JPH0539558Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a cooling device for an observation sample for an electron microscope, and particularly to a device for transferring a frozen sample.

[Prior art] The third frozen sample transfer device for electron microscopes, etc.
A device having a configuration as shown in the figure is known.

In FIG. 3, 11 is a refrigerant tank made of a heat insulating material, 1
Reference numeral 2 indicates an introduction hole for the sample and coolant, 10 indicates a plug member for the introduction hole 12, and 8 indicates a sample holder for an electron microscope.

After a refrigerant, such as liquid nitrogen, is introduced into the refrigerant tank 11 through the introduction hole 12, the introduction hole is plugged with the plug member 10. The liquid nitrogen naturally evaporates within the tank to generate low-temperature nitrogen gas, which cools the sample holder 8 inserted into the tank. After the sample mounting position of the sample holder 8 has been sufficiently cooled, the stopper member 10 is removed and the frozen sample, for example, a frozen sample prepared with a cryomicrotome or the like, is placed in a sealed container in which it is housed in a state where it is isolated from the outside air. is introduced into the refrigerant tank 11, the container is opened, and the frozen sample S is attached to the sample holder 8. After removing the container, the plug member 10 closes the introduction hole 12.
The sample S is kept cool by the low-temperature nitrogen gas until it is introduced into an electron microscope or the like.

[Problems to be solved by the invention] In the frozen sample transfer device configured as described above, the entire internal space of the tank is filled with low-temperature nitrogen gas generated by natural evaporation of liquid nitrogen in the refrigerant tank 11, so that the sample cannot be transferred. When the sample holder 8 is attached to the sample holder 8, the low-temperature nitrogen gas is released from the opening to the outside of the tank, and air containing moisture flows into the tank from outside the tank. Therefore, it is considered a problem that the moisture adheres to the sample and the sample holder as frost.

Furthermore, if it takes time to attach the sample, the liquid nitrogen in the refrigerant tank will gasify within a short time and be released outside the tank, resulting in an increase in the amount of refrigerant consumed.

The present invention takes the above-mentioned problems into account, and aims to provide a frozen sample transfer device that can prevent frost formation on a sample when mounting the sample, and can also suppress refrigerant consumption.

[Means for Solving the Problems] The present invention provides a container made of a heat insulating material that accommodates a refrigerant, a plate that partitions the inside of the container made of a heat insulating material into a bottom refrigerant tank and an upper sample introduction chamber, and a container made of a heat insulating material that accommodates a refrigerant. and an orifice provided in the plate for guiding low temperature gas generated from the refrigerant introduced into the sample introduction chamber into the sample introduction chamber, and a sample holder is inserted into the sample introduction chamber from outside the sample introduction chamber near the orifice. It is characterized by the following.

[Function] In the present invention, an orifice is provided in a plate provided to partition a container made of an insulating material containing a refrigerant into a bottom refrigerant tank and an upper sample introduction chamber, and the By discharging low-temperature gas from the orifice into the sample introduction chamber, and inserting a sample holder from outside the sample introduction chamber near the orifice of the sample introduction chamber, frost formation on the sample is prevented, and the Refrigerant consumption can be suppressed.

[Example] Hereinafter, an example of the present invention will be described based on the drawings. FIG. 1 is a sectional view showing the configuration of a frozen sample transfer device according to the present invention, and FIG. 2 is a perspective view (partially sectional view) of the device shown in FIG. 1.

In FIGS. 1 and 2, 1 is a container made of a heat insulating material, 2 is a container made of a good thermal conductor, 3 is a bottom refrigerant tank, and 4 is a container made of a heat insulating material.
is an upper sample introduction chamber, 5 is a plate that partitions the bottom refrigerant tank 3 and the upper sample introduction chamber 4, 6a and 6b are introduction holes and plug members for introducing the refrigerant into the refrigerant tank, and 7 is provided in the plate 5. 8 is the sample holder,
9 and 10 are heat insulating plug members.

