Heavy ion beam current shielding device for multi-wire drift chamber and manufacturing method thereof

Abstract

The application discloses a heavy ion beam shielding device for a multi-wire drift chamber and a manufacturing method thereof. The heavy ion beam shielding device comprises a first frame and a second frame. The first frame is provided with a first opening, and a first blocking film is fixedly covered on the first opening. The second frame is provided with a second opening, and a second blocking film is fixedly covered on the second opening. The first frame and the second frame are oppositely and fixedly arranged on two sides of a layer of anode wire layers of the multi-wire drift chamber. The first blocking film and the second blocking film cooperate to shield the anode wires between the first blocking film and the second blocking film. Compared with the prior art, the application can realize that the multi-wire drift chamber detector is not sensitive to the heavy ion beam in a local area, so that the anode wire channels in the area through which the beam passes are still sensitive to the secondary reaction products except the beam passing through, thereby improving the effective detection area of the detector and further improving the experimental precision.

Description

Technical Field

[0001] This invention relates to the field of multi-wire drift chamber technology, and more particularly to a heavy ion beam shielding device and its manufacturing method for a multi-wire drift chamber. Background Technology

[0002] A nuclear radiation detector is a component that detects nuclear radiation by utilizing the ionization effect, luminescence, and physical or chemical changes caused by nuclear radiation in gases, liquids, or solids. When charged particles pass through a medium, they interact with the medium, losing some energy by exciting bound electrons in atoms or by ionization. By measuring these interactions, a nuclear radiation detector can directly or indirectly determine parameters such as the type, energy, intensity, or nuclear lifetime of nuclear radiation.

[0003] In nuclear physics experiments, some reaction particles have small scattering angles, very close to the beam direction of the incident particles. To prevent the measurement of these small-angle particles from being affected by the incident beam, the detector needs to be placed outside the beam to avoid it. This leads to incomplete detection of reaction products, thus reducing experimental accuracy. Therefore, to improve experimental accuracy, a multi-wire drift chamber can be set up in the beam inflow direction to detect reaction products. However, under the detector's operating voltage, the beam passes directly through the detector, causing the anode wires to generate a high count rate and saturation signal, and even discharge, rendering the detector and electronics inoperable. This will cause all areas of dozens of anode wire channels in the beam-passing region to malfunction, reducing the effective detection area of ​​the detector and thus lowering experimental accuracy. Especially for multi-wire drift chambers used for high-precision three-dimensional track measurements, which include at least a dozen layers of anode wires, this will prevent hundreds of channels from detecting charged particle tracks. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a heavy ion beam shielding device and manufacturing method for a multi-wire drift chamber. This device enables the detector in the multi-wire drift chamber to be locally insensitive to heavy ion beams, while the anode wire channel in the beam-passing area remains sensitive to secondary reaction products in areas other than where the beam passes through. This increases the effective detection area of ​​the detector and thus improves experimental accuracy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a heavy ion beam shielding device for a multi-wire drift chamber, comprising:

[0007] A first frame, having a first opening, with a first barrier film fixedly covering the first opening;

[0008] A second frame, having a second opening, with a second barrier film fixedly covering the second opening;

[0009] The first frame and the second frame are fixedly disposed on both sides of a layer of anode wire in the multi-wire drift chamber, and the first barrier film and the second barrier film cooperate to shield the anode wire between them.

[0010] Preferably, the first barrier film and the second barrier film are mylar films.

[0011] Preferably, the first frame and the second frame are made of FR-4 substrates made of glass cloth and epoxy resin.

[0012] Preferably, the first frame and the second frame are in the shape of an annulus.

[0013] Preferably, the first frame is provided with a plurality of first pads, and the first pads are connected to the field wires of the anode wire layer to fix the first frame.

[0014] Preferably, the second frame is provided with a plurality of second pads, the second pads are connected to the field wires of the anode wire layer to fix the second frame, and the first frame has a plurality of clearance positions corresponding to the second pads.

[0015] Preferably, the first pad and the second pad are copper pads.

