JP2013040779A - Radiation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radiation detector capable of securing insulation and reducing noise of a detection signal.SOLUTION: A position sensitive detector 10 serving as a radiation detector includes a plurality of detection parts 11 each having a cylindrical outer enclosure 15 serving as a cathode, an anode 16 installed along the center of the inside of the outer enclosure 15 and a pair of terminals 17, 18 attached to both ends of the outer enclosure 15 and connected to both ends of the anode 16. The terminals 17 attached to one-end parts of the plurality of detection parts 11 are connected in series by a naked wire 20. The terminals 17 attached to the one-end parts of the detection parts 11 and the naked wire 20 are integrally stored in a storage space 25 of a case 12. An insulating material 27 for integrally insulating the terminals 17 attached to the one-end parts of the detection parts 11 and the naked wire 20 is filled in the storage space 25 of the case 12.

Description

  Embodiments described herein relate generally to a radiation detector that detects radiation.

  Conventionally, a position sensitive detector is used as a radiation detector for detecting neutrons in a facility that uses an accelerator to study material structure and atomic arrangement. In this position sensitive detector, many position sensitive detectors are arranged so as to cover the analysis data, and neutrons generated radially from the analysis data are detected.

  The detection part of the position sensitive detector has a high-resistance anode in the cylindrical envelope along the center of the envelope, and a rare gas with a large reaction cross-section with neutrons has a high pressure. Terminals connected to both ends of the anode are provided at both ends of the envelope. When two detectors are arranged in parallel and connected in series, terminals at one ends of the two detectors are electrically connected with bare wires. Thus, the reason for using the bare wire is that the cable cannot be covered with the cable having the covering because the distance between the two terminals to be connected is short. If a terminal to which a high voltage is applied or a bare wire is left exposed, there is a problem with the withstand voltage, so the case is covered and protected.

JP 2009-198439 A

  Since the bare wire that connects the terminals of the two detectors of the position sensitive detector is covered and protected by a case, there is no problem with withstand voltage in normal use. Depending on the surrounding environment where the position sensitive detector is installed, such as an environment where the facilities are not sufficient, the humidity in the case becomes high and the insulation properties deteriorate. As described above, if the insulation is deteriorated, noise of the detection signal from the position sensitive detector increases, which may cause a problem in measurement.

  The problem to be solved by the present invention is to provide a radiation detector capable of ensuring insulation and reducing noise in detection signals.

  The radiation detector of the present embodiment is a cylindrical envelope serving as a cathode, an anode installed along the center of the envelope, and connected to both ends of the anode provided at both ends of the envelope. A plurality of detectors having a pair of terminals are provided. Terminals at one ends of the plurality of detection units are connected in series with conductive wires. The terminal and the conductive wire at one end of the plurality of detection units are integrally accommodated in the housing space of the case. The housing space of the case is filled with an insulating material that integrally insulates the terminals at one end of the plurality of detection units and the conductive wires.

It is sectional drawing of the radiation detector which shows one Embodiment.

  Hereinafter, an embodiment will be described with reference to FIG.

  There are a plurality of position sensitive detectors 10 as radiation detectors, and two detectors 11 are provided in this embodiment. These two detectors 11 are arranged in parallel in the radial direction, and one end and the other end of the two detectors 11 are inserted and attached to the cases 12 and 13, respectively, and are held together.

  The detection unit 11 includes an envelope 15 as a cathode formed in a cylindrical and sealed structure using, for example, stainless steel. In this envelope 15, a rare gas having a large reaction cross-section with neutrons as radiation is sealed at a high pressure. A high resistance anode 16 of several kΩ or more is disposed along the center in the envelope 15. Both ends of the anode 16 are electrically connected to and supported by the pair of terminals 17 and 18. The pair of terminals 17, 18 are held by the envelope 15 through the insulating members 19 provided at both ends of the envelope 15.

  A terminal 17 at one end of the two detection units 11 is electrically connected by a bare wire 20 as a conductive wire such as nickel or copper, and the anodes 16 of the two detection units 11 are connected in series.

