April 11th, 2014

Egglofter, rockets

Light Bulbs and Ion Drive

On March 6, I went to Pittcon in Chicago's McCormick Place. Pittcon (originally the Pittsburg Conference) is a roving trade show for instrumentation. They also have seminars at exorbitant prices. However, Thursday was their free admission day, so that is when I went.

At one point, I visited the AirGas booth. They supply both industrial and laboratory gasses. We discussed the declining availability of helium from US supplies and the company's contract for future helium production in the Middle East. While on the topic of Noble Gasses, we touched on Argon being readily available at 1% of the atmosphere. We skipped Krypton (Sorry, Superman) and I learned that there will be a 2 year shortage of Xenon, the heaviest of the non-radioactive noble gasses.

It turns out that with the replacement of classic incandescent light bulbs, quartz-halogen, along with compact fluorescent and LED bulbs are an acceptable high efficiency replacement. The xenon is used as a carrier gas for the iodine used in quartz-halogen bulbs to redeposit tungsten to the filament in the high temperature and therefore more efficient bulbs. The AirGas guy told me that a requested order of xenon from one light bulb manufacturer was the entire world supply of xenon. There are no plans to expand production of xenon due to the high capital costs and expected limited duration of the shortfall.

Meanwhile, on the way to the asteroids Ceres and Vesta, the Dawn Spacecraft is powered by an ion drive that has been fueled with several hundred pounds of xenon.