ohmic and viscous heating were the only mechanisms available for heating the plasma. The goal of the experimental setup is to magnetize and rotate dust with diameter ~1 μm that can be individually captured by particle velocimetry cameras and software. The Bitter-type magnet is planned for a steady field of 10 T with a minimum duration of 10 s per experiment.

Vacuum Compatibility of 3-D-Printed Parts

We present the design and preliminary results of a mass spectrometry system to assess the vacuum compatibility of 3-D-printed parts. The setup consists of a sectional vacuum chamber with a residual gas analyzer, a radiation heater, windows, and an access port for quick sample exchange. The vacuum chamber is set up in such a way that the samples can be inserted and retrieved with minimal contamination to the vacuum system. We perform this by having two connected chambers with independent vacuum pumps, and using one for sample access at atmospheric pressure, and then transferring the sample to the main chamber once vacuum is equalized. The equipment will be used as part of the dusty plasma experiment at UMBC, since many of the plasma-facing parts are 3-D-printed.