No abstract available

[en] The development of large turbogenerators with superconducting exciter winding has moved into the area of considerable economic interest. The advantages and problems of superconductance are discussed. The problems of cooling the cold rotor are especially considered in detail. At the same time, discussions concern what thermal losses are to be expected and what effects occur with respect to coolant flow, heat transmission as well as the change of state of coolant in a rotating system as a result of centrifugal and Coriolis forces. A listing is made as to what formulations are available for solution of these problems and what investigations are to be carried out before a reliable design of a superconducting rotor can result

[en] NbTi cables cooled by internal flow of superfluid helium are considered an option for the design of NET/TF coils with about 11 T peak fields. Starting from an available winding cross section of 0.61x0.61 m² for a 8 MA turns coil made of a 16 kA conductor it is shown that sufficient hydraulic cross section can be provided within such cables to remove the expected thermal load resulting from nuclear heating with exponential decay from inboard to outboard side of the winding. The concept is a pancake type coil with 1.8 K helium fed-in the high field region of each pancake. The temperature distribution within such coils is calculated, and the local safety margin is determined from temperature and field. The calculation takes account of nuclear and a.c. heating, and of thermal conductance between the individual layers and the coil casing. It is shown that operation with 1.8 K inlet and about 3 K outlet temperature is possible. The electrical insulation with about 0.5 mm thickness proves to provide sufficient thermal insulation. No additional thermal shield is required between the coil casing and the winding package. Two different types of conductors are being considered: a) POLO type cable with quadratic cross section and a central circular coolant duct, and b) an LCT type cable with two conductors wound in hand. Both concepts with about 500 m length of the cooland channels are shown to meet the requirements resulting from a peak nuclear heat load of 0.3 mW/cm³ in the inboard turns. The hydraulic diameters are sufficient to operate each coils with self-sustained fountain effect pumps. Even appreciably higher heat loads with up to 3 mW/cm³ of nuclear heating can be tolerated for the POLO type cable when the hydraulic diameter is enlarged to its maximum of 17 mm. (orig.)

[en] The case is put that the sun, our main source of energy in the past, could still be the healthiest, safest and most reliable source of nuclear energy for the future needs of civilization. (F.Q.)

[en] The heat losses occurring during cooling of superconducting magnets are used to produce forced flow in a cooling ciruit. The heat losses are coupled to a fountain pump in such a way that no additional drive power is required and the flow corresponding to the load is automatically set. It is particularly advantageous that the fountain pumps have no mechanical moving parts. (DG)

[en] The refilling of helium from a storage tank into the rotor's helium bath boiling at low pressure is carried out independent of the vapour fraction of the helium to be fed in. To this end, the liquid and the gas of the helium flowing in are separated in a phase separator integrated in the rotor and are then fed into the rotor at suitable points. (DG)

No abstract available

[en] The SSC (Superconducting Super Collider) is supposed to operate with bunched beams and the energy radiated by synchrotron radiation is replaced by the rf-system having a synchronous phase angle slightly different from 180⁰. Here the case of operating the SSC with a coasting beam is considered. In particular the possibility of replacing the radiated energy phase displacement acceleration is investigated

[en] In order to replenish a helium bath in the super-conducting rotor of an electrical machine, in which bath liquid helium boils at subatmospheric pressure, with liquid helium from a helium reservoir, the liquid helium in the reservoir being at ambient pressure and a part of the liquid helium changing to the vapor phase during flow from the reservoir to the bath, liquid helium is introduced into the bath at a distance from the rotor axis of rotation, the liquid and vapor phases of the helium flowing from the reservoir to the bath are separated from one another in a phase separator fixed to the rotor, and the separated vapor phase is extracted from the separator

[en] In order to replenish a helium bath in the super-conducting rotor of an electrical machine, in which bath liquid helium boils at subatmospheric pressure, with liquid helium from a helium reservoir, the liquid helium in the reservoir being at ambient pressure and a part of the liquid helium changing to the vapor phase during flow from the reservoir to the bath, liquid helium is introduced into the bath at a distance from the rotor axis of rotation, the liquid and vapor phases of the helium flowing from the reservoir to the bath are separated from one another in a phase separator fixed to the rotor, and the separated vapor phase is extracted from the separator. (MM)