Attosecond betatron radiation pulse train

High-intensity X-ray sources are essential diagnostic tools for science, technology and medicine. Such X-ray sources can be produced in laser-plasma accelerators, where electrons emit short-wavelength radiation due to their betatron oscillations in the plasma wake of a laser pulse. Contemporary available betatron radiation X-ray sources can deliver a collimated X-ray pulse of duration on the order of several femtoseconds from a source size of the order of several micrometres. In this paper we demonstrate, through particle-in-cell simulations, that the temporal resolution of such a source can be enhanced by an order of magnitude by a spatial modulation of the emitting relativistic electron bunch. The modulation is achieved by the interaction of the that electron bunch with a co-propagating laser beam which results in the generation of a train of equidistant sub-femtosecond X-ray pulses. The distance between the single pulses of a train is tuned by the wavelength of the modulation laser pulse. The modelled experimental setup is achievable with current technologies. Potential applications include stroboscopic sampling of ultrafast fundamental processes

Ariel – a window to the origin of life on early earth?

Is there life beyond Earth? An ideal research program would first ascertain how life on Earth began and then use this as a blueprint for its existence elsewhere. But the origin of life on Earth is still not understood, what then could be the way forward? Upcoming observations of terrestrial exoplanets provide a unique opportunity for answering this fundamental question through the study of other planetary systems. If we are able to see how physical and chemical environments similar to the early Earth evolve we open a window into our own Hadean eon, despite all information from this time being long lost from our planet’s geological record. A careful investigation of the chemistry expected on young exoplanets is therefore necessary, and the preparation of reference materials for spectroscopic observations is of paramount importance. In particular, the deduction of chemical markers identifying specific processes and features in exoplanetary environments, ideally “uniquely”. For instance, prebiotic feedstock molecules, in the form of aerosols and vapours, could be observed in transmission spectra in the near future whilst their surface deposits could be observed from reflectance spectra. The same detection methods also promise to identify particular intermediates of chemical and physical processes known to be prebiotically plausible. Is Ariel truly able to open a window to the past and answer questions concerning the origin of life on our planet and the universe? In this paper, we discuss aspects of prebiotic chemistry that will help in formulating future observational and data interpretation strategies for the Ariel mission. This paper is intended to open a discussion and motivate future detailed laboratory studies of prebiotic processes on young exoplanets and their chemical signatures

Multi probes measurements at the PALS Facility Research Centre during high intense laser pulse interactions with various target materials

During the interaction of high intense laser pulse with solid target, a large amount of hot electrons is produced and a giant Electromagnetic Pulse (EMP) is generated due to the current flowing into the system target–target holder, as well as due to the escaping charged particles in vacuum. EMP production for different target materials is investigated inside and outside the target chamber, using monopole antenna, super wide-band microstrip antenna and Moebius antenna. The EMP consists in a fast transient magnetic field lasting hundreds of nanosecond with frequencies ranging from MHz to tens of GHz. Measurements of magnetic field and return target current in the range of kA were carried out by an inductive target probe (Cikhardt J. et al. Rev. Sci. Instrum. 85 (2014) 103507)

Multi probes measurements at the PALS Facility Research Centre during high intense laser pulse interactions with various target materials

During the interaction of high intense laser pulse with solid target, a large amount of hot electrons is produced and a giant Electromagnetic Pulse (EMP) is generated due to the current flowing into the system target–target holder, as well as due to the escaping charged particles in vacuum. EMP production for different target materials is investigated inside and outside the target chamber, using monopole antenna, super wide-band microstrip antenna and Moebius antenna. The EMP consists in a fast transient magnetic field lasting hundreds of nanosecond with frequencies ranging from MHz to tens of GHz. Measurements of magnetic field and return target current in the range of kA were carried out by an inductive target probe (Cikhardt J. et al. Rev. Sci. Instrum. 85 (2014) 103507)

A methodology for the discrimination of alpha particles from other ions in laser driven proton-boron reactions using CR-39 detectors coupled in a Thomson parabola spectrometer

Solid-state nuclear track detectors (CR-39 type) are frequently used for the detection of ions accelerated by laser-plasma interaction because they are sensitive to each single particle. To the present day, CR-39 detectors are the main diagnostics in experiments focused on laser-driven proton-boron (p11B) fusion reactions to detect alpha particles, which are the main products of such a nuclear reaction, and to reconstruct their energy distribution. However, the acceleration of multispecies ions in the laser-generated plasma makes this spectroscopic method complex and often does not allow to unambiguously discriminate the alpha particles generated from p11B fusion events from the laser-driven ions. In this experimental work, performed at the PALS laser facility (600 J, 300 ps, laser intensity 1016 W/cm2), CR-39 detectors were used as main detectors for the angular distribution of the produced alpha particles during a p11B fusion dedicated experimental campaign. Additionally, a CR-39 detector was set inside a Thomson Parabola (TP) spectrometer with the aim to calibrate the CR-39 response for low energetic laser-driven ions originating from the plasma in the given experimental conditions. The detected ion energies were ranging from hundreds of keV to a few MeV, and the ion track diameters were measured for etching times up to 9 hours. The goal of the test was the evaluation of the detectors’ ability to discriminate the alpha particles from the aforementioned ions. Within this study, the calibration curves for protons and silicon low energy ions are accomplished, the overlapping of the proton tracks and alpha particles is verified, and a methodology to avoid this problem is realized

One-Pot Hydrogen Cyanide-Based Prebiotic Synthesis of Canonical Nucleobases and Glycine Initiated by High-Velocity Impacts on Early Earth

Chemical environments of young planets are assumed to be significantly influenced by impacts of bodies lingering after the dissolution of the protoplanetary disk. We explore the chemical consequences of impacts of these bodies under reducing planetary atmospheres dominated by carbon monoxide, methane, and molecular nitrogen. Impacts were simulated by using a terawatt high-power laser system. Our experimental results show that one-pot impact-plasma-initiated synthesis of all the RNA canonical nucleobases and the simplest amino acid glycine is possible in this type of atmosphere in the presence of montmorillonite. This one-pot synthesis begins with de novo formation of hydrogen cyanide (HCN) and proceeds through intermediates such as cyanoacetylene and urea