CN104096318A - Hadron beam monitoring device and method based on pixel sensor chip - Google Patents

Abstract

The hadron beam current monitoring device based on the pixel sensor chip includes a vertical support and two sets of independent two-dimensional monitoring devices, and the two sets of two-dimensional monitoring devices are fixed on the two vertical plates of the vertical support; each set of two-dimensional monitoring devices Both are composed of silicon pixel chips, chip bonding circuit boards, anode plates, and cathode plates. The monitoring method of the device is as follows: the hadron beam passes through the gas above the silicon pixel chip, ionizes the gas to generate electron clusters, and the electron clusters drift under the action of the electric field above the silicon pixel chip, and are collected by the corresponding pixels on the silicon pixel chip; According to the response of the pixels on the silicon pixel chip, the two-dimensional information of the hadron beam on the plane where the silicon pixel chip is located is obtained; Reconstruction of the three-dimensional distribution of hadron beams. The invention monitors the three-dimensional distribution information of the hadron beam in real time, and has the characteristics of beam non-interception, radiation resistance and high position resolution.

Description

Hadron beam current monitoring device and method based on pixel sensor chip

technical field

The invention relates to the field of hadron therapy, in particular to a hadron beam current monitoring device and method based on a pixel sensor chip, which is used for real-time monitoring of hadron beam current.

Background technique

After the hadron enters the matter, it will not release a large amount of energy immediately, but will release most of its energy only at the position where the hadron is about to stop, forming a sharp energy peak - the Bragg peak, which is called the Bragg peak effect. According to the Bragg peak effect, using hadrons instead of photons and electrons for tumor treatment can avoid healthy tissues around the tumor, inject more radiation dose into the tumor, and have stronger biological effects than electrons and photons.

Currently, there are two beam delivery techniques for hadron therapy: beam scattering and beam scanning. Beam scattering technology uses scatterers to diverge the beam, and then uses custom collimators and compensators to make the scattered dose distribution consistent with the target tumor volume. Beam scanning technology uses a magnet to manipulate a narrow mono-energy beam to scan the target tumor volume by volume under the control of a computer. Since the beam scattering technology needs to customize equipment according to the patient, and a large number of secondary particles will be generated during the scattering process, the beam scanning technology has more advantages: it is convenient and has little damage to healthy tissues. Hadron therapy using beam scanning technology requires real-time monitoring of beam intensity and position distribution, and timely feedback of beam information to the control terminal, so that the control terminal can adjust the beam current.

Contents of the invention

The technical problem to be solved by the present invention is to provide a hadron beam monitoring device and method based on a pixel sensor chip for the problem that the hadron therapy of the existing beam scanning technology needs to monitor the intensity and position distribution of the beam in real time , using silicon pixel chips to monitor hadron beams in real time, with beam non-interception, radiation resistance and high position resolution.

The technical scheme that the present invention adopts for solving the problems of the technologies described above is:

The hadron beam current monitoring device based on the pixel sensor chip includes a vertical bracket and two sets of independent two-dimensional monitoring devices. Each set of two-dimensional monitoring device consists of a silicon pixel chip, a chip bonding circuit board, an anode plate, and a cathode plate. The anode plate and the cathode plate are separated by an alumina ceramic structure and passed through a second A cylindrical head bolt is fixedly connected; the chip bonding circuit board is fixed on the anode plate through epoxy resin glue, and the anode plate is grounded; the silicon pixel chip is fixedly installed on the chip bonding circuit board.

According to the above scheme, the alumina ceramic structures on the two sets of two-dimensional monitoring devices are respectively arranged between the anode plate and the cathode plate at the ends where the two vertical plates of the vertical support do not meet; at the same time, the two sets of two-dimensional monitoring The silicon pixel chips on the chip bonding circuit board of the device are arranged vertically to each other and are arranged between the anode plate and the cathode plate at the end where the two vertical plates of the vertical bracket meet.

According to the above scheme, the two sets of two-dimensional monitoring devices are respectively fixed on the two vertical plates of the vertical support through the second cylindrical head bolts.

