Dome of the detector
Cavity for the detector
Top of the SK detector (before lifting up)
People contributing to the construction 1
Top of the detector (outside, before lifting up
Top of the detector （inside, under lifting up）
Making a PMT-unit
Rear view of PMT units
Mountings the PMTs on the detector wall.
A part of the wall and the outer detector
Detector wall and bottom
working party at the bottom of the tank 1
working party at the bottom of the tank 2
detector wall and top with about 9000 PMTs
detector wall with about 9000 PMTs
entrance to the top of the detector
top of the detector 1
top of the detector 2
working party at the bottom of the tank 2
cabling at the top of the detector 1
cabling at the top of the detector 2
electronics and HV system
rear view of the electronics and HV system
people contributing to the construction 2
people contributing to the construction 3
entrance to the Kamioka underground lab.
Water-filling was started on December 22, 1995.
inner detector with half of water
installation of last PMT module of the inner detector (Mar. 96)
Assembling PMT case 1
Eye check of PMTs
Assembling PMT case 2
Mounting the top PMTs 1
Mounting the top PMTs 2
Mounting the barrel PMTs 1
Mounting the barrel PMTs 2
Mounting the barrel PMTs 3
Mounting the barrel PMTs 4
Completed mounting PMTs 1
(Apr. 7, 2006)
Completed mounting PMTs 2
Completed mounting PMTs 3
Completed mounting PMTs 4
Completed mounting PMTs 5
Replacing Tyvek sheets
Started filling water 1
(Apr. 23, 2006)
Started filling water 2
Started filling water 3
Nearly full water
(Jun. 26, 2006)
Mounting final PMT module 1
Mounting final PMT module 2
- 1. The 2.8m x 4.2m heavy stainless steel cover was replaced with a tentative lighter cover using a crane before the refurbishment work began.
- 2. When the cover is taken off, the white reflection sheet can be seen. The water is just beneath the sheet. People enter the tank from this opening.
- 3. May 31st, 2018, the data collection of Super-Kamiokande was stopped for the refurbishment work.
- 4. A Shinto ceremony was held to pray for the safety and success of the refurbishment.
- 5. The water surface is visible under the white reflection sheet
- 6. The water in Super-Kamiokande is drained from the bottom of the tank.
- 7. The drained water is pumped up 40m and discharged through the side-ditch in the mine.
- 8. The pure water system that has continuously circulated and filtered water for 12 years was switched to inner circulation.
- 9. When the water level is lowered about 2m from the top, the photomultiplier tubes (PMTs) in the outer detector become visible.
- 10. When the PMTs in the outer detector are removed, the back of the PMTs in the inner detector can be seen.
- 11. The PMTs in the inner detector are removed using the crane.
- 12. Three PMTs in the inner detector are fixed as a set.
- 13. The workers are entering the tank with a green gondola lift.
- 14. Once the 24 PMTs at the entrance were removed, the inside of the tank was finally visible. The blue dots are from light being reflected off of the bottom PMTs.
- 15. The view inside the tank when the water level is lowered about 4m from the top.
- 16. People work inside the tank on boats or floating platforms.
- 17. Inspecting new PMTs and assembling the PMT covers.
- 18. Connecting the cables of PMTs installed in the outer detector.
- 19. Measurement of magnetic field in the inner detector.
- 20. The floating platforms are more stable than the boats, and facilitate work in the tank.
- 21. Replacement work of outer detector PMTs.
- 22. Applying waterproofing agents at welding joints of the stainless steel panels.
- 23. Replacement work of inner detector PMTs
- 24. The gondola lift in the inner detector
- 25. Improvement of water piping
- 26. The water level is about 30m. About 11m worth of water has been drained.
- 27. Works in the outer detector. The outer detector is about 2m wide.
- 28. The water level is about 26m. About 15m worth of water has been drained.
- 29. The water levet is about 22m.
- 30. The water levet is about 10m. Measurement of the magnetic field at each ID PMT.
- 31. The ID PMTs are carried using a hoist crane.
- 32. The water level is about 3m. The ID PMTs will be appeared to the surface of water soon.
- 33. The boats and floating platforms are removed.
- 34. The water level is 1m. Checking the situation of the bottom of the tank.
- 35. All of the water of the tank is drained.
- 36. Replacement of the bottom ID PMTs
- 37. Replacement of the bottom OD PMTs
- 38. Applying waterproofing agents near the bottom.
- 39. Applying waterproofing agents at the bottom of the tank.
- 40. Installing the reflection sheets at the bottom of the tank.
- 41. The work at the bottom of the tank was finished.
- 42. Filling the tank with pure water was started.
- 43. The water level is about 3m.
- 44. The water level is about 31m. Cleaning the water surface.
- 45. The water level is about 37m.
- 46. Cleaning at the top of the tank and fixing the reflection sheets.
- 47. The water in the OD region looks so blue.
- 48. Installtion of the reflection sheets at the tank ceiling.
- 49. Removing the light in the tank.
- 50. Pulling up the boat from the tank.
- 51. Installtion of PMTs at the entrance of the inner detector.
- 52. The last cleaning before closing tank.
- 53. After cleaning and checking if there is anything left inside the tank, the tank is finally closed.
- 54. The reflection sheet is installed at the entrance of ID.
- 55. The ID cover is closed.
- 56. When the water level is full, the OD cover is closed.
- 57. The entrances of the tank were closed.
- 58. The PMTs were turned on, Super-Kamiokande data taking restarted.
- 59. The event display after restart. A new phase of observation “SK-V” has started.
- 60. About 250 researchers and about 70 company people participated in this upgrade work.
Planned by ICRR, University of Tokyo, Produced by Iwanami Eizo Company “Super-Kamiokande, Exploring the Secrets of Elementary Particles and the Universe”, 2014, 18min
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