JPS62123325A - Sample temperature measurement for fz furnace - Google Patents

Abstract

PURPOSE:To measure a sample temperature based on a wavelength component in the range of 5-10mum by extracting it of a radiation beam with a monochrometer. CONSTITUTION:A radiation beam of a sample in an FZ furnace is made incident into a box body 11 of a radiation thermometer and focused with concave mirrors 15... through a light chopper 19 and reflected with flat mirrors 16 and changeover reflector 17 to be led out to an emission body tube 14. The use of such mirrors eliminate possible cut in the light with the wavelength exceeding 5mum. The radiation light introduced to the body tube 14 and emitted from the flat mirrors 16 are made incident into a monochrometer 22 through an incident slit 24, which extracts the wavelength component in the range of 5-10mum from the radiation beam to be projected to a light receiving element 23 through an emission slit 25. As he element 23 uses a pyroelectric element and the element itself utilizes changes in the electric charge on the surface, an output is obtained correspondingly to the intensity of radiation beam of the sample projected intermittently with a chopper 19. Therefore, the temperature of the sample at the FZ furnace can be measured by measuring and displaying the output with a measuring device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sample temperature measuring method for measuring the temperature of a heated sample in an FZ (Floating Zone) furnace.

[Prior Art] As shown in FIG. 4, in an FZ furnace, a lamp 2 such as a halogen lamp or a xenon lamp is installed at one focal point F of a furnace body L forming a three-dimensional ellipsoidal mirror, and a lamp 2 such as a halogen lamp or a xenon lamp is installed in the The light from the lamp 2 is focused on a sample placed at the other focal point F2, and the sample is heated and melted to grow a monkey crystal.

Conventionally, thermometers such as M degree thermometers and radiation thermometers have been used to measure the temperature of high-temperature samples, but the temperature of the sample in the FZ furnace described above can be measured using a lamp as a heating source. Therefore, it is difficult to measure with these thermometers.

That is, since the FZ furnace uses the lamp 2 to heat the sample, the reflected light from the lamp 2 reflected from the sample surface is mixed in the radiation rays emitted by the sample.

Since it is impossible to reduce this reflected light to zero, the temperature of the sample cannot be accurately measured unless a means for cutting off the reflected light is added.

[Problems to be solved by the invention] The name of the present invention is that the outer shell of the lamp, which is the heating source of the FZ furnace, is made of quartz glass, and the quartz glass does not transmit light with a wavelength of 5 gm or more. We focused on this property and confirmed that it is possible to measure sample temperature based on wavelength components in the range of 5 to 10 gm, which is not generally used for high temperature measurement due to sensitivity characteristics etc. This led to the invention of wood.

That is, the technical object of the present invention is to enable the temperature of a sample in an FZ furnace to be measured inside a cylinder using the energy of radiation rays.

[Means and effects for solving the problems] In order to solve the above problems, in the present invention, the F
The radiation thermometer for the FZ furnace, which projects the emitted light from the sample of the Z furnace onto the light receiving element through a monochromator in the light receiving section and measures the temperature of the sample based on the output, has a temperature of 71!1.
1 constant, a concave mirror is used to condense the emitted light in the optical path from the incident lens barrel to the light receiving section, and the monochromator of the above light receiving section collects 5 to 10 LL of the emitted light.
l! A technical means is adopted in which wavelength components in a range of 1 are extracted and the sample temperature is measured based on the wavelength components.

According to the measurement method of the present invention, the radiation emitted from the sample in the FZ furnace is focused by the concave mirror and projected onto the light receiving section, and at this time, as in the case of using a lens, the radiation beam is emitted from the sample in the FZ furnace. wavelengths are never cut.

The radiation beam projected onto the light receiving section is split into desired wavelengths by a monochromator and then projected onto the light receiving element, so it is possible to measure the temperature of the sample in the FZ furnace based on the output of the light receiving element. can.

[Example] Figure WJ1 and Figure 2 show an example of a radiation thermometer used in the implementation of the wood invention. The body 11 of this radiation thermometer is -
An entrance lens barrel 12 on one side of which the radiation beam of the sample in the FZ furnace enters, an eyepiece barrel 13 on the other side, and an output lens barrel 14 on the top surface.
and includes a plurality of concave mirrors 15,... and a plane mirror 18 inside.
．． -- are provided, and the radiated light from the sample that enters from the incident lens barrel 12 is condensed and reflected by these mirror surfaces and guided to the eyepiece barrel 13.

Furthermore, at the intersection of the optical paths of the eyepiece barrel 13 and the exit lens barrel 14,
A switching reflector 17 is rotatably provided by a shaft 18, and the switching reflector 17 reflects the reflected light beam to the output barrel 14 at the position shown by the solid line in FIG. Sometimes, the optical path is switched by directing the emitted light to the eyepiece tube 13. Note that these mirrors 15, ], 13, and 17 are plated with gold to increase reflectance and reduce deterioration over time.

