111 research outputs found
Optimization study of high power static inverters and converters Final report
Optimization study and basic performance characteristics for conceptual designs for high power static inverter
Time evolution of stimulated Raman scattering and two-plasmon decay at laser intensities relevant for shock ignition in a hot plasma
Laserâplasma interaction (LPI) at intensities 1015â1016 W cm2 is dominated by parametric instabilities which can be
responsible for a significant amount of non-collisional absorption and generate large fluxes of high-energy nonthermal
electrons. Such a regime is of paramount importance for inertial confinement fusion (ICF) and in particular for the
shock ignition scheme. In this paper we report on an experiment carried out at the Prague Asterix Laser System (PALS)
facility to investigate the extent and time history of stimulated Raman scattering (SRS) and two-plasmon decay (TPD)
instabilities, driven by the interaction of an infrared laser pulse at an intensity 1:2 1016 W cm2 with a 100 mm
scalelength plasma produced from irradiation of a flat plastic target. The laser pulse duration (300 ps) and the high
value of plasma temperature (4 keV) expected from hydrodynamic simulations make these results interesting for a
deeper understanding of LPI in shock ignition conditions. Experimental results show that absolute TPD/SRS, driven at
a quarter of the critical density, and convective SRS, driven at lower plasma densities, are well separated in time, with
absolute instabilities driven at early times of interaction and convective backward SRS emerging at the laser peak and
persisting all over the tail of the pulse. Side-scattering SRS, driven at low plasma densities, is also clearly observed.
Experimental results are compared to fully kinetic large-scale, two-dimensional simulations. Particle-in-cell results,
beyond reproducing the framework delineated by the experimental measurements, reveal the importance of filamentation
instability in ruling the onset of SRS and stimulated Brillouin scattering instabilities and confirm the crucial role of
collisionless absorption in the LPI energy balance
An open Problem on Strongly Consistent Learning of the Best Prediction for Gaussian Processes
Resistance training concomitant to radiotherapy of spinal bone metastases â survival and prognostic factors of a randomized trial
Determination of fission barrier height of Fr 210 and Ra 210 via neutron measurement
Fission barrier heights of short-lived nuclei away from line of ÎČ stability are not known reliably. Low-energy fission of Fr210 and Ra210, produced by (d,p) and (d,n) transfer reaction on the re-accelerated unstable beam Fr209 was investigated at HIE-ISOLDE. Four Timepix3 pixel detectors were installed on the body of the ACTAR TPC demonstrator chamber. Polyethylene converters were used for the detection of fast neutrons. Since no significant background was observed, it was possible to measure the spatial distribution of emitted neutrons reflecting the fission excitation function. Subsequent simulations employing the results of the talys code and available data on fission fragment distributions allowed to estimate directly the value of the fission barrier height for the neutron-deficient nucleus Fr210. This first direct measurement confirmed the reduction of the fission barrier compared to available theoretical calculations by 15-30%
Identification of a 6.6 microsecond isomeric state in 175Ir
An experiment has been performed to study excited states in the neutron-deficient nucleus 175Ir via the use of
the JUROGAM II high-purity germanium detector array and the RITU gas-filled separator at JYFL, JyvÀskylÀ.
By using isomer tagging, an isomeric state with a half-life of 6.58(15) ÎŒs has been observed in 175Ir for the first
time. It has been established that the isomer decays via a 45.2 (E1)â26.1 (M1) keV cascade to new states below
the previously reported ground state in 175Ir with IÏ = (5/2â). We now reassign this (5/2â) state to the isomeric
state discovered in this study.peerReviewe
Response to Letter Regarding Article, âFibrinolysis for Intraventricular Hemorrhage: An Updated Meta-Analysis and Systematic Review of the Literatureâ
ARTHROSCOPIC EVALUATION AND TREATMENT BY TENDON INTERPOSITIONAL ARTHROPLASTY OF FIRST CARPOMETACARPAL JOINT ARTHRITIS
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