Plasma made by Hamburg physicists is a good candidate for this national test because it was somehow more extreme than before. Since it was really dense, the interaction between the charged particles in the electric couplings was very, very strong. Steven Rolston, a pioneer in the field and a scientist at the University of Maryland who was not involved in the study, said that creating strongly interacting plasma has always been a wishlist item and a technical challenge for ultracold plasma physicists. “Plasmas don’t really like to be strongly combined,” he says. Once the plasma atoms become charge ions, he said, if there is enough time, they can increase their potential electrical potential and shake, which strengthens the interactions they hold together.
Engineering in labs and how difficult it is for them to reach space, so strongly paired plasmas represent mostly undiscovered terrain for physicists. These are issues that scientists still do not fully understand and want to explore further.
According to Juliet Simonet, co-leader of the Hamburg team, part of the success of the new experiment has been the combination of ultrasound and ultrafast physicists. This resulted in one or two punches using extremely cold and controlled atoms as the basis of the test and an extremely fast laser as the main tool to handle them. “This is a great collaboration between the two research fields,” he says.
The machine his team built also allowed researchers to directly investigate what the electrons did after they were detached from the atom. In past experiments, physicists simply measured other aspects of plasma to predict what might happen to them. Here they determined that in response to the pull of ions by the laser pulse, the temperature of the electrons skyrocketed to 8,000 degrees Fahrenheit just instantly before they cooled down. “It’s beyond anything we’ve seen so far,” Simonet said of the detailed observation.
According to Killian, such a description has so far excluded the theories of physicists. “People use a lot of standard theories in plasmas that describe the method of conducting electricity or mass transport through the system. It doesn’t work. [interaction] Regime, ”he noted.
To make sure they understood what they were seeing, the Hamburg team turned to computer calculations. Because their plasma was so small, Mario Grossman, the group’s graduate student and research assistant, said they could calculate how each plasma particle interacted with each other. It was like asking a computer to collect the minute details of a conversation between two people and give a word description in a crowded room.
For their 8,000-particle system, he had to wait up to 22 days for the computer to produce results. Encouragingly, the simulated plasma particles were almost identical to the way the researchers looked at the actual particles in their experiments. In the case of this simulation method, larger, naturally occurring plasma would not be practical in any case.
“Most of the theory was really like a really cruel ball – ‘just let me put it on a really big computer and count the interactions – – which scales badly,'” Rolston agreed. He noted that computers may not be strong enough to handle every single particle interaction simultaneously in large plasmas. A more sophisticated theory would zoom out, forgetting the details of the nitty-gritty particle, and predict plasma behavior based entirely on its properties.
This kind of theory will help both ultracold physicists and researchers who study celestial bodies. This can predict when strongly combined plasmas may develop waves or maintain electrical currents. These predictions can be tested in Earth laboratory experiments and give insights into the evolution or even aggregation between white dwarfs in space. “We have super-coupled plasma at the beginning,” says Wessels-Starman. “The funny thing is really maintaining this attachment, so if you are a white dwarf you can really contribute to what’s going on.”