The casing 11 is provided with an optical chopper 19 that is positioned within the entrance lens barrel 12 and rotated by an appropriate rotation means such as an electric motor, and a plurality of light-transmitting windows formed in the chopper blade converts the emitted light. Convert it to intermittent light.

Furthermore, the housing 11 includes a light receiving section 21 on the optical path guided by the plane mirror 18 in the output barrel 14 . The light receiving section 21 includes a monochromator 22 and a light receiving element 23 that receives light separated by the monochromator 22 and converts it into an electrical signal.
An entrance slit 24 and an exit slit 25 are provided between the monochromator 22 and the light receiving element 23, and these slits 24 and 25 are made movable by an appropriate mechanism. In addition, the monochromator 22 is supplied with light having a wavelength of 5#LIII or less.
Cut by cutting.

Alternatively, means are added such as adding a secondary wavelength power filter to the song to cut it.

A pyroelectric link element is used as the light-receiving element 23, and in this case, the element itself uses changes in electric charge on its surface, so a single optical chopper can An output corresponding to the light intensity of the emitted light beam of the sample that is intermittently projected is obtained, and by displaying this output in total with a measuring device (not shown), FZ
It is configured to be able to measure the temperature of the sample in the furnace.

In addition, as shown in FIG. 3, the flow tube 3 in the FZ furnace
A nozzle 5 for extracting radiation is provided, and the radiation is radiated to the radiation thermometer through an infrared transmitting filler 6 made of MgF7, CaF, etc. provided in the nozzle 5. These filters 6 are approximately 1101 cm from the OT viewing range.
It is advantageous in that it has good wavelength transmittance up to L and is not hygroscopic.

When measuring the temperature of a sample in the FZ furnace using a radiation thermometer having the configuration described in -1-, radiation enters the housing 11 from the incident lens barrel 12 through the filter in the nozzle 5 provided in the flow tube 3 of the FZ furnace. The emitted light from the sample includes, in addition to the light emitted by the heated and molten sample, the reflected light from the lamp light reflected on the sample surface. However, since the pump described in F whose outer shell is made of quartz glass does not transmit light with a wavelength of 5 km or more, light reflected from the sample is mixed into the light emitted from the sample and has a wavelength of 5 pLm or more. Not yet.

The radiation light incident on the housing 11 passes through the optical chimney 19 and passes through the concave mirror 15. The light is focused by the plane mirror 16, Φ・
The light is then reflected by the switching reflector 17 and guided to the output lens barrel 14 . By using each of the mirrors described above, light having wavelengths of five or more square layers is not cut off as is the case when lenses are used, and the light including those wavelengths is guided to the output lens barrel 14. In this case, the switching reflector 17 is positioned at two points 'j' in FIG.
J! When rotated to the 4-line position, the condensed and reflected light is guided to the eyepiece tube 13, so that the temperature measurement point on the sample can be visually confirmed.

The radiation beam guided to the output barrel 14 and emitted by the plane mirror 16 passes through the entrance slit 24 and enters the monochromator 22. The monochromator 22 extracts wavelength components in the range of 5 to lQgm in the radiation beam. ,
The light is projected onto the light receiving element 23 through the output slit 25, and the sample temperature is measured and displayed based on the output of the light receiving element 23. In this case, by changing the positions of the entrance slit 24 and the exit slot 25, the area of the measurement surface of one sample can be changed.

[Effects of the Invention] The present invention provides a monochromator with 5
Since the wavelength component in the range of ~10 μm is extracted and the sample temperature is measured based on it, even if the sample is in an FZ furnace where the lamp light reflected on the sample surface mixes with the emitted light, the emitted light will Temperature can be measured, and the configuration for this purpose is quite in-house.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional side view of the main parts of a radiation thermometer implementing the comparative invention, Fig. 2 is a plan view of the same, Fig. 3 is a perspective view showing the relationship between the flow tube and the nozzle in the FZ furnace, and Fig. 4. is a schematic explanatory diagram of an FZ furnace. 12・φ incident lens barrel, 21φφ light receiving section, 22・φ monochromator, 23・fist light receiving element. Designated substitute

Claims (1)

[Claims] 1. The radiation beam of the sample of the FZ furnace that enters from the incident lens barrel,
The radiation thermometer for FZ furnaces projects the light onto the light receiving element via a monochromator in the light receiving part and measures the temperature of the sample based on the output. A sample temperature for an FZ furnace, characterized in that a concave mirror is used to converge the light beam, the monochromator of the light receiving section extracts a wavelength component in the range of 5 to 10 μm in the emitted light beam, and the sample temperature is measured based on it. Measuring method.