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JP3577498B2 - Pulse tube refrigerator and magnetically shielded refrigeration system - Google Patents

Pulse tube refrigerator and magnetically shielded refrigeration system Download PDF

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Publication number
JP3577498B2
JP3577498B2 JP17641398A JP17641398A JP3577498B2 JP 3577498 B2 JP3577498 B2 JP 3577498B2 JP 17641398 A JP17641398 A JP 17641398A JP 17641398 A JP17641398 A JP 17641398A JP 3577498 B2 JP3577498 B2 JP 3577498B2
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tube
pulse tube
regenerator
pulse
refrigerator
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JP2000018744A (en
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久直 尾形
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Kanazawa Institute of Technology (KIT)
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Kanazawa Institute of Technology (KIT)
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/14—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle
    • F25B9/145—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the cycle used, e.g. Stirling cycle pulse-tube cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1406—Pulse-tube cycles with pulse tube in co-axial or concentric geometrical arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1408—Pulse-tube cycles with pulse tube having U-turn or L-turn type geometrical arrangements
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1418—Pulse-tube cycles with valves in gas supply and return lines
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1421—Pulse-tube cycles characterised by details not otherwise provided for
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/14—Compression machines, plants or systems characterised by the cycle used 
    • F25B2309/1424—Pulse tubes with basic schematic including an orifice and a reservoir
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25D—REFRIGERATORS; COLD ROOMS; ICE-BOXES; COOLING OR FREEZING APPARATUS NOT OTHERWISE PROVIDED FOR
    • F25D19/00—Arrangement or mounting of refrigeration units with respect to devices or objects to be refrigerated, e.g. infrared detectors
    • F25D19/006—Thermal coupling structure or interface

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Containers, Films, And Cooling For Superconductive Devices (AREA)
  • Measurement And Recording Of Electrical Phenomena And Electrical Characteristics Of The Living Body (AREA)
  • Measuring Magnetic Variables (AREA)

Description

【０００１】
【発明の属する技術分野】
本発明は、パルス管式冷凍器および磁気遮蔽型冷凍システムに関する。さらに詳しくは、各部の材料差や温度差により発生した熱起電力に起因する電流ループの形成を抑制できるように改良したパルス管式冷凍器、および冷却剤の蒸発量を低減できるように改良した磁気遮蔽型冷凍システムに関する。特に、ＳＱＵＩＤ（Ｓｕｐｅｒｃｏｎｄｕｃｔｉｎｇ ＱＵａｎｔｕｍ Ｉｎｔｅｒｆｅｒｅｎｃｅ Ｄｅｖｉｃｅｓ；超伝導量子干渉計）素子などのセンサー類を冷却するのに有用である。
【０００２】
【従来の技術】
図９は、従来のパルス管式冷凍器の一例を示す構成図である。
このパルス管式冷凍器９００は、内部に蓄冷材１０を充填された蓄冷器管１１と，内部に空洞Ｖを有するパルス管１２と，前記蓄冷器管１０の上端と前記パルス管１２の上端とを連結する連結孔Ｃが形成された連結ブロック１３と，前記蓄冷器管１１の下端の管壁内側にガス配管１４の一端を位置付けると共に前記パルス管１２の下端の管壁内側にオリフィス１５の一端を位置付けるフランジ１６と，前記オリフィス１５の他端に連なるバッファーＢを有する放熱ケース１７とを具備して構成されている。
【０００３】
前記蓄冷材１０は、例えば銅網（網状に編まれた銅線）である。
前記蓄冷器管１１および前記パルス管１２の材料は、機械的に丈夫で，しかも断熱性能の高い金属材料であり、例えばステンレスである。
前記連結ブロック１３および前記放熱ケース１７の材料は、熱伝導率の高い金属材料であり、例えば銅である。
【０００４】
前記連結ブロック１３は、前記蓄冷器管１１および前記パルス管１２内へ冷媒ガスＧｒをパルス的に出し入れすることで、極低温（例えば−２００℃程度）に冷却される。前記冷媒ガスＧｒは、例えばヘリウムガスである。
前記連結ブロック１３の上面には、被冷却体Ｍが載置されている。前記被冷却体Ｍは、例えば、微弱な磁場を検出するためのＳＱＵＩＤ素子を内蔵するセンサーユニットである。
【０００５】
前記蓄冷器管１１や前記パルス管１２の端部からの冷媒ガスＧｒの漏出を防止する見地から、前記蓄冷器管１１と前記連結ブロック１３との間は高気密性のシール部α１によりシールされ、前記蓄冷器管１１と前記フランジ１６との間は高気密性のシール部α２によりシールされ、前記パルス管１２と前記連結ブロック１３との間は高気密性のシール部α３によりシールされ、前記パルス管１２と前記フランジ１６との間は高気密性のシール部α４によりシールされている。
【０００６】
図１０は、図９のパルス管式冷凍器９００を含む冷凍システムの構成図である。
この冷凍システム９１０は、前記パルス管式冷凍器９００のフランジ１６および放熱ケース１７を外部に出し且つ他の部分（蓄冷材１０，蓄冷器管１１，パルス管１２，連結ブロック１３，被冷却体Ｍ）を真空中に収容する真空容器９１と，冷媒ガスＧｒを高圧で送り出す高圧端子Ｈと前記冷媒ガスＧｒを回収する低圧端子Ｌとを有する圧縮機９２と、前記高圧端子Ｈおよび低圧端子Ｌから導出された高圧ガス配管９３および低圧ガス配管９４と、前記パルス管式冷凍器９００のガス配管１４に連結したガス配管９５と、電気配線９６を介して前記圧縮機９２と接続し且つ前記高圧ガス配管９３および低圧ガス配管９４を例えば１〜２０Ｈｚの一定周期で交互に前記ガス配管９５と結合する内部弁を有するモータ駆動切り換え弁９７とを具備して構成されている。
【０００７】
前記モータ駆動切り換え弁９７が内部弁を前記高圧ガス配管９３すなわち前記高圧端子Ｈに切り換えている期間は、前記蓄冷器管１１および連結ブロック１３の連結孔Ｃ（図９）を介して、冷媒ガスＧｒが前記パルス管１２内にパルス的に流入する。このとき、前記パルス管１２の下端（バッファーＢ側）で冷媒ガスＧｒが圧縮されて発熱するが、当該熱は、放熱ケース１７から放熱される。
一方、前記モータ切り換え弁６５が内部弁を前記低圧ガス配管９４すなわち前記低圧端子Ｌに切り換えている期間は、前記連結ブロック１３の連結孔Ｃおよび蓄冷器管１１を介して、前記パルス管１２内の冷媒ガスＧｒがパルス的に流出する。このとき、冷媒ガスＧｒは、前記パルス管１２の上端（蓄冷器管１１側）で断熱的に膨張しながら流出するので、前記上端付近が冷たくなり、その冷気が蓄冷材１０に吸収され、前記連結ブロック１４の温度が低下する。
したがって、前記モータ駆動切り換え弁９７の内部弁の切り換えを継続して行うことで、前記連結ブロック１３の温度を極低温にまで低下させ、被冷却体Ｍを冷却することが出来る。
【０００８】
図１１は、従来の磁気遮蔽型冷凍システムの一例を示す構成図である。
この磁気遮蔽型冷凍システム９２０は、外界から磁気的に遮蔽された内部空間を有する磁気遮蔽装置５１と，容器状の外壁Ｗｏと内壁Ｗｉとを有し前記内壁Ｗｉで囲まれた空間内に冷却剤５２が保持された断熱装置５３と，前記外壁Ｗｏと前記内壁Ｗｉの間の真空層内に設けられた熱遮蔽板５４と，前記内壁Ｗｉの底部に配設されたセンサー５５と、前記内壁Ｗｉの上部に設けられた断熱体５６とを具備して構成して構成されている。前記冷却剤５２は、例えば液体ヘリウムである。前記センサー５５は、例えばＳＱＵＩＤ素子などの磁気検出素子である。
前記冷却剤５２が気化した低温のガスｇは、前記断熱装置５３の内壁Ｗｉと前記断熱体５６との隙間を通って放出される。このとき、前記内壁Ｗｉおよび前記熱遮蔽板５４は、前記ガスｇによって熱が奪取され、冷却される。
【０００９】
【発明が解決しようとする課題】
上記従来のパルス管式冷凍器９００では、図１２に示すように、蓄冷材１０と蓄冷器管１１との材料差および温度差により熱起電力が発生し、その熱起電力により前記蓄冷材１０と前記蓄冷器管１１を伝わる電流ループｉ−１が形成されやすい。同様に、蓄冷器管１１と連結ブロック１３とパルス管１２の間に、熱起電力に起因する電流ループｉ−２が形成されやすい。
