CERN starts pulling the LHC's original focusing magnets to make room for 11.3-tesla replacements

The 40% describes the magnetic field. The new coils reach 11.3 tesla ^[6]. Taken at face value, the percentage puts the magnets now in the machine at roughly 8 tesla ^[13]. Both generations are superconducting: CERN counts the hardware coming out as 28 superconducting magnets ^[5]. The change is in the conductor, with niobium-tin replacing niobium-titanium ^[6]. CERN attributes the step to years of research and development ^[16].

Inner triplets are groups of three quadrupole magnets on both sides of each of the LHC's four main experiments. They squeeze the beams as tightly as possible just before the particles meet inside the detectors ^[2]. The tighter the squeeze, the greater the chance of a collision. Luminosity is the number of collisions in a given period of time ^[3]. On that basis, CERN says the stronger magnets should produce far more collisions for ATLAS and CMS to analyse ^[12]. The thing this doesn't tell you is how many more: the release does not include a luminosity target, and a 40% gain in field should not be read as a 40% gain in data.

So far, the work has all been removal. Crews have been dismantling sections of the collider on either side of ATLAS and CMS since September 7 ^[5]. The first replacement quadrupole is not expected in the tunnel until the start of 2029 ^[7], about 28 months later ^[14]. "In total, 16 cryostats and 28 cryo-assemblies will be installed - a major undertaking," said Jean-Philippe Tock, who heads the LS3 coordination team ^[8].

The magnets leaving the tunnel are the machine's originals. "The current inner triplets date back to the LHC construction phase and were installed in the machine between 2005 and 2007. After nearly twenty years of operation, they will give way to a new generation of even more powerful magnets," said Markus Zerlauth, the HiLumi LHC project leader ^[11].