[en] While full legislation for industrial radiography with gamma and X-rays already exists in many countries, the situation is different for neutron radiography. Therefore, the licensing for equipment and procedures in this field has to be based on basic principles of national and international rules. This contribution will explain how the regulatory body in Switzerland deals with neutron radiography installations in order to maintain national standards of health and safety

[en] The development progress during the reporting period 1988 of the laser surveillance system of spent fuel pools is summarized. The present engineered system comes close to a final version for field application as all technical questions have been solved in 1988. 14 figs., 1 tab. (Author)

[en] We apply recent analytic solutions to the radiation diffusion equation to problems of interest for ICF hohlraums. The solutions provide quantitative values for absorbed energy which are of use for generating a desired radiation temperature vs. time within the hohlraum. Comparison of supersonic and subsonic solutions (heat front velocity faster or slower, respectively, than the speed of sound in the x-ray heated material) suggests that there may be some advantage in using high Z metallic foams as hohlraum wall material to reduce hydrodynamic losses, and hence, net absorbed energy by the walls. Analytic and numerical calculations suggest that the loss per unit area might be reduced ∼ 20% through use of foam hohlraum walls. Reduced hydrodynamic motion of the wall material may also reduce symmetry swings, as found for heavy ion targets

[en] The paper gives a survey of the data processing in an area monitoring system at a small research reactor. Eighteen instruments (ionisation chambers, Geiger Mueller counters, and scintillation counters as well as neutron monitors) are installed in the reactor hall and in some other parts of the institute's building which produce analog and digital signals at the central unit in the control room. If a preset alarm level is reached, optical and acoustical signals are triggered. A microprocessor controlled data logging system as a back-up system compares the analog signals with preset programmed alarm levels and prints the relevant data when certain criteria are fulfilled. For documentation the system scans the radiation levels continuously and prints a protocol several times a day which is available for reactor responsible persons and authorities. (author)

[en] Magnetized Target Fusion (MTF) efforts are based on calculations showing that the addition of a closed magnetic field reduces the driver pressure and rise time requirements for inertial confinement fusion by reducing thermal conductivity. Instabilities that result in convective bulk transport at the Alphen time scale are of particular concern since they are much faster than the implosion time. Such instabilities may occur during compression due to, for example, an increase in the plasma-magnetic pressure ratio β or, in the case of a rotating plasma, spin-up due to angular momentum conservation. Details depend on the magnetic field topology and compression geometry. A hard core z pinch with purely azimuthal magnetic field can theoretically be made that relaxes into a wall supported diffuse profile satisfying the Kadomtsev criterion for the stability of m = 0 modes, which is theoretically preserved during cylindrical outer wall compression. The center conductor radius and current must also be large enough to keep the β below stability limits to stabilize modes with m > 0. The stability of m > 0 modes actually improves during compression. A disadvantage of this geometry, though, is plasma contact with the solid boundaries. In addition to the risk of high Z impurity contamination during the (turbulent) relaxation process, contact thereafter can cause plasma pressure near the outer surface to drop, violating the Kadomtsev criterion locally. The resultant m = 0 instability can then convect impurities inward. Also, the center conductor (which is not part of the Kadomtsev profile) can go m = 0 unstable, convecting impurities outward. One way to mitigate impurity convection is to instead use a Woltjer-Taylor minimum magnetic energy configuration (spheromak). The sheared magnetic field inhibits convection, and the need for the center conductor is eliminated. The plasma, however, would likely still have to be wall supported due to unfavorable β scaling during quasispherical (3-D) compression otherwise. Use of a Field Reversed Configuration (FRC) substantially resolves the wall contact issue, but at the cost of introducing a new (rotational) instability. An FRC has an open magnetic field outside a separatrix which effectively diverts wall material. However, FRC particles diffusing across the separatrix have a preferred angular momentum, causing the FRC within to counter-rotate in response. When the FRC's rotational-diamagnetic drift frequency ratio α reaches a critical value of order unity, the FRC undergoes a rotational instability that results in rapid particle loss. The instability is exacerbated by cylindrical compression since β ∼ R^-2/5 during this phase, assuming angular momentum conservation. A multipole magnetic field frozen into the solid liner during compression may stabilize this mode directly and/or by impeding spin-up without significantly perturbing the implosion's azimuthal symmetry

