萨德伯里微中子观测站实验室

萨德伯里中微子观测站实验室（SNOLAB，简称为“萨实验室”）是位于加拿大安大略省萨德伯里2100米深的镍矿中的地下物理实验室。原本位于此处的萨德伯里微中子观测站（Sudbury Neutrino Observatory，缩写为SNO）实验计画已结束，但其设施已被扩张成为永久物理实验室。

萨实验室乃是全世界在地下比较深处的几个实验设施之一。在地下2316米深处果拉尔金矿的粒子实验（英语：Particle experiments at Kolar Gold Fields）因矿场关闭而于1992年终止运作。^[1]^[2]正在计画中的DUSEL（英语：Sanford Underground Research Facility）实验室也已大幅度缩减，由于国家科学基金会拒绝负担主要开支。^[3]2010年开始运作的中国锦屏地下实验室在那时是全世界最深的地下实验室，缈子通量低于0.2 μ/m²/day ，^[4]萨实验室的缈子通量为0.27 μ/m²/day。^[5] （与之相比，在海平面，缈子通量大约为15 million μ/m²/day。)

虽然与矿坑相连通，实验室本身维持于级别2000标准的洁净室状况，即尺寸不小于1μm的粒子少于2000个每1 m3空气，背景辐射也很低．在其上方有2070 m石头，约6010 米水当量（英语：meter water equivalent）（MWE）的屏蔽，足可挡去大部分的宇宙射线，是设置高灵敏度（英语：sensitivity (electronics)）与超低计数率实验梦寐以求的良好环境。^[5]

历史

萨实验已获得重大成功，并且展示出地下深处物理实验室的宝贵价值，很多基础物理问题都可以从在地下深处完成的物理实验获得答案，例如，在太阳内部进行核融合的状况、中微子的质量、暗物质的探测等等重要问题。2002年，加拿大创新基金会（英语：Canada Foundation for Innovation）批准，将萨观测站扩张成为一所永久性世界级实验研究中心，^[6]该实验室分别又在2007年与2008年获得更多资金。^[7]^[8]

实验

在萨实验室里，主要有六个正在进行的物理实验： ^[9]^[10]^:2

氦与铅观测站（英语：Helium and Lead Observatory）（HALO）：这是一种铅基中微子探测器，专门用来探测银河系内的超新星所产生的中微子。^[11]
电荷耦合器件暗物质探测器（Dark Matter in CCDs，DAMIC）：使用6个含有1g质量矽元素的当今（2015年）最先进的电荷耦合器件，其具有探测质量小于6GeV的大质量弱相互作用粒子类型暗物质的功能。^[12]^[13]
COUPP60气泡室：使用装有37kg过热CF₃I的气泡室来探测大质量弱相互作用粒子类型的暗物质。^[14]
PICO 2L气泡室：使用装有2.9kg过热C₃F₈的气泡室（2公升容量）来探测大质量弱相互作用粒子类型的暗物质。^[10]^:41^[15]
PICO-60气泡室：使用装有60kg过热C₃F₈的气泡室来探测大质量弱相互作用粒子类型的暗物质。^[16]
氩元素暗物质探测器（英语：DEAP）-3600（DEAP-3600）：使用3600 kg 氩液体来探测暗物质，灵敏度超过其它当今（2015年）最先进实验20倍。^[17]^[18]^[10]^:14,21

现在（2015年），还有四个实验项目正在兴建中： ^[9]

SNO+（英语：SNO+）中微子探测器：在原本的萨探测器内，将原本使用的重水更换为液体闪烁剂，其光输出量更高，因此可以探测到低能量太阳中微子、地球中微子、反应炉中微子（reactor neutrino）等等。^[19]
迷你惰气基低温低能量天文物理学（英语：Cryogenic Low-Energy Astrophysics with Neon）（MiniCLEAN）暗物质探测器：使用氩液体或氖液体来探测大质量弱相互作用粒子类型的暗物质。^[10]^:24–32^[20]
超级低温暗物质搜寻计画（Super Cryogenic Dark Matter Search，SuperCDMS）：使用当今（2015年）最先进的低温锗基探测器来搜寻大质量弱相互作用粒子类型的暗物质。^[21]^[22]
DAMIC100探测器：使用18块厚度为675 μm的16Mpix电荷耦合器件来探测暗物质，合计共用到100g矽元素，放射性背景事件率预期超小于1dru（#event/kg·day·keV_ee）。^[13]

