BBT Materials Processing

Advanced TITUS MPP – Multi-Purpose Platform

Advanced Tubular Furnace with Integrated Thermal Anylysis under Space Conditions for material sciences experiments (e.g. crystal growth, solidification, diffusion, physical chemistry) developed in cooperation with DLR-MUSC in Cologne and Humboldt University in Berlin.

INTRODUCTION

The Advanced TITUS MPP – Multi-purpose Platform has been designed for a wide spectrum of material sciences experiments dedicated to e. g. solidification processes, crystal growth, diffusion, differential thermal analysis (DTA), physical chemistry, microgravity measurements etc., moreover new experimental and diagnostic methods can be introduced to keep experimentation at the state-of-the-art and to make space experimentation more attractive to scientists. It is envisaged to accommodate it on board the International Space Station ISS. The following experimentation techniques can be utilised:

• Travelling heater method
• Gradient freezing
• Zone melting
• Isothermal processing

Based on the experience gained from the operation of the TITUS facility on-board the space station MIR a concept has been developed considering the specific requirements of long-term operation in a space station environment. These operational conditions require the improvement of overall reliability and lifetime, in case of failures components shall be easily exchanged and replaced by spare parts without adjustment.
Starting with CSK-1C furnace TITUS was the further development in a series of furnaces and has last been used during the French PERSEUS mission in 1999 successfully serving two experimenters. It comprises the CSK-4C furnace including control electronic, the measurement and data acquisition electronic box TEGRA for temperature and gravitation measurements, and the Crew Interface Computer CIC for setting-up, operating, and controlling the facility.

CONCEPT OF ADVANCED TITUS MPP

According to the results of experimenter interviews and operational experience some conceptual features of the TITUS facility will be retained, e. g.:

• plain interfaces to the station, i.e. only power supply and telemetry will be required. Process heat is dissipated by forces convection via exchanger to the environment
• dedicated external computer of standard laptop type
  • storing process parameters including re-programming capabilities by crew or from ground
  • operating as 'master' of the facility 'slave' and controlling processing
  • crew support by operating software with display of setting-up and shut-down procedures synchronously to the status of the facility
  • storing experimental data (temperature, gravitation, events, failures)
  • providing data transfer by the station telemetry system
• 3-axis acceleration sensor head for continuous measurement of acceleration.

The basic version the TITUS MPP is the furnace mode:

• usable sample volume approx. 250 x Ø15.9 mm
• max. heater temperature 1300 °C
• multi-zone heater comprising 9 individually controlled heater segments
• sample cartridges of the TITUS 'probe' type

For integration into the rack structure the facility is sub-divided into an experiment and an electronic module. The electronic module is accommodated in the rack and tethered to the furnace module. This module can be stored in a rack, but for operation it can be located conveniently and aligned with respect to the vector of the residual gravity to minimize its influence.

Approx. standard cartridge dimensions and exemplary sample container

DTA probe contains four containers for either test or reference materials and is used for study of phase transitions.

Improvements generally focus on the following aspects

• application of a strictly modular concept with components easily to be exchanged for repair or up-grading of the facility to the latest state of development
• reducing µg level by damping of experiment compartment
• increasing of measurement and control accuracy
• modifications with respect to thermal properties and safety
• extension of the operational range down to ambient temperatures (under consideration)
• introducing new diagnostic techniques for extended experimentation
• opening the field of fluid physics to experimentation by introducing a low-temperature control module temperatures (option).

Artist's view of the 'Advanced TITUS MPP' facility

The introduction of the following diagnosis methods is optional:

• determination of solidification front position by electrical resistance measurement
• cartridge rotation
• ultra-sonic analysis of solidification process
• marking of phase boundary
• optical fibre thermometry
• high precision temperature measurement and DTA
• rotating magnetic field
• transparent furnace - aerogel (in-situ monitoring - CCD camera)
• quenching module for the rapid cooling
• automatic sample cartridge exchange capability (up to 20 samples) with an automatic loading system to reduce handling by the crew

Facility Paremeters:

Basic (furnace) version

Bread-board model BM-1	Bread-board model BM-2, Experiment Module	Bread-board model BM-2, Electronic Module

Useful links