ところが、このような電流ループｉ−１，ｉ−２は、磁気雑音Ｎを発生する要因となるため、微弱な磁場を測定する際の誤差が大きくなる問題点がある。
【００１０】
また、上記従来の磁気遮蔽型冷凍システム９２０では、外界からの熱の侵入により冷却剤５２が蒸発しやすいため、当該冷却剤５２を頻繁に補充する必要があり、運転コストが増大する問題点がある。
【００１１】
そこで、本発明の第１の目的は、各部の材料差や温度差により発生した熱起電力に起因する電流ループの形成を抑制できるパルス管式冷凍器を提供することにある。
また、本発明の第２の目的は、冷却剤の蒸発量を低減できる磁気遮蔽型冷凍システムを提供することにある。
【００１２】
【課題を解決するための手段】
第１の観点では、本発明は、内部に導電材料で作成された蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有するパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を連結ブロックにより連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却するタイプのパルス管式冷凍器であって、前記蓄冷器管の内周に、前記蓄冷材を取り囲むように絶縁筒を設け、前記蓄冷器管と前記蓄冷材とを含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器を提供する。
上記第１の観点によるパルス管式冷凍器では、蓄冷器管の内周に蓄冷材を取り囲むように絶縁筒を設けるので、蓄冷材と蓄冷器管とを電気的に絶縁することができ、両者の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。この結果、雑音磁場の発生を抑制でき、微弱な磁場を測定する際の誤差を低減することが出来る。
【００１３】
第２の観点では、本発明は、内部に蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有し且つ導電材料で作成されたパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を導電材料で作製された連結管により連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結管の一部または全部を覆う低温発生部を冷却するタイプのパルス管式冷凍器であって、前記連結管の中間に、当該連結管を伝わる電流を遮断する絶縁部材を介設し、前記蓄冷器管と前記パルス管とを含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器を提供する。
上記第２の観点によるパルス管式冷凍器では、連結管の中間に絶縁部材を介設したので、蓄冷器管とパルス管とを電気的に絶縁することができ、蓄冷器管とパルス管の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。この結果、雑音磁場の発生を抑制して、微弱な磁場を測定する際の誤差を低減することが出来る。
【００１４】
第３の観点では、本発明は、蓄冷器管として機能させるための金属管と、その金属管の内周に同軸状に設けられたパルス管と、前記金属管を外壁とし前記パルス管を内壁とする筒状空間に充填され且つ導電材料で作成された蓄冷材と、前記金属管の内周に前記蓄冷材を取り囲むように設けられ前記金属管と前記蓄冷材とを含む電流ループが形成されることを抑制する絶縁筒と、前記金属管の一端側および前記パルス管の一端側に取り付けられたフランジと、前記金属管の他端側と前記パルス管の他端側とを連結する連結ブロックとを具備し、前記筒状空間および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却することを特徴とするパルス管式冷凍器を提供する。
上記第３の観点によるパルス管式冷凍器では、金属管の内周に、蓄冷材を取り囲むように絶縁筒を設けたので、蓄冷材と金属管とを電気的に絶縁することができ、両者の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。この結果、雑音磁場の発生を抑制でき、微弱な磁場を測定する際の誤差を低減することが出来る。
また、蓄冷器管として機能させるための金属管の内周に、パルス管を同軸状に設けるので、当該同軸構造の両端に相当する２ヶ所をシールするだけで冷媒ガスの漏出を防止でき、構造を簡単化できる。
さらに、金属管とパルス管とを同軸状に設けることで機械的な強度を高めることができ、各管の肉厚を小さくすることが出来る。
さらにまた、蓄冷器管やパルス管を別個独立に設ける場合よりも、小型化することが出来る。
【００１５】
第４の観点では、本発明は、上記第１の観点から第３の観点のいずれかのパルス管式冷凍器において、前記蓄冷器管と前記パルス管のうちの一方または両方の少なくとも一端側に、絶縁材料で作製され且つ前記冷媒ガスの通過孔が穿設されたスペーサを設け、前記蓄冷器管や前記パルス管を含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器を提供する。
上記第４の観点によるパルス管式冷凍器では、蓄冷器管やパルス管の少なくとも一端側に、絶縁材料製のスペーサを設けるので、蓄冷器管やパルス管の壁面と管内物との絶縁性をいっそう高めることができ、電流ループの形成による雑音磁場の発生をいっそう抑制することが出来る。
【００１６】
第５の観点では、本発明は、外界から磁気的に遮蔽された磁気遮蔽空間を内部に有する磁気遮蔽装置と，前記磁気遮蔽空間に設置され且つ容器状の外壁および内壁を有し当該内壁で囲まれた断熱空間内に磁気検出素子を冷却する冷却剤を保持し得る断熱装置と，前記外壁と前記内壁の間の層内に介設された少なくとも１枚の熱遮蔽板とを備えた磁気遮蔽型冷凍システムであって、前記内部空間にパルス管式冷凍器を設置し、前記熱遮蔽板に前記パルス管式冷凍器の低温発生部を熱的に結合させて前記熱遮蔽板を冷却すると共に、前記パルス管式冷凍器に冷媒ガスを送り出すための圧縮機と，前記パルス管式冷凍器と前記圧縮機の間で冷媒ガスをパルス的に往復させるように弁を切り換える切り換え弁とを前記磁気遮蔽装置の外部に設置したことを特徴とする磁気遮蔽型冷凍システムを提供する。
上記第５の観点による磁気遮蔽型冷凍システムでは、磁気遮蔽装置の内部に設置された断熱装置の熱遮蔽板をパルス管式冷凍器で冷やすので、断熱装置の断熱性能を向上して冷却剤の消費量を低減し、運転コストを節減することが出来る。また、ノイズ発生源となりやすい圧縮機や，切り換え弁を磁気遮蔽装置の外部に設置するので、磁気遮蔽装置内へのノイズの侵入を抑制でき、微弱な測定対象（磁気など）の精密測定に適した測定環境を得ることが出来る。
【００１７】
第６の観点では、本発明は、外界から磁気的に遮蔽された磁気遮蔽空間を内部に有する磁気遮蔽装置と，前記磁気遮蔽空間に設置され且つ容器状の外壁および内壁を有し当該内壁で囲まれた断熱空間内に磁気検出素子を冷却する冷却剤を保持し得る断熱装置とを備えた磁気遮蔽型冷凍システムであって、前記内壁の上部に断熱体を設け、前記断熱体に伝熱板を埋設または固設し、前記伝熱板にパルス管式冷凍器の低温発生部を熱的に結合させ且つ前記伝熱板の一部を前記冷却剤の気化ガスに接触させて冷却すると共に、前記パルス管式冷凍器に冷媒ガスを送り出す圧縮機と，前記パルス管式冷凍器と前記圧縮機の間で冷媒ガスをパルス的に往復させるように弁を切り換える切り換え弁を前記磁気遮蔽装置の外部に設置したことを特徴とする磁気遮蔽型冷凍システムを提供する。
上記第６の観点による磁気遮蔽型冷凍システムでは、磁気遮蔽装置の内部に設置された断熱装置の上部に断熱体を設けて、当該断熱体に伝熱板を埋設し（または固設し）、当該伝熱板をパルス管式冷凍器で冷やすので、冷却剤が気化したガス層の温度を下げることが出来る。これにより、断熱装置の断熱性能を向上して冷却剤の消費量を低減し、運転コストを節減することが出来る。また、ノイズ発生源となりやすい圧縮機や，切り換え弁を磁気遮蔽装置の外部に設置するので、磁気遮蔽装置内へのノイズの侵入を抑制でき、微弱な測定対象（磁気など）の精密測定に適した測定環境を得ることが出来る。
【００１８】
第７の観点では、本発明は、内部に導電材料で作成された蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有し且つ導電材料で作成されたパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を連結ブロックにより連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却するタイプのパルス管式冷凍器であって、前記蓄冷器管と前記パルス管の間に、両者を電気的に接続するシャントを介設し、両者の電位をほぼ等しくすることを特徴とするパルス管式冷凍器を提供する。
上記第７の観点によるパルス管式冷凍器では、蓄冷器管とパルス管との間にシャントを介設したから、両者の電位を常にほぼ等しくでき、蓄冷器管と連結ブロックとパルス管とに大電流の電流ループが形成されなくなる。この結果、雑音磁場の発生を抑制でき、微弱な磁場を測定する際の誤差を低減することが出来る。
【００１９】
【発明の実施の形態】
以下、図に示す実施形態により本発明をさらに詳細に説明する。なお、これにより本発明が限定されるものではない。
【００２０】
−第１の実施形態−
図１は、本発明の第１の実施形態にかかるパルス管式冷凍器を示す構成図である。
このパルス管式冷凍器１００は、内部に蓄冷材１０を充填された蓄冷器管１１と，内部に空洞Ｖを有するパルス管１２と，前記蓄冷器管１１の内周に前記蓄冷材１０を取り囲むように設けられた絶縁筒１と，前記蓄冷器管１１の上端と前記パルス管１２の上端とを連結する連結孔Ｃが形成された連結ブロック１３と，前記蓄冷器管１１の下端の管壁内側に冷媒ガスＧｒが供給されるガス配管１４の一端を位置付けると共に前記パルス管１２の下端の管壁内側にオリフィス１５の一端を位置付けるフランジ１６と，前記オリフィス１５の他端に連なるバッファーＢを有する放熱ケース１７とを具備して構成されている。前記冷媒ガスＧｒは、例えばヘリウムガスである。
前記蓄冷器管１１の下端には、前記冷媒ガスＧｒの通過孔が穿設され且つ絶縁材料で作製されたスペーサ２ａが設けられている。また、前記蓄冷器管１１の上端には、冷媒ガスＧｒの通過孔が穿設され且つ絶縁材料で作製されたスペーサ２ｂが設けられている。前記スペーサ２ａ，２ｂの材料は、例えばガラス繊維強化プラスチック（ＦＲＰ；Ｆｉｂｅｒ ｇｌａｓｓ Ｒｅｉｎｆｏｒｃｅｄ Ｐｌａｓｔｉｃ）である。
前記蓄冷器管１１と前記パルス管１２との間には、導電材料で作製されたシャント３−１，３−２，…が介設されている。前記シャント３−１，３−２，…の材料は、例えば銅である。
【００２１】
前記蓄冷材１０は、例えば銅網（網状に編まれた銅線）である。
前記蓄冷器管１１および前記パルス管１２の材料は、機械的に丈夫で，しかも断熱性能の高い非磁性金属材料であり、例えばステンレス鋼や、望ましくはチタン，チタン合金である。
前記絶縁筒１の材料は、例えばポリエステルやポリイミドなどの絶縁性プラスチックフィルムである。
前記連結ブロック１３および前記放熱ケース１７の材料は、熱伝導率の高い金属材料であり、例えば銅である。
【００２２】
前記連結ブロック１３は、前記蓄冷器管１１および前記パルス管１２内へ冷媒ガスＧｒをパルス的に出し入れすることで、極低温（例えば−２００℃程度）に冷却される。前記冷媒ガスＧｒは、例えばヘリウムガスである。
前記連結ブロック１３の上面には、被冷却体Ｍが載置されている。前記被冷却体Ｍは、例えば、微弱な磁場を検出するためのＳＱＵＩＤ素子を内蔵するセンサーユニットである。
