Laser-Plasma Accelerator Workshop 2019

Sitzung

Secondary radiation generation & applications

WG3

07.05.2019, 14:00

MedILS

87. High Field QED Experiments with Lasers Progress and Challenges

Matt Zepf (Helmholtz Institut Jena)

07.05.19, 14:00

Oral Contribution

The combination of GeV electron beams and ultra-intense lasers provides a perfect basis for experiments testing high intensity QED effects from vacuum pair production to determining the equation of motion of an electron in an intense laser field including strong radiation reaction.
Initial experiments (for example [1,2]) have shown significant promise and highlighted the remaining challenges....

120. The control of laser wakefield accelerated electron beams and betatron X-ray radiation using arrays of multiple gas jets

Herr Vidmantas Tomkus (Center for Physical Sciences and Technology)

07.05.19, 14:20

Oral Contribution

The stability of Laser Plasma Wakefield Accelerated (LWFA) electron beams and the efficiency of betatron X-ray sources can be controlled using staged gas targets. Implementation of ionization-assisted [1] and density down-ramp [2] electron injection allows to change the energy and charge of accelerated electron beams. The double-jet betatron source with a low-density LWFA region and a...

5. Creation of Electron-Positron Pairs in Photon-Photon Collisions Driven by 10-PW Laser Pulses

Dr. Jinqing Yu (Peking univeristy)

07.05.19, 14:40

Oral Contribution

A novel approach is proposed to demonstrate the two-photon Breit-Wheeler process by using collimated and wide-bandwidth γ-ray pulses driven by 10-PW lasers. Theoretical calculations suggest that more than 3.2×10^8 electron-positron pairs with a divergence angle of 7° can be created per shot, and the signal-to-noise ratio is higher than 10^3. The positron signal, which is roughly 100 times...

64. 1 MeV Thomson backscatter x-ray source from a 250 MeV laser-plasma accelerator and plasma mirror

Dr. Yenyu Chang (Helmholtz Zentrum Dresden Rossendorf)

07.05.19, 15:00

Oral Contribution

Thomson backscatter (TBS) of near-IR (hνL ~ 1eV) laser pulses from laser-plasma-accelerated (LPA) electron bunches (200 < γe < 4000) provides a compact source of bright, tunable, ultrashort x-rays (0.1 < 4γe2hvL < 100 MeV) for radiography and nuclear science [1]. Inserting a plasma mirror (PM) near the LPA exit to retro-reflect spent LPA drive pulses onto trailing electron bunches [2] is an...

69. Gamma-ray radiation in beam-plasma interaction as a diagnostics for emittance growth in PWFA and for beam filamentation instabilities

Pablo San Miguel (Ecole Polytechnique)

07.05.19, 15:20

Oral Contribution

Low-emittance ultra-relativistic electron beams delivered for next generation of plasma wakefield acceleration (PWFA) experiments are expected to produce very high wakefields over very large distances when going through a plasma. Assessing electron beam dynamics under such fields will be of key importance to achieve the next milestones of the PWFA concept. Here we report on the use of the...

93. Towards an all-optical Thomson source for X-ray flourescence imaging

Dr. Kristjan Poder (DESY)

08.05.19, 16:00

Oral Contribution

Laser wakefield accelerators can provide a very compact source of electron beams, which when combined with intense laser pulses result in a versatile X-ray source. Of particular interest for medical imaging are X-rays in the 50-100 keV energy range, high enough energy to penetrate through human-sized objects. Such beams also form the basis of an all optical Thomson source for X-ray...

6. Using laser plasma accelerator for simultaneous X-ray absorption and 2-photon Light Induced Fluorescence imaging of a car engine spray.

Dr. Diego Guenot (Lund university)

08.05.19, 16:20

Oral Contribution

High-pressure sprays are widely used in various field of industry such as combustion or rocket engines and paint applications. However, quantitative imaging of atomizing sprays is particularly challenging due to the presence of a variety of irregular liquid structures such as ligaments, liquid blobs, droplets, liquid sheets and a possible liquid core. This is why the only measurements of the...

67. Double Optical Gating of XUV pulses in Relativistic Laser-Plasma Interactions

Mark Yeung (Queen's University Belfast)

08.05.19, 16:40

Oral Contribution

Attosecond extreme-ultraviolet (XUV) pulses from laser-matter interactions have provided a unique tool for controlling and measuring electronic dynamics on the atomic scale [1]. Currently these pulses are typically generated via high harmonic generation (HHG) in gases where the highest pulse energies are limited to the microjoule range due to phase-matching effects and ground-state depletion....

58. Relativistic Laser Plasma Interactions at Short Wave Infrared Wavelengths

Prof. Franklin Dollar (University of California, Irvine)

08.05.19, 17:15

Oral Contribution

Recent advances in laser technology have enabled the generation of relativistic laser pulses at wavelengths above the near infrared for the first time. We present a series of experiments which examine laser solid plasma interactions and applications utilizing a normalized vector potential of near unity at wavelengths of 1300 and 2100 nm. We present results which highlight the unique benefits...

27. Generation of tunable relativistic, single-cycle infrared pulses from a tailored plasma structure

Prof. Chih-Hao Pai (Department of Engineering Physics, Tsinghua University, Beijing, China)

08.05.19, 17:35

Oral Contribution

During the past decade, the development of intense few-cycle mid-infrared (mid-IR, λ<5 µm) laser sources has made significant progress, which has opened many opportunities for infrared nonlinear optics, high-harmonic generation and pump-probe experiments in the “molecular fingerprint” region. However, even longer carrier wavelength (~10 µm) are needed in many applications. It is one of the...

