R.K. Khardekar
Center For Advanced Technology
Indore 452013, India
Yuri A. Merkul’ev
P.N. Lebedev Physical Institute
Moscow 117924, Russia
High Aspect Ratio Glass Microballoons are used in various experimental studies leading to investigations towards Inertial Confinement Fusion Energy. Thin glass shells are produced using vertical drop tower furnace with three temperature zone graphite heater. The furnace has uniformly heated central zone operating at maximum of 1800 oC. Drygel initial particles are introduced in the furnace from top and allowed to fall under gravity with back pressure of He and Ar Mixture through 1.5 meter. The aspect ratio and microballoon size is controlled using well optimized Initial particle composition and furnace operating parameters.
Good yield of high quality microballoons of medium and high aspect ratio are obtained. Typical aspect ratios are in range of 20-30 and 300-500. The higher (>2 microns) wall thickness microballoons are tested using compact Mach Zehnder Micro interferometer developed at Center For advanced Technology and sub micron wall thickness is estimated using single color fringe technique. Simple theoretical formulation is presented for these characterization techniques.