【００２３】
前記蓄冷器管１１や前記パルス管１２の端部からの冷媒ガスＧｒの漏出を防止する見地から、前記蓄冷器管１１と前記連結ブロック１３との間は高気密性のシール部α１によりシールされ、前記蓄冷器管１１と前記フランジ１６との間は高気密性のシール部α２によりシールされ、前記パルス管１２と前記連結ブロック１３との間は高気密性のシール部α３によりシールされ、前記パルス管１２と前記フランジ１６との間は高気密性のシール部α４によりシールされている。これらのシール方法は、溶接もしくは鑞付けである。
【００２４】
図２は、図１のパルス管式冷凍器１００を含む冷凍システムの構成図である。この冷凍システム１１０は、前記パルス管式冷凍器１００のフランジ１６および放熱ケース１７を外部に出し且つ他の部分（蓄冷材１０，蓄冷器管１１，絶縁筒１，パルス管１２，連結ブロック１３，被冷却体Ｍ）を真空中に収容する真空容器９１と，冷媒ガスＧｒを高圧で送り出す高圧端子Ｈと前記冷媒ガスＧｒを回収する低圧端子Ｌとを有する圧縮機９２と、前記高圧端子Ｈおよび低圧端子Ｌから導出された高圧ガス配管９３および低圧ガス配管９４と、前記パルス管式冷凍器１００のガス配管１４に連結したガス配管９５と、電気配線９６を介して前記圧縮機９２と接続し且つ前記高圧ガス配管９３および低圧ガス配管９４を一定周期で交互に前記ガス配管９５と結合する内部弁を有するモータ駆動切り換え弁９７とを具備して構成されている。
【００２５】
以上のパルス管式冷凍器１００によれば、蓄冷器管１１の内周に蓄冷材１０を取り囲むように絶縁筒１を設けると共に、蓄冷器管１１の両端に絶縁材料製のスペーサ２ａ，２ｂを設けたので、蓄冷材１０と蓄冷器管１１とを電気的に絶縁することができ、両者の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。また、蓄冷器管１１とパルス管１２との間に、多数のシャント３−１，３−２，…を介設したから、両者の電位を常にほぼ等しくでき、蓄冷器管１１と連結ブロック１３とパルス管１２とに大電流の電流ループが形成されなくなる。
この結果、雑音磁場の発生を抑制でき、微弱な磁場を測定する際の誤差を低減することが出来る。
【００２６】
−第２の実施形態−
図３は、本発明の第２の実施形態にかかるパルス管式冷凍器を示す構成図である。
このパルス管式冷凍器２００は、内部に蓄冷材１０を充填された蓄冷器管１１と，内部に空洞Ｖを有するパルス管１２と，前記蓄冷器管１１の上端と前記パルス管１２の上端とを連結する連結管２１と，その連結管２１の中間に介設され且つ絶縁材料で作製された絶縁継ぎ手２２と，前記連結管２１を覆う低温発生部２３と，前記蓄冷器管１１の下端の管壁内側に冷媒ガスＧｒが供給されるガス配管１４の一端を位置付けると共に前記パルス管１２の下端の管壁内側にオリフィス１５の一端を位置付けるフランジ１６と，前記オリフィス１５の他端に連なるバッファーＢを有する放熱ケース１７とを具備して構成されている。
前記絶縁継ぎ手２２の材料は、例えばポリエステルやポリイミドなどの絶縁性プラスチックあるいはセラミック体である。
以上のパルス管式冷凍器２００によれば、連結管２１の中間に絶縁継ぎ手２２を介設したので、蓄冷器管１１とパルス管１２とを電気的に絶縁することができ、両者の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。
この結果、雑音磁場の発生を抑制して、微弱な磁場を測定する際の誤差を低減することが出来る。
【００２７】
−第３の実施形態−
図４は、本発明の第３の実施形態にかかるパルス管式冷凍器を示す構成図である。
このパルス管式冷凍器３００は、蓄冷器管として機能させるための金属管３１と，その金属管３１の内周に同軸状に設けられたパルス管３２と，前記金属管３１を外壁とし前記パルス管３２を内壁とする筒状空間に充填された蓄冷材３３と，前記金属管３１の内周に前記蓄冷材３３を取り囲むように設けられた絶縁筒４１と，前記金属管３１の上端と前記パルス管３２の上端とを連結する凹部が形成された連結ブロック３４と，前記筒状空間の下端の管壁内側にガス配管１４の一端を位置付けると共に前記パルス管３２の下端の管壁内側にオリフィス１５の一端を位置付けるフランジ１６と，前記オリフィス１５の他端に連なるバッファーＢを有する放熱ケース１７とを具備して構成されている。前記絶縁筒４１の材料は、例えばガラス繊維強化エポキシ樹脂である。前記金属管３１の材料は、例えばりん青銅やチタン合金である。前記パルス管３２の材料は、ガラス繊維強化樹脂やセラミック体である。
前記筒状空間の下端には、冷媒ガスＧｒの通過孔が穿設され且つ絶縁材料で作製されたスペーサ４５ａが設けられている。また、前記パルス管３２の上端には、冷媒ガスＧｒの通過孔が穿設され且つ絶縁材料で作製されたスペーサ４５ｂが設けられている。
前記金属管３１や前記パルス管３２の端部からの冷媒ガスＧｒの漏出を防止する見地から、前記金属管３１および前記パルス管３２と前記連結ブロック３４との間は高気密性のシール部α１１によりシールされ、前記金属管３１および前記パルス管３２と前記フランジ１６との間は高気密性のシール部α１２によりシールされている。
以上のパルス管式冷凍器３００によれば、金属管３１の内周に蓄冷材３３を取り囲むように絶縁筒４１を設けると共に、蓄冷材３３の両端に絶縁材料製のスペーサ４５ａ，４５ｂを設けたので、蓄冷材３３と金属管３１とを電気的に絶縁することができ、両者の間に熱起電力が発生して電流ループが形成されることを抑制することが出来る。この結果、雑音磁場の発生を抑制して、微弱な磁場を測定する際の誤差を低減することが出来る。
また、２ヶ所のシール部α１１，α１２を設けるだけで、蓄冷管として機能する金属管３１や，パルス管３２の両端からの冷媒ガスＧｒの漏出を防止できるので、構造を簡単にでき、製造コストを低減することが出来る。
さらに、金属管３１と，パルス管３２とを同軸状に設けることで機械的な強度を高めることができ、各管の肉厚を小さくすることが出来る。
さらにまた、蓄冷器管やパルス管を別個独立に設ける場合よりも、小型化することが出来る。
【００２８】
−第４の実施形態−
図５は、本発明の第４の実施形態にかかる磁気遮蔽型冷凍システムを示す構成図である。
この磁気遮蔽型冷凍システム４００は、外界から磁気的に遮蔽された内部空間を有する磁気遮蔽装置５１と，容器状の外壁Ｗｏと内壁Ｗｉとを有し前記内壁Ｗｉで囲まれた空間内に冷却剤５２が保持された断熱装置５３と，前記外壁Ｗｏと前記内壁Ｗｉの間の真空層内に設けられた熱遮蔽板５４と，前記内壁Ｗｉの底部に配設されたＳＱＵＩＤ素子などのセンサー５５と，前記熱遮蔽板５４に低温発生部すなわち連結ブロック１３を接触させ且つ放熱ケース１７を断熱装置５３の外部へ出したパルス管式冷凍器９００（図９参照）と，前記内壁Ｗｉの上部に設けられた断熱体５６と、前記パルス管式冷凍器９００にヘリウムガスなどの冷媒ガスＧｒを送り出す圧縮機９２と，前記パルス管式冷凍器９００と前記圧縮機９２の間で前記冷媒ガスＧｒをパルス的に往復させるように弁を切り換えるモータ駆動切り換え弁９７とを具備して構成されている。前記冷却剤５２は、例えば液体ヘリウムである。前記断熱装置５３の壁面の材料は、例えばガラス繊維強化プラスチック（ＦＲＰ）である。前記断熱体５６の材料は、例えば多孔質のポリスチレンである。前記熱遮蔽板５４の材料は、例えば銅やアルミニウム，あるいは絶縁した銅線や銅網，またはそれらを樹脂シートと一体化したものである。
前記圧縮機９２と，前記モータ駆動切り換え弁９７は、前記磁気遮蔽装置５１の外部に設置されている。
前記冷却剤５２が気化した低温のガスｇは、前記断熱装置５３の内壁Ｗｉと前記断熱体５６との隙間を通って放出される。このとき、前記内壁Ｗｉおよび前記熱遮蔽板５４は、前記ガスｇによって熱が奪取され、冷却される。
なお、前記パルス管式冷凍器９００と前記モータ駆動切り換え弁９７とを接続するガス配管９５は、前記磁気遮蔽装置５１内へのノイズの侵入を防止する見地から、できる限り短くし且つ磁気遮蔽装置５１の内側と外側とで電気的に絶縁することが好ましい。また、ガス配管９５が導電性の材料で作製されている場合には、当該ガス配管９５を前記磁気遮蔽装置５１の壁面と同電位にすることが好ましい。
以上の磁気遮蔽型冷凍システム４００によれば、熱遮蔽板５４にパルス管式冷凍器９００の連結ブロック１３を接触させて当該熱遮蔽板５４を冷やすので、断熱性能を向上して冷却剤５２の消費量を低減し、運転コストを節減することが出来る。
また、ノイズ発生源となりやすい圧縮機９２と，モータ駆動切り換え弁９７を、磁気遮蔽装置５１の外部に設置するので、磁気遮蔽装置５１内へのノイズの侵入を抑制し、微弱な磁気などを正確に測定することが出来る。
【００２９】
−第５の実施形態−
図６は、本発明の第５の実施形態にかかる磁気遮蔽型冷凍システムを示す構成図である。
この磁気遮蔽型冷凍システム５００は、外界から磁気的に遮蔽された内部空間を有する磁気遮蔽装置５１と，容器状の外壁Ｗｏと内壁Ｗｉとを有し前記内壁Ｗｉで囲まれた空間内に冷却剤５２が保持された断熱装置５３と，前記外壁Ｗｏと前記内壁Ｗｉの間の真空層内に設けられた熱遮蔽板５４と，前記内壁Ｗｉの底部に配設されたＳＱＵＩＤ素子などのセンサー５５と、前記内壁Ｗｉの上部に設けられ且つ両端面が前記熱遮蔽板５４と対面した伝熱板６１を埋設された（または固設された）断熱体５６と，前記伝熱板６１に低温発生部すなわち連結ブロック１３を接触させたパルス管式冷凍器９００（図９参照）と，そのパルス管式冷凍器９００にヘリウムガスなどの冷媒ガスＧｒを送り出す圧縮機９２と、前記パルス管式冷凍器９００と前記圧縮機９２の間で前記冷媒ガスＧｒをパルス的に往復させるように弁を切り換えるモータ駆動切り換え弁９７とを具備して構成されている。前記伝熱板６１の材料は、例えば銅である。
前記圧縮機９２と，モータ駆動切り換え弁９７は、前記磁気遮蔽装置５１の外部に設置されている。
前記伝熱板６１の両端面は、冷却剤５２が気化したガスｇの層を介して、前記熱遮蔽板５４と熱的に接続されるので、前記ガスｇが、前記伝熱板６１と前記熱遮蔽板５４との間隙で冷却される。
以上の磁気遮蔽型冷凍システム５００によれば、冷却剤５２が気化したガスｇの温度をいっそう下げて断熱性能を向上できるので、冷却剤５２の消費量を低減し、運転コストを節減することが出来る。
また、ノイズ発生源となりやすい圧縮機９２と，モータ駆動切り換え弁９７を、磁気遮蔽装置５１の外部に設置するので、磁気遮蔽装置５１内へのノイズの侵入を抑制し、微弱な磁気などを正確に測定することが出来る。
【００３０】
−第６の実施形態−
図７は、本発明の第６の実施形態にかかる磁気遮蔽型冷凍システムを示す構成図である。
この磁気遮蔽型冷凍システム６００は、上記第１の実施形態にかかるパルス管式冷凍器１００（図１参照）の連結ブロック１３を、熱遮蔽板５４に接触させて、当該熱遮蔽板５４を冷却する構成である。
以上の磁気遮蔽型冷凍システム６００によれば、熱遮蔽板５４にパルス管式冷凍器１００の連結ブロック１３を接触させて当該熱遮蔽板５４を冷やすので、冷却剤５２の消費量を低減して、運転コストを節減することが出来る。
また、上記第１の実施形態にかかるパルス管式冷凍器１００を用いるので、蓄冷器管（図１の１１）と，その内部に充填された蓄冷材（図１の１０）とを電気的に絶縁でき、電流ループの形成による磁気雑音の発生を低減することが出来る。
【００３１】
−第７の実施形態−
図８は、本発明の第７の実施形態にかかる磁気遮蔽型冷凍システムを示す構成図である。
この磁気遮蔽型冷凍システム７００は、上記第１の実施形態にかかるパルス管式冷凍器１００（図１参照）の連結ブロック１３を、断熱体５６に埋設された伝熱板６１に接触させて、当該伝熱板６１を冷却する構成である。