[0016] In a second aspect, the present invention provides a method for manufacturing a heavy ion beam shielding device as described in the first aspect above, comprising the following steps:

[0017] A single sheet of barrier membrane is stretched using a membrane stretching platform;

[0018] The first frame and the second frame are respectively fixedly connected to the barrier membrane;

[0019] Cut the first frame and the second frame, along with the barrier film fixedly covering the first opening and the second opening, from the whole piece of barrier film along the edges of the first frame and the second frame, respectively.

[0020] The first frame and the second frame are fixedly connected to both sides of an anode wire layer in the multi-wire drift chamber, so that the blocking membranes on the first opening and the second opening cooperate to block both sides of the anode wire in the anode wire layer.

[0021] Preferably, when the multi-filament drift chamber is provided with multiple layers of anode wires, multiple first frames and second frames can be fabricated respectively, and the anode wires of each anode wire layer can be shielded by the first frames and second frames.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention provides a blocking film on both sides of the corresponding anode wire layer region through which the beam passes in a multi-wire drift chamber. The blocking film prevents the primary electrons generated by ionization when the beam passes through the detector from drifting to the vicinity of the anode wire, thus avoiding avalanche amplification of electrons and preventing the anode wire from responding to the beam. This allows the multi-wire drift chamber to partially shield the heavy ion beam, making the detector insensitive to the heavy ion beam in certain areas. This ensures that the anode wire channel in the beam-passing region remains sensitive to secondary reaction products, thereby increasing the effective detection area of ​​the detector and improving experimental accuracy. Attached Figure Description

[0024] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. It should be noted that in all the drawings, the elements or parts are not necessarily drawn to actual scale.

[0025] Figure 1 This is a schematic diagram of the overall structure of the heavy ion beam shielding device for a multi-wire drift chamber as described in an embodiment of the present invention;

[0026] Figure 2 This is a schematic diagram of the overall structure of the first frame of the heavy ion beam shielding device for a multi-wire drift chamber according to an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the overall structure of the second frame of the heavy ion beam shielding device for a multi-wire drift chamber according to an embodiment of the present invention;

[0028] Figure 4 The figure shows the experimental results for verifying the shielding effect of the heavy ion beam shielding device for the multi-wire drift chamber described in this embodiment of the invention.

[0029] In the picture:

[0030] 1. First frame; 11. First barrier film; 12. First pad; 13. Clearance space; 2. Second frame; 21. Second barrier film; 22. Second pad; 3. Anode wire; 4. Field wire. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0032] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the system or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., used to define components are merely for the convenience of distinguishing the aforementioned components. Unless otherwise stated, these terms have no special meaning and should not be construed as indicating or implying relative importance.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0034] In nuclear physics experiments, multi-wire drift chambers are typically used to detect reaction products from particles with relatively small scattering angles, positioned along the beam's trajectory. However, under the detector's operating voltage, the beam passes directly through the multi-wire drift chamber, causing the anode filaments to generate high count rates and saturation signals, and even discharge, rendering the detector or electronics inoperable. This results in all areas of the dozens of anode filament channels in the beam-passing region malfunctioning, reducing the detector's effective detection area and thus lowering experimental accuracy. Therefore, this invention provides a heavy ion beam shielding device and its fabrication method for a multi-wire drift chamber. This device enables localized insensitivity of the multi-wire drift chamber detector to the heavy ion beam, while ensuring that the anode filament channels outside the beam-passing region remain sensitive to secondary reaction products, thereby increasing the detector's effective detection area and ultimately improving experimental accuracy.

[0035] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0036] like Figures 1-3 As shown, this embodiment of the invention provides a heavy ion beam shielding device for a multi-wire drift chamber, comprising:

[0037] A first frame 1, the first frame 1 having a first opening, and a first barrier film 11 fixedly covering the first opening;

[0038] The second frame 2 has a second opening, and a second barrier membrane 21 is fixedly covered on the second opening.

[0039] The first frame 1 and the second frame 2 are fixedly disposed on both sides of a layer of anode wire in the multi-wire drift chamber. The first barrier film 11 and the second barrier film 21 cooperate to shield the anode wire 3 between them.

