阅读说明：本技术 Squid探测模块及squid传感器 (SQUID detection module and SQUID sensor ) 是由 王永良 张树林 张国峰 荣亮亮 谢晓明 于 2019-11-27 设计创作，主要内容包括：本发明提供一种SQUID探测模块及SQUID传感器,包括：SQUID器件及超导线圈环,所述SQUID器件感应所述超导线圈环探测到的磁通并转换为电信号；其中,所述超导线圈环包括首尾相连的第一超导线圈单元及第二超导线圈单元,所述第一超导线圈单元及所述第二超导线圈单元的连接节点作为引线端子接收反馈信号。本发明的SQUID探测模块及SQUID传感器无需反馈线圈,节省端口、成本,简化版图设计难度,降低工艺难度,提高了成品率；且采用直接电反馈,减少了磁通泄露,对于多通道应用具有重要意义,可以大大降低通道间磁通干扰和耦合,解决多通道间信号串扰问题,降低了系统信号提取的难度。(The invention provides a SQUID detection module and a SQUID sensor, comprising: the SQUID device induces the magnetic flux detected by the superconducting coil ring and converts the magnetic flux into an electric signal; the superconducting coil loop comprises a first superconducting coil unit and a second superconducting coil unit which are connected end to end, and a connection node of the first superconducting coil unit and the second superconducting coil unit serves as a lead terminal to receive feedback signals. The SQUID detection module and the SQUID sensor do not need a feedback coil, so that ports and cost are saved, layout design difficulty is simplified, process difficulty is reduced, and yield is improved; and direct electrical feedback is adopted, magnetic flux leakage is reduced, the method has important significance for multi-channel application, magnetic flux interference and coupling among channels can be greatly reduced, the problem of signal crosstalk among multiple channels is solved, and the difficulty in system signal extraction is reduced.)

1. A SQUID detection module, characterized in that it comprises at least:

the SQUID device induces the magnetic flux detected by the superconducting coil ring and converts the magnetic flux into an electric signal; the superconducting coil loop comprises a first superconducting coil unit and a second superconducting coil unit which are connected end to end, and a connection node of the first superconducting coil unit and the second superconducting coil unit serves as a lead terminal to receive feedback signals.

2. The SQUID detection module of claim 1, wherein: the first superconducting coil unit includes at least a detection coil, and the second superconducting coil unit includes at least an input coil.

3. The SQUID detection module of claim 2, wherein: the first superconducting coil unit further includes a first auxiliary coil connected in series with the detection coil.

4. The SQUID detection module of claim 2 or 3, wherein: the second superconducting coil unit further includes a second auxiliary coil connected in series with the input coil.

5. The SQUID detection module of claim 1, wherein: the first superconducting coil unit at least comprises a third auxiliary coil, and the second superconducting unit at least comprises a detection coil and an input coil which are connected in series.

6. The SQUID detection module of claim 5, wherein: the second superconducting coil unit further includes a fourth auxiliary coil connected in series with the detection coil and the input coil.

7. The SQUID detection module of claim 1, wherein: and two lead terminals in the superconducting coil ring are respectively led out through leads.

8. The SQUID detection module of claim 7, wherein: the material of the wire comprises a superconducting material or a non-superconducting conductive material.

9. The SQUID detection module of claim 1, wherein: the SQUID device includes a first Josephson junction and a second Josephson junction in parallel.

10. A SQUID sensor, characterized in that it comprises at least:

the SQUID detection module and readout module of any of claims 1 to 9;

two lead terminals of a SQUID device in the SQUID detection module are respectively connected with the input end of the readout module, and two lead terminals of a superconducting coil ring in the SQUID detection module are respectively connected with the feedback end of the readout module.

Technical Field

The invention relates to the field of SQUID detection, in particular to a SQUID detection module and a SQUID sensor.

Background

The magnetic sensor based on Superconducting Quantum Interference Device (SQUID) is the most sensitive magnetic sensor known at present, wherein the sensitivity of low-temperature Superconducting SQUID is better than 10 femtolite, and the sensitivity of high-temperature Superconducting SQUID is better than 100 femtolite. The SQUID magnetic sensor is an important high-end application sensor, is widely applied to the fields of biomagnetism, geophysical detection, extremely low field nuclear magnetic resonance and other weak magnetic field detection, and has very high scientific research and application values.

The conventional dc SQUID sensor chip 1 comprises a SQUID device, an input coil Li and a feedback coil Lf.

As shown in fig. 1, which is a standard connection mode of a conventional dc SQUID sensor chip 1, the SQUID device is formed by connecting two josephson junctions in parallel, and when a proper current is applied to the connection terminals S + and S-of the josephson junctions, a voltage is generated at both ends, and the voltage is related to the magnetic flux coupled in the SQUID device, so that the SQUID device is a magnetic flux sensitive element, and the two ends of the SQUID device are connected with a sensing circuit 2 to realize magnetic flux-voltage conversion. The input coil Li is used for being connected with a detection coil Lp (also called a magnetic flux pickup coil) of the magnetic probe to form a superconducting loop, so that transmission of signal magnetic flux is realized, loop current can be formed in the superconducting loop formed by the detection coil Lp and the input coil Li, the current is in direct proportion to the induced magnetic flux, and after the current flows to the input coil Li, the current can generate magnetic flux to be coupled into the SQUID device and is induced by the SQUID device to generate voltage. The feedback coil Lf is used for being connected with the matched readout circuit 2, the two ends F + and F-of the feedback coil Lf are connected to a feedback loop in the readout circuit 2, the feedback coil Lf converts the loaded feedback current into magnetic flux and couples the magnetic flux to the SQUID device, and the feedback coil Lf is matched with the readout circuit 2 to realize linear readout of the magnetic flux-voltage.