以上の磁気遮蔽型冷凍システム７００によれば、冷却剤５２が気化したガスｇの温度をいっそう下げて断熱性能を向上できるので、冷却剤５２の消費量を低減し、運転コストを節減することが出来る。
また、上記第１の実施形態にかかるパルス管式冷凍器１００を用いるので、蓄冷器管（図１の１１）と，その内部に充填された蓄冷材（図１の１０）とを電気的に絶縁でき、電流ループの形成による磁気雑音の発生を低減することが出来る。
【００３２】
【発明の効果】
本発明のパルス管式冷凍器によれば、蓄冷器管と蓄冷材とを蓄冷器管の内周に設けた絶縁筒により絶縁したり，蓄冷器管とパルス管とを連結管に介設した絶縁部材で絶縁するので、電流ループの形成に起因する雑音を低減でき、微弱な物理量（磁気など）を正確に測定することが出来る。
また、本発明の磁気遮蔽型冷凍システムによれば、磁気遮蔽装置内の断熱装置の熱遮蔽板をパルス管式冷凍器で冷やすか、または、断熱体に埋設されるか固設された伝熱板をパルス管式冷凍器で冷やして当該伝熱板と熱遮蔽板との間のガス層の温度を下げるので、断熱性能を向上でき、冷却剤の消費量を低減できる。
【図面の簡単な説明】
【図１】本発明の第１の実施形態にかかるパルス管式冷凍器を示す構成図である。
【図２】図１のパルス管式冷凍器を含む冷凍システムの構成図である。
【図３】本発明の第２の実施形態にかかるパルス管式冷凍器を示す構成図である。
【図４】本発明の第３の実施形態にかかるパルス管式冷凍器を示す構成図である。
【図５】本発明の第４の実施形態にかかる磁気遮蔽型冷凍システムの構成図である。
【図６】本発明の第５の実施形態にかかる磁気遮蔽型冷凍システムの構成図である。
【図７】本発明の第６の実施形態にかかる磁気遮蔽型冷凍システムの構成図である。
【図８】本発明の第７の実施形態にかかる磁気遮蔽型冷凍システムの構成図である。
【図９】従来のパルス管式冷凍器の一例を示す構成図である。
【図１０】図９のパルス管式冷凍器を含む冷凍システムを示す構成図である。
【図１１】従来の磁気遮蔽型冷凍システムを示す構成図である。
【図１２】図９のパルス管式冷凍器の各部に形成された電流ループの説明図である。
【符号の説明】
１００，２００，３００ パルス管式冷凍器
４００，５００，６００，７００ 磁気遮蔽型冷凍システム
１，４１ 絶縁筒
２ａ，２ｂ，４５ａ，４５ｂ スペーサ
３−１，３−２，３−３，３−４ シャント
１０，３３ 蓄冷材
１１ 蓄冷器管
１２，３２ パルス管
１３ 連結ブロック
２２ 絶縁継ぎ手
３１ 金属管
５１ 磁気遮蔽装置
５２ 冷却剤
５３ 断熱装置
５４ 熱遮蔽板
５５ センサー
５６ 断熱体
６１ 伝熱板
９２ 圧縮機
９７ モータ駆動切り換え弁[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a pulse tube refrigerator and a magnetically shielded refrigeration system. More specifically, a pulse tube refrigerator that has been improved to suppress the formation of a current loop caused by a thermoelectromotive force generated due to a material difference and a temperature difference in each part, and has been improved so as to reduce the amount of evaporation of a coolant. The present invention relates to a magnetic shield type refrigeration system. In particular, it is useful for cooling sensors such as SQUIDs (Superconducting Quantum Interference Devices).
[0002]
[Prior art]
FIG. 9 is a configuration diagram showing an example of a conventional pulse tube refrigerator.
The pulse tube refrigerator 900 includes a regenerator tube 11 filled with a regenerator material 10, a pulse tube 12 having a cavity V therein, an upper end of the regenerator tube 10 and an upper end of the pulse tube 12. A connecting block 13 formed with a connecting hole C for connecting a gas pipe 14 and one end of a gas pipe 14 inside a pipe wall at a lower end of the regenerator tube 11 and an end of an orifice 15 inside a pipe wall at a lower end of the pulse pipe 12. And a heat radiating case 17 having a buffer B connected to the other end of the orifice 15.
[0003]
The cold storage material 10 is, for example, a copper net (copper wire woven in a net shape).
The material of the regenerator tube 11 and the pulse tube 12 is a metal material that is mechanically strong and has high heat insulation performance, for example, stainless steel.
The material of the connection block 13 and the heat radiation case 17 is a metal material having a high thermal conductivity, for example, copper.
[0004]
The connection block 13 is cooled to an extremely low temperature (for example, about -200 ° C.) by putting the refrigerant gas Gr into and out of the regenerator tube 11 and the pulse tube 12 in a pulsed manner. The refrigerant gas Gr is, for example, helium gas.
A cooling target M is placed on the upper surface of the connection block 13. The cooled object M is, for example, a sensor unit having a built-in SQUID element for detecting a weak magnetic field.
[0005]
From the viewpoint of preventing the refrigerant gas Gr from leaking from the ends of the regenerator tube 11 and the pulse tube 12, the space between the regenerator tube 11 and the connection block 13 is sealed by a highly airtight seal portion α1. The space between the regenerator tube 11 and the flange 16 is sealed by a highly airtight seal portion α2, and the space between the pulse tube 12 and the connection block 13 is sealed by a highly airtight seal portion α3. The space between the pulse tube 12 and the flange 16 is sealed by a highly airtight seal portion α4.
[0006]
FIG. 10 is a configuration diagram of a refrigeration system including the pulse tube refrigerator 900 of FIG.
In this refrigeration system 910, the flange 16 and the radiating case 17 of the pulse tube refrigerator 900 are exposed to the outside and the other parts (the cold storage material 10, the cold storage tube 11, the pulse tube 12, the connection block 13, the cooling target M ) In a vacuum, a compressor 92 having a high-pressure terminal H for sending the refrigerant gas Gr at high pressure and a low-pressure terminal L for collecting the refrigerant gas Gr, and a high-pressure terminal H and a low-pressure terminal L. The high-pressure gas pipe 93 and the low-pressure gas pipe 94, the gas pipe 95 connected to the gas pipe 14 of the pulse tube refrigerator 900, and the high-pressure gas connected to the compressor 92 via an electric wiring 96. A motor drive switching valve 97 having an internal valve for alternately connecting the pipe 93 and the low-pressure gas pipe 94 to the gas pipe 95 at a constant period of, for example, 1 to 20 Hz is provided. It is configured Te.
