Browse Prior Art Database

Sensor System

IP.com Disclosure Number: IPCOM000073499D
Original Publication Date: 1970-Dec-01
Included in the Prior Art Database: 2005-Feb-22
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Blum, SE: AUTHOR [+3]

Abstract

Sapphire light pipes and light radiation detection can be used for temperature sensing and control. A sapphire light pipe system is especially attractive when detection within or near a radiofrequency field is required (see S. B. Blum et al, Rev. Sci. Inst. 39, 277 (1968).

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Sensor System

Sapphire light pipes and light radiation detection can be used for temperature sensing and control. A sapphire light pipe system is especially attractive when detection within or near a radiofrequency field is required (see S.
B. Blum et al, Rev. Sci. Inst. 39, 277 (1968).

This temperature system shown schematically in the drawing is especially useful in connection with a high pressure crystal puller 12. A sapphire rod 14 and a radiation sensor support rod 16 are connected to radiation sensor support device 18. The spacing 15 between the end of sapphire rod 14 and the bottom 17 of crucible 24 must be accurately maintained constant during crystal pulling via pull rod 19. Threaded support rod 16 and seal 20 are joined directly to the radiation sensor support device 18. The threaded rod 16 and coupling 22 provide a rigid element around the sapphire rod 14. The control signal from the radiation sensor support device 18 is used to control the temperature in crucible 24 via radiofrequency coil 26. Since the distance between the sapphire end and the crucible must be kept constant, conventional pipe feed-throughs into pressure systems are unsatisfactory because slipping of the sapphire rod through the feed-through causes a signal variation. Also, these feed-throughs do not provide protection to the fragile and easily fractured sapphire rod which is particularly critical in high pressure systems for safety reasons.

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