According to the above scheme, the anode plate and the cathode plate are arranged facing each other, and the silicon pixel chip is centrally arranged between the anode plate and the cathode plate (for ensuring uniform distribution of the electric field above the silicon pixel chip).

According to the above scheme, the silicon pixel chip is based on a CMOS integrated circuit and is composed of pixel arrays, the pixel size is on the order of microns, and each pixel includes a top layer of metal, and the silicon pixel chip is used to directly collect electrons drifting from the gas in the external space, And generate a charge signal, which can be converted into an analog signal or a digital signal and read out in the pixel.

According to the above scheme, the chip bonding circuit board includes a 3.3V voltage conversion circuit, a 5.0V voltage conversion circuit, an analog output voltage drive circuit, a digital-to-analog converter, a digital signal processing circuit and an MCX adapter; the 3.3V voltage conversion circuit is respectively Connected with digital signal processing circuit, silicon pixel chip, digital-to-analog converter, used to provide analog power and digital power for digital signal processing circuit, silicon pixel chip, digital-to-analog converter; said digital signal processing circuit is connected with silicon pixel chip , for converting differential digital signals into single-ended digital signals to provide digital control signals for silicon pixel chips; the digital-to-analog converter is connected to silicon pixel chips for converting digital signals into analog signals to provide silicon pixel chips External reset voltage; the 5.0V voltage conversion circuit is connected with the analog output voltage drive circuit to provide voltage for the analog output voltage drive circuit; the analog output terminal of the silicon pixel chip is connected with the MCX adapter through the analog output voltage drive circuit, and the analog output The voltage drive circuit is used to provide voltage drive for the analog readout of the silicon pixel chip, so that the analog readout of the silicon pixel chip is output through the MCX adapter.

According to the above scheme, the 3.3V voltage conversion circuit and the 5.0V voltage conversion circuit adopt LM1117-3.3 chip and LM1117-5.0 chip respectively, the analog output voltage drive circuit adopts THS4281 chip, and the digital-to-analog converter adopts DAC8568 chip, The digital signal processing circuit adopts SN65LVDT14 chip.

The present invention also provides a method for monitoring hadron beam current according to the hadron beam current monitoring device based on the pixel sensor chip, comprising the following steps:

1) An electric field is generated between the cathode plate and the anode plate of the two sets of two-dimensional monitoring devices, and the hadron beam passes through the gas above the silicon pixel chip, ionizing the gas to generate electron clusters, and the electron cluster acts on the electric field above the silicon pixel chip The lower drift is collected by the corresponding pixel on the silicon pixel chip;

2) Obtain the two-dimensional information of the hadron beam on the plane where the silicon pixel chip is located according to the response of the pixels on the silicon pixel chip;

3) Reconstruct the three-dimensional distribution of the hadron beam by passing the hadron beam sequentially over the silicon pixel chips perpendicular to each other on two sets of two-dimensional monitoring devices.

According to the above scheme, in the step 1), the hadron beam passes above the silicon pixel chip and does not directly hit the silicon pixel chip.

According to the above scheme, the anode plate and the cathode plate described in the step 1) are distributed oppositely, and the silicon pixel chip is centrally arranged between the anode plate and the cathode plate to ensure that the electric field above the silicon pixel chip is evenly distributed (cathode plate and cathode plate) An electric field is generated between the anode plates).

The beneficial effect of the invention is that the three-dimensional distribution information of the hadron beam can be monitored in real time, the position resolution is high, the radiation resistance is good, the beam is non-intercepting, and a sealed gas environment is not required.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Fig. 2 is the structural representation of every set of two-dimensional monitoring device of the present invention;

Fig. 3 is a structural block diagram of the chip bonding circuit board and the silicon pixel chip of the present invention being cooperatively connected;

Fig. 4 is a schematic structural view of an embodiment of the silicon pixel chip and its peripheral circuits in Fig. 3;

Fig. 5 is the embodiment structure diagram of 3.3V voltage conversion circuit in Fig. 3;