[0007]
During the period when the motor drive switching valve 97 switches the internal valve to the high-pressure gas pipe 93, that is, the high-pressure terminal H, the refrigerant gas is supplied through the regenerator tube 11 and the connection hole C of the connection block 13 (FIG. 9). Gr flows into the pulse tube 12 in a pulsed manner. At this time, the refrigerant gas Gr is compressed at the lower end (buffer B side) of the pulse tube 12 to generate heat, and the heat is radiated from the heat radiation case 17.
On the other hand, during the period when the motor switching valve 65 is switching the internal valve to the low-pressure gas pipe 94, that is, the low-pressure terminal L, the pulse pipe 12 is connected to the inside of the pulse tube 12 through the connection hole C of the connection block 13 and the regenerator tube 11. Refrigerant gas Gr flows out in a pulsed manner. At this time, since the refrigerant gas Gr flows out while adiabatically expanding at the upper end (the regenerator tube 11 side) of the pulse tube 12, the vicinity of the upper end becomes cold, and the cool air is absorbed by the cold storage material 10, and The temperature of the connection block 14 decreases.
Therefore, by continuously switching the internal valve of the motor drive switching valve 97, the temperature of the connection block 13 can be reduced to an extremely low temperature, and the object to be cooled M can be cooled.
[0008]
FIG. 11 is a configuration diagram showing an example of a conventional magnetically shielded refrigeration system.
The magnetically shielded refrigeration system 920 includes a magnetically shielded device 51 having an inner space magnetically shielded from the outside, a container-shaped outer wall Wo and an inner wall Wi, and cooling in a space surrounded by the inner wall Wi. A heat insulating device 53 holding an agent 52, a heat shield plate 54 provided in a vacuum layer between the outer wall Wo and the inner wall Wi, a sensor 55 disposed at the bottom of the inner wall Wi, And a heat insulator 56 provided above Wi. The coolant 52 is, for example, liquid helium. The sensor 55 is a magnetic detection element such as a SQUID element.
The low-temperature gas g vaporized by the coolant 52 is discharged through a gap between the inner wall Wi of the heat insulating device 53 and the heat insulator 56. At this time, the inner wall Wi and the heat shielding plate 54 receive heat from the gas g and are cooled.
[0009]
[Problems to be solved by the invention]
In the above-described conventional pulse tube refrigerator 900, as shown in FIG. 12, a thermoelectromotive force is generated due to a material difference and a temperature difference between the regenerator material 10 and the regenerator tube 11, and the thermoelectromotive force generates the thermoelectromotive force. And a current loop i-1 transmitted through the regenerator tube 11 is easily formed. Similarly, a current loop i-2 due to the thermoelectromotive force is easily formed between the regenerator tube 11, the connection block 13, and the pulse tube 12.
However, since such current loops i-1 and i-2 cause magnetic noise N, there is a problem that an error in measuring a weak magnetic field increases.
[0010]
Further, in the above-described conventional magnetically shielded refrigeration system 920, since the coolant 52 is liable to evaporate due to the intrusion of heat from the outside, the coolant 52 needs to be replenished frequently, and the operating cost increases. is there.
[0011]
Therefore, a first object of the present invention is to provide a pulse tube refrigerator capable of suppressing the formation of a current loop caused by a thermoelectromotive force generated due to a material difference or a temperature difference between components.
A second object of the present invention is to provide a magnetically shielded refrigeration system that can reduce the amount of evaporation of a coolant.
[0012]
[Means for Solving the Problems]
In a first aspect, the present invention providesMade of conductive materialFilled with cold storage materialAnd made of conductive materialA regenerator tube and a pulse tube having a cavity therein are arranged substantially in parallel, flanges are attached to one end of the regenerator tube and one end of the pulse tube, and the other end of the regenerator tube and the pulse A pulse tube refrigerator of a type in which the other end of the tube is connected by a connection block, and the regenerator tube and the pulse tube are cooled to cool the connection block by introducing and removing a refrigerant gas in a pulsed manner. An insulating cylinder is provided on the inner periphery of the regenerator tube so as to surround the regenerator material.Suppressing the formation of a current loop including the regenerator tube and the regenerator material.A pulse tube refrigerator is provided.
In the pulse tube refrigerator according to the first aspect, the insulating tube is provided so as to surround the regenerator material on the inner periphery of the regenerator tube, so that the regenerator material and the regenerator tube can be electrically insulated. The formation of a current loop due to the generation of a thermoelectromotive force during the period can be suppressed. As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
[0013]
In a second aspect, the present invention provides a cold storage material filled therein.And made of conductive materialHas a regenerator tube and a cavity insideAnd made of conductive materialA pulse tube and a pulse tube are arranged substantially in parallel, flanges are attached to one end of the regenerator tube and one end of the pulse tube, and a conductive path is provided between the other end of the regenerator tube and the other end of the pulse tube. A pulse tube type of a type that is connected by a connecting pipe made of a material and cools a low-temperature generating portion that covers a part or the entirety of the connecting pipe by pulsating refrigerant gas into and out of the regenerator tube and the pulse tube. In a refrigerator, an insulating member for interrupting a current transmitted through the connection pipe is provided in the middle of the connection pipe.Suppressing the formation of a current loop including the regenerator tube and the pulse tube.A pulse tube refrigerator is provided.
In the pulse tube refrigerator according to the second aspect, since the insulating member is provided in the middle of the connecting tube, the regenerator tube and the pulse tube can be electrically insulated. It is possible to suppress the formation of a current loop due to generation of a thermoelectromotive force in between. As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
[0014]
In a third aspect, the present invention provides a metal tube for functioning as a regenerator tube, a pulse tube provided coaxially on the inner periphery of the metal tube, an outer wall having the metal tube as an inner wall, And filled into the cylindrical spaceAnd made of conductive materialCold storage material, provided on the inner periphery of the metal tube so as to surround the cold storage materialSuppress formation of a current loop including the metal tube and the cold storage materialAn insulating cylinder, a flange attached to one end of the metal tube and one end of the pulse tube, and a connection block for connecting the other end of the metal tube and the other end of the pulse tube; A pulse tube refrigerator is provided in which the connection block is cooled by pulsating refrigerant gas into and out of the cylindrical space and the pulse tube.
In the pulse tube refrigerator according to the third aspect, since the insulating tube is provided on the inner periphery of the metal tube so as to surround the cold storage material, the cold storage material and the metal tube can be electrically insulated. The formation of a current loop due to the generation of a thermoelectromotive force during the period can be suppressed. As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
In addition, since the pulse tube is provided coaxially on the inner periphery of the metal tube for functioning as a regenerator tube, leakage of the refrigerant gas can be prevented only by sealing two places corresponding to both ends of the coaxial structure. Can be simplified.
Further, by providing the metal tube and the pulse tube coaxially, mechanical strength can be increased, and the wall thickness of each tube can be reduced.
Furthermore, the size can be reduced as compared with a case where a regenerator tube and a pulse tube are separately provided.
[0015]
In a fourth aspect, the present invention provides the pulse tube refrigerator according to any one of the first to third aspects, wherein at least one end of one or both of the regenerator tube and the pulse tube is provided. Providing a spacer made of an insulating material and having a hole through which the refrigerant gas passes.To prevent the current loop including the regenerator tube and the pulse tube from being formed.A pulse tube refrigerator is provided.
In the pulse tube refrigerator according to the fourth aspect, a spacer made of an insulating material is provided on at least one end side of the regenerator tube or the pulse tube. Therefore, it is possible to further increase the noise magnetic field due to the formation of the current loop.
[0016]
In a fifth aspect, the invention is magnetically shielded from the outside worldMagnetic shielding space insideA magnetic shielding device havingMagnetic shieldingIt is installed in a space and has a container-like outer wall and inner wall, and is surrounded by the inner wall.InsulationIn spaceCool the magnetic sensing elementInsulation device that can hold coolantAnd beforeA magnetically shielded refrigeration system comprising at least one heat shield plate interposed in a layer between the outer wall and the inner wall,Install a pulse tube refrigerator in the internal space,To the heat shield plateSaidThe low temperature generating part of the pulse tube refrigerator is thermally coupledTo cool the heat shieldA compressor for sending refrigerant gas to the pulse tube refrigerator; and a switching valve for switching a valve to reciprocate the refrigerant gas between the pulse tube refrigerator and the compressor in a pulsed manner. A magnetic shield type refrigeration system is provided outside the magnetic shield device.
In the magnetically shielded refrigeration system according to the fifth aspect, the heat shield plate of the heat insulating device installed inside the magnetic shield device is cooled by the pulse tube refrigerator, so that the heat insulating performance of the heat insulating device is improved and the coolant is cooled. The consumption can be reduced and the operating cost can be saved. In addition, since a compressor and a switching valve, which are likely to be noise sources, are installed outside the magnetic shielding device, it is possible to suppress the intrusion of noise into the magnetic shielding device, and it is suitable for precise measurement of weak measurement targets (magnetism etc.) Measurement environment can be obtained.
[0017]
In a sixth aspect, the invention is magnetically shielded from the outside worldMagnetic shielding space insideA magnetic shielding device havingMagnetic shieldingIt is installed in a space and has a container-like outer wall and inner wall, and is surrounded by the inner wall.InsulationIn spaceCool the magnetic sensing elementInsulation device that can hold coolantAndA magnetically shielded refrigeration system comprising: a heat insulator provided on an upper portion of the inner wall;BiographyA hot plate is buried or fixed, and the low-temperature generating part of the pulse tube refrigerator is thermally coupled to the heat transfer plate.And cooling a portion of the heat transfer plate by contacting the vaporized gas of the coolant.And a switching valve for switching a valve to reciprocate the refrigerant gas between the pulse tube refrigerator and the compressor in a pulsed manner. Provided is a magnetically shielded refrigeration system, which is installed outside the apparatus.
