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Mann, I.

Publications and source records attributed to Mann, I..

Physics and applications of dusty plasmas: The Perspectives 2023

Dusty plasmas are electrically quasi-neutral media that, along with electrons, ions, neutral gas, radiation, and electric and/or magnetic fields, also contain solid or liquid particles with sizes ranging from a few nanometers to a few micrometers. These media can be found in many natural environments as well as in various laboratory setups and industrial applications. As a separate branch of plasma physics, the field of dusty plasma physics was born in the beginning of 1990s at the intersection of the interests of the communities investigating astrophysical and technological plasmas. An additional boost to the development of the field was given by the discovery of plasma crystals leading to a series of microgravity experiments of which the purpose was to investigate generic phenomena in condensed matter physics using strongly coupled complex (dusty) plasmas as model systems. Finally, the field has gained an increasing amount of attention due to its inevitable connection to the development of novel applications ranging from the synthesis of functional nanoparticles to nuclear fusion and from particle sensing and diagnostics to nano-contamination control. The purpose of the present perspectives paper is to identify promising new developments and research directions for the field. As such, dusty plasmas are considered in their entire variety: from classical low-pressure noble-gas dusty discharges to atmospheric pressure plasmas with aerosols and from rarefied astrophysical plasmas to dense plasmas in nuclear fusion devices. Both fundamental and application aspects are covered.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

South-North and radial traverses through the interplanetary dust cloud

Identical in situ dust detectors are flown on board the Galileo and Ulysses spacecraft. They record impacts of micrometeoroids in the ecliptic plane at heliocentric distances from 0.7 to 5.4 AU and in a plane almost perpendicular to the ecliptic from -79 deg to +79 deg ecliptic latitude. The combination of both Ulysses and Galileo measurements yield information about the radial and latitudinal distributions of micron and sub-micron sized dust in the solar system. Two types of dust particles were found to dominate the dust flux in interplanetary space: (1) Interplanetary micrometeoroids covering a wide mass range from 10(exp -16) to 10(exp -6) gr are mostly recorded inside 3 AU, and at latitudes below 30 deg; and (2) Interstellar grains with masses between 10(exp -14) and 10(exp -12) gr have been positively identified outside 3 AU near the ecliptic plane and outside 1.8 AU at high ecliptic latitudes (> 50 deg). Interstellar grains move on hyperbolic trajectories through the planetary system and constitute the dominant dust flux (1.5 x 10(exp -4)/ sq m sec) in the outer solar system and at high ecliptic latitudes. In order to compare and analyze the Galileo and Ulysses data sets, a new model is developed based on Divine's (1993) "Five populations of interplanetary meteoroids" model. By using this model, which takes into account the measured velocities and the effect of radiation pressure on small particles, we define four populations of meteoroids on elliptical orbits plus one population on hyperbolic orbits that all can fit the micrometeoroid flux observed by Galileo and Ulysses.

Gruen, E.↗

The 1997 Reference of Diffuse Night Sky Brightness

In the following we present material in tabular and graphical form, with the aim to allow the non specialist to obtain a realistic estimate of the diffuse night sky brightness over a wide range of wavelengths from the far UV longward of Ly to the far-infrared.

Night sky brightness airglow zodiacal light integr↗

On the Dynamics of the Zodiacal Dust Cloud Close to the Sun

We study the interplanetary dust cloud near the Sun - inside Mercury's orbit - with particular emphasis on the clouds out-of-ecliptic distribution. In addition to the Poynting-Robertson effect, we discuss the Lorentz force, the relativistic advance of the perihelion, and the perturbation of the gravitational potential due to the rotation of the Sun, and planetary perturbations.

Scherer, K.↗

(abstract) Microwave Instrument for Rosetta Orbiter (MIRO)

MIRO is a scientific instrument designed for the orbiter of the Rosetta International Mission. It will address the nature of the cometary nucleus, outgassing, and the development of the coma as strongly interrelated aspects of cometary physics. Detailed parameters of the MIRO instrument and the scientific objectives to be met will be discussed. Simulated observations with the MIRO instrument will be shown.

comet microwaves MIRO Microwave Instrument for Ros↗

Columbus proto-planetesimal dust aggregation experiment

A microgravity experiment to study the growth of dust particles which has been proposed to be flown on one of the Columbus precursor flights is described. The microgravity environment will allow for low collision velocities (of order of mm/s) of the dust grains and for a large Knudsen number of the embedding gas; conditions expected in the early solar nebula. The outcome of the experiment will yield estimates of the sticking efficiency and the critical velocity for agglomeration. The values of these two parameters will provide substantial improvements in the constraints for models of the formation of planetesimals. In particular, the questions related to growth rate and mode of the aggregation process will be answered. The range of material type, collision velocities, properties of the environment in which growth takes place, and other factors permit a natural extension of this experiment to take advantage of the capabilities of the Space Station Columbus. Other astrophysical applications, such as processes in Saturnian rings, with somewhat different regimes could also be investigated.

Keller, H. U.↗

Galileo and Ulysses dust measurements - From Venus to Jupiter

The Galileo and Ulysses spaceprobes carry two similar dust detectors through interplanetary space from Venus to Jupiter. Impacts are reported which correspond to dust particles above a mass threshold of about 10 exp 13 g for which complete records exist. Between December 1989 and January 1992 Galileo repeatedly traversed interplanetary space between 0.7 and 2.26 AU and recorded 374 impacts. The observed impact rates ranged from 0.1 to about 3 impacts per day strongly dependent on whether the spacecraft moved toward or away from the sun. From October 1990 to January 1992 the Ulysses spacecraft had reached a distance of 5.17 AU from the sun and had recorded 72 impacts at rates between 0.1 and 0.5 per day. Inside about 2 AU the observed fluxes are compatible with a population of interplanetary dust particles moving on low to moderately eccentric and low inclination orbits. Outside this distance a dust particle population on different orbits is required in order to explain the Ulysses data.

Gruen, E.↗