另有五个实验项目已按计画圆满达成目标，现已关闭运作：

原本的重水基萨德伯里中微子观测站实验。
北极星：这是个位于萨实验室的地下实验计画，专门观测在地球深层非常坚硬的硬岩（英语：Underground mining (hard rock)）所产生的地震信号。
第一代COUPP4气泡室：使用装有4kg过热CF₃I的气泡室来探测大质量弱相互作用粒子类型的暗物质。^[23]
氩元素暗物质探测器（英语：DEAP）-1：使用7 kg 氩液体为与大质量弱相互作用粒子相互作用的标靶，主要目的是在鉴别氩液体的脉冲形状。^[24]
加拿大探索超对称物体计画（英语：PICASSO (dark matter)）：使用过热的C₄F₁₀液体，以小液滴形式分散在聚合介质或黏性介质内，可以用来探测暗物质。假设有暗物质与小液滴发生碰撞，则小液滴会变换为气泡，并且伴随著可记录的声脉冲。^[25]^:3

萨实验室正在考虑添加更多实验计画，例如，下一代冨集氙观测站（英语：Enriched Xenon Observatory）（nEXO）^[26]^[27]^:16、探索无中微子双贝他衰变的眼镜蛇实验（英语：COBRA experiment）^[28]^:27、发展圆球形气体探测器来探测暗物质的新圆球实验（英语：New Experiments With Spheres）（NEWS）^[29]。萨实验室计画兴建一个更大的PICO-250L气泡室 ^[10]^:44。

