Production follow-up of the LHC main dipoles through magnetic measurements at room temperature
In this paper, we review the tools used for controlling the production of the LHC main dipoles through warm magnetic measurements. For the collared coil measurements, control limits are based on the statistics relative to the pre-series production. For the cold mass, the difference between collared coil and cold mass is considered, allowing a very stringent test. In both cases, measurements are split in straight part average, variations and coil ends contributions. Two different alarm levels exist in case the measured field is out of limits. The analysis can be carried out at the manufacturer and allows detection of anomalies in the measured magnetic field. These can be either due to wrong measurements or caused by assembly defects. Techniques used to work out information on the magnet assembly from the field harmonics are outlined. We summarize the experience gathered on about 180 collared coils and 120 cold masses, pointing out the bad cases and investigating the reliability of the measurements.
Superconducting magnets for the LHC main lattice
The main lattice of the Large Hadron Collider (LHC) employs about 1600 main magnets and more than 4000 corrector magnets. All superconducting and working in pressurized superfluid helium bath, these impressive line of magnets fills more than 20 km of the underground tunnel. With almost 70 main dipoles already delivered and 10 main quadrupoles almost completed, we passed the 5% of the production and now all manufacturers have fully entered into series production. In this paper the most critical issues encountered in the ramping up in such a real large scale fabrication is addressed; uniformity of the coil size and of prestress, special welding technique, tolerances on curvature (dipoles) or straightness (quadrupoles) and of the cold mass extremities, harmonic content and, most important, the integrated field uniformity among magnets. The actual limits and the solution for improvements are discussed. Finally a realistic schedule based on actual achievements is presented.
Industrial production of RHIC magnets
``Doing more with less`` has always been the signature of the military man and is especially true of Air Force weapons handlers. However, as the military drawdown continues, the phase takes on new meaning and becomes an unmistakable way of life for many. Unfortunately, all the resourcefulness in the world cannot overcome some obstacles, forcing a review of utility and mission effectiveness. How can we continue to reduce our resources and still meet our requirements? This paper documents the efforts under way to create a new tool for high fidelity, dexterous, heavy payload manipulation tasks. The ultimate goal of the Next Generation Munitions Handler Advanced Technology Demonstrator (ATD) is the identification and integration of the enabling technologies necessary to produce a system that reduces weapon loading times and operator workload while addressing mobility requirements.