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Transcript: Main parameters of the cable SUPPORT AND MOVING STRUCTURE THANK YOU FOR YOUR ATTENTION! Technical Design Report The magnet transport system comprises A rail track (two parallel rails attached to the foundation) ~30 m long Four roller skates under two magnet cradles. Two hydraulic cylinders to move the magnet. The pole transport system comprises Rail tracks for the poles (two pairs of parallel rails attached to the foundation) ~8.1 m long Four roller skates under each pole platform Two pairs of hydraulic cylinders to move the poles Design description Task definition The support cylinder serves to limit the azimuthal stresses in the aluminum matrix of the superconducting cable, which result from magnetic pressure, provide indirect cooling of the coil, and fix the coil inside the cryostat against weight load and magnetic decentering forces. The cylinder will be made of the Al 5083 aluminum alloy. The weight of the cylinder is 6950 kg. The cylinder length is 7598 mm; its outer diameter is 5092 mm, the thickness is 18 mm in the central part and 45 mm at the ends, where tie rods are attached for suspending the cylinder on the outer vacuum shell of the cryostat and keeping it stable against the axial shifts. The conductor preinsulated by dry fiberglass tape is wound onto inside the support cylinder with the larger side of its cross section kept radially directed. Internal winding and indirect conductor cooling simplify the cryostat design and allow the amount of liquid He in the coil to be minimized, thus avoiding the risk of emergency pressure increase in the cryostat. MAIN FEATURES The yoke comprises two support rings, 24 barrel beams, two poles with trim coils and transportation platforms, and a support structure consisting of two cradles, six stationary supports, and four roller skates. The total mass of the assembled yoke is 727 t. During the operation at the maximum solenoid current without any technological deviations each yoke beam is pressed against the support rings by an axial magnetic force of 116 kN and radial force of 125 kN. YOKE BARREL Main principles Task Definition Design Description Overview Detailed Description A cryostat with a superconducting coil and a control Dewar A flux return yoke with two support rings, 24 bars, and two poles with trim coils Magnet support cradles Auxiliary platforms for moving the poles Stationary supports Hydraulic actuators for displacement of the yoke and poles Roller skates for movement of the magnet and its poles. Cryogenic system A helium satellite refrigerator with a liquefaction performance of about 150 l/h of liquid helium will be used for cooling (heating) and cryostatting the superconducting winding of the MPD magnet. Application of the satellite refrigerator allows the system to meet two contradictory requirements as high reliability and efficiency. This type of refrigerator contauins heat exchangers and vessel for liquid helium and doesn’t include helium expander. It takes liquid helium from the main refrigerator and compressed gas for its operation. The refrigerator is placed on the top platform of the magnet and connected with the main refrigerator of the NICA collider circuit by transfer lines. ЬMPD Solenoidal Magnet The superconducting magnet of MPD is intended for providing a highly homogeneous magnetic field of 0.5 T in an aperture 4596 mm in diameter at NICA accelerator complex. The field inhomogeneity in the TPC region must be less than 0.001 Rated current of the magnet is 1790 A (it corresponds to a field in the aperture of 0.5 T). The maximum magnet field at which the specified value of the integral of the radial component of the induction in the area of TPC Int ≤ 0.775 mm is maintained, and which can be achieved with a maximum level of technological deviations from the optimized geometry of the magnetic system, is 0.57 T. CONTROL DEWAR MAGNET AND POLE SUPPORTS The vacuum connecting tube (chimney) connects the vacuum volumes of the cryostat and the control Dewar. Its vacuum jacket of stainless steel encloses superconducting bus bar lines, direct and return helium and nitrogen tubes, measurement cables, and a thermal shield. Superconducting bus bar lines cooled by a direct liquid helium flow are necessary to connect the superconducting coil lead-outs with the vapor-cooled current leads placed in the control Dewar. The control Dewar is a functional unit of the cryogenic system. It is placed between the superconducting coil cryostat and the helium satellite refrigerator. The control Dewar serves to accumulate the liquid helium in the helium bath, maintain the required parameters of the helium and nitrogen flows (flow rate, pressure, temperature), and to provide cooling of the current leads. Current leads cooled by vapors of boiling helium, control valves, temperature and pressure sensors are allocated in the vacuum volume of the control Dewar. Safety valves, sensor connectors, bayonet connectors of the transfer lines are placed on the