Event Display

These images can be used for your publication under the conditions, described here.

 

How to See the Event Display

The display shows the expansion of the cylindrical detector. The center larger figure is a display of the inner detector (ID) with its 11,129 20inch photomultiplier tubes and the smaller figure shows the data of outer detector (OD). The colored dots visualize information on which tubes got hit in the event on display. Two modes are possible: Color can either encode the charge (Q) registered at that particular tube or the time (T) when the tube was hit. Which mode of display was chosen for the particular event you are looking at can be determined from the entry "Current:" in the upper left corner of the display. Below it you find more printed information on that current event.

 

Muon Events

Super-Kamiokande detects about 2 Hz of comic ray muons. Some interesting images are shown here.

Stopping muon

Stopping muon

Corner edge clipping muon

Corner edge clipping muon

Double muon (Timing distribution)

Double muon (Timing distribution)

Double muon (Charge distribution)

Double muon (Charge distribution)

Triple muons

Triple muons

Stopping muon entering from the top (Charge distribution)

Stopping muon entering from the top (Charge distribution)

Stopping muon entering from the top (Timing distribution)

Stopping muon entering from the top (Timing distribution)

Detected an electron emitted from muon decay

An electron emitted from muon decay

 

Neutrino Events

The neutrino events and the cosmic ray muon events are distinguished by the number of photons detected by the PMTs of the outer detector. When the cosmic ray muon enters the outer detector, the Cherenkov light is emitted immediately because the cosmic ray muon is a charged particle. The cosmic ray muon runs into the water and continues to emit the Cherenkov light, which is detected by the inner PMTs.

 

On the other hand, a neutrino itself does not emit the Cherenkov light because it is a neutral particle. When a neutrino interacts with the charged particle in water, the charged particle emits the Cherenkov light. Therefore in most case of neutrino events, only the inner PMTs have hits and the outer PMTs do not have hits. The outer PMTs are very effective to roughly distinguish neutrino events from charged particles such as cosmic ray muons.

 

A Cherenkov ring occured by a muon neutrino. A muon neutrino interacts with a nucleon in water and transforms to a muon. The outer detector has few hits in the right-upper display.

 

An electron neutrino event. An electron neutrino scatters an electron in water. The emitted electron generates a electromagnetic shower,leading to the fuzzy edge of the Cherenkov ring.

 

Perspective View

 

Real-time Monitor (Test)

This display shows the data detected by Super-Kamiokande in real time. (This is test operation and subject to change without notice)