March 29, 2024

Hot Electron Production Using a Short-Pulse, High-Contrast Laser on Cone and Planar Targets

The cone geometry is a Compound Parabolic Concentrator (CPC) developed to focus the laser to the suggestion. The cone geometry reveals higher hot electron temperatures than planar foils. Simulations determined that the main source of this temperature level enhancement is the intensity boost caused by the CPC.
Led by LLNL postdoctoral appointee Dean Rusby, the research findings are featured in Physical Review E.
” We were able enhance the temperature level of the electron beam from our high-intensity laser interactions by shooting into a focusing cone target,” Rusby stated. “It reveals that we comprehend how the substance parabolic concentrator works under these laser conditions.”
Rusby stated increasing the coupling into high-energy electrons in these interactions is important for developing applications from laser-plasma interactions.
” It is very motivating to see considerable improvements are possible utilizing the CPC target platform on a petawatt 100 fs class laser system, which is currently capable of near diffraction limited operation,” stated Andrew MacPhee, co-author of the paper. “Non-imaging optics used to laser target interactions are redefining the criterion area accessible to the neighborhood.”
This image reveals the experimental setup showing the target, laser and electron spectrometer. A 3D drawing of the CPC, tantalum substrate and the inbound laser also is revealed. Credit: Lawrence Livermore National Laboratory
The group utilized the Texas petawatt laser system at the University of Austin during a six-week period, which has a short pulse and high contrast that permitted the experiment to work. The target is a substance CPC that is specifically developed to focus more laser energy toward the idea and increase the strength.
” The increase in electron temperature highly concurred with the boost we would anticipate when using the CPC,” Rusby said.
The Department of Energys Office of Science supported the LaserNetUS effort at Texas Petawatt and LLNLs Laboratory Directed Research and Development program funded the group and the most importantly important target advancement from General Atomics.
The team has actually been granted additional time through LaserNetUS at the Texas petawatt to continue research study on CPCs targets. This time, the team will focus on the acceleration of the protons from the rear surface and the enhancement that the CPCs supply.
Andrew Mackinnon, a co-author of the paper and a primary private investigator for a Strategic Initiative Laboratory Directed Research & & Development, is using these CPC targets for the project..
” These experiments revealed that miniature plasma mirror targets do enhance coupling of petawatt-class lasers to MeV (mega-electronvolt) electrons, which benefits possible applications such as laser-based MeV radiography,” he said.
Reference: “Enhancements in laser-generated hot-electron production via focusing cone targets at short pulse and high contrast” by D. R. Rusby, P. M. King, A. Pak, N. Lemos, S. Kerr, G. Cochran, I. Pagano, A. Hannasch, H. Quevedo, M. Spinks, M. Donovan, A. Link, A. Kemp, S. C. Wilks, G. J. Williams, M. J.-E. Manuel, Z. Gavin, A. Haid, F. Albert, M. Aufderheide, H. Chen, C. W. Siders, A. Macphee and A. Mackinnon, 14 May2 2021, Physical Review E.DOI: 10.1103/ PhysRevE.103.053207.
In addition to Rusby, MacPhee and Mackinnon, co-authors consist of Paul King, Arthur Pak, N. Lemos, Shaun Kerr, Ginny Cochran, Anthony Link, Andreas Kemp, Scott Wilks, George Williams, Felicie Albert, Maurice Aufderheide, H. Chen, Craig Siders and Andrew Macphee from LLNL; I. Pagano, A. Hannasch, H. Quevedo, M. Spinks and M. Donovan from the University of Austin; and M. J.-E. Manuel, Z. Gavin and A. Haid from General Atomics.

This image reveals the augmentation of the laser in simulations and the electrons being accelerated. Credit: Lawrence Livermore National Laboratory
Researchers concentrate on cone targets to improve temperature level of electron beams.
Intense short-pulse laser-driven production of intense high-energy sources, such as Protons, neutrons and x-rays, has actually been revealed to be an important tool in the study of high energy density science.
In an effort to resolve a few of the most challenging applications, such as X-ray radiography of high areal density things for national and industrial security applications, both the yield and energy of the sources need to be increased beyond what has actually presently been attained by cutting edge high-intensity laser systems.
A group of scientists from Lawrence Livermore National Laboratory ( LLNL), University of Austin and General Atomics handled this difficulty. Specifically, the group conducted experimental measurements of hot electron production utilizing a short-pulse, high-contrast laser on cone and planar targets.

The cone geometry is a Compound Parabolic Concentrator (CPC) created to focus the laser to the suggestion. The cone geometry shows greater hot electron temperatures than planar foils. Simulations identified that the main source of this temperature enhancement is the intensity increase triggered by the CPC.
This image reveals the experimental setup displaying the laser, target and electron spectrometer. A 3D drawing of the CPC, tantalum substrate and the incoming laser likewise is shown.