Proton Beam Experiments Open New Areas of Research
Researchers used the Trident sub-picosecond laser at Los Alamos National Laboratory to conduct their experiments.
Photo: Los Alamos National Laboratory
San Diego, Calif., Dec. 5 -- By focusing proton beams and using high-intensity lasers, a team of scientists have discovered a new way to heat materials and create new states of matter in the laboratory. For example, they recreated conditions that allowed the study of the properties of warm, dense matter found in the interior of giant planets, such as Jupiter.
New applications for using proton beams range from heating materials, to creating new types of matter that couldn’t be made by any other means, to medical applications, to insights into planetary science.
“The ability to generate high-intensity well-focused proton beams can open the door to new regimes in high-energy density science,” said Teresa Bartal, the lead author.
Lead author Teresa Bartal.
She is a Ph.D. student in the department of mechanical and aerospace engineering at the Jacobs School of Engineering at UC San Diego and a researcher at the Lawrence Livermore National Laboratory.
Professor Farhat Beg, from the department of mechanical and aerospace engineering at the Jacobs School and his research team consisting of two other graduate students, Drew Higginson and Leonard C. Jarrott, also contributed to the study, as did scientists at Lawrence Livermore National Laboratory, Los Alamos National Laboratory, Hemoltz-Zentrum Dresden-Rossendorf of Germany, Technische Universitat Darmstadt of Germany and General Atomics of San Diego.
They unveiled new findings about how proton beams can be used in myriad applications in the Dec. 4 issue of the journal Nature Physics.
Professor Farhat Beg.
“This work has given a new direction to the conventional thinking of proton beam focusing in short-pulse laser-matter interaction,” said Jacobs School Professor Beg. “Surely it will impact heating of pre-compressed materials to temperatures observed at the core of the sun and any future applications in proton oncology using high-intensity lasers."
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 unexpected 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, a scientist at the Lawrence Livermore National Laboratory.
Laser-produced proton beams also are making an impact on medical applications such as isotope production for positron emission tomography (PET) and proton oncology.