Time filter

Source Type

Darmstadt, Germany

The GSI Helmholtz Centre for Heavy Ion Research is a federally and state co-funded heavy ion research center in the Arheilgen suburb of Darmstadt, Germany. It was founded in 1969 as the Society for Heavy Ion Research , abbreviated GSI, to conduct research on and with heavy-ion accelerators. It is the only major research center in the State of Hesse. The current director of GSI is Horst Stöcker who succeeded Walter F. Henning in August 2007.The laboratory performs basic and applied research in physics and related natural science disciplines. Main fields of study include plasma physics, atomic physics, nuclear structure and reactions research, biophysics and medical research. The lab is a member of the Helmholtz Association of German Research Centres.Shareholders are the German Federal Government and the State of Hesse . As a member of the Helmholtz Association, the current name was given to the facility on 7 October 2008 in order to bring it sharper national and international awareness. Wikipedia.

Durante M.,Helmholtz Center for Heavy Ion Research | Cucinotta F.A.,NASA
Reviews of Modern Physics

The health risks of space radiation are arguably the most serious challenge to space exploration, possibly preventing these missions due to safety concerns or increasing their costs to amounts beyond what would be acceptable. Radiation in space is substantially different from Earth: high-energy (E) and charge (Z) particles (HZE) provide the main contribution to the equivalent dose in deep space, whereas γ rays and low-energy α particles are major contributors on Earth. This difference causes a high uncertainty on the estimated radiation health risk (including cancer and noncancer effects), and makes protection extremely difficult. In fact, shielding is very difficult in space: the very high energy of the cosmic rays and the severe mass constraints in spaceflight represent a serious hindrance to effective shielding. Here the physical basis of space radiation protection is described, including the most recent achievements in space radiation transport codes and shielding approaches. Although deterministic and Monte Carlo transport codes can now describe well the interaction of cosmic rays with matter, more accurate double-differential nuclear cross sections are needed to improve the codes. Energy deposition in biological molecules and related effects should also be developed to achieve accurate risk models for long-term exploratory missions. Passive shielding can be effective for solar particle events; however, it is limited for galactic cosmic rays (GCR). Active shielding would have to overcome challenging technical hurdles to protect against GCR. Thus, improved risk assessment and genetic and biomedical approaches are a more likely solution to GCR radiation protection issues. © 2011 American Physical Society. Source

The radiative capture cross sections for the He3(α,γ)Be7 and H3(α,γ)Li7 reactions are calculated in the fully microscopic fermionic molecular dynamics approach using a realistic effective interaction that reproduces the nucleon-nucleon scattering data. At large distances bound and scattering states are described by antisymmetrized products of He4 and He3/H3 ground states. At short distances the many-body Hilbert space is extended with additional many-body wave functions needed to represent polarized clusters and shell-model-like configurations. Properties of the bound states are described well, as are the scattering phase shifts. The calculated S factor for the He3(α,γ)Be7 reaction agrees very well with recent experimental data in both absolute normalization and energy dependence. In the case of the H3(α,γ)Li7 reaction the calculated S factor is larger than available experimental data by about 15%. © 2011 American Physical Society. Source

Helmholtz Center for Heavy Ion Research | Date: 2014-09-09

The invention concerns the production of segmented nanowires and components having said segmented nanowires. For the production of the nanowire structural element, a template based process is used preferably, wherein the electrochemical deposition of the nanowires in nanopores is carried out. In this manner, numerous nanowires are created in the template foil. For the electrochemical deposition of the nanowires, a reversed pulse procedure with an alternating sequence consisting of cathodic deposition pulses and anodic counter-pulses is carried out. By this means, segmented nanowires can be produced.

German Electron Synchrotron and Helmholtz Center for Heavy Ion Research | Date: 2015-04-09

A laser pulse shaper device includes shaper unit including first dispersive element for spatially separating spectral components of laser pulses, second dispersive element for parallelizing and deflecting spectral components into Fourier plane of dispersive elements, and mirror for back-reflecting of laser pulses via dispersive elements, and light modulator in Fourier plane of dispersive elements, which is capable of modulating spectral components of laser pulses, wherein beam path of shaper unit includes forward beam path from first dispersive element via second dispersive element to mirror and return beam path from mirror via second dispersive element to first dispersive element, and focusing device is arranged at input side of forward beam path before first dispersive element for focusing spatially separated spectral components of laser pulses to Fourier plane of dispersive elements. Furthermore, a method for stretching or compressing laser pulses is described.

German Electron Synchrotron and Helmholtz Center for Heavy Ion Research | Date: 2015-04-08

A method of generating white light pulses (

Discover hidden collaborations