Intense (10/sup 11/ particles/1 /spl mu/s /spl sim/300 MeV/u) heavy ion beams are generated in the heavy-ion synchrotron (SIS) of the GSI-Darmstadt facility. Large volumes of strongly coupled plasmas ...are produced by heavy ion beam interaction with solid targets, with plasma densities close to the solid state, pressures of about 100 kbar, and temperatures of up to 1 eV, with relevance for equation of state (EOS) of matter, astrophysics, and low-entropy shock compression of solids. The plasmas created by ion beam interaction with metallic converters and cryogenic crystals were studied by backlighting shadowgraphy and by time-resolved spectroscopy in the visible and vacuum ultraviolet ranges. Low entropy weak shock waves induced by the ion beams in the metal-plexiglass multilayered targets were visualized by time resolved schlieren measurements, revealing induced multiple shockwaves with pressures higher than 15 kbar in a plexiglass window and propagation velocities up to 35% higher than the speed of sound in plexiglass at room temperature. To get an insight into the plasma dynamics, both types of experiments are simulated by the BIG-2 two-dimensional hydrodynamic code.
Experimental investigations of heavy-ion-generated shock waves in
solid, multilayered targets were performed by applying a Schlieren and
a laser-deflection technique. Shock velocity and the ...corresponding
pressures, temporal and spatial density profiles inside the material
compressed by multiple shock waves, and details of the shock dynamics
were determined. Important for equation-of-state and phase transition
studies, such experiments extend their relevance to inertial
confinement fusion and astrophysical fundamental research.
At the Gesellschaft für Schwerionenforschung (GSI) Darmstadt, intense beams of energetic heavy ions have been used to generate hot dense plasmas by impact on solid targets. Recently, we have measured ...time evolution of the energy loss of intense beams (10
9–10
10 particles/pulse) of 190 MeV/u
238
U
as well as of 300 MeV/u
86
Kr
in cryogenic crystals of neon and xenon, respectively. For this purpose, a new time resolving energy loss spectrometer has been set up. We observed continuous reduction in the energy loss due to hydrodynamic motion of the ion beam heated target matter. These are the first measurements of this kind. Two-dimensional hydrodynamic simulations were also carried out using the above beam and target parameters. Good agreement has been found between the experimental results and the simulations.
Volume 23, Number 1, Pages 47-53, 2005 Below is the complete Reference citation for Neumayer et al. (2005). Neumayer, P., Bock, R., Borneis, S., Brambrink, E., Brand, H., Caird, J., Campbell, E.M., ...Gaul, E., Goette, S., Haefner, C., Hahn, T., Heuck, H.M., Hoffmann, D.H.H., Javorkova, D., Kluge, H.-J., Kuehl, Th., Kunzer, S., Merz, T., Onkels, E., Perry, M.D., Reemts, D., Roth, M., Samek, S., Schaumann, G., Schrader, F., Seelig, W., Tauschwitz, A., Thiel, R., Ursescu, D., Wiewior, P., Wittrock, U. & Zielbauer, B. (2005). Status of PHELIX laser and first experiments. Laser Part. Beams 23, 87-93. PUBLICATION ABSTRACT
At the Gesellschaft für Schwerionenforschung (GSI, Darmstadt)
intense beams of energetic heavy ions have been used to generate
high-energy-density (HED) state in matter by impact on solid
targets. ...Recently, we have developed a new method by which we
use the same heavy ion beam that heats the target to provide
information about the physical state of the interior of the
target (Varentsov et al., 2001). This is accomplished
by measuring the energy loss dynamics (ELD) of the
beam emerging from the back surface of the target. For this
purpose, a new time-resolving energy loss spectrometer
(scintillating Bragg-peak (SBP) spectrometer) has been developed.
In our experiments we have measured energy loss dynamics of
intense beams of 238U, 86Kr, 40Ar,
and 18O ions during the interaction with solid rare-gas
targets, such as solid Ne and solid Xe. We observed continuous
reduction in the energy loss during the interaction time due
to rapid hydrodynamic response of the ion-beam-heated target
matter. These are the first measurements of this kind.
Two-dimensional hydrodynamic simulations were carried out using
the beam and target parameters of the experiments. The conducted
research has established that the ELD measurement technique
is an excellent diagnostic method for HED matter. It specifically
allows for direct and quantitative comparison with the results
of hydrodynamic simulations, providing experimental data for
verification of computer codes and underlying theoretical models.
The ELD measurements will be used as a standard diagnostics
in the future experiments on investigation of the HED matter
induced by intense heavy ion beams, such as the HI-HEX (Heavy
Ion Heating and EXpansion) EOS studies (Hoffmann et al.,
2002).
The high current upgrade of the accelerator facilities at GSI Darmstadt, Germany, has created possibilities for a new class of experiments with heavy ion beams. Intense pulses of heavy ions can ...rapidly heat converter targets to high temperatures. The hydrodynamic response of these converters, the temperature development and the emitted radiation are investigated experimentally. Moreover, measurements are compared to numerical simulations.
In addition, the expansion of the converters can be employed to compress cryogenic solid hydrogen that is located next to the converters for fundamental research on the equation of state of hydrogen at high pressures.
Due to the long range of the ions in the converters rather large volumes of hydrogen can be compressed homogeneously, allowing for high precision in the diagnostics. Various geometries for planar or radial compression are under discussion.
With a 300
MeV/u
40Ar
18+ beam of 2×10
10 particles and 400
μm radius (HWHM), delivered within a pulse of 300
ns width (FWHM), lead targets were brought to hydrodynamic expansion and collision. Maximum expansion velocities were 570
m/s. The numerical simulations yielded maximum temperatures of 0.17
eV and maximum pressures of 2.8
GPa in direct heating.
Abstract
The novel coronavirus (severe acute respiratory syndrome coronavirus-2) has led to a global pandemic. In the adult population, coronavirus disease 2019 (COVID-19) has been found to cause ...multiorgan system damage with predicted long-term sequelae. We present a case of a 10-year-old boy with a history of ROHHAD (rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation) who presented with hypoxia, emesis, and abdominal pain. Imaging found bilateral ground glass opacities in the lungs and a pericardial effusion. Laboratory evaluation was concerning for elevated inflammatory markers. Remdesivir, hydroxychloroquine, and anticoagulation (heparin and enoxaparin) were utilized. The patient's severe respiratory failure was managed with conventional mechanical ventilation, inhaled nitric oxide, and airway pressure release ventilation. We hope that this report provides insight into the course and management of the severe acute pediatric COVID-19 patient, specifically with underlying comorbidities such as ROHHAD. Clinical trial registration is none.
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