  A signal cable 21, which is a coated cable having an insulation coating, is connected to the terminal 18 at the other end of the two detection units 11 by soldering or welding, and a band including the connection portion is covered and insulated by a shrinkable tube 22. ing.

  Further, the case 12 on one end side that holds one end of the two detection units 11 is formed of, for example, an insulating resin material, and the fitting port 24 that fits one end of the two detection units 11 and two The detecting section 11 has a receiving space 25 that integrally accommodates the terminal 17 and the bare wire 20, and one end of the receiving space 25 is formed with an opening. A lid body 26 is attached to the case 12 to close the opening on one end side of the accommodation space 25.

  The housing space 25 of the case 12 is filled with an insulating material 27 that integrally insulates the terminals 17 at one end of the two detection units 11 and the bare wires 20 before closing the lid 26. As this insulating material 27, for example, an insulating resin such as silicon resin is used, and a sufficient vacuum defoaming process is performed before filling. By performing this vacuum defoaming treatment, the air in the resin material is removed, and the withstand voltage is further improved. Further, since the insulating material 27 is exposed to a radiation field for a long period of time, it needs to be excellent in radiation resistance. Since the resin cannot be replaced many times due to its structure, it is preferable to use, for example, a silicon resin having excellent radiation resistance used in the space business.

  In addition, the case 13 on the other end side that holds the other ends of the two detection units 11 is formed of, for example, an insulating resin material, and has a fitting port 29 for fitting the other ends of the two detection units 11. In addition, an insertion hole 30 for drawing out the signal cable 21 connected to the terminal 18 at the other end of the two detection units 11 is formed.

  The position sensitive detector 10 applies a high voltage of several thousand volts to the anode 16 of the detection unit 11 through the signal cable 21. When neutrons incident on the detector 11 react with the noble gas in the envelope 15 to generate electrons, the electrons are attracted to the anode 16 by the potential difference between the envelope 15 and the anode 16 serving as the cathode. In addition, detection signals are output from both ends of the anode 16. The detection signal output from both ends of the anode 16 is amplified and shaped by the pre-processing unit, and the position where the neutron is detected is measured by calculating the ratio of the detection signal output from both ends of the anode 16 by the calculator. ing.

  Further, the terminal 17 and the bare wire 20 at one end of the two detection units 11 are accommodated and covered in the accommodation space 25 of the case 12 and are integrally insulated by the insulating material 27 filled in the accommodation space 25 of the case 12. Therefore, the insulation can be maintained regardless of the surrounding environment where the position sensitive detector 10 is installed. Since the insulation of the terminal 17 and the bare wire 20 at one end of the two detection units 11 can be ensured, the noise of the detection signal can be reduced and the measurement can be performed accurately.

  Thus, according to the position sensitive detector 10, the insulation of the terminal 17 at one end of the two detectors 11 and the portion of the bare wire 20 can be ensured, and the noise of the detection signal can be reduced.

  Further, by using an insulating resin that has been subjected to vacuum defoaming treatment for the insulating material 27, it is possible to reliably ensure the insulation of the terminal 17 at one end of the two detection units 11 and the portion of the bare wire 20, The withstand voltage can be improved.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

10 Position sensitive detector as a radiation detector
11 Detector
12 cases
15 Envelope
16 anode
17, 18 terminals
20 Bare wire as conductive wire
25 containment space
27 Insulation material

Claims (2)

A cylindrical envelope serving as a cathode, an anode installed along the center of the envelope, and a plurality of terminals provided at both ends of the envelope and connected to both ends of the anode A detection unit;
A conductive wire connecting the terminals of one end of the plurality of detection units in series;
A case having an accommodating space for integrally accommodating the terminals at one end of the plurality of detection units and the conductive wires;
A radiation detector comprising: a housing space of the case; and an insulating material that integrally insulates the terminals of the plurality of detection units and the conductive wires. The radiation detector according to claim 1, wherein the insulating material is an insulating resin subjected to a vacuum defoaming process.

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