CERN, Geneva, Switzerland.
Philos Trans A Math Phys Eng Sci. 2012 Feb 28;370(1961):831-58. doi: 10.1098/rsta.2011.0453.
The construction of the Large Hadron Collider (LHC) has been a massive endeavour spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing large electron-positron (LEP) collider tunnel of 27 km circumference and with a tunnel diameter of only 3.8 m has required considerable innovation. The first was the development of a two-in-one magnet, where the two rings are integrated into a single magnetic structure. This compact two-in-one structure was essential for the LHC owing to the limited space available in the existing LEP collider tunnel and the cost. The second was a bold move to the use of superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor.
大型强子对撞机（LHC）的建造是一项庞大的工程，从构思到调试，历时近 30 年。在周长为 27 公里、直径仅为 3.8 米的现有大型正负电子（LEP）对撞机隧道中，以尽可能高的能量（7 TeV）建造这台机器需要大量的创新。首先是开发出一种双环一体的磁铁，其中两个环集成到一个单一的磁结构中。由于现有 LEP 对撞机隧道空间有限且成本高昂，这种紧凑的双环一体结构对于 LHC 来说是必不可少的。其次是大规模使用超流氦冷却的大胆举措，这是由于需要使用经济实惠的 Nb-Ti 超导体来实现高（8.3 T）磁场。
