CN112558137B - A beam transverse and longitudinal detector device based on ceramic vacuum tube - Google Patents

Abstract

The invention relates to a beam transverse and longitudinal detector device based on a ceramic vacuum pipeline, which comprises: the device comprises a ceramic vacuum pipeline, a periodic annular slotting unit, a 16-path broadband combiner unit and a detector bracket for supporting the components; two ends of the ceramic vacuum pipeline are respectively connected with the existing annular accelerator and used for providing a channel for beam current; the periodic annular slotting unit is sleeved on the outer surface of the ceramic vacuum pipeline and is internally provided with a plurality of electrodes for inducing beams passing through the ceramic vacuum pipeline; the 16-path broadband combiner unit is arranged outside the periodic annular slotting unit, is connected with each electrode arranged inside the periodic annular slotting unit, and is used for adding and synthesizing induction signals of the electrodes to obtain correction signals and outputting the correction signals to a subsequent particle correction system. The invention can be widely applied to the field of beam cooling or beam feedback of the heavy ion beam (including proton beam) annular accelerator.

Description

A beam transverse and longitudinal detector device based on ceramic vacuum tube

technical field

The invention relates to a beam transverse and longitudinal detector device based on a ceramic vacuum pipe, belonging to the field of beam cooling or beam feedback of a heavy ion beam (including a proton beam) annular accelerator.

Background technique

The beam stochastic cooling technology uses a broadband microwave feedback system to cool the beam. The beam detector located upstream of the beam detects a radio frequency signal proportional to the particle deviation. The output signal is filtered, delayed, phase-shifted and After the amplification system is added to the downstream impactor, the particles are corrected proportional to the deviation on the impactor, so as to achieve the purpose of cooling. Of course this requires that the correction signal arrives at the impactor in synchrony with the particles. The random cooling system is mainly composed of beam transverse and longitudinal detectors, low noise amplifiers, microwave bridges, filters, phase shifters, variable attenuators, phase equalizers, adjustable delay lines, power amplifiers and impactors. Among them, the beam transverse and longitudinal detector is one of the core components of the stochastic cooling hardware system, which is located at the front end of the stochastic cooling system. Its pros and cons directly affect the working efficiency of the stochastic cooling system.

The beam transverse and longitudinal detector structures of stochastic cooling systems can be divided into traveling wave structures and standing wave (resonant) structures. One of the most important specifications of this beam detector structure is the shunt impedance, which represents the efficiency of the structure. Among them, the shunt impedance of the traveling wave structure is proportional to the square of the total length of the structure along the beam direction, such as a periodically slotted coaxial structure. The maximum characteristic of such a structure requires the phase velocity of the polar plate and the Beta value of the beam. The shunt impedance of the standing wave structure is proportional to the total length of the structure along the beam direction, and a typical standing wave (resonant) structure includes a resonant cavity similar to a Pillbox. Most of the beam detectors of the stochastic cooling system currently in operation have the disadvantages of complex structure and low shunt impedance. For example, the beam detector of the stochastic cooling system of the CERN With the super-electrode quarter-wavelength microstrip line structure, the total longitudinal shunt impedance of the two-meter-long structure is only 1600Ω, that is, 800Ω/m.

SUMMARY OF THE INVENTION

In view of the above-mentioned problems, the purpose of the present invention is to provide a beam transverse and longitudinal detector device based on a ceramic vacuum pipe, the detector has high shunt impedance, is suitable for 350° high temperature and ultra-high vacuum baking, and has installation, operation The advantages of simple and reliable maintenance, etc., can solve the deficiencies in the prior art.

In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: a beam horizontal and vertical detector device based on a ceramic vacuum pipe, which includes: a ceramic vacuum pipe, a periodic annular slotting unit, a wide-band combiner unit, and a support unit for supporting The detector bracket of the above components; the two ends of the ceramic vacuum pipe are respectively connected to the annular accelerator to provide a channel for the beam; the periodic annular slotted unit is sleeved on the outer surface of the ceramic vacuum pipe, and the inner There are several electrodes for inducing the beam current passing through the ceramic vacuum tube; the broadband combiner unit is arranged outside the periodic annular slotted unit, and is arranged inside the periodic annular slotted unit Each of the electrodes is connected to each other, and is used for adding and synthesizing the induction signals of the electrodes to obtain a correction signal, which is output to the subsequent particle correction system.

