Submission Title

Increasing the Longevity of Tungsten Filaments in a Zone Refiner

Location

Jereld R. Nicholson Library: Grand Avenue

Subject Area

Physics/Applied Physics

Description

Zone refining is used for its ability to manipulate impurities in crystals and growing single crystals. To produce these single crystals, a floating molten zone, generated from electron bombardment, passed over the polycrystalline. While zone refining like this, the filaments that produce the electron bombardment can blow out during a run. The longevity of tungsten filaments in a zone refiner was investigated. A new lower insert was constructed to prevent the filaments from blowing out. The new lower insert had a shield machined into it to protect the filaments from the impurities striking them. It was found that the new lower insert did not significantly increase the lifespan of the filaments. The longevity of the tungsten filaments was longer in a zone refiner that had a larger area of where the electron bombardment took place. It is thought that this increased room allows for more locations for the impurities to strike.

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Increasing the Longevity of Tungsten Filaments in a Zone Refiner

Jereld R. Nicholson Library: Grand Avenue

Zone refining is used for its ability to manipulate impurities in crystals and growing single crystals. To produce these single crystals, a floating molten zone, generated from electron bombardment, passed over the polycrystalline. While zone refining like this, the filaments that produce the electron bombardment can blow out during a run. The longevity of tungsten filaments in a zone refiner was investigated. A new lower insert was constructed to prevent the filaments from blowing out. The new lower insert had a shield machined into it to protect the filaments from the impurities striking them. It was found that the new lower insert did not significantly increase the lifespan of the filaments. The longevity of the tungsten filaments was longer in a zone refiner that had a larger area of where the electron bombardment took place. It is thought that this increased room allows for more locations for the impurities to strike.