阅读说明：本技术 带有磁极定位环的四极透镜组件和该定位环安装方法 (Quadrupole lens assembly with magnetic pole positioning ring and method for mounting the positioning ring ) 是由 王琪 尹蒙 于 2021-06-17 设计创作，主要内容包括：本发明公开了一种带有磁极定位环的四极透镜组件和该定位环的安装方法,该组件包括靠近小半径处设有周向90度均匀间隔的四块磁极、以及环绕在四块磁极外侧磁轭,该四极透镜组件轴向的前、后端面上,各设有第一级磁极定位机构和第二级磁极定位机构,该第一级磁极定位机构为布设在上半个四极透镜和下半个四极透镜对接处的左右两个骑缝销钉,该第二级磁极定位机构为环绕连接四极透镜小半径处四个磁极的磁极定位环,该方法是：配打定位销孔前,测量磁场并确定相对位置；配打每一组四极透镜外圈和内圈的定位销孔,安装束流管道前拆卸四极透镜,安装束流管道后采用销钉复位组装N个四极透镜组件。本发明使得磁场均匀度误差由千分之三提高到万分之五。(The invention discloses a quadrupole lens component with a magnetic pole positioning ring and a mounting method of the positioning ring, the component comprises four magnetic poles which are uniformly spaced at 90 degrees in the circumferential direction and are arranged near a small radius, and a magnetic yoke which surrounds the outer sides of the four magnetic poles, the axial front end surface and the axial rear end surface of the quadrupole lens component are respectively provided with a first-stage magnetic pole positioning mechanism and a second-stage magnetic pole positioning mechanism, the first-stage magnetic pole positioning mechanism is a left and a right dowel pin which are arranged at the joint of an upper half quadrupole lens and a lower half quadrupole lens, the second-stage magnetic pole positioning mechanism is a magnetic pole positioning ring which surrounds and connects the four magnetic poles at the small radius of the quadrupole lens, and the method comprises the following steps: measuring a magnetic field and determining a relative position before matching and punching a positioning pin hole; and (3) drilling positioning pin holes on the outer ring and the inner ring of each group of quadrupole lenses, disassembling the quadrupole lenses before installing the beam pipeline, and resetting and assembling N quadrupole lens assemblies by adopting pins after installing the beam pipeline. The invention can improve the magnetic field uniformity error from three per thousand to five per ten thousand.)

1. The utility model provides a quadrupole lens subassembly with magnetic pole holding ring, this quadrupole lens subassembly are close to small radius department and are equipped with four magnetic poles of circumference 90 degrees evenly spaced and encircle and be close to the yoke of quadrupole lens subassembly large radius department in the four magnetic poles outsides, its characterized in that: the axial front end surface and the axial rear end surface of the quadrupole lens component are respectively provided with a first-stage magnetic pole positioning mechanism and a second-stage magnetic pole positioning mechanism, the first-stage magnetic pole positioning mechanism is a left and a right riding pin arranged at the butt joint of the upper half quadrupole lens and the lower half quadrupole lens, and the left and the right riding pins are used for roughly positioning a magnetic pole; this second level magnetic pole positioning mechanism is for encircleing two magnetic pole holding rings of connecting two terminal surface small radius department magnetic poles around every group quadrupole lens respectively, and these two magnetic pole holding rings are used for the magnetic pole of accurate positioning this group quadrupole lens, realize that the high accuracy of this group quadrupole lens magnetic pole is coaxial and the high accuracy is concentric, and high accuracy is coaxial and the concentricity reaches 0.03 millimeter.

2. The quadrupole lens assembly with the retaining ring of claim 1, wherein: the diameters of the left and right dowel pins at the joint of the upper half quadrupole lens and the lower half quadrupole lens are 8 mm, and the accuracy of positioning magnetic poles is 0.1 mm; the four magnetic pole positioning rings surrounding the four magnetic poles at the small radius of the quadrupole lens are provided with four magnetic pole mounting holes at the 90-degree uniform intervals of the outer rings of the positioning rings and 4 magnetic pole positioning holes at the 90-degree uniform intervals of the inner rings of the positioning rings, the diameters of the 4 magnetic pole positioning holes are 6 millimeters, and the magnetic pole positioning precision is 0.03 millimeter.