Further, the ceramic vacuum pipe includes an alumina ceramic pipe, the inner surface of the alumina ceramic pipe is provided with a TiN coating layer, and the two ends of the alumina ceramic pipe are respectively connected to the first end face flange and the second end face flange through two kovars. The end face flanges are welded, and the first end face flange and the second end face flange are connected with other elements in the annular accelerator.

Further, the alumina ceramic pipes are made of 96%-99% AI ₂ O ₃ ceramics, the relative permittivity is 9.6-9.8, and the loss tangent is 0.01-0.03%.

Further, the wall thickness of the alumina ceramic pipe is 5-10mm, and the pipe diameter of the alumina ceramic pipe is 1-3mm larger than the size of the beam pipe that requires the smallest beam dynamics; the thickness of the TiN coating layer is 1-3 mm. -10nm.

Further, the periodic annular slotted unit includes two identical half annular slotted units, the outer edges of the two semi annular slotted units together form a regular octagonal structure, and the two half annular slotted units together form a regular octagonal structure. The inner edges of the units together form a circular structure, and two adjacent sides of the two semi-annular slotted units are provided with screw holes for fixing by bolts to form a surrounding on the outer surface of the alumina ceramic pipe The inner side of the two semi-annular slotted units is provided with a slotted structure, and the two slotted structures are evenly provided with a total of 8 electrodes from the first to the eighth, and the first electrode is located in one of the At the upper end of the slotted structure, other electrodes are distributed in the middle of the other sides of the regular octagon in turn counterclockwise, and are drawn out through the end needles arranged on the outer sidewall of the semi-annular slotted unit, and then connected with the wide-band combiner. units are connected.

Further, the height of the groove height of the grooved structure is half of the height of the outer side of the semi-annular grooved unit.

Further, the characteristic impedance of the microstrip line formed by each of the electrodes and the half-ring slotted unit is 50Ω.

Further, each of the electrodes is made of copper gold-plated material.

Further, the broadband combiner unit adopts a 16-channel broadband combiner, and the 16-channel broadband combiner includes a 16-channel broadband combiner and a combiner base plate; each of the combiner base plates is respectively fixed on the on each side of the octagon of the periodic annular slotted unit, and the ends of each of the combiner base plates are respectively connected with each electrode of the periodic annular slotted unit, and the head end of each of the combiner base plates They are respectively connected with one end of each of the wideband combiners, and the other end of each of the wideband combiners is connected with the detector support.

Further, the 16-channel broadband combiner unit is implemented by two-stage cascaded Wilkinson power dividers/combiners.

Further, the 16-channel broadband combiner unit obtains vertical, horizontal and vertical correction signals by performing sum-difference operation processing on the induction signals of the upper electrodes of each of the half-ring slotted units, and the calculation formula is as follows:

Longitudinal signal=first electrode+second electrode+...+eighth electrode

Vertical signal=(first electrode+second electrode)-(fourth electrode+fifth electrode)

Horizontal signal=(second electrode+third electrode)-(sixth electrode+seventh electrode)

Further, the detector bracket includes two detector bracket semicircular structures, four vertical rods and an italic part of the detector bracket; the inner walls of the two detector bracket semicircular structures are provided with each of the 16-channel broadband combiner units. The matching groove of the broadband combiner is used to connect with each of the broadband combiners; one of the lower parts of the semicircular structure of the detector support is connected with the two vertical rods respectively, and the other semicircular structure of the detector support The lower part is respectively connected with the other two vertical rods; the italic part of the detector bracket includes a detection clip bracket italic body and two fixing structures arranged on the upper surface of the detector bracket italic body, wherein one of the fixing structures is used for connecting with the two said fixing structures. The lower ends of the vertical rods are fixedly connected, and the other fixed structure is used for fixed connection with the lower ends of the other two vertical rods.