In the magnetic shield type refrigeration system according to the sixth aspect, a heat insulator is provided above the heat insulator installed inside the magnetic shield device, and the heat insulator is provided.BiographyThe heat plate is buried (or fixed) and the heat transfer plate is cooled by a pulse tube refrigerator, so the temperature of the gas layer where the coolant has vaporizedBelowI can do it. Thereby, the heat insulating performance of the heat insulating device can be improved, the consumption of the coolant can be reduced, and the operating cost can be reduced. In addition, since a compressor and a switching valve, which are likely to be noise sources, are installed outside the magnetic shielding device, it is possible to suppress the intrusion of noise into the magnetic shielding device, and it is suitable for precise measurement of weak measurement targets (magnetism etc.) Measurement environment can be obtained.
[0018]
In a seventh aspect, the present invention provides:A regenerator tube filled with a regenerator material made of a conductive material and made of a conductive material and a pulse tube made of a conductive material and having a cavity therein are arranged substantially parallel to each other. A flange is attached to one end of the instrument tube and one end of the pulse tube, and the other end of the regenerator tube and the other end of the pulse tube are connected by a connection block. A pulse tube refrigerator of a type that cools the connection block by pulsating refrigerant gas into and out of the tube, wherein a shunt is provided between the regenerator tube and the pulse tube to electrically connect the two. And a pulse tube type refrigerator characterized in that both have substantially equal potentials.
In the pulse tube refrigerator according to the seventh aspect, since the shunt is interposed between the regenerator tube and the pulse tube, the potentials of both can always be substantially equal, and the regenerator tube, the connection block, and the pulse tube are connected to each other. A large current loop is not formed. As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the drawings. Note that the present invention is not limited to this.
[0020]
-1st Embodiment-
FIG. 1 is a configuration diagram showing a pulse tube refrigerator according to a first embodiment of the present invention.
The pulse tube refrigerator 100 includes a regenerator tube 11 filled with a regenerator 10, a pulse tube 12 having a cavity V therein, and the regenerator 10 surrounded on the inner periphery of the regenerator tube 11. Block 13 having a connecting hole C connecting the upper end of the regenerator tube 11 and the upper end of the pulse tube 12, and a tube wall at the lower end of the regenerator tube 11. It has a flange 16 for positioning one end of a gas pipe 14 to which the refrigerant gas Gr is supplied and one end of an orifice 15 inside the tube wall at the lower end of the pulse tube 12, and a buffer B connected to the other end of the orifice 15. The heat radiation case 17 is provided. The refrigerant gas Gr is, for example, helium gas.
At the lower end of the regenerator tube 11, a through hole for the refrigerant gas Gr is provided, and a spacer 2a made of an insulating material is provided. At the upper end of the regenerator tube 11, a through hole for the refrigerant gas Gr is provided, and a spacer 2b made of an insulating material is provided. The material of the spacers 2a and 2b is, for example, a fiber glass reinforced plastic (FRP).
Shunts 3-1, 3-2,... Made of a conductive material are interposed between the regenerator tube 11 and the pulse tube 12. The material of the shunts 3-1, 3-2,... Is, for example, copper.
[0021]
The cold storage material 10 is, for example, a copper net (copper wire woven in a net shape).
The material of the regenerator tube 11 and the pulse tube 12 is a non-magnetic metal material that is mechanically strong and has high heat insulation performance, for example, stainless steel, or desirably titanium or a titanium alloy.
The material of the insulating cylinder 1 is, for example, an insulating plastic film such as polyester or polyimide.
The material of the connection block 13 and the heat radiation case 17 is a metal material having a high thermal conductivity, for example, copper.
[0022]
The connection block 13 is cooled to an extremely low temperature (for example, about -200 ° C.) by putting the refrigerant gas Gr into and out of the regenerator tube 11 and the pulse tube 12 in a pulsed manner. The refrigerant gas Gr is, for example, helium gas.
A cooling target M is placed on the upper surface of the connection block 13. The cooled object M is, for example, a sensor unit having a built-in SQUID element for detecting a weak magnetic field.
[0023]
From the viewpoint of preventing the refrigerant gas Gr from leaking from the ends of the regenerator tube 11 and the pulse tube 12, the space between the regenerator tube 11 and the connection block 13 is sealed by a highly airtight seal portion α1. The space between the regenerator tube 11 and the flange 16 is sealed by a highly airtight seal portion α2, and the space between the pulse tube 12 and the connection block 13 is sealed by a highly airtight seal portion α3. The space between the pulse tube 12 and the flange 16 is sealed by a highly airtight seal portion α4. These sealing methods are welding or brazing.
[0024]
FIG. 2 is a configuration diagram of a refrigeration system including the pulse tube refrigerator 100 of FIG. In this refrigeration system 110, the flange 16 and the heat radiating case 17 of the pulse tube refrigerator 100 are taken out and other parts (the cold storage material 10, the cold storage tube 11, the insulating tube 1, the pulse tube 12, the connection block 13, A vacuum vessel 91 for accommodating the object to be cooled M) in a vacuum, a compressor 92 having a high-pressure terminal H for sending the refrigerant gas Gr at a high pressure, and a low-pressure terminal L for collecting the refrigerant gas Gr; A high-pressure gas pipe 93 and a low-pressure gas pipe 94 derived from the low-pressure terminal L, a gas pipe 95 connected to the gas pipe 14 of the pulse tube refrigerator 100, and an electric wiring 96 connected to the compressor 92. And a motor drive switching valve 97 having an internal valve for connecting the high-pressure gas pipe 93 and the low-pressure gas pipe 94 alternately with the gas pipe 95 at regular intervals. To have.
[0025]
According to the pulse tube refrigerator 100 described above, the insulating cylinder 1 is provided so as to surround the regenerator material 10 on the inner periphery of the regenerator tube 11, and spacers 2 a and 2 b made of an insulating material are provided at both ends of the regenerator tube 11. Since it is provided, the regenerator material 10 and the regenerator tube 11 can be electrically insulated, and the formation of a current loop due to generation of a thermoelectromotive force therebetween can be suppressed. Further, since a large number of shunts 3-1, 3-2,... Are interposed between the regenerator tube 11 and the pulse tube 12, the potentials of both can always be substantially equal, and the regenerator tube 11 and the connecting block 13 are connected. And the pulse tube 12 no longer forms a large current loop.
As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
[0026]
-2nd Embodiment-
FIG. 3 is a configuration diagram illustrating a pulse tube refrigerator according to a second embodiment of the present invention.
The pulse tube refrigerator 200 includes a regenerator tube 11 filled with a regenerator material 10, a pulse tube 12 having a cavity V therein, an upper end of the regenerator tube 11, and an upper end of the pulse tube 12. , An insulating joint 22 provided in the middle of the connecting pipe 21 and made of an insulating material, a low-temperature generating part 23 covering the connecting pipe 21, and a lower end of the regenerator tube 11. A flange 16 that positions one end of the gas pipe 14 to which the refrigerant gas Gr is supplied inside the pipe wall and one end of the orifice 15 inside the pipe wall at the lower end of the pulse tube 12, and a buffer B connected to the other end of the orifice 15 And a heat radiating case 17 having the following.
The material of the insulating joint 22 is, for example, an insulating plastic such as polyester or polyimide or a ceramic body.
According to the above-described pulse tube refrigerator 200, since the insulating joint 22 is provided in the middle of the connecting tube 21, the regenerator tube 11 and the pulse tube 12 can be electrically insulated. The formation of a current loop due to the generation of thermoelectromotive force can be suppressed.
As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
[0027]
-Third embodiment-
FIG. 4 is a configuration diagram illustrating a pulse tube refrigerator according to a third embodiment of the present invention.
The pulse tube refrigerator 300 includes a metal tube 31 for functioning as a regenerator tube, a pulse tube 32 coaxially provided on the inner periphery of the metal tube 31, and the pulse tube 32 having the metal tube 31 as an outer wall. A cold storage material 33 filled in a cylindrical space having a tube 32 as an inner wall; an insulating tube 41 provided on the inner periphery of the metal tube 31 so as to surround the cold storage material 33; A connection block formed with a concave portion connecting the upper end of the pulse tube; and an end of the gas pipe positioned inside a tube wall at a lower end of the cylindrical space, and an orifice formed inside a tube wall at a lower end of the pulse tube. The orifice 15 includes a flange 16 for positioning one end of the orifice 15 and a heat dissipation case 17 having a buffer B connected to the other end of the orifice 15. The material of the insulating cylinder 41 is, for example, a glass fiber reinforced epoxy resin. The material of the metal tube 31 is, for example, phosphor bronze or a titanium alloy. The material of the pulse tube 32 is a glass fiber reinforced resin or a ceramic body.
At the lower end of the cylindrical space, there is provided a spacer 45a formed with a passage hole for the refrigerant gas Gr and made of an insulating material. At the upper end of the pulse tube 32, a spacer 45b formed with a through hole for the refrigerant gas Gr and made of an insulating material is provided.
From the viewpoint of preventing leakage of the refrigerant gas Gr from the ends of the metal tube 31 and the pulse tube 32, a highly airtight seal portion α11 is provided between the metal tube 31 and the pulse tube 32 and the connection block 34. The gap between the metal tube 31 and the pulse tube 32 and the flange 16 is sealed by a highly airtight seal portion α12.
According to the pulse tube refrigerator 300 described above, the insulating tube 41 is provided on the inner periphery of the metal tube 31 so as to surround the cold storage material 33, and the spacers 45 a and 45 b made of an insulating material are provided at both ends of the cold storage material 33. Therefore, the cold storage material 33 and the metal tube 31 can be electrically insulated, and the formation of a current loop due to generation of a thermoelectromotive force therebetween can be suppressed. As a result, generation of a noise magnetic field can be suppressed, and errors in measuring a weak magnetic field can be reduced.