Fig. 6 is a schematic structural view of an embodiment of a 5V voltage conversion circuit in Fig. 3;

Fig. 7 is a schematic structural diagram of an embodiment of the analog output voltage drive circuit in Fig. 3;

Fig. 8 is a structural representation of the MCX adapter in Fig. 3;

Fig. 9 is a schematic structural diagram of an embodiment of a digital-to-analog converter in Fig. 3;

Fig. 10 is a schematic structural diagram of an embodiment of a digital signal processing circuit in Fig. 3;

Fig. 11 is a schematic diagram of the circuit structure of the connector connecting the silicon pixel chip and the external input in Fig. 3;

In Figures 1 to 2, 1-vertical support, 2-two-dimensional monitoring device, 3-silicon pixel chip, 4-chip bonding circuit board, 5-anode plate, 6-cathode plate, 7-alumina ceramic structure, 8 - 1st cylinder head bolt, 9 - 2nd cylinder head bolt.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to Figures 1 to 2, the hadron beam monitoring device based on the pixel sensor chip of the present invention includes a vertical support 1 and two sets of independent two-dimensional monitoring devices 2, the vertical support 1 is composed of two vertical The two sets of two-dimensional monitoring devices 2 are respectively fixed on the two vertical plates of the vertical support 1 (the outer sides of the two vertical plates); each set of two-dimensional monitoring devices 2 is composed of a silicon pixel chip 3, chip bonding Composed of a circuit board 4, an anode plate 5, and a cathode plate 6, the anode plate 5 and the cathode plate 6 are separated by an alumina ceramic structure 7 and fixedly connected by first cylindrical head bolts 8; the chip bonding circuit board 4 The anode plate 5 is fixed on the anode plate 5 by epoxy glue, and the anode plate 5 is grounded; the silicon pixel chip 3 is fixedly installed on the chip bonding circuit board 4 .

The alumina ceramic structures 7 on the two sets of two-dimensional monitoring devices 2 are respectively arranged between the anode plate 5 and the cathode plate 6 at the ends where the two vertical plates of the vertical support 1 do not meet; at the same time, the two sets of two-dimensional The silicon pixel chips 3 on the chip bonding circuit board 4 of the monitoring device 2 are arranged perpendicular to each other and are arranged between the anode plate 5 and the cathode plate 6 at the end of the vertical support 1 where the two vertical plates meet.

The two sets of two-dimensional monitoring devices 2 are respectively fixed on the two vertical plates of the vertical support 1 through the second cylindrical head bolts 9 .

The anode plate 5 and the cathode plate 6 are oppositely distributed, and the silicon pixel chip 3 is centrally arranged between the anode plate 5 and the cathode plate 6 to ensure that the electric field above the silicon pixel chip 3 is evenly distributed (the cathode plate 6 and the anode plate 5 generate an electric field between them).

The silicon pixel chip 3 is based on a CMOS integrated circuit and is composed of pixel arrays. The pixel size is on the order of microns. Each pixel contains a top layer of metal. The silicon pixel chip 3 is used to directly collect electrons drifting from the gas in the external space and generate Charge signal, charge signal can be converted into analog signal or digital signal readout in the pixel. In the embodiment, the silicon pixel chip 3 is specifically a silicon pixel chip designed and disclosed in the patent publication number CN102931202A.

