The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Characterizing and optimizing hot electrons accelerated by short pulse lasers is of great interest, especially for Fast Ignition (FI) research. To date, most research on electron source and transport has been done using lasers with intrinsic prepulses. However, even a relatively low amount of prepulse (1–10 mJ in 3 ns) creates an underdense plasma that causes instabilities such as filamentation and...
Recent experiments and simulations of proton generation and focusing in cone geometries have led to a better understanding of the important effects of the electric fields in and around the focused beam.1 The surrounding cone structure is shown to improve the focusing significantly, resulting in beam fluence diameters ≈ 55µm for protons with energies Ep >3 MeV. PIC-hybrid simulations predict that...
Proton focusing following the interaction of a short (tp<1 ps), ultra-intense (IL>1018Wcm−2) laser pulse with curved surfaces has been reported [1]. However a thorough understanding of proton focusing in terms of focal position and achievable focal spot size is essential for applications such as isochoric heating, fast ignition and medical applications.
The characteristics of relativistic electrons generated in short-pulse laser plasma interactions are important for evaluating the success of the fast ignition concept. The important parameters include the spectrum, laser to electron conversion efficiency, and divergence angle of the electrons at the interface. Simulation results using 3-D particle-in-cell (PIC) techniques in fast ignition geometries...
Proton generation, focusing, and heating of solid density material using intense high energy picosecond laser pulses irradiating thin curved foils are simulated using the PIC Hybrid code LSP The efficiency of proton production is studied using a variety of H-rich surface materials, with the highest efficiencies found with heavy hydride surface layers. Using hemispherical targets, improvements in focusing...
Summary form only given. We report on recent experimental studies on the variations in proton conversion efficiency as a function of target thickness, molecular composition and laser pulse length. Experiments were carried out on the Titan laser at LLNL at laser intensities (1018-1020) and pulse lengths (0.7-5 ps). Erbium hydride was added to the rear surface of the target to study the effect of the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.