In addition, the leakage of the refrigerant gas Gr from both ends of the metal tube 31 functioning as a cold storage tube and the pulse tube 32 can be prevented only by providing the two seal portions α11 and α12, so that the structure can be simplified and the manufacturing cost can be reduced. Can be reduced.
Further, by providing the metal tube 31 and the pulse tube 32 coaxially, mechanical strength can be increased, and the wall thickness of each tube can be reduced.
Furthermore, the size can be reduced as compared with a case where a regenerator tube and a pulse tube are separately provided.
[0028]
-Fourth embodiment-
FIG. 5 is a configuration diagram illustrating a magnetically shielded refrigeration system according to a fourth embodiment of the present invention.
This magnetically shielded refrigeration system 400 has a magnetically shielded device 51 having an inner space magnetically shielded from the outside, a container-shaped outer wall Wo and an inner wall Wi, and cooling in a space surrounded by the inner wall Wi. A heat insulating plate 53 holding the agent 52, a heat shielding plate 54 provided in a vacuum layer between the outer wall Wo and the inner wall Wi, and a sensor 55 such as a SQUID element disposed at the bottom of the inner wall Wi. And a pulse tube refrigerator 900 (see FIG. 9) in which the low-temperature generating portion, that is, the connecting block 13 is brought into contact with the heat shield plate 54 and the heat radiation case 17 is extended outside the heat insulating device 53; A heat insulator 56 provided, a compressor 92 for sending a refrigerant gas Gr such as helium gas to the pulse tube refrigerator 900, and the refrigerant gas between the pulse tube refrigerator 900 and the compressor 92. It is configured by including a motor drive switching valve 97 for switching the valve so as to reciprocate the r in a pulsed manner. The coolant 52 is, for example, liquid helium. The material of the wall surface of the heat insulating device 53 is, for example, glass fiber reinforced plastic (FRP). The material of the heat insulator 56 is, for example, porous polystyrene. The material of the heat shielding plate 54 is, for example, copper or aluminum, an insulated copper wire or a copper net, or a material obtained by integrating them with a resin sheet.
The compressor 92 and the motor drive switching valve 97 are installed outside the magnetic shielding device 51.
The low-temperature gas g vaporized by the coolant 52 is discharged through a gap between the inner wall Wi of the heat insulating device 53 and the heat insulator 56. At this time, the inner wall Wi and the heat shielding plate 54 receive heat from the gas g and are cooled.
In addition, the gas pipe 95 connecting the pulse tube refrigerator 900 and the motor drive switching valve 97 is made as short as possible from the viewpoint of preventing intrusion of noise into the magnetic shield device 51, and is provided with a magnetic shield device. It is preferable that the inside and outside of 51 are electrically insulated. When the gas pipe 95 is made of a conductive material, it is preferable that the gas pipe 95 has the same potential as the wall surface of the magnetic shielding device 51.
According to the magnetic shield type refrigeration system 400 described above, the connection block 13 of the pulse tube refrigerator 900 is brought into contact with the heat shield plate 54 to cool the heat shield plate 54, so that the heat insulation performance is improved and the coolant 52 The consumption can be reduced and the operating cost can be saved.
In addition, since the compressor 92 and the motor drive switching valve 97, which are likely to be noise sources, are installed outside the magnetic shielding device 51, it is possible to suppress noise from entering the magnetic shielding device 51 and accurately detect weak magnetism. Can be measured.
[0029]
-Fifth embodiment-
FIG. 6 is a configuration diagram illustrating a magnetically shielded refrigeration system according to a fifth embodiment of the present invention.
This magnetically shielded refrigeration system 500 includes a magnetically shielded device 51 having an inner space magnetically shielded from the outside, a container-shaped outer wall Wo and an inner wall Wi, and cooling in a space surrounded by the inner wall Wi. A heat insulating plate 53 holding the agent 52, a heat shielding plate 54 provided in a vacuum layer between the outer wall Wo and the inner wall Wi, and a sensor 55 such as a SQUID element disposed at the bottom of the inner wall Wi. A heat insulator 56 buried (or fixed) with a heat transfer plate 61 provided above the inner wall Wi and having both end faces facing the heat shielding plate 54; Unit, that is, the connecting block 13 is brought into contact with the pulse tube refrigerator 900 (see FIG. 9), a compressor 92 for sending a refrigerant gas Gr such as helium gas to the pulse tube refrigerator 900, and the pulse tube refrigerator. 900 and It is configured by including a motor drive switching valve 97 for switching the valve so as to pulsed manner reciprocating the refrigerant gas Gr between the serial compressor 92. The material of the heat transfer plate 61 is, for example, copper.
The compressor 92 and the motor drive switching valve 97 are installed outside the magnetic shielding device 51.
Since both end surfaces of the heat transfer plate 61 are thermally connected to the heat shielding plate 54 through a layer of the gas g in which the coolant 52 is vaporized, the gas g is connected to the heat transfer plate 61 with the heat transfer plate 61. It is cooled in the gap with the heat shielding plate 54.
According to the above magnetically shielded refrigeration system 500, the temperature of the gas g vaporized by the coolant 52 can be further reduced and the heat insulation performance can be improved, so that the consumption of the coolant 52 can be reduced and the operating cost can be reduced. I can do it.
In addition, since the compressor 92 and the motor drive switching valve 97, which are likely to be noise sources, are installed outside the magnetic shielding device 51, the intrusion of noise into the magnetic shielding device 51 is suppressed, and the weak magnetism and the like can be accurately detected. Can be measured.
[0030]
-Sixth embodiment-
FIG. 7 is a configuration diagram illustrating a magnetically shielded refrigeration system according to a sixth embodiment of the present invention.
The magnetic shield refrigeration system 600 cools the heat shield plate 54 by bringing the connection block 13 of the pulse tube refrigerator 100 (see FIG. 1) according to the first embodiment into contact with the heat shield plate 54. Configuration.
According to the above magnetically shielded refrigeration system 600, the connection block 13 of the pulse tube refrigerator 100 is brought into contact with the heat shield plate 54 to cool the heat shield plate 54, so that the consumption of the coolant 52 is reduced. , Operation costs can be reduced.
In addition, since the pulse tube refrigerator 100 according to the first embodiment is used, the regenerator tube (11 in FIG. 1) and the regenerator material (10 in FIG. 1) filled therein are electrically connected. Insulation can be achieved, and generation of magnetic noise due to formation of a current loop can be reduced.
[0031]
-Seventh embodiment-
FIG. 8 is a configuration diagram illustrating a magnetically shielded refrigeration system according to a seventh embodiment of the present invention.
In this magnetically shielded refrigeration system 700, the connection block 13 of the pulse tube refrigerator 100 (see FIG. 1) according to the first embodiment is brought into contact with the heat transfer plate 61 embedded in the heat insulator 56, The configuration is such that the heat transfer plate 61 is cooled.
According to the above magnetically shielded refrigeration system 700, the temperature of the gas g vaporized by the coolant 52 can be further reduced and the heat insulation performance can be improved, so that the consumption of the coolant 52 can be reduced and the operating cost can be reduced. I can do it.
In addition, since the pulse tube refrigerator 100 according to the first embodiment is used, the regenerator tube (11 in FIG. 1) and the regenerator material (10 in FIG. 1) filled therein are electrically connected. Insulation can be achieved, and generation of magnetic noise due to formation of a current loop can be reduced.
[0032]
【The invention's effect】
According to the pulse tube refrigerator of the present invention, the regenerator tube and the regenerator material are insulated by the insulating cylinder provided on the inner periphery of the regenerator tube, or the regenerator tube and the pulse tube are interposed in the connecting tube. Since insulation is performed by the insulating member, noise due to the formation of a current loop can be reduced, and a weak physical quantity (such as magnetism) can be accurately measured.
Further, according to the magnetic shield type refrigeration system of the present invention, the heat shield plate of the heat insulating device in the magnetic shield device is cooled by a pulse tube refrigerator, or heat transfer embedded or fixed in the heat insulator. Since the plate is cooled by a pulse tube refrigerator to lower the temperature of the gas layer between the heat transfer plate and the heat shielding plate, the heat insulation performance can be improved, and the consumption of the coolant can be reduced.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a pulse tube refrigerator according to a first embodiment of the present invention.
FIG. 2 is a configuration diagram of a refrigeration system including the pulse tube refrigerator of FIG. 1;
FIG. 3 is a configuration diagram illustrating a pulse tube refrigerator according to a second embodiment of the present invention.
FIG. 4 is a configuration diagram showing a pulse tube refrigerator according to a third embodiment of the present invention.
FIG. 5 is a configuration diagram of a magnetically shielded refrigeration system according to a fourth embodiment of the present invention.
FIG. 6 is a configuration diagram of a magnetically shielded refrigeration system according to a fifth embodiment of the present invention.
FIG. 7 is a configuration diagram of a magnetically shielded refrigeration system according to a sixth embodiment of the present invention.
FIG. 8 is a configuration diagram of a magnetically shielded refrigeration system according to a seventh embodiment of the present invention.
FIG. 9 is a configuration diagram illustrating an example of a conventional pulse tube refrigerator.
FIG. 10 is a configuration diagram showing a refrigeration system including the pulse tube refrigerator of FIG. 9;
FIG. 11 is a configuration diagram showing a conventional magnetically shielded refrigeration system.
12 is an explanatory diagram of a current loop formed in each part of the pulse tube refrigerator of FIG.