Further, the inclination angle range of the italic body of the detection clip bracket is 30°-60°.

Due to the adoption of the above technical solutions, the present invention has the following advantages: 1. The present invention introduces a ceramic vacuum pipe into the beam transverse and longitudinal detection device, which can effectively improve the shunt impedance of the beam detector. 2. The present invention makes the structure of the beam detector located outside the vacuum pipe by introducing a ceramic vacuum pipe, which is suitable for 350° high temperature and ultra-high vacuum baking, and has the advantages of simple and reliable installation, operation and maintenance, and can be widely used in heavy ion beam ( Including proton beams) in the field of stochastic cooling of toroidal accelerator beams. 3. In the present invention, a periodic annular slotting unit is arranged outside the ceramic vacuum pipe, and the shunt impedance of the detector is effectively improved by adjusting the slot width of the slotted structure and the wall thickness of the ceramic vacuum pipe. The invention can be widely used in the fields of beam cooling or beam feedback in a heavy ion beam annular accelerator.

Description of drawings

1 is a schematic diagram of the overall closure of the horizontal and vertical detector device based on a ceramic vacuum pipe beam in the present invention;

2 is a schematic diagram of the overall opening of the horizontal and vertical detector device based on the ceramic vacuum pipe beam in the present invention;

Fig. 3 is the schematic diagram of ceramic vacuum pipeline in the present invention;

Fig. 4 is a schematic diagram of a periodic annular slotting unit composed of two half-ring slotting units in the present invention;

5 is a schematic diagram of a half-ring type slotted unit in the present invention;

Fig. 6 is a longitudinal shunt impedance simulation result diagram of a periodic annular slotted unit in the present invention (unit longitudinal length is 13.5mm, inner diameter of ceramic pipe is 118mm);

Fig. 7 is the simulation result diagram of the total longitudinal shunt impedance of 74 periodic annular slotted units (the total longitudinal length is 1m, and the inner diameter of the ceramic pipe is 118mm) in the present invention;

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings. It should be understood, however, that the accompanying drawings are provided only for a better understanding of the present invention, and they should not be construed to limit the present invention.

As shown in FIG. 1 , FIG. 2 , FIG. 3 , FIG. 4 and FIG. 5 , the present invention provides a beam transverse and longitudinal detector device based on a ceramic vacuum pipe, including a ceramic vacuum pipe 1 and a periodic annular slotting unit 2 , a 16-channel broadband combiner unit 3 and a detector bracket 4 for supporting the above components. Among them, the two ends of the ceramic vacuum pipe 1 are respectively connected with other components in the annular accelerator, which are used for beam current to pass through and improve the shunt impedance of the detector; the periodic annular slotting unit 2 is sleeved on the outer surface of the ceramic vacuum pipe 1 , which is provided with several electrodes for sensing the beam current information passing through the ceramic vacuum tube 1; the 16-channel broadband combiner unit 3 is arranged outside the periodic annular slotting unit 2, and is connected with the periodic annular slotting unit 2. The electrodes set in the unit 2 are connected to each other, and are used to add and synthesize the induction signals of each electrode to obtain a correction signal and output, and the correction signal is added to the downstream impactor after filtering, delaying, phase shifting and amplifying system. The particles are corrected proportional to the deviation on the impactor, thereby achieving cooling.

Further, as shown in FIG. 3 , the ceramic vacuum pipe 1 includes an alumina ceramic pipe 106 , the inner surface of the alumina ceramic pipe 106 is provided with a TiN coating layer 104 , and the two ends of the alumina ceramic pipe 106 are respectively connected with the Kovar 103 and the Kovar 105 . The first end face flange 101 and the second end face flange 102 are welded, and the first end face flange 101 and the second end face flange 102 are used to connect with other elements in the ring accelerator such as bellows or stainless steel vacuum pipes.

