Strong permanent magnet device of magnetized material under vacuum system

10-04-2020 дата публикации
Номер:
CN0110988005A
Контакты:
Номер заявки: 30-11-20191311
Дата заявки: 17-12-2019

[1]

Technical Field

[2]

The invention relates to the field, of vacuum technology,angle-resolved photoelectron spectroscopy characterization, permanent magnet applications, and particularly relates to a strong permanent magnet device, of a magnetized material under a vacuum system.

[3]

Background Art

[4]

. The magnetic field strength of the simple permanent magnet, which is determined by the complexity and sensitivity of the vacuum system, is very difficult to reach a Tesla, and the magnetic field strength is limited to more than a Tesla by using electromagnets or electromagnets, and the magnetic field strength is limited in the vacuum system (, especially superconducting coils PPMS)(, for example Lashley J C,Hundley M F,Migliori A,et al.Criticalexamination of heat capacity measurements made on a Quantum Design physicalproperty measurement system[ J].Cryogenics,2003,43(6):369-378.). in ultrahigh vacuum environments . is a practical product, property measurement system, in a vacuum system, especially in an ultra-high vacuum environment, and the magnetic field strength is limited to more than a Tesla magnetic field by using an electromagnet in an ultra-high vacuum environment, respectively . and the magnet surface, is extremely difficult to meet extreme testing requirements (1T), of magnetic material magnetic field strength measurement instrument magnetic field, strength measurement instrument magnetic field strength measurement instrument is very, mature, measurement instrument, magnetic field strength limit; measurement instrument is difficult to meet requirements of extreme tests in, a vacuum system, especially in a super.high vacuum environment, to achieve a strong magnetic field.

[5]

The Halbach array (Halbach Array) is a novel permanent magnet arrangement mode . and the permanent magnets in different magnetization directions are arranged, in a certain order, so that the magnetic field in the array is remarkably enhanced, while the other side is significantly weakened.

[6]

Halbach array (is found in reference https:www.kjmagnetics.com/blog.asp. p=halbach-arrays) Has been proposed Klaus Halbach in 1979 by, in the United States, and the application range of high-energy physics fields, mainly applied to synchrotron radiation devices of particle accelerators, and, due to excellent magnetic field distribution characteristics, is gradually expanded to industrial fields such as nuclear magnetic resonance, maglev, permanent magnet special motors, for example, in the field.

[7]

This particular magnet arrangement allows the magnetic field of the magnet to be connected to a whole, and to concentrate the magnetic field within a narrow range, so that the strength exponentially increases, that the maximum permanent magnet peak magnetic strength is 0.6T or less and the Halbach magnet array of the ideal design can break through this value.

[8]

In view of the research value of the magnetic material and the blank, in the field of vacuum magnetization, the strong permanent magnet device, without interference, which can be widely used in vacuum equipment has an important significance, in the scientific research field.

[9]

Content of the invention

[10]

An object of the present invention is to provide a strong permanent magnet device, of magnetized material in a vacuum system capable of applying a strong magnetic field (ARPES) higher than 1T to a material in an angle-resolved optoelectronic spectrum, while ensuring that the magnet pair does not interfere, with the electronic energy analyzer of the device and the residual magnetic field of the sample is not damaged, during transmission.

[11]

To the technical scheme of the invention, permanent magnet device, of magnetized material under a vacuum system comprises: permanent magnet structure, vacuum cavity and sample holder.

[12]

The permanent magnet structure, is composed N52 of a, neodymium magnet or a samarium cobalt magnet which is oriented in a Halbach distribution by eight or twelve magnetic poles, and the number and material; magnets of the magnet are fixed, through a specially designed shell and connected to the vacuum cavity, through a screw rod to apply more than 1T constant magnetic field; to the magnetic material.

[13]

The vacuum chamber body, is symmetrically and orthogonally distributed by 15-20cm vacuum tubes of the radial length CF63 as flanges of three, of the body CF35 and a, flange port deviating from the orthogonal axis CF35 degrees as the observation window 20 or larger, flange CF63 flange is used for connecting the other large (flanges of various vacuum test instruments CF, for connection of the sample holder; CF).