3. The quadrupole lens assembly with the retaining ring of claim 1, wherein: the magnetic pole positioning ring surrounding and connecting the four magnetic poles at the small radius of the quadrupole lens is made of brass with a non-magnetic-permeability material, and the magnetic pole positioning ring with the non-magnetic-permeability material is used for not influencing a magnetic field in a magnetic pole working state; the inner diameter of a beam pipeline hole of the magnetic pole positioning ring is larger than the outer diameter of a beam pipeline flange; the sum of the diameters of the magnetic pole mounting hole and the magnetic pole positioning pin hole of the magnetic pole positioning ring is required to be smaller than the difference between the outer diameter of the magnetic pole positioning ring and the inner diameter of the beam pipeline hole of the magnetic pole positioning ring; the thickness of the magnetic pole positioning ring is equal to the sum of the length of the positioning pin of the magnetic pole positioning ring and the depth of the positioning hole on the magnetic pole.

4. A pole positioning ring mounting method for a quadrupole lens assembly of claim 1 having a pole positioning ring, comprising the steps of:

firstly, measuring a magnetic field and determining a relative position before matching and punching a positioning pin hole: when the quadrupole lenses are assembled for the first time, firstly, the magnetic field of each group of quadrupole lenses is measured respectively, the magnetic pole positions of the quadrupole lenses are adjusted according to the magnetism measurement result, and when the magnetism measurement result meets the design requirement, the relative positions of the upper half quadrupole lens and the lower half quadrupole lens are determined;

step two, according to the determined relative position of the magnetic poles of the upper and lower quadrupole lenses, matching and punching the positioning pin holes of the outer ring and the inner ring of each group of quadrupole lenses, and installing the positioning pin holes of the outer ring and the inner ring: the positioning pin hole of the outer ring is a joint-riding pin hole on the magnetic yoke of the outer ring, and the positioning pin hole of the inner ring is a magnetic pole mounting hole and a magnetic pole positioning hole on the magnetic pole positioning ring of the inner ring;

step three, disassembling the quadrupole lens before installing the beam pipeline: when a beam pipeline is installed, the quadrupole lens matched and punched with the positioning pin holes is disassembled into an upper half part and a lower half part of the quadrupole lens, before the disassembly, two magnetic pole positioning rings on the front end face and the rear end face of each group of quadrupole lenses are firstly disassembled, and then a vacuum pipeline of the quadrupole lenses is placed on the lower half part of the quadrupole lenses;

step four, after the beam pipeline is installed, resetting the quadrupole lens by using a pin: resetting and assembling the upper half part of the quadrupole lens and the lower half part of the quadrupole lens which are disassembled before the beam pipeline is installed, respectively sleeving magnetic pole positioning rings at two ends of the beam pipeline if only one group of quadrupole lenses exist, moving each magnetic pole positioning ring to the magnetic pole position at the same side for installation and positioning, and respectively inserting four positioning pins of each magnetic pole positioning ring into positioning holes, thereby realizing the resetting of the magnetic pole position on the group of quadrupole lenses;

step five, resetting and assembling N (N is more than 1) quadrupole lens assemblies: sleeving a shared vacuum pipeline of N quadrupole lenses into 2N-2 magnetic pole positioning rings, wherein the 2N-2 magnetic pole positioning rings are all the other magnetic pole positioning rings except the magnetic pole positioning rings at two ends of the N quadrupole lenses, placing the shared vacuum pipeline of the N quadrupole lenses on the lower half parts of the N arranged quadrupole lenses, and the front, back and end faces of the N quadrupole lenses are removed, a magnetic pole positioning ring is respectively arranged on the front and back magnetic pole faces of each quadrupole lens, the upper half part of each quadrupole lens and the lower half part of each quadrupole lens are sequentially assembled, the two end faces of the beam pipeline are respectively sleeved with the magnetic pole positioning rings which are not installed, each magnetic pole positioning ring is moved to the adjacent magnetic pole for installation and positioning, and the four positioning pins of each magnetic pole positioning ring are respectively inserted into the positioning holes to realize the resetting of the magnetic pole position of each quadrupole lens.

Technical Field

The invention belongs to the technical field of accelerators, and particularly relates to a quadrupole lens assembly with a magnetic pole positioning ring and a positioning ring installation method.

