A method for bulk production of polysilicon in a CVD reactor, the reactor comprising: an electrical current source for supplying a heating current to a solid-rod silicon filament at a voltage that is sufficient to initiate heating of the solid rod filament; a base plate system configured with filament supports adapted to support said solid-rod filament; an enclosure attachable to said base plate system so as to form a deposition chamber; at least one solid-rod, cylindrical, 7mm diameter silicon filament disposed within said chamber on said filament supports; the electrical current source being connectible to both ends of said filament via electrical feedthroughs in said base plate system, for heating said filament adapted for connection of said electrical current source to both ends of said solid-rod silicon filament; a gas inlet in said base plate system connectible to a source of silicon-containing gas; and a gas outlet in said base plate system whereby gas may be released from said chamber; characterized by: mounting on said filament supports in place of said solid-rod filament a tubular filament having a starting outer diameter of at least 20mm and a ratio of wall thickness to starting outer diameter of not greater than 1/4, said tubular filament being formed by EFG crystallization out of a shaping die, said tubular filament having a wall thickness that is uniform to within a tolerance of 10% and having a cross-section area chosen such that the voltage needed for initiating heating of the tubular filament is the same as the voltage that is needed to initiate heating of said solid-rod filament; heating the filament with electrical current from said electrical current source; and conducting a CVD process with silicon-containing gas within said reactor. an electrical current source for supplying a heating current to a solid-rod silicon filament at a voltage that is sufficient to initiate heating of the solid rod filament; a base plate system configured with filament supports adapted to support said solid-rod filament; an enclosure attachable to said base plate system so as to form a deposition chamber; at least one solid-rod, cylindrical, 7mm diameter silicon filament disposed within said chamber on said filament supports; the electrical current source being connectible to both ends of said filament via electrical feedthroughs in said base plate system, for heating said filament adapted for connection of said electrical current source to both ends of said solid-rod silicon filament; a gas inlet in said base plate system connectible to a source of silicon-containing gas; and a gas outlet in said base plate system whereby gas may be released from said chamber; characterized by: mounting on said filament supports in place of said solid-rod filament a tubular filament having a starting outer diameter of at least 20mm and a ratio of wall thickness to starting outer diameter of not greater than 1/4, said tubular filament being formed by EFG crystallization out of a shaping die, said tubular filament having a wall thickness that is uniform to within a tolerance of 10% and having a cross-section area chosen such that the voltage needed for initiating heating of the tubular filament is the same as the voltage that is needed to initiate heating of said solid-rod filament; heating the filament with electrical current from said electrical current source; and conducting a CVD process with silicon-containing gas within said reactor. mounting on said filament supports in place of said solid-rod filament a tubular filament having a starting outer diameter of at least 20mm and a ratio of wall thickness to starting outer diameter of not greater than 1/4, said tubular filament being formed by EFG crystallization out of a shaping die, said tubular filament having a wall thickness that is uniform to within a tolerance of 10% and having a cross-section area chosen such that the voltage needed for initiating heating of the tubular filament is the same as the voltage that is needed to initiate heating of said solid-rod filament; heating the filament with electrical current from said electrical current source; and conducting a CVD process with silicon-containing gas within said reactor.