[14]

The sample holder, comprises a large CF flange, infusion tube and a copper cold head assembly . wherein the liquid circulation passage, is internally provided with a groove, for placing a sample holder and the infusion tube is connected, through a flange. The sample holder is connected, with the vacuum chamber through, a flange. The, sample holder is fixed on the flange, by a flange and is connected with the vacuum cavity.

[15]

Further, samples of the sample holder are coated with magnesium carbonate as the heat insulation coating, so that the temperature rise, of the sample holder in contact with the normal temperature part in the process of transferring to other cavities can be effectively prevented.

[16]

, Stainless steel plate, base also uses 30mm, stainless steel material 60mm, to enlarge 1:2 magnet's fixed cover piece material, and the clearance between base steel pipe and the cover piece that the clearance between base steel pipe and the cover piece of, mm diameter is 1mm is not more than 0.2mm. 316 mm's material and clearance fit degree guarantees that the magnetic field shape of magnet does not receive, interference, and does not, leak intensity 316 0.2mm.

[17]

Further, Sample holder is made of iron-cobalt-nickel alloy material, without residual magnetism . and four equidistant screw holes, can fix the thin film sample; with 1mm × 10mm rectangular metal areas (on the two sides of the table board without covering the coating), to make contact, of the sample holder and other testing equipment are conductive.mesa height is 1mm, compatible.

[18]

The invention has the advantages and positive effects of :

[19]

Compared, with the electromagnet, the device does not need to use a large current (>100A) and a thermal insulation device to maintain the magnetic field, so that the magnetic field generated by the device is less, far higher than, far higher than the magnetic field intensity, magnetic field of the conventional magnet in the magnetization area. The device generates additional interference 1T, The device generates no additional current to the measurement system and is distributed uniformly, in the magnetization area, magnetic field is distributed evenly, The device generates additional interference.

[20]

Description of drawings

[21]

1 Is a schematic; of a linear Halbach array.

[22]

2 Is a schematic, of the magnetic pole of the annular magnet used in the present invention, and 2(a) are 8-order Halbach array rings, and 2(b) are 12-order Halbach array rings.

[23]

3 Is a top view and front view, of the base of FIG. 3(a) of FIG. and FIG. 3(b) is a plan view and a front view, of the ferrule 3(c) .

[24]

4 Is a top view; of a cavity body.

[25]

5 Is a sample holder design diagram, FIG. 5(a) is a sample holder integral structure, FIG. 5(b) is an internal liquid circulation path and a sample tank structure; of the cold head.

[26]

6 Is a sample holder design diagram .

[27]

7 Is a schematic, of a magnet clamp assembly, of FIG. 7(a) is a magnet upper cover sheet structure, and FIG. 7(b) is a magnet fixing base structure .

[28]

8 Is an assembled permanent magnet schematic .

[29]

9 Is a schematic structural view; of a robot.

[30]

10 Is a structural plan; of a complete device.

[31]

11 Is a structural side view, of a complete device.

[32]

Mode of execution

[33]

The present invention, will be further described with reference to the drawings and specific embodiments.

[34]

1.Permanent magnet array design

[35]

As 2 shows, the magnetic field strength, of more than 8 can be obtained by arranging the magnets in 12 or, magnetizing directions 2, and the working temperature can reach (DEG C). and the working temperature cannot exceed, N52 DEG C, to select 80 neodymium iron boron magnets which are uniformly distributed according to whether the device needs high-temperature baking. DEG C is needed. 1T arrowhead magnets are uniformly distributed according to whether the device needs high-temperature baking to select the, neodymium-iron-boron magnet with 8 a magnetic field strength of more than a 12 circle, 180 by, arrowhead magnets in the field of the device according to whether the device, needs high-temperature baking.

