Laser helps to promote the research of high energy density physics

When the pressure exceeds the atmospheric pressure on the earth by one million times or even one billion times, the atomic behavior will be very different. Understanding the reactions of atoms under such high pressure conditions can lead to the production of new materials and enable scientists to provide valuable insights into the composition of stars and planets and the universe itself.

These are one of the reasons why the University of Rochester has shifted its attention to the relatively new field of high-energy density physics. Another reason is that the university is ready to make a significant contribution to this field.

Rob Clark, vice president and vice president of Research Department of the University of Rochester, said: “our researchers and the resources we have put us in a unique position to obtain important insights in the field of high-energy density physics.”

The Laser Dynamics Laboratory of the University of Rochester is the location of Omega laser. The 10 meter high and 100 meter long Omega is the world’s largest university laser.

Rochester also specially hired Gilbert (RIP) Collins to lead a new multidisciplinary research program in the field of high energy density physics. Collins was formerly the director of the center for high energy density physics at Lawrence Livermore National Laboratory. He is now a professor in the Department of mechanical engineering / Department of physics and Astronomy and a senior scientist in the laser energy laboratory of the University. Collins pointed out that “this research will make the collaboration between chemistry, engineering, physics and astronomy easier”, thus accelerating the progress in this field.

In addition to other studies, Collins also studied the bonding of atoms under extreme pressure conditions. Generally, the outermost electrons of an atom react with the electrons of other atoms. However, when the pressure applied to the atom is greatly increased, the internal electrons will intervene, and an interesting phenomenon will occur.

Collins pointed out: “under extreme pressure, the chemical properties of elements we are familiar with are no longer applicable. For different pressure conditions, we need a new periodic table of elements. Diamonds are a well-known material formed under high pressure.” If carbon is placed 100 miles deep on the earth, its pressure is nearly 50000 times higher than the pressure on the earth’s surface, and the temperature is higher than 2000 degrees Fahrenheit, its atomic structure will become very organized, and we call it diamond.

However, when it comes to high-energy density physics, this pressure level is still low. Under more extreme pressure, such as 2 million atmospheres, sodium can be converted into an insulator; At 10 million atmospheres, hydrogen energy becomes superconducting superfluid; When the pressure exceeds 200 million atmospheres, aluminum can be made transparent.

The above Omega laser can enable researchers to achieve such pressure conditions.

Collins said: “many people think that the laser is just a high-temperature heat source. However, the laser can also be used as a highly concentrated pressure source; and the Omega laser enables us to study materials under the conditions of millions to billions of atmospheres. Understanding the behavior of atoms under extreme pressure will enable researchers to purposefully process materials to form some new and unusual materials.”

Robert McCrory, vice president and director of the laser energy laboratory, said that Collins enjoys a high international reputation and is suitable for leading the University’s projects. He pointed out that the laser laboratory, Lawrence Livermore’s national ignition device and other facilities have opened up new frontiers of high-energy density physics and ensured the leadership of the United States in this field.

For the creation of new materials, high-energy density physics can provide more. Michael Campbell, deputy director of the laser energy laboratory, called this field “enduring science”.