arXiv subjects

A. G. Krygier

Publications and source records attributed to A. G. Krygier.

5 recordsLinked to original sources

arXiv2015

Calibration of Time Of Flight Detectors Using Laser-driven Neutron Source

Calibration of three scintillators (EJ232Q, BC422Q and EJ410) in a time-of-flight (TOF) arrangement using a laser drive-neutron source is presented. The three plastic scintillator detectors were calibrated with gamma insensitive bubble detector spectrometers, which were absolutely calibrated over a wide range of neutron energies ranging from sub MeV to 20 MeV. A typical set of data obtained simultaneously by the detectors are shown, measuring the neutron spectrum emitted from a petawatt laser irradiated thin foil.

physics.ins-det↗

arXiv2014

Characterisation of deuterium spectra from laser driven multi-species sources by employing differentially filtered image plate detectors in Thomson spectrometers

A novel method for characterising the full spectrum of deuteron ions emitted by laser driven multi-species ion sources is discussed. The procedure is based on using differential filtering over the detector of a Thompson parabola ion spectrometer, which enables discrimination of deuterium ions from heavier ion species with the same charge-to-mass ratio (such as C6+, O8+, etc.). Commonly used Fuji Image plates were used as detectors in the spectrometer, whose absolute response to deuterium ions over a wide range of energies was calibrated by using slotted CR-39 nuclear track detectors. A typical deuterium ion spectrum diagnosed in a recent experimental campaign is presented.

physics.plasm-ph↗

arXiv2014

Enhancing Bremsstrahlung Production From Ultraintense Laser-Solid Interactions With Front Surface Structures

We report the results of a combined study of particle-in-cell and Monte Carlo modeling that investigates the production of Bremsstrahlung radiation produced when an ultraintense laser interacts with a tower-structured target. These targets are found to significantly narrow the electron angular distribution as well as produce significantly higher energies. These features combine to create a significant enhancement in directionality and energy of the Bremstrahlung radiation produced by a high-Z converter target. These studies employ short-pulse, high intensity laser pulses, and indicate that novel target design has potential to greatly enhance the yield and narrow the directionality of high energy electrons and $γ$-rays. We find that the peak $γ$-ray brightness for this source is 6.0$\times$10$^{19}$ ${\rm s^{-1}mm^{-2}mrad^{-2}}$ at 10MeV and 1.4$\times$10$^{19}$ ${\rm s^{-1}mm^{-2}mrad^{-2}}$ at 100MeV (0.1$\%$ bandwidth).

physics.plasm-ph↗

arXiv2014

On The Origin of Super-Hot Electrons from Intense Laser Interactions with Solid Targets having Moderate Scale Length Preformed Plasmas

We use PIC modeling to identify the acceleration mechanism responsible for the observed generation of super-hot electrons in ultra-intense laser-plasma interactions with solid targets with pre-formed plasma. We identify several features of direct laser acceleration (DLA) that drive the generation of super-hot electrons. We find that, in this regime, electrons that become super-hot are primarily injected by a looping mechanism that we call loop-injected direct acceleration (LIDA).

physics.plasm-ph↗

arXiv2013

The Effects of Front-Surface Target Structures on Properties of Relativistic Laser-Plasma Electrons

We report the results of a study of the role of prescribed geometrical structures on the front of a target in determining the energy and spatial distribution of relativistic laser-plasma electrons. Our 3D PIC simulation studies apply to short-pulse, high intensity laser pulses, and indicate that a judicious choice of target front-surface geometry provides the realistic possibility of greatly enhancing the yield of high energy electrons, while simultaneously confining the emission to narrow (< 5 degree) angular cones.

physics.plasm-ph↗