JPH054240Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a sample holding device in a cyclotron target box.

Conventionally, in this type of target box, the sample was fixed to the wall surface of the target box. However, some of the samples are thin plates and are fragile, so they must be cooled by helium spray to prevent them from cracking due to heat generation due to energy loss in the incident beam. However, even with this method, there were drawbacks such as cracking of the sample due to some heat generation and cracking due to the pressure of helium spraying.

In order to prevent this, the present invention provides a beam and a foil with an irradiation port in front of the sample, and a foil for helium spray pressure relief at the rear.
Further, by providing a communication port for communicating the pressure difference between the front chamber and the rear chamber, cracking of the sample due to the pressure difference is prevented.

An embodiment of the present invention will be described in detail below with reference to the drawings.

A target box 4 is connected to the tip of a duct 2 of a beam 1 of charged particles such as protons and deutrons emitted from a small cyclotron (not shown) via a vacuum-blocking foil 3. This target box 4 consists of two ring-shaped casings 5, a holder 6, and a cooling plug 7.

The housing 5 is provided with a concave conical surface 11 that tightly fits the conical end surface 10 of the holder 6. Further, the holder 6 is provided with a concave conical surface 14 that tightly fits the conical end surface 13 of the cooling plug body 7, and a communication port 12 to eliminate the pressure difference between the front chamber 32 and the rear chamber 33.

The annular surface 10a at the tip of the holder 6 has a thickness of
Sample 16 is placed through a 10μ sample holding foil 15.
A ring-shaped holding flange 18 is placed in contact with the front surface of the sample 16 via an annular sample holding oil 17, and a stopper 19 is inserted through the sample holding flange 18 and the sample holding oil 15, 17. , 19 to the end face of the holder 6, and the peripheral portion of the sample 16 is clamped and fixed by a pair of sample holding oils 15, 17.

Cooling water (or fluorocarbon) passages 20 and 21 are provided in the housing 5 and the stopper 7, with cooling water inlets 22 and 23 at the top and cooling water outlets 24 and 25 at the bottom. The housing 5 includes a nozzle 26 that spouts cooling helium toward the foil 3 and the sample 16.
27 and a helium inlet 28 and outlet 29.

The plug body 7 is also provided with a nozzle 30 for spouting cooling helium toward the opposite surface of the sample 16, and a helium inlet 31.

Next, the operation of this device will be explained.

Inside the target 4, the front and rear corner chambers of the sample 16 are evacuated to eliminate beam loss. The beam 1 traveling through the duct 2 passes through the foil 3 and collides with the sample 16, causing the foil 3 and the sample 16 to generate heat. Furthermore, the beam that passes through the sample 16 hits the stopper 7, causing it to generate heat. .

On the other hand, the cooling helium supplied from the inlet 28 is ejected from the nozzle 26 and hits the foil 3 to cool it, and the cooling helium ejected from the nozzle 27 hits the front surface of the sample 16 and cools it. . On the other hand, the cooling helium supplied from the inlet 31 is ejected from the nozzle 30 and hits the sample holding oil 15 in contact with the rear surface of the sample 16 to cool it. After this cooling, the helium is discharged from the outlet 29.
more excreted.

On the other hand, the cooling water flows from the inlets 22 and 23 through the passages 20 and 21 inside the casing 5 and the stopper 7, respectively, cooling them and cooling the vicinity of the helium passage, reducing heat loss until it spouts out. In addition, the excess beam 1 cools the plug body 7 which generates heat.

Further, the communication port 12 between the front chamber 32 and the rear chamber 33 eliminates the difference in indoor pressure caused by the blowing pressure of cooling helium.

As described above, in this invention, since the sample holding foil is in contact with the rear surface of the sample, the sample can be supported against the helium spray pressure applied to the front surface, and the area around the sample is supported by the pair of sample holding foils. Since the sample is supported by sandwiching the parts, even if the sample thermally expands due to heat generation, the sample holding oil can escape and allow the deformation.
Moreover, it is possible to prevent the sample from breaking or cracking due to the pressure difference between the front and rear chambers.

[Brief explanation of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is an exploded view thereof. 4... Target box, 6... Ring-shaped holder, 10a... Tip annular surface, 15, 17... Sample holding oil, 16... Sample, 18... Annular holding flange, 19... Stop, 12... ...Communication port.

Claims (1)

[Scope of utility model registration request] In the target box, the rear surface of the sample is brought into contact with the annular surface at the tip of the ring-shaped holder through a specimen holding foil, and the annular holding flange is brought into contact with the front surface of this sample through an annular specimen holding foil. The sample holding flange and sample holding oil are fixed to the ends of the holder using fasteners, and the periphery of the sample is clamped and fixed by the pair of sample holding oils, and the communication port between the front chamber and the rear chamber is closed. Sample holding device in the cyclotron target box.