Further, the alumina ceramic pipe 106 is made of 96%-99% AI ₂ O ₃ ceramics, the relative permittivity is 9.6-9.8, and the loss tangent is 0.01-0.03%.

Further, the wall thickness of the alumina ceramic pipe 106 is 5-10mm, and the diameter of the alumina ceramic pipe 106 is 1-3mm larger than the size of the beam pipe that requires the smallest beam dynamics to prevent the beam from hitting the inner wall of the ceramic pipe. ; The thickness of the TiN coating layer 104 is about 1-10 nm, and its main purpose is to release the electrostatic charge induced by the beam current.

Further, as shown in FIG. 4 and FIG. 5 , the periodic annular slotting unit 2 includes two identical semi-annular slotted units, and the outer edges of the two semi-annular slotted units jointly form a regular octagonal structure. The inner edges of the semi-annular slotted units together form a circular structure, and two adjacent outer surfaces of the two semi-annular slotted units are provided with screw holes 212 for fixing by bolts to form a surrounding aluminum oxide ceramic pipe. 106 Torus on the outer surface. Wherein, the inner side of the two half annular slotted units are provided with a slotted structure 211, and eight electrodes 201-208 are evenly arranged on the two slotted structures 211, so that each electrode is located at the center of each side of the regular octagonal structure , and is connected with the 16-channel broadband combiner unit 3 after being drawn out through the terminal needle 209 arranged on the outer side wall of the semi-annular slotted unit.

As shown in FIG. 6 and FIG. 7 , after simulation analysis, the lateral slot width of the slotted structure 211 determines the resonance frequency corresponding to the peak value of the shunt impedance. When the lateral slot width of the slotted structure 211 increases, the peak value of the shunt impedance corresponds to The resonant frequency of the shunt decreases. When the transverse slot width of the slotted structure 211 is 33mm and the wall thickness of the alumina ceramic pipe is 8mm, the resonant frequency corresponding to the peak value of the shunt impedance is about 0.95GHz, and when beta=0.83, the longitudinal split The circuit impedance is 4000Ω/m, which is five times higher than the beam detector shunt impedance of the CERN Antiproton Decelerator (AD) random cooling system.

Further, the height of the groove height 210 of the grooved structure 211 is half the height of the outer side of the semi-annular grooved unit.

Further, the characteristic impedance of the microstrip line formed by the electrodes 201 to 208 and the semi-annular slotted unit is 50Ω.

Further, the electrodes 201-208 are made of copper gold-plated material to reduce insertion loss.

Further, as shown in FIG. 2 , the 16-channel broadband combiner unit 3 includes a 16-channel broadband combiner 301 and a combiner base plate 302 . Wherein, each combiner base plate 302 is respectively fixed on each side of the regular octagon at the outer edge of the periodic annular slotting unit 2 , and the ends of each combiner base plate 302 are respectively connected with each electrode of the periodic annular slotting unit 2 . The first end of each combiner base plate 302 is connected to one end of each broadband combiner 301 respectively, and the other end of each broadband combiner 301 is connected to the detector bracket 4 .

Further, the connection between the electrodes 201 to 208 and each combiner base plate 302 in the 16-channel broadband combiner unit 3 adopts a crimping method.

Further, as shown in FIG. 2 , the detector bracket 4 includes two detector bracket semicircular structures 401 to 402 , vertical rods 405 to 408 and italic parts of the detector bracket. Among them, the inner walls of the semicircular structures 401 and 402 of the detector brackets are provided with grooves that match the wideband combiners 301 in the 16-channel wideband combiner unit 3, and are used to connect with the wideband combiners 301; the detector brackets The lower part of the semicircular structure 401 is respectively connected with the vertical rods 405 and 406, and the lower part of the semicircular structure 402 of the detector bracket is connected with the vertical rods 407 and 408 respectively; There are fixed structures 403 and 404; wherein, the fixed structure 403 is used for fixed connection with the lower ends of the vertical rods 405 and 406; the fixed structure 404 is used for fixed connection with the lower ends of the vertical rods 407 and 408.