Referring to Figures 3 to 4, the chip bonding circuit board 4 includes a 3.3V voltage conversion circuit, a 5.0V voltage conversion circuit, an analog output voltage drive circuit, a digital-to-analog converter, a digital signal processing circuit and an MCX adapter; The 3.3V voltage conversion circuit is respectively connected with the digital signal processing circuit, the silicon pixel chip 3, and the digital-to-analog converter, and is used to provide analog power and digital power for the digital signal processing circuit, the silicon pixel chip, and the digital-to-analog converter; the digital signal The processing circuit is connected to the silicon pixel chip 3, and is used to convert the differential digital signal into a single-ended digital signal, and provides a digital control signal for the silicon pixel chip 3; the digital-to-analog converter is connected to the silicon pixel chip 3, and is used to convert the digital signal Convert into analog signal, provide external reset voltage for silicon pixel chip 3; Described 5.0V voltage conversion circuit is connected with analog output voltage drive circuit, is used for providing voltage for analog output voltage drive circuit; The analog output end of silicon pixel chip 3 is passed through The analog output voltage drive circuit is connected to the MCX adapter, and the analog output voltage drive circuit is used to provide voltage drive for the analog readout of the silicon pixel chip 3, so that the analog readout of the silicon pixel chip 3 is output through the MCX adapter.

The 3.3V voltage conversion circuit and the 5.0V voltage conversion circuit adopt the LMS1117-3.3 chip shown in Figure 5 and the LM1117-5.0 chip shown in Figure 6 respectively, and the analog output voltage drive circuit adopts the Texas Instruments shown in Figure 7 (TexasInstruments) company's THS4281 chip, the output end of THS4281 chip is connected with the MCX adapter shown in Figure 8, and described digital-to-analog converter adopts DAC8568 chip shown in Figure 9, and described digital signal processing circuit adopts the shown in Figure 10 SN65LVDT14 chip; the silicon pixel chip 3 is connected to the external input through the connector shown in FIG. 11 .

The silicon pixel chip 3 is fixed on the chip bonding circuit board 4 by bonding technology, and the chip bonding circuit board 4 is used to provide the silicon pixel chip 3 with analog power supply, digital power supply, digital control signal, external reset voltage and analog output voltage drive, The analog readout converted by the silicon pixel chip 3 is output through the MCX adapter on the chip bonding circuit board 4 .

The method for monitoring the hadron beam current by the hadron beam current monitoring device based on the pixel sensor chip of the present invention comprises the following steps:

1) An electric field is generated between the cathode plate 6 and the anode plate 5 of the two sets of two-dimensional monitoring devices 2, and the hadron beam passes through the gas above the silicon pixel chip 3 to ensure that the hadron beam passes above the silicon pixel chip 3 , does not directly hit the silicon pixel chip 3, so that the gas is ionized to generate electron clusters, and the electron clusters drift under the action of the electric field above the silicon pixel chip 3, and are collected by the corresponding pixels on the silicon pixel chip 3; meanwhile, the silicon pixel chip 3 is centered It is arranged between the anode plate 5 and the cathode plate 6 to ensure that the electric field above the silicon pixel chip 3 is evenly distributed;

2) According to the response of the pixels on the silicon pixel chip 3, obtain the two-dimensional information of the hadron beam on the plane where the silicon pixel chip 3 is located;

3) Reconstruct the three-dimensional distribution of hadron beams by passing the hadron beams sequentially over the silicon pixel chips 3 perpendicular to each other on the two sets of two-dimensional monitoring devices 2 .

Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent replacements to the technical solution of the present invention by those skilled in the art will not depart from the present invention. The essence and scope of the technical solution of the invention.

Claims (10)

1. the hadron line supervising device based on pixel sensing chip, it is characterized in that, comprise a vertical support frame (1) and independently two-dimentional supervising device (2) of two covers, vertical support frame (1) forms by two vertical plates are affixed, and the two two-dimentional supervising devices of cover (2) are separately fixed on two vertical plates of vertical support frame (1); The two-dimentional supervising device of every cover (2), by silicon pixel chip (3), chip bonding circuit board (4), positive plate (5), minus plate (6) composition, is separated, is also fixedly connected with by the first cylinder head bolt (8) by alumina ceramic structure (7) between described positive plate (5) and minus plate (6); It is upper that described chip bonding circuit board (4) is fixed on positive plate (5) by epoxide-resin glue, positive plate (5) ground connection; Described silicon pixel chip (3) is fixedly mounted on chip bonding circuit board (4).

