This news item is part of LPP’s December 30th, 2013 report–Download the full report in PDF format here. Join the discussion of this news item at the Focus Fusion Society forums here.
Tungsten samples pass another test
LPP’s plans for greatly increasing density and cutting impurities in the plasma depend on substituting tungsten electrodes for the present silver-plated copper ones. Since the tungsten electrodes are expensive and have a lead time of three months, LPP’s team wanted to ensure that the prospective supplier, Tungsten Heavy Powder ,could provide material that would easily withstand the condition in the FF-1 device. In the latest tests, an impendent testing company measured the impact strength of tungsten samples from the supplier. Since tungsten is a brittle material, LPP need to make sure that the tungsten could withstand the sudden mechanical stress that occurs when the magnetic fields in the device, generated by million-amp currents, push on the electrodes.
The two samples passed the test with flying colors, exhibiting an impact tight of 25 kJ/m2, far above the impact energy expected in FF-1, even at its peak planed current of 2.8 MA. After one further test for tensile strength, LPP expects to order the tungsten electrodes in early January, and begin experiments with them in April, 2014.
