Heater in hot-zone of single crystal pulling apparatus and single crystal pulling apparatus

A single crystal pulling apparatus, comprising:

• a heater in a Hot-Zone of the single crystal pulling apparatus, the heater in the Hot-Zone of the single crystal pulling apparatus including a side-main heater and an auxiliary heater, each of the side-main heater and the auxiliary heater being a cylindrical structure with openings at two ends thereof, each of the side-main heater and the auxiliary heater including a top open end and a bottom open end, wherein the auxiliary heater is sleeved around the side-main heater, and the top open end of the auxiliary heater extends out of the top open end of the side-main heater;
• the side-main heater includes a heater body located between the top open end of the side-main heater and the bottom open end of the side-main heater;
• wherein the auxiliary heater includes:
• a protective casing surrounding the side-main heater;
• and
• an electromagnetic induction coil accommodated in the protective casing;
• wherein the protective casing includes an inner casing and an outer casing that are fastened to each other;
• and
• wherein,
• each of the inner casing and the outer casing is cylindrical;
• the inner casing covers and surrounds an entire outer peripheral side of the heater body of the side-main heater;
• the outer casing is sleeved around the inner casing with a chamber defined between the outer casing and the inner casing;
• the inner casing includes a first inner side wall that cooperates with the outer casing to define the chamber;
• the electromagnetic induction coil is accommodated in the chamber;
• the electromagnetic induction coil is spirally wound around the first inner side wall from a top open end of the inner casing to a bottom open end of the inner casing;
• and
• two ends of the electromagnetic induction coil extend out of the protective casing, respectively.