[Explanation of symbols]
100, 200, 300 Pulse tube refrigerator
400, 500, 600, 700 Magnetically shielded refrigeration system
1,41 insulating tube
2a, 2b, 45a, 45b Spacer
3-1, 3-2, 3-3, 3-4 shunt
10,33 Cool storage material
11 Regenerator tube
12,32 pulse tube
13 Connecting block
22 Insulation fitting
31 metal tube
51 Magnetic shielding device
52 Coolant
53 Insulation device
54 Heat shield
55 sensors
56 Insulation
61 Heat transfer plate
92 compressor
97 Motor drive switching valve

Claims (7)

内部に導電材料で作成された蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有するパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を連結ブロックにより連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却するタイプのパルス管式冷凍器であって、
前記蓄冷器管の内周に、前記蓄冷材を取り囲むように絶縁筒を設け、前記蓄冷器管と前記蓄冷材とを含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器。 A regenerator tube filled with a regenerator material made of a conductive material and made of a conductive material, and a pulse tube having a cavity therein are arranged substantially in parallel, and one end of the regenerator tube and the pulse A flange is attached to one end of the tube, the other end of the regenerator tube and the other end of the pulse tube are connected by a connection block, and refrigerant gas is pulsed into the regenerator tube and the pulse tube. A pulse tube refrigerator that cools the connection block by taking in and out,
A pulse tube , wherein an insulating cylinder is provided on the inner periphery of the regenerator tube so as to surround the regenerator material, and a current loop including the regenerator tube and the regenerator material is suppressed from being formed. Type refrigerator. 内部に蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有し且つ導電材料で作成されたパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を導電材料で作製された連結管により連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結管の一部または全部を覆う低温発生部を冷却するタイプのパルス管式冷凍器であって、
前記連結管の中間に、当該連結管を伝わる電流を遮断する絶縁部材を介設し、前記蓄冷器管と前記パルス管とを含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器。And inside is filled with a cold accumulating material and conductive material regenerator tube created by, and arranged substantially parallel to the been the pulse tube created and conductive material have a cavity therein, one end of the regenerator tube and A flange is attached to one end of the pulse tube, and the other end of the regenerator tube and the other end of the pulse tube are connected by a connection tube made of a conductive material. A pulse tube refrigerator of a type that cools a low-temperature generating portion that covers a part or the entirety of the connection pipe by putting refrigerant gas in and out of the pipe in a pulsed manner,
In the middle of the connecting pipe, an insulating member for interrupting a current transmitted through the connecting pipe is provided to suppress formation of a current loop including the regenerator tube and the pulse tube. Pulse tube refrigerator. 蓄冷器管として機能させるための金属管と、その金属管の内周に同軸状に設けられたパルス管と、前記金属管を外壁とし前記パルス管を内壁とする筒状空間に充填され且つ導電材料で作成された蓄冷材と、前記金属管の内周に前記蓄冷材を取り囲むように設けられ前記金属管と前記蓄冷材とを含む電流ループが形成されることを抑制する絶縁筒と、前記金属管の一端側および前記パルス管の一端側に取り付けられたフランジと、前記金属管の他端側と前記パルス管の他端側とを連結する連結ブロックとを具備し、前記筒状空間および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却することを特徴とするパルス管式冷凍器。A metal tube for functioning as a regenerator tube, a pulse tube coaxially provided on the inner periphery of the metal tube, and a cylindrical space filled with the metal tube as an outer wall and the pulse tube as an inner wall, and conductive. a cold accumulating material is made of a material, and suppressing insulating cylinder that current loop is formed including the provided so as to surround the cold accumulating material to the inner periphery of the metal pipe and the metal pipe and the cold accumulating material, the A flange attached to one end of the metal tube and one end of the pulse tube, and a connection block for connecting the other end of the metal tube and the other end of the pulse tube, the cylindrical space and A pulse tube type refrigerator, wherein the connection block is cooled by putting refrigerant gas into and out of the pulse tube in a pulsed manner. 請求項１から請求項３のいずれかに記載のパルス管式冷凍器において、前記蓄冷器管と前記パルス管のうちの一方または両方の少なくとも一端側に、絶縁材料で作製され且つ前記冷媒ガスの通過孔が穿設されたスペーサを設け、前記蓄冷器管や前記パルス管を含む電流ループが形成されることを抑制したことを特徴とするパルス管式冷凍器。The pulse tube refrigerator according to any one of claims 1 to 3, wherein at least one end of one or both of the regenerator tube and the pulse tube is made of an insulating material, and the refrigerant gas is cooled. A pulse tube refrigerator having a spacer provided with a through-hole to suppress formation of a current loop including the regenerator tube and the pulse tube . 外界から磁気的に遮蔽された磁気遮蔽空間を内部に有する磁気遮蔽装置と，前記磁気遮蔽空間に設置され且つ容器状の外壁および内壁を有し当該内壁で囲まれた断熱空間内に磁気検出素子を冷却する冷却剤を保持し得る断熱装置と，前記外壁と前記内壁の間の層内に介設された少なくとも１枚の熱遮蔽板とを備えた磁気遮蔽型冷凍システムであって、
前記内部空間にパルス管式冷凍器を設置し、前記熱遮蔽板に前記パルス管式冷凍器の低温発生部を熱的に結合させて前記熱遮蔽板を冷却すると共に、前記パルス管式冷凍器に冷媒ガスを送り出すための圧縮機と，前記パルス管式冷凍器と前記圧縮機の間で冷媒ガスをパルス的に往復させるように弁を切り換える切り換え弁とを前記磁気遮蔽装置の外部に設置したことを特徴とする磁気遮蔽型冷凍システム。 Magnetic sensor magnetically shielded magnetically shielded space from outside the magnetic shielding apparatus included therein, the magnetic shield is placed in the space and the container outer wall and the inner wall surrounded by a heat insulating space has an inner wall and insulating device capable of retaining a coolant for cooling, a magnetic shield type refrigeration system comprising at least one heat shielding plate that is interposed in a layer between the front Kigaiheki said inner wall a,
The interior space established a pulse tube type refrigerating apparatus to the heat shield plate to the pulse tube type refrigerator cold generating unit The rewritable cooling the heat shield plate is thermally coupled, the pulse tube refrigerating A compressor for sending refrigerant gas to a compressor and a switching valve for switching a valve to reciprocate refrigerant gas between the pulse tube refrigerator and the compressor in a pulsed manner are provided outside the magnetic shielding device. A magnetically shielded refrigeration system, characterized in that: 外界から磁気的に遮蔽された磁気遮蔽空間を内部に有する磁気遮蔽装置と，前記磁気遮蔽空間に設置され且つ容器状の外壁および内壁を有し当該内壁で囲まれた断熱空間内に磁気検出素子を冷却する冷却剤を保持し得る断熱装置とを備えた磁気遮蔽型冷凍システムであって、
前記内壁の上部に断熱体を設け、前記断熱体に伝熱板を埋設または固設し、前記伝熱板にパルス管式冷凍器の低温発生部を熱的に結合させ且つ前記伝熱板の一部を前記冷却剤の気化ガスに接触させて冷却すると共に、前記パルス管式冷凍器に冷媒ガスを送り出す圧縮機と，前記パルス管式冷凍器と前記圧縮機の間で冷媒ガスをパルス的に往復させるように弁を切り換える切り換え弁を前記磁気遮蔽装置の外部に設置したことを特徴とする磁気遮蔽型冷凍システム。 Magnetic sensor magnetically shielded magnetically shielded space from outside the magnetic shielding apparatus included therein, the magnetic shield is placed in the space and the container outer wall and the inner wall surrounded by a heat insulating space has an inner wall a magnetic shield type refrigeration system comprising a heat insulating device capable of retaining a coolant for cooling the,
The thermal insulator is provided in an upper portion of the inner wall, the heat transfer plate embedded or fixed on the heat insulating member, the heat transfer plate to the cold generating portion of the pulse tube type refrigerator of and is thermally coupled the heat transfer plate the rewritable cooling part in contact with the vaporized gas of the coolant, a pulse compressor, the refrigerant gas between the compressor and the pulse tube type refrigerator for feeding the refrigerant gas in the pulse tube type refrigerator A magnetically shielded refrigeration system, characterized in that a switching valve for switching a valve so as to reciprocate is installed outside the magnetically shielded device. 内部に導電材料で作成された蓄冷材を充填され且つ導電材料で作成された蓄冷器管と，内部に空洞を有し且つ導電材料で作成されたパルス管とを略平行に配列し、前記蓄冷器管の一端側および前記パルス管の一端側にフランジを取り付け、前記蓄冷器管の他端側と前記パルス管の他端側との間を連結ブロックにより連結し、前記蓄冷器管および前記パルス管内に冷媒ガスをパルス的に出し入れして前記連結ブロックを冷却するタイプのパルス管式冷凍器であって、A regenerator tube filled with a regenerator made of a conductive material and made of a conductive material, and a pulse tube made of a conductive material and having a cavity therein are arranged substantially parallel to each other. A flange is attached to one end of the vessel tube and one end of the pulse tube, and the other end of the regenerator tube and the other end of the pulse tube are connected by a connection block. A pulse tube refrigerator of a type that cools the connection block by pulsating refrigerant gas into and out of the tube,
前記蓄冷器管と前記パルス管の間に、両者を電気的に接続するシャントを介設し、両者の電位をほぼ等しくすることを特徴とするパルス管式冷凍器。  A pulse tube refrigerator having a shunt between the regenerator tube and the pulse tube for electrically connecting the two and making the potentials substantially equal.
JP17641398A 1998-06-23 1998-06-23 Pulse tube refrigerator and magnetically shielded refrigeration system Expired - Fee Related JP3577498B2 (en)

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KR100393792B1 (en) * 2001-02-17 2003-08-02 엘지전자 주식회사 Pulstube refrigerator
GB0125188D0 (en) * 2001-10-19 2001-12-12 Oxford Magnet Tech A pulse tube refrigerator sleeve
GB0125189D0 (en) * 2001-10-19 2001-12-12 Oxford Magnet Tech A pulse tube refrigerator
JP2008241215A (en) * 2007-03-28 2008-10-09 Kyushu Univ Cold storage type cryogenic refrigerating machine
JP2012104781A (en) * 2010-11-15 2012-05-31 Railway Technical Research Institute High-temperature superconductive magnet cooling system with vehicle-mounted pulse tube refrigerator
JP6305285B2 (en) 2014-09-10 2018-04-04 住友重機械工業株式会社 Pulse tube refrigerator

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