Background

The accelerator is a special electric, magnetic and high vacuum device which can make charged particles reach high energy by being controlled by magnetic field force and accelerated by electric field force in a high vacuum field, is modern equipment for artificially providing various high-energy particle beams or radiant rays, and is an important instrument in high-energy physics.

The beam streamline is an important component of the accelerator, and the beam current led out from the accelerator is transmitted to each experiment terminal through the beam streamline.

Quadrupole lenses are the main beam line magnets on the beam line, which is usually formed by connecting multiple groups of quadrupole lenses in series, and the center of each group of quadrupole lenses is a beam duct. When energized, the magnetic field produced by the quadrupole lens imparts a focusing force on the particles, so that the beam passing therethrough is prevented from deviating from the central trajectory. In the prior art, for a technical scheme of a quadrupole lens, such as an installation collimation device and an installation collimation method of the quadrupole lens on a patent CN2867584Y magnetic quadrupole lens and a patent CN108735328A proton beam line, the technical scheme only relates to a structure of the quadrupole lens, but does not relate to how to solve the problem of accurate positioning of magnetic poles on the quadrupole lens, because the accurate positioning of the magnetic poles of the quadrupole lens is difficult to achieve.

The reason why the precise positioning of the poles of the quadrupole lens is difficult is that: and the positioning between the magnetic poles adopts a hoisting positioning method, before hoisting positioning, the two magnetic poles of the lower half quadrupole lens and the two magnetic poles of the upper half quadrupole lens are respectively installed, and then the upper half quadrupole lens and the lower half quadrupole lens are assembled. Before the assembly, semicircular holes for installing the dowel pins are respectively formed in the left side and the right side of the upper half quadrupole lens magnetic yoke and the left side and the right side of the lower half quadrupole lens magnetic yoke, the dowel pins are arranged in the semicircular holes, and at the moment, the length direction of the dowel pins is perpendicular to the transverse plane direction of the quadrupole lenses. During the equipment, because the hoist and mount location is soft location, the hoist and mount in-process, first half quadrupole lens can take place to rock all around, when first half quadrupole lens rocks about, if the diameter of riding the seam round pin top is too little, will be by quadrupole lens when rocking about will ride seam round pin roll deformation. Based on this, the diameter of the seam pin for positioning the quadrupole lens in engineering can not be too thin, but must be relatively thick, the diameter of the seam pin can not be smaller than 0.8 mm at least, and the positioning precision can only reach 0.1 mm.

The magnetic poles of the quadrupole lens are difficult to position accurately, which means that the magnetic poles at the two ends of the quadrupole lens cannot ensure strict coaxiality and strict concentricity. The condition that strict coaxiality cannot be ensured means that a connecting line at two ends of each magnetic pole is not parallel to the axis of the quadrupole lens but has a certain angle; the condition that strict concentricity cannot be ensured means that two magnetic poles of the upper half quadrupole lens and two magnetic poles of the lower half quadrupole lens are staggered left and right, so that the four magnetic poles cannot be concentric; when the magnetic poles of the quadrupole lens have non-concentricity or non-concentricity of more than or equal to 0.1 mm, the deviation of the beam can be amplified by 25 times (which is obtained by calculation of strict beam dynamics), and meanwhile, the error of the magnetic field uniformity in measurement can only reach three per thousand, but the requirement that the error of the magnetic field uniformity is less than five per ten thousandth can not be met.

Disclosure of Invention

The invention provides a quadrupole lens assembly with a magnetic pole positioning ring and an installation method of the positioning ring, aiming at solving the problem that the magnetic pole of the quadrupole lens in the prior art is difficult to accurately position.

In order to solve the technical problem, the invention adopts the following technical scheme:

the utility model provides a quadrupole lens subassembly with magnetic pole holding ring, this quadrupole lens subassembly are close to small radius department and are equipped with four magnetic poles of circumference 90 degrees evenly spaced and encircle and be close to the yoke of quadrupole lens subassembly large radius department in the four magnetic poles outsides, its characterized in that: the axial front end surface and the axial rear end surface of the quadrupole lens component are respectively provided with a first-stage magnetic pole positioning mechanism and a second-stage magnetic pole positioning mechanism, the first-stage magnetic pole positioning mechanism is a left and a right riding pin arranged at the butt joint of the upper half quadrupole lens and the lower half quadrupole lens, and the left and the right riding pins are used for roughly positioning a magnetic pole; this second level magnetic pole positioning mechanism is for encircleing two magnetic pole holding rings of connecting two terminal surface small radius department magnetic poles around every group quadrupole lens respectively, and these two magnetic pole holding rings are used for the magnetic pole of accurate positioning this group quadrupole lens, realize that the high accuracy of this group quadrupole lens magnetic pole is coaxial and the high accuracy is concentric, and high accuracy is coaxial and the concentricity reaches 0.03 millimeter.

