Proton Beam Experiments Open New Areas Of Research

By focusing proton beams using high-intensity lasers, a team of scientists have discovered a new way to heat material and create new states of matter in the laboratory. Researchers from Lawrence Livermore National Laboratory; Jacobs School of Engineering at the University of California, San Diego; Los Alamos National Laboratory; Hemoltz-Zentrum Dresden-Rossendorf of Germany; Technische Universitat Darmstadt of Germany, and General Atomics of San Diego unveiled new findings about how proton beams can be used in myriad applications.

Using the Trident sub-picosecond laser at Los Alamos, the team generated and focused a proton beam using a cone-shaped target. The protons were found to have unexpectedly curved trajectories due to the large electric fields in the beam. A sheath electric field also channeled the proton beam through the cone tip, substantially improving the beam focus.

"These results agree well with our particle simulations and provide the physics basis for many future applications," said Mark Foord, one of the LLNL scientists on the team.

Other Livermore researchers include lead author Teresa Bartal (also a UCSD Ph.D student and Lawrence scholar), Claudio Bellei, Michael Key, Pravesh Patel, Drew Higginson and Harry McLean. The research appears in the Dec. 4 issue of the journal Nature Physics.

Bartal said the experiments provide a new understanding of the physics involved in proton focusing, which affects how proton beams can be used in the future -- from heating material to creating new types of matter that couldn't be made by any other means, to medical applications and insights into planetary science.