[36]

2.Assembly of permanent magnet array

[37]

The magnet fixing, is made of non-magnetic. stainless steel 3 through induction heating and quenching by conventional means, as shown. 3(a) and 3(b), the magnet fixing device, is formed by induction heating and quenching the magnet. 3(c) through induction heating and quenching. The material of the ferrule is selected to be sufficient to resist the magnetic force 316 of the magnet, to produce interference, magnet assembly effect between magnets. The magnetic field distribution of a Halbach array is prevented from being disturbed by the magnetic force of the magnetic force of the magnet by induction heating . The magnet is made. of. brass, through induction heating and quenching.

[38]

3.Design of vacuum cavity

[39]

As 4 shown, the flange port of flange flange flange is, used flange for mounting the vacuum chamber, design first 1, second of vacuum 2, third 3 gauge angle valve. CF35 degree . The, flange, flange is, a standard flange for mounting the glass viewing window whose angle is degrees or less, fourth for installation of 4 the CF35 vacuum, gauge of . degree to about, first 80 1 degree. The. flange 20 port of the vacuum device, is, fifth used in vacuum 5, 6th equipment such 6, as angle- resolved photoelectron spectrometers. degree. The flange port of the vacuum chamber is generally, degree with DEG C. CF degree, The flange port of the vacuum device is standard CF63, 100, 150. The flange port of the vacuum gauge is used in vacuum equipment such as angle-resolved photoelectron spectroscopy.

[40]

4.Design of sample holder

[41]

Since the Curie transition temperature, of a lot of magnetic materials is very low, a sample holder, for transporting liquid nitrogen is made of, stainless steel, which is filled with flowing coolant at a temperature below the transition temperature, into the cold head of the observation window 5 . The cooling liquid circulation circuit 51, with good wear resistance, for transporting liquid nitrogen is filled with the flowing coolant to ensure that the cold head maintains the low temperature 108.9/(m.k), for placing the sample holder in the cold head part, of the cold head of the test sample holder is made of brass 52,heat conductivity coefficient. 54. 53, The invention provides an infusion, tube 304 for transporting liquid nitrogen. The invention 55, provides. cooling, comprising, stainless steel for 56, holding a sample holder in a cold header of a cold, head of the sample holder in a cold header of the sample holder.

[42]

5.Design of sample holder

[43]

Since the design of the sample holder, of the various vacuum instruments does not show as much as, of the sample holder design ARPES of a, spectrometer, the appearance of the core idea, torr of the present invention can be modified, according to the specific situation.

[44]

As shown 6, the core idea of the present invention is that magnesium carbonate having a thermal conductivity of only, is prevented from being heated, by applying a layer 6 of magnesium carbonate to the surface of the metallic support and exposed 61, wide metallic parts 62 only 1mm positions in, while the heat transfer coefficient low white magnesium carbonate can effectively prevent contact heat transfer and infrared radiation, 0.0692w/(m · k) of the surrounding heat source to have a good heat insulating. effect.

[45]

7 Is a schematic, of the magnet clamp member of the present apparatus, and 316 stainless steel, is selected, and the weak portions of the cover sheet are subjected to quenching treatment.

[46]

8 Is a view, of the effect of FIG. 6 after the permanent magnet assembly is completed, wherein the bottom portion of the base, covering FIG. 6 covers the cover plate . and then the ferrule is sleeved on the base, and then the magnet, is fixed, by pressing, with the cover sheet after each pair of magnets are mounted.

[47]

9 Is a structural diagram, of a manipulator in the present invention, and a commercialized magnetic rod-type robot, is adopted to correct the position of the sample inside the magnet, and a detailed structure of, is omitted here.

[48]

10, 11 Is an effect diagram, after assembly of the device of the present invention in which permanent magnet array 101, is secured to vacuum chamber 108 through connecting rod 102 for connecting the cold head of, sample holder 103, through current vacuum gauge 104, 106 to reach magnetic field strongest position, magnetic pole 107, manipulator 105 for sample holder from other vacuum cavities to, some corrective action, on the sample holder.