The diameters of the left and right dowel pins at the joint of the upper half quadrupole lens and the lower half quadrupole lens are 8 mm, and the accuracy of positioning magnetic poles is 0.1 mm; the four magnetic pole positioning rings surrounding the four magnetic poles at the small radius of the quadrupole lens are provided with four magnetic pole mounting holes at the 90-degree uniform intervals of the outer rings of the positioning rings and 4 magnetic pole positioning holes at the 90-degree uniform intervals of the inner rings of the positioning rings, the diameters of the 4 magnetic pole positioning holes are 6 millimeters, and the magnetic pole positioning precision is 0.03 millimeter.

The magnetic pole positioning ring surrounding and connecting the four magnetic poles at the small radius of the quadrupole lens is made of brass with a non-magnetic-permeability material, and the magnetic pole positioning ring with the non-magnetic-permeability material is used for not influencing a magnetic field in a magnetic pole working state; the inner diameter of a beam pipeline hole of the magnetic pole positioning ring is larger than the outer diameter of a beam pipeline flange; the sum of the diameters of the magnetic pole mounting hole and the magnetic pole positioning pin hole of the magnetic pole positioning ring is required to be smaller than the difference between the outer diameter of the magnetic pole positioning ring and the inner diameter of the beam pipeline hole of the magnetic pole positioning ring; the thickness of the magnetic pole positioning ring is equal to the sum of the length of the positioning pin of the magnetic pole positioning ring and the depth of the positioning hole on the magnetic pole.

A method of installing a magnetic pole positioning ring, comprising the steps of:

firstly, measuring a magnetic field and determining a relative position before matching and punching a positioning pin hole: when the quadrupole lenses are assembled for the first time, firstly, the magnetic field of each group of quadrupole lenses is measured respectively, the magnetic pole positions of the quadrupole lenses are adjusted according to the magnetism measurement result, and when the magnetism measurement result meets the design requirement, the relative positions of the upper half quadrupole lens and the lower half quadrupole lens are determined;

step two, according to the determined relative position of the magnetic poles of the upper and lower quadrupole lenses, matching and punching the positioning pin holes of the outer ring and the inner ring of each group of quadrupole lenses, and installing the positioning pin holes of the outer ring and the inner ring: the positioning pin hole of the outer ring is a joint-riding pin hole on the magnetic yoke of the outer ring, and the positioning pin hole of the inner ring is a magnetic pole mounting hole and a magnetic pole positioning hole on the magnetic pole positioning ring of the inner ring;

step three, disassembling the quadrupole lens before installing the beam pipeline: when a beam pipeline is installed, the quadrupole lens matched and punched with the positioning pin holes is disassembled into an upper half part and a lower half part of the quadrupole lens, before the disassembly, two magnetic pole positioning rings on the front end face and the rear end face of each group of quadrupole lenses are firstly disassembled, and then a vacuum pipeline of the quadrupole lenses is placed on the lower half part of the quadrupole lenses;

step four, after the beam pipeline is installed, resetting the quadrupole lens by using a pin: resetting and assembling the upper half part of the quadrupole lens and the lower half part of the quadrupole lens which are disassembled before the beam pipeline is installed, respectively sleeving magnetic pole positioning rings at two ends of the beam pipeline if only one group of quadrupole lenses exist, moving each magnetic pole positioning ring to the magnetic pole position at the same side for installation and positioning, and respectively inserting four positioning pins of each magnetic pole positioning ring into positioning holes, thereby realizing the resetting of the magnetic pole position on the group of quadrupole lenses;

