Cold crucible structure

A cold crucible structure comprising:

• a cold crucible unit including hollow top and bottom caps, a plurality of segments connecting the top cap and the bottom cap, slits each extending from a bottom of the top cap to a top of the bottom cap in an axis direction of the cold crucible unit and being disposed between the segments in a circumference direction of the cold crucible unit, and a reaction area surrounded by the segments, the top and bottom caps being free of the slits;
• and
• an induction coil unit disposed to cover the outer side of the cold crucible unit and disposed across the longitudinal directions of the segments and the slits,
• wherein a diameter of the reaction area is defined as a crucible diameter, the crucible diameter is 100 to 300 mm, and a width of each of the slits is defined by the following Equation 1,
• d
• slit
• ≤
• 0.3
• ×
• ∅
• 50
• ⁢
• (
• mm
• )
• [
• Equation
• ⁢
• ⁢
• 1
• ]
• where dslit is the width of each of the slits and Ø is the crucible diameter.