[en] Solutions to the radiation diffusion equation predict the absorbed energy (''wall loss'') within an inertial confinement fusion (ICF) hohlraum. Comparing supersonic vs. subsonic solutions suggests that a high Z metallic foam as hohlraum wall material will reduce hydrodynamic losses, and hence, net absorbed energy by ∼20%. We derive an analytic expression for the optimal density (for any given drive temperature and pulse-length) that will achieve this reduction factor and which agrees well with numerical simulations. This approach can reduce the cost of a reactor driver. Radiation heat waves, or Marshak waves, play an important role in energy transport and in the energy balance of laser, z-pinch and heavy ion beam hohlraums for ICF and high energy density physics experiments. In these experiments, a power source, e.g. a laser, delivers energy to the interior of a high Z cavity that is converted to x-rays. Typically, most of the energy is absorbed in a thin, diffusively heated layer on the hohlraum interior surface, and re-emission from the heated layer sets the radiation temperature T achieved in the hohlraum. In our recent paper, (henceforward referred to as HR) we developed an analytic theory of Marshak waves via a perturbation theory using a small parameter (var_epsilon) = β/(4 + α) where the internal energy varies as T^β and the opacity varies as T^-α. A consistent theory was built up order-by-order in (var_epsilon), with the benefits of good accuracy and order-by-order energy conservation. We first derived analytic solutions for supersonic Marshak waves, which remarkably allowed for arbitrary time variation of the surface temperature. We then solved the full set of subsonic equations, though specialized to the case that the surface temperature varies as t^k, where self-similar solutions can be found. Our solutions compared very well with exact analytic solutions (for the specialized cases for which they exist) and with radiation-hydrodynamic simulations. In this paper we apply those results to the following question: Can we save on driver energy by making hohlraum walls out of low density high Z foams, which have less hydrodynamic motion and hence, reduced net absorbed energy by the walls? We answer this question using our HR analytic theory, as well as by numerical simulations. To the degree that the ''pure'' HR theory diverges from the simulations we derive non-ideal non-self-similar corrections to the theory that bring it into agreement with the simulations. We show that low-density high Z foams can indeed bring a savings of ∼20% in the required driver energy. Remarkably, this reduction is universal- independent of drive T and its pulse-duration τ. We derive an analytic expression for the optimal density (for any given T and τ) that will achieve this reduction factor and which agrees very well with numerical simulations. For a nominal 5B$ ICF reactor driver of 5 MJ, this 20% savings could save 0.5-1B$. Reduced hydrodynamic motion of the wall material may also reduce symmetry swings, as found for heavy ion beam targets

[en] Included are 15 presentations on field reversal topics. The topics discussed include instabilities, heating, transport, and various magnetic confinement geometries

[en] Research programs carried out at the TRIGA Mark II reactor Vienna are reported in the presentation. Many of the research programs presented at the previous TRIGA Conference in Istambul have been completed and a number of new research programs have been started some of them in cooperation or with support of the International Atomic Energy Agency. The most important project titles are: (1) Development of a laser surveillance system for spent fuel pools, (2) Identification of LWR fuel bundeles by magnetic scanning, and (3) Test of fission chambers in intense gamma fields. A damaged TRIGA fuel rod which was stored for more than 20 years has been cut in October 1983 into several pieces. The U-Zr-H samples are now being used for burn-up calibration as they contain only Cs-137. (orig.)

[en] The documentation system developed for the reactor to replace the automatic data logger is described in the paper. It is based on former experiences with the data logger which had led to a selection of representative data and useful data formats, but also made clear that the paper reports produced by the hardcopy terminal were not useful for further evaluation. A special pre-buffer hardware was provided to connect the data logger to the VAX. Because of its proven reliability an Epson-HX20 microcomputer was selected for this purpose. The documentation system hardware and the software are presented. The system has been operational for about ten months, collecting a daily average of 30kByte of data, and overcome a number of VAX system crashes, maintenance days and VAX/VMS updates. Various software extensions have been developed for processing the daily reports. Among these extensions there are programs for convenient tape backup, procedures for formatted printer output, and other. It is especially helpful to use commercial personal computer software for further data processing, in particular when PCs are connected in a network with the VAX or, on the other hand, emulate VAX terminals. There is a vast number of spread-sheet or database programs with excellent computational and graphic support available for PCs. Most of them allow data import, though format conversion programs will be necessary in most of the cases

[en] A summary is given of the type of inspections, the responsability and the frequency carried out at the triga mark 2 reactor Vienna. All safety related systems and components to be inspected are listed. 1 fig. (Author)