Further, the inclination angle of the italic body of the detector bracket is in the range of 30°-60°, and is preferably 45° in the present invention.

Further, the 16-channel broadband combiner unit 3 is implemented by two-stage cascaded Wilkinson power dividers/combiners.

Further, the 16-channel broadband combiner unit 3 is used to realize the function of adding and synthesizing the induction signals of the electrodes. The vertical, horizontal and vertical correction signals can be obtained by sum-difference processing of the induction signals of the electrodes on each half-ring slotted unit. The calculation formula is as follows:

1) Vertical signal = electrode 201 + electrode 202 + electrode 203 + electrode 204 + electrode 205 + electrode 206 + electrode 207 + electrode 208

2) Vertical signal=(electrode 201+electrode 208)-(electrode 204+electrode 205)

3) Horizontal signal=(electrode 202+electrode 203)-(electrode 206+electrode 207)

The specific use process of the ceramic vacuum pipeline beam transverse and longitudinal detector device proposed by the present invention is as follows:

Firstly, the ceramic vacuum pipe 1 is installed at the position of the beam line pipe where the random cooling detector of the toroidal accelerator is located, and then the detector support 4 includes the semicircular structures 401-402 of the detector support, the vertical rods 405-408 and the italic part 403 of the detector support ～404 are installed in place. The specific installation sequence is to install the italic parts 403 to 404 of the detector bracket first, then install the vertical rods 405 to 408, then install the semicircular structures 401 to 402 of the detector bracket, and finally slot the installed periodic ring. The unit 2 and the 16-channel broadband combiner unit 3 are fixed on the semicircular structures 401-402 of the detector brackets, so that they are finally closed to form an overall annular structure of the detector.

When the beam passes through the beam pipe, the periodic annular slotting unit 2 collects the beam information in the pipe, uses the 16-channel broadband combiner unit 3 to add and synthesize the electrode induction signals, The induction signals of the electrodes on the slotted unit are processed by sum-difference operation to obtain vertical, horizontal and vertical correction signals. The output correction signals are added to the downstream impactor after filtering, delaying, phase shifting and amplifying systems. The correction proportional to the deviation is obtained on the device, so as to achieve the purpose of cooling.

The above-mentioned embodiments are only used to illustrate the present invention, and the structure, connection method and manufacturing process of each component can be changed to some extent. Any equivalent transformation and improvement based on the technical solution of the present invention should not be used. Excluded from the scope of protection of the present invention.

Claims (11)