参考资料

^ Naba K. Mondal. Status of India-based Neutrino Observatory (INO) (PDF). Proc Indian Natn Sci Acad. January 2004, 70 (1): 71–77 [2007-08-28]. （原始内容存档 (PDF)于2013-07-09）.
^ M. R. Krishnaswamy; et al. The Kolar Gold Fields Neutrino Experiment. II. Atmospheric Muons at a Depth of 7000 hg cm-2 (Kolar). Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. 6 July 1971, 323 (1555): 511–522. JSTOR 78071.
^ Pioneer, Wendy Pitlick Black Hills. DUSEL no more. Black Hills Pioneer. [2022-04-21]. （原始内容存档于2019-03-30）（英语）. Lesko said the scaled back plans boil down to just one underground research campus. Originally, lab officials planned to build a major surface campus, a science campus 4,850 feet underground that included two lab modules, and a smaller lab module campus 7,400 feet underground. The Sanford Underground Research Facility, Lesko said, focuses on building just one campus at the 4,850-foot level that will host experiments in dark matter, double beta decay, and long baseline neutrino research.
^ Wu, Yu-Cheng; Hao, Xi-Qing; Yue, Qian; Li, Yuan-Jing; Cheng, Jian-Ping; Kang, Ke-Jun; Chen, Yun-Hua; Li, Jin; Li, Jian-Min. Measurement of cosmic ray flux in the China JinPing underground laboratory. Chinese Physics C. 2013-08, 37 (8): 086001 [2022-04-21]. Bibcode:2013ChPhC..37h6001W. ISSN 1674-1137. arXiv:1305.0899 . doi:10.1088/1674-1137/37/8/086001. （原始内容存档于2022-04-21）.
^ ^5.0 ^5.1 SNOLAB User’s Handbook Rev. 2 (PDF): 13, 2006-06-26 [2013-02-01], （原始内容 (PDF)存档于2016-03-04）
^ Canada selects 9 projects to lead in international research (新闻稿). Canada Foundation for Innovation. 2002-06-20 [2007-09-21]. ^{[失效链接]}
^ Province Supports Expansion of World's Deepest Lab Administered by Carleton University (新闻稿). Carleton University. 2007-08-21 [2007-09-21]. （原始内容存档于2012-08-18）.
^ New Funding will Support Underground Lab Operations as SNOLAB nears Completion (PDF) (新闻稿). SNOLAB. 2008-01-18 [2008-02-26]. （原始内容 (PDF)存档于2016-03-04）.
^ ^9.0 ^9.1 Experiments. SNOLAB. [2022-04-21]. （原始内容存档于2022-01-07）（美国英语）.
^ ^10.0 ^10.1 ^10.2 ^10.3 ^10.4 Noble, Tony. Dark Matter Physics at SNOLAB and Future Prospects (PDF). Fourth International Workshop for the Design of the ANDES Underground Laboratory. 2014-01-31 [2015-10-31]. （原始内容 (PDF)存档于2016-03-04）.
^ Home Page. Helium and Lead Observatory. [2015-11-03]. （原始内容存档于2021-03-18）.
^ DAMIC now running at SNOLAB. 2012-12-10 [2013-05-13]. （原始内容存档于2020-09-25）.
^ ^13.0 ^13.1 Chavarria, A. E. DAMIC at SNOLAB. Journal of Physics: Conference Series. 2020-01-01, 1342 (1): 012057 [2022-04-21]. ISSN 1742-6588. arXiv:1407.0347 . doi:10.1088/1742-6596/1342/1/012057. （原始内容存档于2022-04-21）.
^ COUPP-60 Up and Running at SNOLAB. 2013-05-03 [2013-05-13]. （原始内容存档于2020-09-25）.
^ PICO-2L now running at SNOLAB!. 2013-11-04 [2015-10-31]. （原始内容存档于2020-09-20）.
^ PICO experiment: PICO 60. [2015-08-17]. （原始内容存档于2019-11-06）.
^ Field, Louisa. Biggest dark matter detector lies in wait for antisocial WIMPs (3108). 23 April 2015 [2015-10-31]. （原始内容存档于2015-05-05）. At the end of April, it will join other underground detectors worldwide in the race to find dark matter. |journal=被忽略 (帮助)
^ Walding, Joseph. IOP 2013: High Energy and Astrop Particle Physics. Institute of Physics: 3. 2013-04-10 [2013-05-19]. |contribution=被忽略 (帮助)
^ SNO+. SNOLAB. [2015-11-03]. （原始内容存档于2020-12-03）.
^ Rielage, K.; Akashi-Ronquest, M.; Bodmer, M.; Bourque, R.; Buck, B.; Butcher, A.; Caldwell, T.; Chen, Y.; Coakley, K. Update on the MiniCLEAN Dark Matter Experiment. Physics Procedia. 2015, 61: 144–152 [2022-04-21]. arXiv:1403.4842 . doi:10.1016/j.phpro.2014.12.024. （原始内容存档于2022-06-20）（英语）.
^ Second generation dark matter experiment coming to SNOLAB (新闻稿). SNOLAB. 2014-07-18 [2014-09-18]. （原始内容存档于2019-03-30）.
^ Saab, Tarek. SLAC Summer Institute 2012 (PDF). SLAC National Accelerator Laboratory. 2012-08-01 [2012-11-28]. （原始内容 (PDF)存档于2014-10-29）. |contribution=被忽略 (帮助)
^ Behnke, E.; Behnke, J.; Brice, S. J.; Broemmelsiek, D.; Collar, J. I.; Conner, A.; Cooper, P. S.; Crisler, M.; Dahl, C. E. First dark matter search results from a 4-kg CF 3 I bubble chamber operated in a deep underground site. Physical Review D. 2012-09-05, 86 (5): 052001. Bibcode:2012PhRvD..86e2001B. ISSN 1550-7998. arXiv:1204.3094 . doi:10.1103/PhysRevD.86.052001. FERMILAB-PUB-12-098-AD-AE-CD-E-PPD （英语）.
^ Dark matter Experiment with Argon and Pulse-shape discrimination. DEAP-1. [2015-11-03]. （原始内容存档于2016-03-05）.
^ Smith, Nigel. Advanced Instrumentation Techniques in SNOLAB (PDF). 2015 Canadian Association of Physicists Congress. 17 June 2015 [2015-11-03]. （原始内容 (PDF)存档于2016-03-04）.
^ Sinclair, David. The SNOLAB Science Programme (PDF). 13th International Conference on Topics in Astroparticle and Underground Physics. Asilomar, California. 12 September 2013 [2014-11-21]. （原始内容 (PDF)存档于2016-12-24）.
^ Pocar, Andrea. Searching for neutrino-less double beta decay with EXO-200 and nEXO (PDF). Neutrino Oscillation Workshop. Otranto. 8 September 2014 [2015-01-10]. （原始内容 (PDF)存档于2015-09-23）.
^ Smith, Nigel J.T., Infrastructure Development for underground labs—SNOLAB experience (PDF), 13th International Conference on Topics in Astroparticle and Underground Physics, Asilomar, California, 2013-09-08 [2015-11-04], （原始内容 (PDF)存档于2017-01-25）
^ NEWS: New Experiments With Spheres. [2015-08-16]. （原始内容存档于2016-03-04）.

