Ion beam technology for the resource enhancement of responsible parts of a high speed friction unit

The needles from carbon steel “U10”, a details of high speed couple of friction “needle-thrust plate” of the gas centrifuge is investigated, in the initial, post-operational state and after irradiation by C+ ions different doses on the pulse-frequency “Raduga” accelerator. The purpose of this study is to increase the operability and service life of the responsible friction unit of the gas centrifuge. This purpose is achieved by mod-ification of the working sliding surface of the needle (which is a responsible part of the high-speed friction pair “needle-thrust plate”) by the pulse-frequency implantation with carbon ions. The dose of implantation (1018 cm−2 of C+ ions), was established, at which an optimal combination of mechanical and tribological properties of the working surface is achieved, which provides wear resistance increase during the operation of the friction pair. This method of surface treatment is recommended to use in case of operation of couple of friction “needle-thrust plate” for the purpose of increase in working capacity and a resource of operation of high speed couple of friction of the gas centrifuge.

Waves in the gas centrifuge: asymptotic theory and similarities with the atmosphere

We study the stratified gas in a rapidly rotating centrifuge as a model for the Earth's atmosphere. Based on methods of perturbation theory, it is shown that in certain regimes, internal waves in the gas centrifuge have the same dispersion relation to leading order as their atmospheric siblings. Assuming an air filled centrifuge with a radius of around 50 cm, the optimal rotational frequency for realistic atmosphere-like waves is around 10 000 revolutions per minute. Using gases of lower heat capacities at constant pressure, such as xenon, the rotational frequencies can be even halved to obtain the same results. Similar to the atmosphere, it is feasible in the gas centrifuge to generate a clear scale separation of wave frequencies and therefore phase speeds between acoustic waves and internal waves. In addition to the centrifugal force, the Coriolis force acts in the same plane. However, its influence on axially homogeneous internal waves appears only as a higher-order correction. We conclude that the gas centrifuge provides an unprecedented opportunity to investigate atmospheric internal waves experimentally with a compressible working fluid.

Atmospheric gravity waves in a gas centrifuge

<p>Field observations of nonlinear atmospheric gravity waves are sparse and involved due to many challenges for the instrumentation. Due to these complications of field measurements, laboratory experiments are an indispensable tool.</p><p>As of today, all laboratory experiments on gravity waves have in common that they were performed with water as the working fluid. Due to flow similarities, most of the features observed in the water tanks are equally valid for the atmosphere. However, one particular property of air cannot be emulated by water: compressibility. Especially for the dynamics of nonlinear waves, compressibility plays a significant role.</p><p>We propose a laboratory experiment by means of a rapidly rotating gas centrifuge. The centrifugal forces act on the gas like the gravitational pull causing a stratified compressible working fluid. In this device, atmosphere-like gravity waves would be observable under controlled and replicable conditions for the first time.</p><p>We show that the waves in a centrifuge would theoretically behave like their atmospheric counterparts; they exhibit the same dispersion and polarization relations. Futhermore, spinning the centrifuge with the right frequency, there is a clear scale separation between acoustic and gravity waves. In addition to the centrifugal force, the Coriolis force acts in the same plane potentially spoiling the similarities. However, the influence of the Coriolis force on the wave is negligibly small.</p>