105. Terahertz Pulse Generation by Laser Plasma Wakefield Accelerator

Jérémy Déchard (CEA DAM)

08.05.19, 17:55

Oral Contribution

In the past 10 years, the generation of terahertz (THz) radiation by ultrashort
laser pulses has become an active field of research due to many promising
applications in medicine, security, telecommunication and spectroscopy [1].
In gas, two-color near infrared laser pulses with moderate pump intensities
and temporally asymmetric profile trigger transverse currents
through photoionization...

21. An Innovative Beam Cooling Technique using a Laser-Plasma Undulator

Oznur Apsimon (The University of Manchester)

Poster Contribution

Beam cooling is a crucial step for the luminosity delivery system in a linear collider or an accelerator based light source to achieve ultra low beam emittance required for high luminosity and high brightness, respectively. Damping rings equipped with wiggler magnets and accelerating cavities were previously proposed for systematic reduction of horizontal phase space area through radiation...

97. Applications of tunable Thomson sources

Frau Sabine Schindler (Ludwig-Maximilians-Universität München)

Poster Contribution

We report results on all-optical Thomson scattering within a laser wakefield accelerator. We show that the pulse collision can be detected using transverse shadowgraphy, facilitating alignment and permitting accurate determination of the scattering position. As the electron beam energy is evolving inside the accelerator, the emitted spectrum changes with the scattering position. Such a...

86. Characterizing high energy bremsstrahlung emission from laser plasma experiments at moderately relativistic intensity

Dr. Sushil Singh (ELI Beamlines, Institute of Physics of the ASCR, )

Poster Contribution

Abstract

Many applications of laser matter interaction at relativistic intensities, for e.g., ion acceleration, fast ignition, X-ray and neutron radiography, depend crucially on the laser absorption into hot electrons. Measurement of bremsstrahlung spectra generated by these hot electrons inside the target provides information on the electron energy distribution and their transport inside...

125. Hard X-ray Sources from Laser-driven Relativistic Electrons at ELI Beamlines

Dr. Stefan Karatodorov (ELI Beamlines, Institute of Physics ASCR)

Poster Contribution

We report the status of the LWFA driven X-ray sources at ELI beamlines facility. Gammatron beamline, that covers the X-ray energies from 1-100 keV in betatron scheme, and up to a few MeV in Compton scheme will be implemented in the Experimental hall E2. A state-of-the-art Ti:Sa diode-pumped HAPLS laser system (L3 laser) generating laser pulse of less than 30 fs, with energies of up to 30 Joule...

53. Investigation of photon and positron emission in laser collision with relativistic electrons

Yuan Zhao (University of Manchester)

Poster Contribution

In the regime of Quantum Electricdynamics (QED), relativistic electrons collide with an ultra-intense laser pulse can generate high-energy gamma-rays by nonlinear Compton scattering. All-optical nonlinear Compton scattering regime have been analysed by using different laser-plasma acceleration schemes in past decades. However, since the process involves electron acceleration, non-linear...

17. Laser-plasma X-Ray microfocus source for high resolution imaging applications

Frau Lucía Martín (Universidad de Santiago de Compostela)

Poster Contribution

Development of novel X-ray sources has a significant impact on the society due to its applications on very different fields such as medicine, biology, chemistry, industry. Laser-plasma X-ray sources provides a new route to high brightness and small source size somewhere in the middle of low cost microfocus X-rays and large-scale synchrotron facilities. We explore one application of this new...

52. Numerical simulations of Betatron Radiation from wakeless plasma channel

Frau Monika Yadav (University of Liverpool)

Poster Contribution

Plasma accelerators provide unique opportunities for the generation of high quality, short-pulse electrons beams which are an ideal basis for high quality radiation generation. This provides an exciting way forward to the generation of very high brightness X-ray betatron radiation from an ultra-bright, plasma-injected beam in a plasma. In this contribution, we present initial results from...

112. Numerical studies on polarized betatron radiation from laser wakefield accelerators

Tim Hager

Poster Contribution

We investigate the generation of polarized betatron radiation in laser wakefield accelerators. Due to the isotropic fields of the wakefield cavity, betatron oscillations usually have no preferential direction and hence, the resulting betatron radiation is unpolarized. However, interaction with the laser pulse can induce oscillations along the laser’s polarization axis. We use particle-in-cell...

142. Picosecond x-ray driver for isochoric heating in LWFA pump-probe experiments

Cary Colgan

Poster Contribution

Isochoric heating is a necessary step in generating warm-dense matter (WDM) conditions from near solid-density targets. The volumetric heating of the sample must be rapid to limit expansion, and reach temperatures of 10’s of eVs for relevant applications to the Jovian interior and ICF capsule implosions. Here, the viability of x-ray heating from a picosecond, laser-driven thin-foil Ge target...

33. X-ray sources using a kJ-class laser driven plasma accelerator

Nuno Lemos (Lawrence Livermore National Laboratory)

Poster Contribution

X-ray photon beams in the keV to MeV energy range are essential to study high energy density (HED) matter and to improve the understanding of inertial confinement fusion and astrophysical systems. HED experiments produce highly transient matter under extreme states of temperatures and pressures and it is essential to develop light sources that are: in the hard x-ray energy range (0.01-1 MeV),...