Aims and obstacles, gains and setbacks: German women, 1945-1960

No description supplie

Streamer Propagation as a Pattern Formation Problem: Planar Fronts

Streamers often constitute the first stage of dielectric breakdown in strong electric fields: a nonlinear ionization wave transforms a non-ionized medium into a weakly ionized nonequilibrium plasma. New understanding of this old phenomenon can be gained through modern concepts of (interfacial) pattern formation. As a first step towards an effective interface description, we determine the front width, solve the selection problem for planar fronts and calculate their properties. Our results are in good agreement with many features of recent three-dimensional numerical simulations.Comment: 4 pages, revtex, 3 ps file

Propagation and Structure of Planar Streamer Fronts

Streamers often constitute the first stage of dielectric breakdown in strong electric fields: a nonlinear ionization wave transforms a non-ionized medium into a weakly ionized nonequilibrium plasma. New understanding of this old phenomenon can be gained through modern concepts of (interfacial) pattern formation. As a first step towards an effective interface description, we determine the front width, solve the selection problem for planar fronts and calculate their properties. Our results are in good agreement with many features of recent three-dimensional numerical simulations. In the present long paper, you find the physics of the model and the interfacial approach further explained. As a first ingredient of this approach, we here analyze planar fronts, their profile and velocity. We encounter a selection problem, recall some knowledge about such problems and apply it to planar streamer fronts. We make analytical predictions on the selected front profile and velocity and confirm them numerically. (abbreviated abstract)Comment: 23 pages, revtex, 14 ps file

THE APPLICATION OF MUON TOMOGRAPHY TO SAFETY AND SAFEGUARDING IN GEOLOGICAL REPOSITORIES

Muon tomography is a technique that harnesses naturally occurring cosmic radiation to perform non-invasive andnon-destructive imaging of otherwise inaccessible objects. The paper will consider the application of muon tomography toaspects of the monitoring of nuclear waste with a focus on safety and safeguards in a geological repository (GR). Muontomography is capable of providing critical information on the overburden of a prospective underground facility and wouldbe able to identify unknown features such as voids or undocumented tunnels not declared before the construction of a GR.The paper will present the results from simulations that address some of these questions and, in particular, whichexplore the limitations in the muon tomography technique (measurement time, detector resolution, etc.). The paper will alsosummarise a series of experiments proposed for the Grimsel Test Site that will help to develop an empirical understanding ofhow this exciting technology may complement the "Safety and Safeguards measurement tool kit”

The Use of Muon Tomography in Safeguarding Nuclear Geological Disposal Facilities

Muon attenuation tomography is a powerful tool that employs naturally occurring cosmic ray muons for locating, identifying, and measuring density irregularities in geological overburdens. First applied in the 1950s [3], the technique has very many diverse applications including imaging civil infrastructure such as railway tunnels [4], identifying ore bodies in mines, monitoring magma chambers in volcanoes [5], and identifying voids in pyramids [6, 7]. Muon scattering tomography, which requires the muons to be tracked both entering and leaving the object of interest, can provide valuable information on the atomic number, Z, of objects being imaging in addition to density information. The following reports on a series of simulation studies we have performed to assess the capability of muon radiography to detect a series of potential features that may need to be identified for safeguarding or safety purposes in geological disposal facilities (GDFs) for nuclear waste. Similarly, the application of muon scattering tomography to characterizing the materials encased in nuclear waste drums and to assessing unauthorized diversion scenarios is also presented