Sandia circuit passes muster

An electrical circuit that should carry enough power to produce controlled high-yield nuclear fusion every 10 seconds has undergone tests at Sandia National Laboratories’ Z machine facility.

Z, when it fires, is already the largest producer of X-rays on Earth and has been used to produce fusion neutrons. But rapid bursts are necessary for future generating plants to produce electrical power from seawater. This had not been thought achievable until now.

For the Z machine’s inertial confinement method of producing energy, the circuit must deliver enough energy to fuse pellets of hydrogen every 10 seconds and keep that pace up for millions of shots. The circuit is easily able to fire every 10.2 seconds in brief, powerful bursts.

The new system, called a linear transformer driver (LTD), was created by researchers at the Institute of High Current Electronics in Tomsk, Russia, in collaboration with colleagues at Sandia.

The circuit, consisting of a switch tightly coupled to two capacitors, is about the size of a shoebox and is termed a ‘brick.’ When bricks are tightly packed in groups of 20 and electrically connected in parallel in a ring-shaped container, the aggregate, or ‘cavity’ can transmit a current of 0.5 megamperes at 100 kilovolts.