2. the hadron line supervising device based on pixel sensing chip according to claim 1, it is characterized in that, the alumina ceramic structure (7) on described two covers two-dimentional supervising devices (2) is separately positioned on and between positive plate (5) and minus plate (6), is positioned at the end that vertical support frame (1) two vertical plate does not join; Meanwhile, the silicon pixel chip (3) on the chip bonding circuit board (4) of the described two two-dimentional supervising devices of cover (2) is arranged vertically and is all arranged on the end that is positioned at vertical support frame (1) two vertical plate handing-over between positive plate (5) and minus plate (6) mutually.

3. the hadron line supervising device based on pixel sensing chip according to claim 1, it is characterized in that, the described two two-dimentional supervising devices of cover (2) are fixed on two vertical plates of vertical support frame (1) by the second cylinder head bolt (9) respectively.

4. the hadron line supervising device based on pixel sensing chip according to claim 1, it is characterized in that, described positive plate (5), minus plate (6) are just to distributing, and silicon pixel chip (3) is arranged between positive plate (5), minus plate (6) between two parties.

5. the hadron line supervising device based on pixel sensing chip according to claim 1, it is characterized in that, described silicon pixel chip (3) is based on CMOS integrated circuit, formed by pixel array, Pixel Dimensions is in micron dimension, each pixel comprises top-level metallic, and the electronics that silicon pixel chip (3) comes for the direct Gas drift of collecting space outerpace also produces charge signal, and charge signal can convert analogue signal in pixel or digital signal is read.

6. the hadron line supervising device based on pixel sensing chip according to claim 1, it is characterized in that, described chip bonding circuit board (4) comprises 3.3V voltage conversion circuit, 5.0V voltage conversion circuit, analog output voltage drive circuit, digital to analog converter, digital signal processing circuit and MCX adapter; Described 3.3V voltage conversion circuit is connected with digital signal processing circuit, silicon pixel chip (3), digital to analog converter respectively; Described digital signal processing circuit is connected with silicon pixel chip (3); Described digital to analog converter is connected with silicon pixel chip (3); Described 5.0V voltage conversion circuit is connected with analog output voltage drive circuit; The analog output of silicon pixel chip (3) is connected with MCX adapter through analog output voltage drive circuit.

7. the hadron line supervising device based on pixel sensing chip according to claim 6, it is characterized in that, described 3.3V voltage conversion circuit, 5.0V voltage conversion circuit adopt respectively LM1117-3.3 chip, LM1117-5.0 chip, described analog output voltage drive circuit adopts THS4281 chip, described digital to analog converter adopts DAC8568 chip, and described digital signal processing circuit adopts SN65LVDT14 chip.

8. a method of carrying out the monitoring of hadron line according to the above-mentioned hadron line supervising device based on pixel sensing chip, is characterized in that, comprises the following steps:

1) between the minus plate (6) of the two two-dimentional supervising devices of cover (2) and positive plate (5), produce electric field, hadron line is through the gas of silicon pixel chip (3) top, make gas ionization produce rain of electrons, rain of electrons drifts about under the effect of the electric field of silicon pixel chip (3) top, is collected by the upper corresponding pixel of silicon pixel chip (3);

2) according to the response of the upper pixel of silicon pixel chip (3), obtain the two-dimensional signal of hadron line in silicon pixel chip (3) place plane;

3) by hadron line is passed above orthogonal silicon pixel chip (3) successively from two cover two dimension supervising devices (2), rebuild the distributed in three dimensions of hadron line.

9. the method that the hadron line supervising device based on pixel sensing chip according to claim 8 carries out the monitoring of hadron line, it is characterized in that, described step 1) in hadron line pass from the top of silicon pixel chip (3), directly do not hit silicon pixel chip (3).

10. the method that the hadron line supervising device based on pixel sensing chip according to claim 8 carries out the monitoring of hadron line, it is characterized in that, described step 1) described in positive plate (5), minus plate (6) just to distributing, silicon pixel chip (3) is arranged between positive plate (5), minus plate (6) between two parties, is uniformly distributed for the electric field that ensures silicon pixel chip (3) top.