step five, resetting and assembling N (N is more than 1) quadrupole lens assemblies: sleeving a shared vacuum pipeline of N quadrupole lenses into 2N-2 magnetic pole positioning rings, wherein the 2N-2 magnetic pole positioning rings are all the other magnetic pole positioning rings except the magnetic pole positioning rings at two ends of the N quadrupole lenses, placing the shared vacuum pipeline of the N quadrupole lenses on the lower half parts of the N arranged quadrupole lenses, and the front, back and end faces of the N quadrupole lenses are removed, a magnetic pole positioning ring is respectively arranged on the front and back magnetic pole faces of each quadrupole lens, the upper half part of each quadrupole lens and the lower half part of each quadrupole lens are sequentially assembled, the two end faces of the beam pipeline are respectively sleeved with the magnetic pole positioning rings which are not installed, each magnetic pole positioning ring is moved to the adjacent magnetic pole for installation and positioning, and the four positioning pins of each magnetic pole positioning ring are respectively inserted into the positioning holes to realize the resetting of the magnetic pole position of each quadrupole lens.

Advantageous effects of the invention

The invention adopts the method of combining the rough positioning, the accurate positioning and the positioning at two ends of the magnetic pole of the quadrupole lens, so that the magnetic field uniformity error is improved from three per thousand to five per ten thousandth, and the quantity grade is improved! The uniformity of the magnetic field is improved by one order of magnitude, and the quality of the beam is improved by dozens of times. Specifically, three positioning methods are organically combined: the coarse positioning lays a foundation for the fine positioning, and the fine positioning does not exist without the foundation of the coarse positioning; the fine positioning makes up the deficiency of the coarse positioning, and the requirement of the magnetic field uniformity error cannot be met only if the coarse positioning does not have the fine positioning; the high-precision coaxiality of the magnetic field can not be realized because the thick positioning and the thin positioning only solve the problem of high-precision concentricity of the magnetic poles at one end face of the quadrupole lens, but if the magnetic poles at one end of the quadrupole lens are concentric and the magnetic poles at the other end are not concentric, namely the magnetic pole positioning ring is not arranged at the other end, the magnetic poles at the other end can not realize high-precision concentricity, and the high-precision coaxiality and the high-precision concentricity can be realized only if the magnetic poles at the end faces at the two ends of the quadrupole lens are all provided with the magnetic pole positioning rings. The invention obtains prominent substantive progress and remarkable effect by adopting the methods of rough positioning, accurate positioning, organic combination of positioning at two ends, mutual support and interdependence of the magnetic poles of the quadrupole lens.

Drawings

FIG. 1 is a front view of the assembly effect of a quadrupole lens with a retaining ring according to the present invention;

fig. 2 is a perspective view of a magnetic pole positioning ring for a quadrupole lens of the present invention:

fig. 3 is a schematic illustration of the magnetic pole positioning ring mounting for the first set of quadrupole lenses of the present invention:

fig. 4 is a perspective view of the assembly effect of a single set of quadrupole lenses with a retaining ring according to the present invention:

fig. 5 is a perspective view showing the assembly effect of the multi-group quadrupole lens with the positioning ring according to the present invention.

In the figure: 1-1: upper half of quadrupole lens, 1-2: lower half of quadrupole lens, 2-1: a first magnetic pole; 2-2: a second magnetic pole; 2-3: a magnetic pole III; 2-4: a fourth magnetic pole; 3: a magnetic pole positioning ring and 3-1 beam pipeline holes; 3-2, mounting holes; 3-3, positioning holes; 4: a bolt; 5: and a positioning pin.

Detailed Description

Design principle of the invention

Firstly, measuring a magnetic field and then positioning a pin hole. The pin holes comprise a seam-riding pin hole on the outer ring magnetic yoke and a positioning pin hole on the inner ring magnetic pole. After the upper half quadrupole lens and the lower half quadrupole lens are hoisted and aligned, firstly, whether the uniformity of a magnetic field formed by the upper half quadrupole lens and the lower half quadrupole lens reaches an index with an error not exceeding five ten-thousandths is measured, if the uniformity of the magnetic field does not reach the index, the relative position of the upper quadrupole lens and the lower quadrupole lens is moved through a crane, and the magnetic field is continuously measured until the uniformity of the magnetic field meets the index requirement, at the moment, the relative position between the upper half quadrupole lens and the lower half quadrupole lens, and the positions of the pin hole of the outer ring and the pin hole of the inner ring are determined. After the pin hole position is determined, a riding pin on the outer ring magnetic yoke and a magnetic pole mounting hole and a positioning hole on the inner ring magnetic pole positioning ring can be matched.

