A ring-based Higgs factory with a center-of-mass energy of 240 GeV residing in the existing LEP tunnel is studied at a level of concrete lattice. We found that low-emittance lattice is essential to mitigate the effect of beamstrahlung on the beam lifetime. To achieve a luminosity of $1.0\times10^{ 34}{ \rm cm}^{ -2}{ \rm s}^{ -1}$, we simplified final focusing system and improved its momentum aperture by a factor of 5 to 2.5%.
Categories: physics.acc-ph hep-ex