外部链接

（英文）萨实验室网站
（法文）SNOLAB的法语介绍
（英文）Experiment Cave. WIRED Science. 第104集. 2007-10-24 [2015-11-09]. PBS. （原始内容存档于2009-12-08）.
Jepsen, Kathryn. Voyage to SNOLAB. symmetry magazine. [2022-04-21]. （原始内容存档于2021-01-25）（英语）.
Semeniuk, Ivan. Going deep underground in Canada in search of dark matter. The Globe and Mail. 2014-03-22 [2022-04-21]. （原始内容存档于2022-04-21）（加拿大英语）.

46°28.3′N 81°11.2′W / 46.4717°N 81.1867°W / 46.4717; -81.1867 (SNOLAB surface building)

[1] Naba K. Mondal. Status of India-based Neutrino Observatory (INO) (PDF). Proc Indian Natn Sci Acad. January 2004, 70 (1): 71–77 [2007-08-28]. （原始内容存档 (PDF)于2013-07-09）.

[2] M. R. Krishnaswamy; et al. The Kolar Gold Fields Neutrino Experiment. II. Atmospheric Muons at a Depth of 7000 hg cm-2 (Kolar). Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences. 6 July 1971, 323 (1555): 511–522. JSTOR 78071.

[3] Pioneer, Wendy Pitlick Black Hills. DUSEL no more. Black Hills Pioneer. [2022-04-21]. （原始内容存档于2019-03-30）（英语）. Lesko said the scaled back plans boil down to just one underground research campus. Originally, lab officials planned to build a major surface campus, a science campus 4,850 feet underground that included two lab modules, and a smaller lab module campus 7,400 feet underground. The Sanford Underground Research Facility, Lesko said, focuses on building just one campus at the 4,850-foot level that will host experiments in dark matter, double beta decay, and long baseline neutrino research.

[JinPing-4] Wu, Yu-Cheng; Hao, Xi-Qing; Yue, Qian; Li, Yuan-Jing; Cheng, Jian-Ping; Kang, Ke-Jun; Chen, Yun-Hua; Li, Jin; Li, Jian-Min. Measurement of cosmic ray flux in the China JinPing underground laboratory. Chinese Physics C. 2013-08, 37 (8): 086001 [2022-04-21]. Bibcode:2013ChPhC..37h6001W. ISSN 1674-1137. arXiv:1305.0899 . doi:10.1088/1674-1137/37/8/086001. （原始内容存档于2022-04-21）.

[handbook-5] 5.0 ^5.1 SNOLAB User’s Handbook Rev. 2 (PDF): 13, 2006-06-26 [2013-02-01], （原始内容 (PDF)存档于2016-03-04）

[6] Canada selects 9 projects to lead in international research (新闻稿). Canada Foundation for Innovation. 2002-06-20 [2007-09-21]. ^{[失效链接]}

[7] Province Supports Expansion of World's Deepest Lab Administered by Carleton University (新闻稿). Carleton University. 2007-08-21 [2007-09-21]. （原始内容存档于2012-08-18）.

[8] New Funding will Support Underground Lab Operations as SNOLAB nears Completion (PDF) (新闻稿). SNOLAB. 2008-01-18 [2008-02-26]. （原始内容 (PDF)存档于2016-03-04）.

[current_ex-9] 9.0 ^9.1 Experiments. SNOLAB. [2022-04-21]. （原始内容存档于2022-01-07）（美国英语）.

[andes2014-10] 10.0 ^10.1 ^10.2 ^10.3 ^10.4 Noble, Tony. Dark Matter Physics at SNOLAB and Future Prospects (PDF). Fourth International Workshop for the Design of the ANDES Underground Laboratory. 2014-01-31 [2015-10-31]. （原始内容 (PDF)存档于2016-03-04）.

[11] Home Page. Helium and Lead Observatory. [2015-11-03]. （原始内容存档于2021-03-18）.

