University fusion lab sustains plasma for 90 seconds, a record for its reactor class

Researchers at the university's plasma physics lab held a fusion plasma stable for 90 seconds on Tuesday, more than doubling the previous record for compact stellarators.

The result was published in the journal Nuclear Fusion and confirmed by two outside groups who reviewed the diagnostic data.

Stellarators use twisted magnetic fields to confine plasma. They are harder to build than the more common tokamak design but, in theory, easier to run continuously.

'Ninety seconds does not sound like much,' said lead scientist Dr. Yuki Tanaka. 'But every instability we see in the first ten seconds is now something we can study for eighty more.'

The lab's reactor, about the size of a delivery van, does not produce net energy and was never designed to.

Its purpose is to test the magnetic-coil geometry that a full-scale commercial stellarator would need.

The team's next target is five minutes, which Tanaka said would require upgrading the cooling system for the coils.

The project is funded by the Department of Energy and two private fusion companies.