An international team of researchers has come up with a plasma-based way to produce and separate oxygen within the Martian environment. It’s a complementary approach to NASA’s Mars Oxygen In-Situ Resource Utilization Experiment, and it may deliver high rates of molecule production per kilogram of instrumentation sent to space.

Such a system could play a critical role in the development of life-support systems on Mars and the feedstock and base chemicals necessary for processing fuels, building materials, and fertilizers.
Natural conditions on the red planet are nearly ideal for in situ resource utilization by plasmas, since the atmosphere is primarily formed by carbon dioxide that can be split to produce oxygen and its pressure is favorable for plasma ignition.

Two big hurdles stand in the way of producing oxygen on Mars.

“First, the decomposition of carbon dioxide molecules to extract oxygen. It’s a very difficult molecule to break,” said author Vasco Guerra, of the University of Lisbon. “Second, the separation of the produced oxygen from a gas mixture that also contains, for example, carbon dioxide and carbon monoxide. We’re looking at these two steps in a holistic way to solve both challenges at the same time. This is where plasmas can help.”

Plasma is the fourth natural state of matter, and it contains free charged particles, such as electrons and ions. Electrons are light and easily accelerated up to very high energies with electric fields.

“When bulletlike electrons collide with a carbon dioxide molecule, they can directly decompose it or transfer energy to make it vibrate,” Guerra said. “This energy can be channeled, to a large extent, into carbon dioxide decomposition. Together with our colleagues in France and the Netherlands, we experimentally demonstrated the validity of these theories. Moreover, the heat generated in the plasma is also beneficial for the separation of oxygen.”

Oxygen is key to creating a breathable environment, as well as the starting point to produce fuels and fertilizers for future Martian agriculture. Local production of fuels will be important for future missions. All are essential for future human settlement on Mars.

By dissociating carbon dioxide molecules to produce green fuels and recycle chemicals, the plasma technology may also aid in addressing climate change on Earth.

Journal of Applied Physics is an influential international journal publishing significant new experimental and theoretical results of applied physics research.

http://jap.aip.org/

AR #118

Why is the Martian Sky Blue

by William B. Stoecker

Scientists at the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) have uncovered critical new details about fusion facilities that use lasers to compress the fuel that produces fusion energy. The new data could help lead to the improved design of future laser facilities that harness the fusion process that drives the sun and stars.

Fusion combines light elements in the form of plasma — the hot, charged state of matter composed of free electrons and atomic nuclei — that generates massive amounts of energy. Scientists are seeking to replicate fusion on Earth for a virtually inexhaustible supply of power to generate electricity.

Major experimental facilities include tokamaks, the magnetic fusion devices that PPPL studies; stellarators, the magnetic fusion machines that PPPL also studies and have recently become more widespread around the world; and laser devices used in what are called inertial confinement experiments.

The researchers explored the impact of adding tungsten metal, which is used to make cutting tools and lamp filaments, to the outer layer of plasma fuel pellets in inertial confinement research. They found that tungsten boosts the performance of the implosions that cause fusion reactions in the pellets. The tungsten helps block heat that would prematurely raise the temperature at the center of the pellet.

The research team confirmed the findings by making measurements using krypton gas, sometimes used in fluorescent lamps. Once added to the fuel, the gas emitted high-energy light known as X-rays that was captured by an instrument called a high-resolution X-ray spectrometer. The X-rays conveyed clues about what was happening inside the capsule.
“I was excited to see that we could make these unprecedented measurements using the technique we have been developing these past few years. This information helps us evaluate the pellet’s implosion and helps researchers calibrate their computer simulations,” said PPPL physicist Lan Gao, lead author of the paper reporting the results in Physical Review Letters. “Better simulations and theoretical understanding in general can help researchers design better future experiments.”

The scientists performed the experiments at the National Ignition Facility (NIF), a DOE user facility at Lawrence Livermore National Laboratory. The facility shines 192 lasers onto a gold cylinder, or hohlraum, that is one centimeter tall and encases the fuel. The laser beams heat the hohlraum, which radiates X-rays evenly onto the fuel pellet within.

https://www.pppl.gov/news/2022/uncovering-novel-way-bring-earth-energy-powers-sun-and-stars