Prior to use, the plug members 9, 10 and 6b are removed, and after introducing a refrigerant such as liquid nitrogen into the refrigerant tank 3 through the introduction hole 6a, the introduction hole 6a is inserted into the plug member 6b.
At the same time, the container 1 made of a heat-insulating material is also plugged with plug members 9 and 10, thereby insulating the container 2 made of a good thermal conductor from the outside air. Low-temperature nitrogen gas generated by natural evaporation of liquid nitrogen in the refrigerant tank is discharged from an orifice 5 provided in the plate 3 into the sample introduction chamber. The sample holder 8 inserted from the outside of the container into the sample introduction chamber 4 near the orifice 7 is covered and intensively cooled by a flow of low-temperature nitrogen gas discharged from the refrigerant tank 3 through the orifice. After the sample mounting portion of the sample holder 8 has been sufficiently cooled, the plug member 10 is removed and the frozen sample S is attached to the sample holder 8 from the opening. Then, the opening is again closed with the stopper member 10 and left to stand, so that the sample is kept cool by low-temperature nitrogen gas until it is introduced into an electron microscope or the like.

In this way, the sample holder and the sample are covered by the low-temperature gas flow released through the orifice, so the moisture-laden air that flows in from outside the tank when the sample is attached cannot reach the vicinity of the sample holder and frozen sample. Therefore, frost formation on the sample can be prevented.

In addition, since the sample introduction chamber 4 made of the thermally conductive container 2 is cooled by the refrigerant introduced into the bottom refrigerant tank 3 which is also made of the thermally conductive container 2, when the sample S is attached to the sample holder 8, the opening Even if moisture-containing air flows in from the sample introduction chamber 4, most of the moisture in the air is adsorbed on the wall surface of the sample introduction chamber 4.

It should be noted that the above-described embodiment is only one embodiment of the present invention, and the present invention can be modified and implemented.

For example, in the embodiment described above, the refrigerant introduction hole 6a and its plug member 6b were provided in the plate body 5, but
Instead of providing an introduction hole in the plate 5, the entire plate 5 may be removed when introducing the refrigerant.

[Effects of the invention] As is clear from the above explanation, according to the invention, an orifice is provided in the plate provided to partition the container made of a heat-insulating material into a bottom refrigerant tank and an upper sample introduction chamber, and the refrigerant is The low-temperature gas generated from the refrigerant introduced into the tank is released from the orifice into the sample introduction chamber, and the sample holder is inserted from outside the sample introduction chamber near the orifice of the sample introduction chamber. Since the sample is covered with a low-temperature gas flow, frost formation on the sample can be prevented when the sample is attached.

In addition, since the orifice suppresses the gas flow rate,
When mounting the sample, the liquid nitrogen in the refrigerant tank does not suddenly gasify in a short period of time and is released outside the tank, and this reduction in consumption allows for sufficient cooling during the sample cooling process after mounting the sample. A low temperature state can be obtained for a long time.

Furthermore, in this example, since the bottom refrigerant tank and the upper sample introduction chamber are formed by a container made of a good thermal conductor and housed in a container made of a heat insulating material, the opening is closed when the sample is attached to the sample holder. Moisture in the air flowing in from the sample introduction chamber is adsorbed by the cooled wall surface of the sample introduction chamber. Therefore, frost formation on the sample can be prevented.

In addition, since the sample holder and sample are covered with a low-temperature gas flow and are intensively cooled, the cooling speed increases and the time required for cooling can be shortened. It is also possible to prepare a frozen sample by attaching it to a holder and leaving it.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the configuration of a frozen sample transfer device according to the present invention, Fig. 2 is a perspective view (partial sectional view) of the device shown in Fig. 1, and Fig. 3 is a diagram for explaining a conventional example. It is. 1... Container made of a heat insulating material, 2... Container made of a good thermal conductor, 3... Bottom refrigerant tank, 4... Upper sample introduction chamber,
5... Plate body, 6a... Refrigerant introduction hole, 6b... Plug member, 7... Orifice, 8... Sample holder,
9, 10...Insulating plug member.

Claims (1)

[Scope of utility model registration request] A container made of a heat insulating material that accommodates a refrigerant; a plate that partitions the inside of the container made of a heat insulating material into a bottom refrigerant tank and an upper sample introduction chamber; a sample is introduced into the low temperature gas generated from the refrigerant introduced into the refrigerant tank A frozen sample transfer device comprising: an orifice provided on the plate for guiding the sample into the sample chamber; and a sample holder is inserted into the sample introduction chamber from outside the sample introduction chamber near the orifice.