[0040] In this embodiment of the invention, the anode wire layer region through which the heavy ion beam passes can be correspondingly set in the multi-wire drift chamber. The blocking film shields the anode wire 3, preventing the primary electrons generated by ionization when the beam passes through the detector from drifting to the vicinity of the anode wire 3, thus avoiding avalanche amplification of electrons and preventing the anode wire 3 from responding to the beam. This allows the multi-wire drift chamber to partially shield the heavy ion beam, while the anode wire 3 channel in the beam-passing area remains sensitive to secondary reaction products in areas other than where the beam passes through, thereby increasing the effective detection area of ​​the detector and improving experimental accuracy.

[0041] It is understood that, since different types and energies of heavy ion beams have different deflection radii in a magnetic field, the locations that need to be shielded in a multi-filament drift chamber are different. The shape, size, and placement of the first frame 1, the second frame 2, and the blocking membrane in this embodiment can be set according to actual needs, and the present invention does not limit this.

[0042] Preferably, the first blocking film 11 and the second blocking film 21 are mylar films. Mylar films are insulating materials with good ductility, can be stretched flat, and can be made to a thickness of several micrometers, or even less than 1 micrometer. They deposit less energy when a beam passes through and have a long service life. Of course, in other embodiments of the present invention, the first blocking film 11 and the second blocking film 21 can also be made of other film materials that can block primordial electrons.

[0043] Preferably, the first frame 1 and the second frame 2 are made of FR-4 substrates made of glass cloth and epoxy resin.

[0044] It should be noted that in some other embodiments of the present invention, the first frame 1 and the second frame 2 may also be made of other types of materials, such as FR-1 substrate (phenolic paper), FR-3 substrate (paper, epoxy resin), CEM-1 substrate (cotton paper, epoxy resin) and CEM-3 substrate (glass cloth, epoxy resin) and other types of substrates.

[0045] Furthermore, the first frame 1 and the second frame 2 are in the shape of a ring. It is understood that in some other embodiments, the shapes of the first frame 1 and the second frame 2 can be set according to actual factors such as the type of heavy ion beam, for example, they can be set as square rings, elliptical rings, etc.

[0046] Specifically, such as Figure 2 and Figure 3 The first frame 1 is provided with a plurality of first pads 12, the first pads 12 are connected to the field wires 4 of the anode wire layer to fix the first frame 1, the second frame 2 is provided with a plurality of second pads 22, the second pads 22 are connected to the field wires 4 of the anode wire layer to fix the second frame 2, the first frame 1 has a plurality of first clearance positions 13 corresponding to the second pads 22, and the second frame 2 has a plurality of second clearance positions 13 corresponding to the first pads 12.

[0047] In this embodiment, during the fixing process, the first frame 1 can be welded and fixed to the field wire 4 of the anode wire layer from one side of the anode wire layer through the first pad 12. Then, the second frame 2 can be welded and fixed to the field wire 4 of the anode wire layer from the other side of the anode wire layer through the clearance position 13 and the second pad 22. Thus, the first frame 1 and the second frame 2 are fixed to the two sides of the anode wire layer, and the blocking film on the first frame 1 and the second frame 2 blocks the anode wire 3 in the beam passing area.

[0048] Preferably, the first pad 12 and the second pad 22 are copper pads. Of course, in other embodiments of the present invention, the first pad 12 and the second pad 22 may also be pads of other materials.

[0049] It should be noted that the first frame 1 and the second frame 2 of the present invention are not limited to being fixed by the welding method described above. In some other embodiments, they can also be fixed by other fixing methods such as bonding.

[0050] In one embodiment of the present invention, the shielding effect of the present invention embodiment was verified using a 55Fe radioactive source. The specific verification process is as follows: the collimated 55Fe radioactive source was sequentially irradiated into the shielded area and the unshielded area of ​​the anode wire 3, and the response (i.e., count rate) of different areas to the 55Fe radioactive source was tested. The detector was subjected to noise reduction processing, and the noise was reduced to a reasonable level. The count threshold was set slightly higher than the noise level.