[49]

1, Mounting step:

[50]

If high-temperature baking, is needed, the magnet selects samarium cobalt material, to connect the infusion tube of the device to liquid nitrogen or liquid helium dewar flask CF63 for ten minutes or more, to wait for more than ten minutes, and the temperature of the cold head at this time is stable, to be magnetized, below 10 ^ -8mbar at the time when installation is complete, The utility model is used . 106. The magnet is selected, below the, test chamber through the suction flange connection vacuum, pump group . for ten minutes or more.

[51]

2, Preparation of samples

[52]

The test device contact, of the metal part reserved on the left and right sides of the sample support, of the special sample holder coated with magnesium carbonate ensures that the conductive, sample holder is finally transferred to the magnetization cavity, through the multi-stage vacuum cavity body.

[53]

3, Magnetization process

[54]

To the Curie temperature selection cooling liquid, of the material, holds the sample holder at the groove, of the cold head, and the magnetic field maximum point, of the permanent magnet is kept 10 minutes or more, magnetization can complete, rapidly transferring the sample support to the test chamber of the angle-resolved photoelectron spectrometer.



[55]

The permanent magnet device, comprises: permanent magnet structures, vacuum cavity body, sample racks, wherein the sample racks and the permanent magnets are installed inside the vacuum cavity body, for cooling and applying magnetic fields, respectively to the sample racks and the thermal insulation device to maintain the magnetic field (>100A). The device does not need large current, and a thermal insulation device to maintain the magnetic field, magnetic field intensity, magnetic field is less, far higher than that of a traditional magnet magnetic field intensity magnetic field in the magnetization area and is distributed uniformly 1T, magnetic field intensity distribution is less than, magnetic field intensity distribution, uniformity . The device is suitable for being applied to ultra-high. vacuum environment.



1.The strong permanent magnet device, is characterized in: comprising: permanent magnet structures, a vacuum cavity and a sample holder.

The permanent magnet structure, is composed N52 of a, neodymium magnet or a samarium cobalt magnet which is oriented in a Halbach distribution by eight or twelve magnetic poles, and the number and material; magnets of the magnet are fixed, through a specially designed shell and connected to the vacuum cavity, through a screw rod to apply more than 1T constant magnetic field; to the magnetic material.

The vacuum chamber body, is symmetrically and orthogonally distributed by 15-20cm vacuum tubes of the radial length CF63 as flanges of the three, bodies CF35 and a, flange port deviating from the orthogonal axis CF35 degrees as the observation window 20 vacuum chamber is used for connecting the other large; flanges of various vacuum test instruments CF63 CF, for connecting the sample; racks CF.

The sample holder, comprises a large CF flange, infusion tube and a copper cold head assembly, wherein the liquid circulation passage, is internally provided with a groove, for placing a sample holder and the infusion tube is connected, through a flange . The sample holder is connected, with the vacuum chamber through, a flange. The, sample holder is fixed on the flange, by a flange and is connected with the vacuum cavity.

2.The strong permanent magnet device according to Claim 1, is characterized in: the tail end of the sample holder is coated with magnesium carbonate as the heat insulation coating, so that the temperature rise, of the sample holder in contact with the normal temperature part in the process of transferring to other cavities can be effectively prevented.

3.according to Claim 1, Stainless steel sheet: base also uses, stainless steel material 30mm, to amplify 60mm, magnet's fixed cover piece material, and the clearance between base steel pipe and the cover piece that the clearance does not exceed 1:2 brass that the clearance between base steel pipe of, mm diameter is 1mm, and the cover piece does not exceed 0.2mm, 316 mm's material and clearance fit degree guarantees that the magnetic field shape of magnet is not, disturbed, non- leakage intensity 316 0.2mm.

4.The strong permanent magnet device according to Claim 1, is characterized in: sample holders are made of an iron-cobalt-nickel alloy material, without residual magnetism, and four equidistant screw holes, are arranged on the table surface with; uncovering coating rectangular metal regions 1mm × 10mm for ensuring that the sample holder and other testing devices are electrically conductive, mesas are compatible, 1mm, with the sample racks of various types of vacuum equipment respectively.