The “Baikal” project and investigations of radiating Z-pinches at the “Angara-5-1” facility

Abstract

Work on Z-pinches, that is under way at the SRC RF TRINITI, is aimed at the resolution of two basic problems: to investigate the problem of physics of X-ray generation in a Z-pinch scheme with the goal of its application for ICF at the "Angara-5-1" facility to develop the engineering aspects of multimegampere facilities intended for using them in a Z-pinch scheme for ICF and making the "Baikal" project. At the "Angara-5-1 facility" the measurements of plasma production rates for the wire and foam liners were taken. It has been shown that for Mo, W, Cu, Fe, and Al a current sheath with a radial thickness much larger than the skin- layer forms. The value of the plasma production rate for these metals was obtained. In the case of the liner from agar-agar foam no formation of such a layer was observed. The spectral measurements taken in hybrid Al-W liners make it possible to estimate the electron temperature and concentration from the spectrum of Al ions. It is also shown that an addition of tungsten into the array compound at a constant mass leads to a decrease of not only the electron temperature but also the final radius of stagnation. The measurements of the hard X-radiation appearing at the moment close to a peak of the X-ray pulse are likely to indicate the formation of an several kiloamperes electron beam. The experiments with conical arrays consisting of tungsten wires demonstrate the effects which arise when the wire array is imploded both in radial and axial directions. For large cone angles there appear two separate radiating regions. The corresponding X-ray pulses have a double-peak structure. Calculations of such liner compression are used to test the programs describing both radial and axial plasma compression. The results obtained at the IMM RAS fairly well provide a quantitative description of the X-ray pulse structure. Such conical liners prove to be a promising tool to test complicated RMHD codes. A pulse generation scheme relevant to the "Baikal" project is under development at the MOL facility. A 30-fold reliable current multiplication in the inductive storage has been obtained. The storage energy was effectively transferred to the subsequent stage of formation, i.e. a magnetic amplifier. The current in the latter was multiplied by a factor of 1.55. At the "Angara-5-1" facility the MEVL code reporting the process of magnetic insulation arising in the in-parallel- connected magnetically insulated vacuum lines has been tested.