How water tanks can detect gamma rays

There's a whole variety of reasons why someone might purchase a water tank – from wanting to lower their water bills, to a guaranteed yearly water supply, to helping out the environment. There is also a surprising, extra use for water tanks going on at the base of the Sierra Negra volcano near Puebla, Mexico.

The High-Altitude Water Cherenkov Gamma-Ray Observatory

At an altitude of 4,100 metres (13,500 feet) corrugated steel water tanks are being used to detect gamma rays and cosmic rays within 100 GeV (billion election-volt) and 100 TeV (trillion electron-volt).

The project, named The High-Altitude Water Cherenkov Gamma-Ray Observatory (HAWC) uses water tanks are used to detect particles and dark matter.

Extensive air showers

According to the HAWC website, a chain-reaction particle cascade is set off when high-energy cosmic rays and gamma rays enter the atmosphere – this is known as an "extensive air shower".

Cherenkov light

So where do water tanks come in? When particles from these extensive air showers pass through water, they release Cherenkov light. This release occurs because particles travel faster than the speed of light when in water. These arrays of light are call Cherenkov detectors.

Water Cherenkov Tanks

Cherenkov production is successful in water because water has a high index of refraction. According to HAWC, Cherenkov light is transmitted into a forward cone. This cone surrounds the direction of motion of the charged particle.

Because water is dense, gamma-rays produce a charge once inside the water tank. Then, these gamma-ray particles produce Cherenkov radiation as they speed through the water.

Alkatuff water tanks are made to be tough enough to withstand Australia's unique climate and conditions. While they may not detect gamma-ray particles, they will perform under constant sun exposure without failure or cracking.

Get in touch with Alkatuff today to find more about getting a water tank.

By Gerald Beckton