[0051] The verification results are as follows Figure 4 As shown, by Figure 4 It can be seen that the embodiments of the present invention have a good shielding effect.

[0052] Example 2

[0053] This invention provides a method for manufacturing a heavy ion shielding device for a multi-wire drift chamber as described in Embodiment 1, comprising the following steps:

[0054] Step 1: Use a membrane stretching platform to stretch a whole sheet of barrier membrane;

[0055] Step 2: Fix the first frame 1 and the second frame 2 onto the barrier membrane respectively;

[0056] Step 3: Cut the first frame 1 and the second frame 2, along with the barrier film fixed to cover the first opening and the second opening, from the whole barrier film along the edges of the first frame 1 and the second frame 2 respectively.

[0057] Step 4: Fix the first frame 1 and the second frame 2 to both sides of the anode wire layer of the multi-wire drift chamber so that the blocking films on the first opening and the second opening can block both sides of the anode wire 3 of the anode wire layer.

[0058] Specifically, in step two, the first frame 1 and the second frame 2 can be fixedly connected to the barrier membrane by means of epoxy adhesive or other methods. In step four, the method for fixing the first frame 1 and the second frame 2 to both sides of a layer of anode wire in the multi-wire drift chamber is as follows:

[0059] First, the first frame 1 is welded and fixed to the field wire 4 of the anode wire layer from one side of the anode wire layer through the first pad 12. Then, the second frame 2 is welded and fixed to the field wire 4 of the anode wire layer from the other side of the anode wire layer through the clearance position 13 and the second pad 22.

[0060] It is understandable that when the multi-filament drift chamber is provided with multiple layers of anode wires, multiple first frames 1 and second frames 2 can be made respectively, and the anode wires 3 of each anode wire layer can be shielded by the first frames 1 and the second frames 2.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for fabricating a heavy ion beam shielding device, used to fabricate a heavy ion beam shielding device for a multi-wire drift chamber, the heavy ion beam shielding device for the multi-wire drift chamber comprising: A first frame (1) has a first opening, and a first barrier film (11) is fixedly covered on the first opening; The second frame (2) has a second opening, and a second barrier film (21) is fixedly covered on the second opening; The first frame (1) and the second frame (2) are fixedly disposed on both sides of a layer of anode wire in the multi-wire drift chamber. The first barrier film (11) and the second barrier film (21) cooperate to shield the anode wire (3) between them. Wherein, the first barrier film (11) and the second barrier film (21) are mylar films; The first frame (1) and the second frame (2) are made of FR-4 substrates made of glass cloth and epoxy resin; The first frame (1) and the second frame (2) are in the shape of a ring; The first frame (1) is provided with a plurality of first pads (12), and the first pads (12) are connected to the field wires (4) of the anode wire layer to fix the first frame (1); The second frame (2) is provided with a plurality of second pads (22), the second pads (22) are connected to the field wires (4) of the anode wire layer to fix the second frame (2), and the first frame (1) has a plurality of first clearance positions (13) corresponding to the second pads (22); The first pad (12) and the second pad (22) are copper pads; Its characteristic is that it includes the following steps: Step 1: Use a membrane stretching platform to stretch a whole sheet of barrier membrane; Step 2: Fix the first frame (1) and the second frame (2) to the barrier membrane respectively; Step 3: Cut the first frame (1) and the second frame (2) together with the barrier film fixedly covering the first opening and the second opening from the whole piece of barrier film along the edges of the first frame (1) and the second frame (2) respectively; Step 4: Fix the first frame (1) and the second frame (2) to both sides of the anode wire layer of the multi-wire drift chamber so that the blocking film on the first opening and the second opening can block both sides of the anode wire (3) of the anode wire layer. When the multi-filament drift chamber is provided with multiple layers of anode wires, multiple first frames (1) and second frames (2) can be made respectively, and the anode wires (3) of each anode wire layer can be shielded by the first frames (1) and second frames (2).

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