What is vacuum bomb? Russia accused of using thermobaric weapon during invasion, claims Ukraine

Kyiv, Mar 1: Ukraine's ambassador to the US and human rights groups said on Monday accused Russia of using vacuum bombs and cluster bombs in the ongoing conflict. Amnesty also accused them of attacking a preschool where civilians had taken shelter.

Ukrainian ambassador Oksana Markarova told reporters that Russia has used a thermobaric weapon, which is also known as a vacuum bomb, in its invasion of her country. "They used the vacuum bomb today," Markarova said on Monday, after a meeting with lawmakers. "...The devastation that Russia is trying to inflict on Ukraine is large."

But what is a vacuum bomb?

A thermobaric weapon, aerosol bomb, or vacuum bomb is a type of explosive that uses oxygen from the surrounding air to generate a high-temperature explosion.

Terminology

The term thermobaric is derived from the Greek words for 'heat' and 'pressure'.

Other terms used for the family of weapons are high-impulse thermobaric weapons, heat and pressure weapons, vacuum bombs, and fuel-air explosives.

In practice, the blast wave typically produced by these weapons lasts significantly longer than that of a conventional condensed explosive. The fuel-air explosive is one of the best-known types of thermobaric weapon.

Most conventional explosives consist of a fuel-oxidizer premix (black powder, for example, contains 25% fuel and 75% oxidizer), but thermobaric weapons are almost 100% fuel and so are significantly more energetic than conventional condensed explosives of equal weight. Their reliance on atmospheric oxygen makes them unsuitable for use under water, at high altitude, and in adverse weather.

They are, however, considerably more destructive when used against field fortifications such as foxholes, tunnels, bunkers, and caves, partly because of the sustained blast wave and partly by the consumption of the oxygen inside it.

Many types of thermobaric weapons can be fitted to hand-held launchers.

However, there has been no official confirmation that thermobaric weapons have been used in the conflict in Ukraine.