As shown in fig. 2, which is an indirect feedback connection mode of a conventional dc SQUID sensor chip 1, based on a standard connection mode, a feedback magnetic flux generated by a feedback coil Lf does not directly act on the SQUID, but acts on a superconducting loop formed by a detection coil Lp and an input coil Li, and is coupled to the SQUID device through the input coil Li, and then the read-out of the detected magnetic flux is realized through a read-out circuit 2. The indirect feedback connection mode only adjusts the path acted by the feedback magnetic flux, and the working principle of the sensor is not changed.

In the application of the traditional dc SQUID sensor chip, two paths are needed to apply magnetic flux to the SQUID device, one path is measured magnetic flux, the other path is feedback magnetic flux, and therefore two paths of magnetic flux are needed to be matched with corresponding coils. The SQUID device has small loop and limited space, and the layout design difficulty and the introduction of distribution parameters are increased by a plurality of coils. The indirect feedback mode reduces the number of coupling coils of the SQUID device, but increases the design complexity of the superconducting loop for flux transmission, and additional inductance and mutual inductance are necessarily introduced to establish the coupling of the feedback coil and the superconducting loop, which changes the strength of the input of the detected flux signal.

Therefore, how to reduce the number of coils, reduce the difficulty of coil design, and not change the performance of the SQUID sensor has become one of the problems to be solved by those skilled in the art.

Disclosure of Invention

In view of the above drawbacks of the prior art, an object of the present invention is to provide a SQUID detection module and a SQUID sensor, which are used to solve the problems of the prior art, such as a large number of coils, a large difficulty in designing coils, and an influence on the performance of the SQUID sensor.

To achieve the above and other related objects, the present invention provides a SQUID detection module, which at least comprises:

the SQUID device induces the magnetic flux detected by the superconducting coil ring and converts the magnetic flux into an electric signal; the superconducting coil loop comprises a first superconducting coil unit and a second superconducting coil unit which are connected end to end, and a connection node of the first superconducting coil unit and the second superconducting coil unit serves as a lead terminal to receive feedback signals.

Optionally, the first superconducting coil unit comprises at least a detection coil and the second superconducting coil unit comprises at least an input coil.

More optionally, the first superconducting coil unit further comprises a first auxiliary coil connected in series with the detection coil.

More optionally, the second superconducting coil unit further includes a second auxiliary coil connected in series with the input coil.

Optionally, the first superconducting coil unit includes at least a third auxiliary coil, and the second superconducting unit includes at least a detection coil and an input coil connected in series.

More optionally, the second superconducting coil unit further includes a fourth auxiliary coil connected in series with the detection coil and the input coil.

Optionally, two lead terminals in the superconducting coil loop are respectively led out through a lead wire.

More optionally, the material of the wire comprises a superconducting material or a non-superconducting conductive material.

Optionally, the SQUID device comprises a first josephson junction and a second josephson junction in parallel.

To achieve the above and other related objects, the present invention provides a SQUID sensor, comprising at least:

the SQUID detection module and the readout module;

two lead terminals of a SQUID device in the SQUID detection module are respectively connected with the input end of the readout module, and two lead terminals of a superconducting coil ring in the SQUID detection module are respectively connected with the feedback end of the readout module.

As described above, the SQUID detection module and the SQUID sensor of the present invention have the following advantageous effects:

1. the SQUID detection module and the SQUID sensor do not need a feedback coil, so that ports and cost are saved, layout design difficulty is simplified, process difficulty is reduced, and yield is improved.

2. The SQUID detection module and the SQUID sensor change magnetic flux feedback into direct electrical feedback, reduce magnetic flux leakage, have great significance for multi-channel application, can greatly reduce magnetic flux interference and coupling among channels, solve the problem of signal crosstalk among the channels and reduce the difficulty of system signal extraction.

Drawings

Fig. 1 shows a schematic structure diagram of a standard connection mode of a conventional dc SQUID sensor chip in the prior art.

Fig. 2 shows a schematic structure diagram of an indirect feedback connection mode of a conventional dc SQUID sensor chip in the prior art.

Fig. 3 is a schematic structural diagram of the SQUID detection module according to the present invention.

Fig. 4 is a schematic diagram showing another structure of the SQUID detection module of the present invention.

Fig. 5 is a schematic diagram showing another structure of the SQUID detection module according to the present invention.

Fig. 6 is a schematic diagram showing a structure of the SQUID sensor of the present invention.

Fig. 7 is a schematic view showing another structure of the SQUID sensor of the present invention.

Description of the element reference numerals

1 traditional dc SQUID sensor chip

2 readout circuit

3 SQUID detection module

31 SQUID device

32 superconducting coil loop

321 first superconducting coil unit

322 second superconducting coil unit

4 readout module

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 3 to 7. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.