[12] DAMIC now running at SNOLAB. 2012-12-10 [2013-05-13]. （原始内容存档于2020-09-25）.

[Chavarria-13] 13.0 ^13.1 Chavarria, A. E. DAMIC at SNOLAB. Journal of Physics: Conference Series. 2020-01-01, 1342 (1): 012057 [2022-04-21]. ISSN 1742-6588. arXiv:1407.0347 . doi:10.1088/1742-6596/1342/1/012057. （原始内容存档于2022-04-21）.

[14] COUPP-60 Up and Running at SNOLAB. 2013-05-03 [2013-05-13]. （原始内容存档于2020-09-25）.

[15] PICO-2L now running at SNOLAB!. 2013-11-04 [2015-10-31]. （原始内容存档于2020-09-20）.

[16] PICO experiment: PICO 60. [2015-08-17]. （原始内容存档于2019-11-06）.

[17] Field, Louisa. Biggest dark matter detector lies in wait for antisocial WIMPs (3108). 23 April 2015 [2015-10-31]. （原始内容存档于2015-05-05）. At the end of April, it will join other underground detectors worldwide in the race to find dark matter. |journal=被忽略 (帮助)

[18] Walding, Joseph. IOP 2013: High Energy and Astrop Particle Physics. Institute of Physics: 3. 2013-04-10 [2013-05-19]. |contribution=被忽略 (帮助)

[19] SNO+. SNOLAB. [2015-11-03]. （原始内容存档于2020-12-03）.

[20] Rielage, K.; Akashi-Ronquest, M.; Bodmer, M.; Bourque, R.; Buck, B.; Butcher, A.; Caldwell, T.; Chen, Y.; Coakley, K. Update on the MiniCLEAN Dark Matter Experiment. Physics Procedia. 2015, 61: 144–152 [2022-04-21]. arXiv:1403.4842 . doi:10.1016/j.phpro.2014.12.024. （原始内容存档于2022-06-20）（英语）.

[21] Second generation dark matter experiment coming to SNOLAB (新闻稿). SNOLAB. 2014-07-18 [2014-09-18]. （原始内容存档于2019-03-30）.

[22] Saab, Tarek. SLAC Summer Institute 2012 (PDF). SLAC National Accelerator Laboratory. 2012-08-01 [2012-11-28]. （原始内容 (PDF)存档于2014-10-29）. |contribution=被忽略 (帮助)

[23] Behnke, E.; Behnke, J.; Brice, S. J.; Broemmelsiek, D.; Collar, J. I.; Conner, A.; Cooper, P. S.; Crisler, M.; Dahl, C. E. First dark matter search results from a 4-kg CF 3 I bubble chamber operated in a deep underground site. Physical Review D. 2012-09-05, 86 (5): 052001. Bibcode:2012PhRvD..86e2001B. ISSN 1550-7998. arXiv:1204.3094 . doi:10.1103/PhysRevD.86.052001. FERMILAB-PUB-12-098-AD-AE-CD-E-PPD （英语）.

[24] Dark matter Experiment with Argon and Pulse-shape discrimination. DEAP-1. [2015-11-03]. （原始内容存档于2016-03-05）.

[25] Smith, Nigel. Advanced Instrumentation Techniques in SNOLAB (PDF). 2015 Canadian Association of Physicists Congress. 17 June 2015 [2015-11-03]. （原始内容 (PDF)存档于2016-03-04）.

[26] Sinclair, David. The SNOLAB Science Programme (PDF). 13th International Conference on Topics in Astroparticle and Underground Physics. Asilomar, California. 12 September 2013 [2014-11-21]. （原始内容 (PDF)存档于2016-12-24）.

[27] Pocar, Andrea. Searching for neutrino-less double beta decay with EXO-200 and nEXO (PDF). Neutrino Oscillation Workshop. Otranto. 8 September 2014 [2015-01-10]. （原始内容 (PDF)存档于2015-09-23）.

[Asilomar2013-28] Smith, Nigel J.T., Infrastructure Development for underground labs—SNOLAB experience (PDF), 13th International Conference on Topics in Astroparticle and Underground Physics, Asilomar, California, 2013-09-08 [2015-11-04], （原始内容 (PDF)存档于2017-01-25）

[29] NEWS: New Experiments With Spheres. [2015-08-16]. （原始内容存档于2016-03-04）.

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