IPCG will investigate this area. IPCG will produce interference patterns, similar to these ground tests, by splitting then recombing laser light. The experiment is managed by the MSFC Microgravity Research Program Office, Biotechnology Project Office. The program manager is Ron Porter. The principal investigator is Dr. Alexander McPherson of the University of California at Riverside.
Impurities also control the growth rate.
PCG studies on Earth are often thwarted by convective flow since the attachment of molecules to the crystal depletes the concentration. This depleted volume is less dense and tends to rise, thus causing the solution to flow across the crystal surface. The low-g environment of space eliminates convective flows caused by differences in density. Thus, an optical system which shows variations in density can be a powerful diagnostic technique for distinguising how temperature, concentration, or pH differences drive crystal growth. A cube beamsplitter takes a beam of light, splits it and passes half through a medium and the other half through the same distance in open space, the recombines the two beams.