And secondly, disassembling the quadrupole lens before installing the beam pipeline. The uniformity of the measuring magnetic field can only be measured before the beam pipeline is installed, and once the beam pipeline is installed, the condition of the measuring magnetic field is not met, so that the beam pipeline can only be installed in a magnetic pole pore passage of the quadrupole lens after the magnetic field is measured. The installation method is that the upper half quadrupole lens is taken away, the beam pipeline is laid in a neutral position between two magnetic poles of the lower half quadrupole lens, and then the upper half quadrupole lens is installed, so that the beam pipeline is surrounded between gaps of the upper and lower four magnetic poles. Before the beam pipeline is installed, in order to measure a magnetic field and match pin holes, the upper half quadrupole lens is installed on the lower half quadrupole lens, and the dowel pin on the outer ring magnetic yoke and the positioning pin on the inner ring magnetic pole positioning ring are installed completely, so the installed quadrupole lens, the related pin and the magnetic pole positioning ring need to be disassembled before the beam pipeline is installed.

And thirdly, resetting the quadrupole lens by using a pin when the quadrupole lens is remounted. When the quadrupole lens is installed again after the beam pipeline is installed, the position of the beam pipeline blocks the position of the measuring magnetic field, and the condition of the measuring magnetic field is not available at this time, so a pin resetting method is required. In order to ensure that the original accuracy that the magnetic field uniformity error does not exceed five ten-thousandths can be achieved when the pin is reset, the invention adopts a method of internal and external combined reset and two-end combined reset, thereby realizing that each group of quadrupole lens magnetic poles can ensure strict coaxiality and strict concentricity:

the inner and outer combined reset is adopted, namely, the inner ring of the quadrupole lens is reset in a coarse granularity mode, and the outer ring of the quadrupole lens is reset in a fine granularity mode, wherein the outer ring of the quadrupole lens is reset in a coarse granularity mode; the fine-grained resetting of the inner ring is because the outer ring completes coarse-grained resetting when the fine-grained resetting is carried out, and a hoisting positioning method is not needed any more, so that the pin for positioning the small-radius inner ring can be made as thin as possible, and the positioning accuracy is higher as the pin is thinner, so that the resetting of the inner ring is fine-grained resetting. The method of combining inside and outside or combining thickness is adopted for resetting, so that high-precision concentricity of the magnetic poles after resetting is ensured; in the embodiment of the invention, the diameter of a dowel pin on the outer ring magnetic yoke is 8 mm, the coarse positioning precision is 0.1 mm, the positioning pin on the inner ring magnetic pole is 6 mm, and the positioning precision of the magnetic pole reaches 0.03 mm after the outer ring coarse positioning is combined with the inner ring fine positioning.

The method of combining two ends for resetting is characterized in that magnetic pole positioning rings are respectively arranged on the magnetic pole surfaces at the two ends of a group of quadrupole lenses, and because the magnetic pole positioning rings at the two ends simultaneously achieve the high concentricity of each magnetic pole surface, the connection line of the magnetic poles at the two ends is ensured to be parallel to the axis, thereby realizing the high-precision coaxiality of the magnetic poles during resetting.

Because the invention adopts the high-precision resetting method of combining the inner part and the outer part and combining the two ends when the quadrupole lens is reset, compared with the original method of resetting only by the outer ring dowel pin, the resetting precision is improved from 0.1 mm to 0.03 mm, the magnetic field uniformity error is improved from three thousandth to five ten thousandth, a quantity grade is improved, and the improvement of the quantity grade has important significance for the quality of the beam, because the magnetic field precision is improved by 0.1 mm, the quality of the beam can be improved by 25 times, which is the conclusion obtained by accurate calculation of beam dynamics.

Based on the inventive principle, the invention relates to a quadrupole lens assembly with a magnetic pole positioning ring.