1. A beam transverse and longitudinal detector device based on ceramic vacuum pipes, characterized in that, comprising: Ceramic vacuum pipes, periodic annular slotted units, broadband combiner units, and detector brackets for supporting the above components; Both ends of the ceramic vacuum pipe are respectively connected with the existing annular accelerator, and are used for providing a channel for the beam; Wherein, the ceramic vacuum pipe includes an alumina ceramic pipe, the inner surface of the alumina ceramic pipe is provided with a TiN coating layer, and the two ends of the alumina ceramic pipe are respectively connected to the first end face flange and the second end face flange through two kovars. The end face flange is welded, and the first end face flange and the second end face flange are connected with other elements in the annular accelerator; The periodic annular slotted unit is sleeved on the outer surface of the ceramic vacuum pipe, and a plurality of electrodes for inducing the beam passing through the ceramic vacuum pipe are arranged therein; Wherein, the periodic annular slotted unit includes two identical half annular slotted units, the outer edges of the two half annular slotted units jointly form a regular octagonal structure, and the two half annular slotted units The inner edges of the slotted units together form a circular structure, and two adjacent sides of the two half-ring slotted units are provided with screw holes, which are used for fixing by bolts to form a surrounding area of the alumina ceramics. A ring on the outer surface of the pipe; The inner sides of the two semi-ring type slotted units are both provided with a slotted structure, and the two slotted structures are evenly provided with a total of eight electrodes from the first to the eighth, and the first electrode is located in one of the slotted structures. The other electrodes are distributed in the middle of the other sides of the regular octagon in turn counterclockwise, and are drawn out through the end needles arranged on the outer sidewall of the half-ring slotted unit, and then connected to the broadband combiner unit. ; The broadband combiner unit is arranged outside the periodic annular slotting unit, and is connected to each of the electrodes arranged inside the periodic annular slotting unit, and is used to add the induction signals of the electrodes The correction signal is synthesized and output to the subsequent particle correction system. 2 . The beam-flow transverse and longitudinal detector device based on ceramic vacuum pipes according to claim 1 , wherein the alumina ceramic pipes are made of 96%-99% AI ₂ O ₃ ceramics, which are relatively medium. 3 . The electric constant is 9.6-9.8, and the loss tangent is 0.01-0.03%. 3 . The beam-flow transverse and longitudinal detector device based on ceramic vacuum pipes according to claim 1 , wherein the wall thickness of the alumina ceramic pipe is 5-10 mm, and the pipe diameter of the alumina ceramic pipe is 5-10 mm. 4 . It is 1-3mm larger than the size of the beam pipeline with the smallest beam dynamic requirements; the thickness of the TiN coating layer is 1-10nm. 4 . The beam transverse and longitudinal detector device based on a ceramic vacuum tube according to claim 1 , wherein the height of the groove of the grooved structure is half of the height of the outer side of the half-ring grooved unit. 5 . . 5 . The device of claim 1 , wherein the characteristic impedance of the microstrip line formed by each of the electrodes and the half-ring-shaped slotted unit is 50Ω. 6 . 6 . The device of claim 1 , wherein each of the electrodes is made of gold-plated copper material. 7 . 7 . The device of claim 1 , wherein the wideband combiner unit adopts a 16-channel wideband combiner, and the 16-channel wideband combiner The unit includes a 16-way broadband combiner and a combiner base plate; each of the combiner base plates is respectively fixed on each side of the octagon of the periodic annular slotted unit, and each of the combiner base plates is respectively fixed on each side of the octagon of the periodic annular slotted unit The ends are respectively connected with the electrodes of the periodic annular slotted unit, the head ends of the base plates of the combiners are respectively connected with one end of the wideband combiners, and the other ends of the wideband combiners are connected with the wideband combiners. connected to the detector bracket. 8. A ceramic vacuum tube beam-based transverse and longitudinal detector device as claimed in claim 7, wherein the 16-channel broadband combiner unit adopts two-stage cascaded Wilkinson power divider/combiner implement. 9 . The beam transverse and longitudinal detector device based on a ceramic vacuum tube according to claim 7 , wherein the 16-channel broadband combiner unit passes through the upper electrode of each half-ring type slotted unit. 10 . The induction signal is processed by sum-difference operation to obtain vertical, horizontal and vertical correction signals. The calculation formula is as follows: Longitudinal signal=first electrode+second electrode+...+eighth electrode Vertical signal=(first electrode+second electrode)-(fourth electrode+fifth electrode) Horizontal signal=(second electrode+third electrode)-(sixth electrode+seventh electrode). 10. A beam-transverse and longitudinal detector device based on a ceramic vacuum tube as claimed in claim 7, wherein the detector bracket comprises two detector bracket semicircular structures, four vertical rods and an italic part of the detector bracket ; The inner walls of the semicircular structures of the two detector brackets are provided with grooves that match each broadband combiner in the 16-channel broadband combiner unit, for connecting with each of the broadband combiners; one of the The lower part of the semicircular structure of the detector bracket is respectively connected with the two vertical rods, and the lower part of the semicircular structure of the other detector bracket is respectively connected with the other two vertical rods; the italic part of the detector bracket includes a detection clip bracket italic and a set Two fixing structures on the upper surface of the italic body of the detector bracket, one of the fixing structures is used for fixed connection with the lower ends of the two vertical rods, and the other fixed structure is used for fixed connection with the lower ends of the other two vertical rods. 11 . The beam transverse and longitudinal detector device based on a ceramic vacuum pipe according to claim 10 , wherein the inclination angle of the italic body of the detection clip bracket is in the range of 30°-60°. 12 .

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