A beam deflection apparatus with high resolution for monitoring TGS crystal growth

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:500884

Musazzi, S ^[1]; Affinito, A ^[2]; Stenzel, C; Fabritius, G ^[3]

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1. CISE, Segrate (Italy)
2. Univ. of Milan (Italy)
3. DASA/Dornier, Friedrichshafen (Germany)

A beam deflection apparatus with a high resolution has been developed which allows monitoring of temperature and concentration gradients in the region around a TGS (triglycine sulphate) crystal growing from an aqueous solution. The developed optical setup consists of two measuring arms that allow inspection of the test region along two perpendicular directions. With a lateral position sensing device the deflection of a mildly focused laser beam traversing the medium to be tested have been measured along one inspection axis, while a two-dimensional analysis of the test region is performed in the orthogonal direction by means of a properly focused light blade and a CCD camera. Experimental verification of the technique has been performed utilizing TGS crystal growth by means of the cooled sting method. The experiment takes place in a double-wall glass cell, the temperature of the TGS crystal can be adjusted independently from the solution temperature. Systematic measurements have been performed which allow to characterize concentration gradients and thermal convection in the vicinity of the crystal. Analysis of experimental results shows the high sensitivity of this method. This technique is well suited as a diagnostic tool for monitoring and controlling crystal growth experiments in microgravity.

• OSTI ID: 500884
• Report Number(s): CONF-960848--; ISBN 0-8194-2197-9
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH
DIAGNOSTIC TECHNIQUES
EXPERIMENTAL DATA
GLYCINE
LASER RADIATION
OPTICAL SYSTEMS
SULFATES
TEMPERATURE MONITORING
WEIGHTLESSNESS