A quadrupole lens assembly with a magnetic pole positioning ring is shown in fig. 1, fig. 2, fig. 3, fig. 4 and fig. 5, the quadrupole lens assembly is provided with four magnetic poles 2-1, 2-2, 2-3 and 2-4 which are uniformly spaced at 90 degrees in the circumferential direction near the small radius part, and a magnetic yoke which surrounds the outer sides of the four magnetic poles near the large radius part of the quadrupole lens assembly, a first-stage magnetic pole positioning mechanism 5 and a second-stage magnetic pole positioning mechanism 3 are respectively arranged on the front end surface and the rear end surface of the axial direction of the quadrupole lens assembly, the first-stage magnetic pole positioning mechanism is a left and a right two seam-riding pins 5 which are arranged at the joint of an upper half quadrupole lens and a lower half quadrupole lens, and the left and the right two seam-riding pins are used for roughly positioning the magnetic poles; the second-stage magnetic pole positioning mechanism 3 is two magnetic pole positioning rings 3 respectively connected with the magnetic poles at the small radiuses of the front and the rear end surfaces of each group of quadrupole lenses in a surrounding manner, the two magnetic pole positioning rings 3 are used for accurately positioning the magnetic poles 2-1, 2-2, 2-3 and 2-4 of the group of quadrupole lenses, so that the high-precision coaxiality and the high-precision concentricity of the magnetic poles 2-1, 2-2, 2-3 and 2-4 of the group of quadrupole lenses are realized, and the high-precision coaxiality and the concentricity reach 0.03 mm.

Supplementary explanation:

1. the boundary of the magnetic poles and the magnetic yokes is shown in figure 1, four magnetic yokes are arranged outside a circle line close to the small radius, four magnetic poles are arranged inside the circle line, the magnetic poles and the magnetic yokes are connected inside the quadrupole lens, the outer side of the quadrupole lens cannot be seen, and the internal connection schematic diagram of the four groups of magnetic poles and the magnetic yokes is shown in four dotted lines from the circle center to the large radius in figure 1.

2. The left and right groups of magnetic poles and magnetic yokes of the upper half quadrupole lens and the lower half quadrupole lens are pre-installed together through respective bolts 4 before hoisting, and the pin tops including the upper and lower riding seams are also installed before hoisting. A space is arranged between each group of adjacent magnetic poles and the magnetic yoke.

The diameters of the left and right dowel pins 5 at the butt joint of the upper half quadrupole lens 1-1 and the lower half quadrupole lens 1-2 are 8 mm, and the accuracy of positioning magnetic poles is 0.1 mm; the four-pole four-lens four-pole magnetic positioning structure is characterized in that a magnetic pole positioning ring 3 which is connected with four magnetic poles at the small radius of the four-pole lens in a surrounding mode is provided with four magnetic pole mounting holes 3-3 which are evenly spaced at 90 degrees on the outer ring of the positioning ring and 4 magnetic pole positioning holes 3-2 which are evenly spaced at 90 degrees on the inner ring of the positioning ring, the diameter of each 4 magnetic pole positioning hole 3-3 is 6 mm, and the magnetic pole positioning precision is 0.03 mm.

Supplementary explanation:

when the magnetic pole positioning ring is installed, the magnetic pole positioning ring 3 and the magnetic poles 2-1, 2-2, 2-3 and 2-4 are fixed through the magnetic pole installation hole 3-2 in the outer ring of the magnetic pole positioning ring 3, and the magnetic pole positioning pin 3-1 is needed to accurately position the magnetic poles due to certain amount of the magnetic pole installation hole.

The magnetic pole positioning ring 3 which surrounds and is connected with four magnetic poles at the small radius of the quadrupole lens is made of brass with a non-magnetic-permeability material, and the magnetic pole positioning ring with the non-magnetic-permeability material is used for not influencing a magnetic field in a magnetic pole working state; the inner diameter of a beam pipeline hole 3-1 of the magnetic pole positioning ring 3 is larger than the outer diameter of a beam pipeline flange; the sum of the diameters of a magnetic pole mounting hole 3-3 of the magnetic pole positioning ring 3 and a magnetic pole positioning pin hole 3-2 is required to be smaller than the difference between the outer diameter of the magnetic pole positioning ring and the inner diameter of a beam pipeline hole of the magnetic pole positioning ring; the thickness of the magnetic pole positioning ring 3 is equal to the sum of the length of the positioning pin of the magnetic pole positioning ring and the depth of the positioning hole on the magnetic pole.

