In-depth experimental search for a coupling between gravity and electromagnetism with steady fields.

Any means to control gravity like electromagnetism is currently out of reach by many orders of magnitude even under extreme laboratory conditions. Some often poorly executed experiments or pseudoscience theories appear from time to time claiming for example anomalous forces from capacitors that suggest a connection between the two fields. We developed novel and high resolution horizontal-, vertical- and rotation-balances that allow to test electric devices completely shielded and remotely controlled under high vacuum conditions to perform the first in-depth search for such a coupling using steady fields.

A systematic approach to the modelling and comparison of the geometries of spherical electrodes in inertial electrostatic confinement fusion devices.

Inertial electrostatic confinement fusion (IECF) devices often use two concentric spherical electrodes to converge ions in a plasma electrostatically. Using a highly transparent inner cathode, the ions can move through the cathode and collide at the center to undergo fusion reactions. This is a simple method to build a neutron source.

Design and performance of a nano-Newton torsion balance.

Here, we present a novel torsion balance with a torsional spring that can reach a resolution in the nano-Newton range while allowing for a total experimental weight of 2 kg. The balance uses an off-the-shelf electromagnetic actuator, which was calibrated. The oscillation of the balance is damped using an adaptable eddy-current brake to fine-tune the damping factor.

Electron guiding in macroscopic borosilicate capillaries with large bending angles.

This work presents experiments about the transmission of electrons with an energy of around 15 keV with beam currents up to 20 µA through macroscopic glass capillaries. A systematic study was conducted to experimentally investigate the transmission of electrons through borosilicate glass capillaries with curve angles of 90°, 180°, 270° and 360° for the first time. The focus of the work was to identify the conditions under which the injected electron current is transmitted through the capillary.

Yield of dwarf tomatoes grown with a nutrient solution based on recycled synthetic urine.

Extended human spaceflight missions require not only the processing, but also the recycling of human waste streams in bio-regenerative life support systems, which are rich in valuable resources. The Combined Regenerative Organic food Production project of the German Aerospace Center aims for recycling human metabolic waste products to produce useful resources. A biofiltration process based on natural communities of microorganisms has been developed and tested.

Polyatomic ions from a high current ion implanter driven by a liquid metal ion source.

High current liquid metal ion sources are well known and found their first application as field emission electric propulsion thrusters in space technology. The aim of this work is the adaption of such kind of sources in broad ion beam technology. Surface patterning based on self-organized nano-structures on, e.

Review and analysis of over 40 years of space plant growth systems.

The cultivation of higher plants occupies an essential role within bio-regenerative life support systems. It contributes to all major functional aspects by closing the different loops in a habitat like food production, CO2 reduction, O2 production, waste recycling and water management. Fresh crops are also expected to have a positive impact on crew psychological health.

The beam divergence of an indium LMIS at a distance of 50 μm as determined by plasma diagnostic measurements.

The current-dependent beam divergence at a distance of 50 μm from an indium-liquid metal ion source is derived from experimental data obtained by measuring the beam spread with a 3D Plasma diagnostic system at a distance of 10 cm from the needle tip. The observed relationship between emission current and beam divergence in vicinity of the emitting needle is used to design a focusing electrode for a field-emission electric propulsion thruster operating at currents up to 150 μA. Another application involves focused ion beam columns which may choose to forego a beam-limiting aperture, such as LMIS-based rapid machining tools with large beam currents.

Reprint of: High current liquid metal ion source using porous tungsten multiemitters.

We recently developed an indium Liquid-Metal-Ion-Source that can emit currents from sub-μA up to several mA. It is based on a porous tungsten crown structure with 28 individual emitters, which is manufactured using Micro-Powder Injection Molding (μPIM) and electrochemical etching. The emitter combines the advantages of internal capillary feeding with excellent emission properties due to micron-size tips.

High current liquid metal ion source using porous tungsten multiemitters.

We recently developed an indium Liquid-Metal-Ion-Source that can emit currents from sub-μA up to several mA. It is based on a porous tungsten crown structure with 28 individual emitters, which is manufactured using Micro-Powder Injection Molding (μPIM) and electrochemical etching. The emitter combines the advantages of internal capillary feeding with excellent emission properties due to micron-size tips.

Liquid-metal-ion source development for space propulsion at ARC.

The Austrian Research Centers have a long history of developing indium Liquid-Metal-Ion Source (LMIS) for space applications including spacecraft charging compensators, SIMS and propulsion. Specifically the application as a thruster requires long-term operation as well as high-current operation which is very challenging. Recently, we demonstrated the operation of a cluster of single LMIS at an average current of 100muA each for more than 4800h and developed models for tip erosion and droplet deposition suggesting that such a LMIS can operate up to 20,000h or more.

Indium ion emission from nanotube fibres.

The manufacture of a liquid metal ion source based on carbon nanotubes is described. Multi-wall carbon nanotubes were attached to the tip of a tungsten needle forming a fibre which was subsequently coated with a layer of indium. The onset of ion emission was observed at about 850 V, a value much lower than that for a conventional indium needle emitter.