A method of installing a magnetic pole positioning ring, comprising the steps of:

firstly, measuring a magnetic field and determining a relative position before matching and punching a positioning pin hole: when the quadrupole lenses are assembled for the first time, firstly, the magnetic field of each group of quadrupole lenses is measured respectively, the magnetic pole positions of the quadrupole lenses are adjusted according to the magnetism measurement result, and when the magnetism measurement result meets the design requirement, the relative positions of the upper half quadrupole lens and the lower half quadrupole lens are determined;

supplementary explanation:

when the quadrupole lens is assembled for the first time, in the quadrupole lens of fig. 1, only the longitudinal 2 seam-riding pin holes and pins of the upper half quadrupole lens and the lower half quadrupole lens are already laid, and all other pin holes and pins are not provided, and during magnetic measurement, the magnetic field uniformity is adjusted only according to the mutual positions of the upper half quadrupole lens and the lower half quadrupole lens, and the positions of the magnetic pole mounting holes and the magnetic pole positioning holes of the left and right 2 seam-riding pin holes and the middle magnetic pole positioning ring can be determined when the magnetic field uniformity meets the requirement.

Step two, according to the determined relative position of the magnetic poles of the upper and lower quadrupole lenses, matching and punching the positioning pin holes of the outer ring and the inner ring of each group of quadrupole lenses, and installing the positioning pin holes of the outer ring and the inner ring: the positioning pin hole of the outer ring is a joint-riding pin hole on the magnetic yoke of the outer ring, and the positioning pin hole of the inner ring is a magnetic pole mounting hole and a magnetic pole positioning hole on the magnetic pole positioning ring of the inner ring;

supplementary explanation:

after the magnetic field measurement meets the requirements, required pin holes can be matched according to the current positions of the upper half quadrupole lens and the lower half quadrupole lens, and meanwhile, all screws and pins are installed, including the left and right joint-riding pins on the outer ring magnetic yoke and the fixing screws and pins on the inner ring magnetic pole positioning ring.

Step three, disassembling the quadrupole lens before installing the beam pipeline: when a beam pipeline is installed, the quadrupole lens matched and punched with the positioning pin holes is disassembled into an upper half part and a lower half part of the quadrupole lens, before the disassembly, two magnetic pole positioning rings on the front end face and the rear end face of each group of quadrupole lenses are firstly disassembled, and then a vacuum pipeline of the quadrupole lenses is placed on the lower half part of the quadrupole lenses;

supplementary notes

Because the magnetic measurement and the matching of the installation pin conflict with the position of the beam pipeline, the beam pipeline cannot be installed when the magnetic measurement and the matching of the installation pin are carried out. However, after the magnetic field measurement and the installation pin matching are finished, a beam pipeline is also required to be installed, because the quadrupole lens is designed for the beam pipeline.

Step four, after the beam pipeline is installed, resetting the quadrupole lens by using a pin: as shown in fig. 4: resetting and assembling the upper half part of the quadrupole lens and the lower half part of the quadrupole lens which are disassembled before the beam pipeline is installed, respectively sleeving magnetic pole positioning rings at two ends of the beam pipeline if only one group of quadrupole lenses exist, moving each magnetic pole positioning ring to the magnetic pole position at the same side for installation and positioning, and respectively inserting four positioning pins of each magnetic pole positioning ring into positioning holes, thereby realizing the resetting of the magnetic pole position on the group of quadrupole lenses;

step five, resetting and assembling N (N is more than 1) quadrupole lens assemblies as shown in figure 5: sleeving a shared vacuum pipeline of N quadrupole lenses into 2N-2 magnetic pole positioning rings, wherein the 2N-2 magnetic pole positioning rings are all the other magnetic pole positioning rings except the magnetic pole positioning rings at two ends of the N quadrupole lenses, placing the shared vacuum pipeline of the N quadrupole lenses on the lower half parts of the N arranged quadrupole lenses, and the front, back and end faces of the N quadrupole lenses are removed, a magnetic pole positioning ring is respectively arranged on the front and back magnetic pole faces of each quadrupole lens, the upper half part of each quadrupole lens and the lower half part of each quadrupole lens are sequentially assembled, the two end faces of the beam pipeline are respectively sleeved with the magnetic pole positioning rings which are not installed, each magnetic pole positioning ring is moved to the adjacent magnetic pole for installation and positioning, and the four positioning pins of each magnetic pole positioning ring are respectively inserted into the positioning holes to realize the resetting of the magnetic pole position of each quadrupole lens.

The present embodiment is only for explaining the present invention, and it is not limited to the present invention, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present invention.